A structure in which the formal charges are as close to zero as possible is preferred. It is not possible to write a single Lewis structure for \({\text{NO}}_{2}{}^{\text{}}\) in which nitrogen has an octet and both bonds are equivalent. Depending on which one we choose, we obtain either. Type of paper. The sum of the formal charges of all atoms in a molecule must be zero; the sum of the formal charges in an ion should equal the charge of the ion. Resonance is a way of describing delocalized electrons within certain molecules or polyatomic ions where the bonding cannot be expressed by a single Lewis formula. Using the Bohr model, we can calculate the energy of an electron and the radius of its orbit in any one-electron system. Example 4.9. 6. PubMed comprises more than 34 million citations for biomedical literature from MEDLINE, life science journals, and online books. Which one of the following is the correct set of Lewis Symbols for CaCl? This book uses the Chloroform (CHCl) is an important laboratory solvent with a relatively high vapor pressure at room temperature. Assigning Formal charges to atoms in the molecules is one mechanism to identify the viability of a resonance structure and determine its relative magnitude among other structures. Because we can write three identical resonance structures, we know that the actual arrangement of electrons in the carbonate ion is the average of the three structures. The structure with a terminal oxygen atom best satisfies the criteria for the most stable distribution of formal charge: The number of atoms with formal charges are minimized (Guideline 2), there is no formal charge with a magnitude greater than one (Guideline 2), the negative formal charge is on the more electronegative element (Guideline 4), and the less electronegative atom is in the center position. Because we can write three identical resonance structures, we know that the actual arrangement of electrons in the carbonate ion is the average of the three structures. The SN equation uses the classical image potential energy to represent the physical effect "correlation and exchange". Browse our listings to find jobs in Germany for expats, including jobs for English speakers or those in your native language. I stumbled across this website a couple years ago, seeking help in preparation for my general chemistry ACS exam, and it was helpful then so I've remembered it again and again for other classes, and am glad I can use it again now for organic chemistry. Like oxygen, nitrogen has room for more electrons in a second shell, specifically, there is room for three more. The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo A double bond between two atoms is shorter (and stronger) than a single bond between the same two atoms. The resonance for HPO 3 2-, and the formal charges (in red). Resonance: All elements want an octet, and we can do that in multiple ways by moving the terminal atom's electrons around (bonds too). How Do We Know Methane (CH4) Is Tetrahedral? Jun 23, 2022 OpenStax. A molecular structure in which all formal charges are zero is preferable to one in which some formal charges are not zero. Thus, we calculate formal charge as follows: We can double-check formal charge calculations by determining the sum of the formal charges for the whole structure. All Rights Reserved. are not subject to the Creative Commons license and may not be reproduced without the prior and express written Because we can write three identical resonance structures, we know that the actual arrangement of electrons in the carbonate ion is the average of the three structures. Example 7.7. 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Revisions are made for you at no charge. If you are redistributing all or part of this book in a print format, (Remember the Lewis Structure rules.). In methoxide, oxygen has 6 valence electrons, 6 electrons in lone pairs and 2 bonding electrons, therefore the formal charge = 6-[6+1/2(2)] = -1. two atoms share valence electrons and those shared electrons form the chemical bond. Determine the number of valence electrons in SO and then draw the corresponding Lewis structure (with minimized formal charges). Oxidation state is obtained by summing the heteronuclear-bond orders at the atom as positive if that atom is the electropositive partner in a particular bond and as negative if not, and the atoms formal charge (if any) is added to that sum. Revisions are made for you at no charge. Determine the number of valence electrons in cyanide (CN) and then draw the corresponding Lewis structure. Determine the total number of valence (outer shell) electrons. In order to calculate a formal charge, electrons are assigned to individual atoms within the molecule based on two different rules: bonding electrons must be divided equally across the different bonded atoms, and non-bonding electrons are considered part of the atom they are located at. - Formal charges can be used to select the most important resonance structures for a species. Does The Arrow Of Time Apply To Quantum Systems? Creative Commons Attribution License About 90 billion pounds are produced each year in the United States alone. Except where otherwise noted, textbooks on this site The two resonance structures in this example are non-equivalent, so one is more stable than the other.By applying the formal charge guideline, the - formal charge is more preferable on oxygen, which is more electronegative than nitrogen, so the 2 nd structure is the more stable one with lower energy, and makes more contribution to the actual structure in this species. It involves constructing multiple Lewis structures that, when combined, represent the full electronic structure of the molecule. After filling out the order form, you fill in the sign up details. Again, experiments show that all three CO bonds are exactly the same. Write the resonance forms of the nitrite ion, \({\text{NO}}_{\text{2}}{}^{\text{}}\text{.}\). This is just awesome. Photo: By J Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=12017486. Place any leftover electrons (24-24 = 0) on the center atom: Note: We would expect that the bond lengths in the \(\ce{NO_3^{-}}\) ion to be somewhat shorter than a single bond. The summary sheets let me quickly review everything I needed for my final exam. Since there are five electrons in nitrogens outer shell, nitrogen can be satisfied by giving these five electrons away and having only the two electrons in its inner shell. A few guidelines involving formal charge can be helpful in deciding which of the possible structures is most likely for a particular molecule or ion: To see how these guidelines apply, let us consider some possible structures for carbon dioxide, CO2. Draw the Lewis structure of BH and then determine its electron domain and molecular geometries. Calculating the formal charge for a molecule allows you to determine which resonance structure is more likely to be the molecules correct structure, and the Lewis structure which is considered the most correct will be the structure that has formal charges distributed evenly all throughout the molecule. organic professor too! Just as a rhinoceros is neither a dragon sometimes nor a unicorn at other times, a resonance hybrid is neither of its resonance forms at any given time. Which of the following bonds is the most polar? Again, experiments show that all three CO bonds are exactly the same. Also, it places the least electronegative atom in the center, and the negative charge on the more electronegative element (Guideline 4). Again, experiments show that all three CO bonds are exactly the same. Example 4.9. Assigning one bonding pair of electrons to each oxygenoxygen bond gives, 4. Calculate the formal charge for each atom in the carbon monoxide molecule: Answer: C 1, O +1. We know from our previous discussion that the less electronegative atom typically occupies the central position, but formal charges allow us to understand why this occurs. Formal charge can be calculated using the following equation: formal charge = [# of valence electrons] - [electrons in lone pairs + 1/2 the number of bonding electrons]. The latest Lifestyle | Daily Life news, tips, opinion and advice from The Sydney Morning Herald covering life and relationships, beauty, fashion, health & wellbeing New California laws will create 4 million jobs, reduce the states oil use by 91%, cut air pollution by 60%, protect communities from oil drilling, and accelerate the states transition to clean A bond could be formed from the overlap of which two orbitals? We can use the concept of formal charges to help us predict the most appropriate Lewis structure when more than one is reasonable. A bond angle is the angle formed by the nuclei of _____ surrounding atoms with the nucleus of a central atom. Which of the following structures would we expect for nitrous acid? then you must include on every digital page view the following attribution: Use the information below to generate a citation. Draw the Lewis structure of CS and then determine the number of nonbonding electron pairs on the central atom. It didnt work out. This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus.The term atomic orbital may also refer to the physical region or space where the electron can be This frequently happens when sodium atoms interact with chlorine atoms. Let's motivate the discussion by building the Lewis structure for ozone. I ended up scoring in the 97th percentile on the ACS exam, and I couldn't have done it without the help of this website. We call the individual Lewis structures resonance forms. studies at night, it is often impossible to find a professor or TA who is awake to extinguish my burning questions, and even difficult to find a knowledgable friend. Key Equations If the Lewis structure must have nonzero formal charges, the arrangement with the smallest nonzero formal charges is preferable. Or another way of saying that, formal charge is equal to the number of valence electrons the atom is supposed to have minus the number of valence electrons that the atom actually has in the drawing. About Our Coalition. A Lewis structure for sulfate (SO) is shown below, however, its formal charges are not minimized. Assign formal charges to each atom in the interhalogen molecule BrCl3. The SN equation uses the classical image potential energy to represent the physical effect "correlation and exchange". Diels-Alder Reaction: Kinetic and Thermodynamic Control, Regiochemistry In The Diels-Alder Reaction, Electrocyclic Ring Opening And Closure (2) - Six (or Eight) Pi Electrons, Aromatic, Non-Aromatic, or Antiaromatic? The arrangement of atoms in a molecule or ion is called its molecular structure. The Lewis structure of NO is shown on the left below with numbers on the corresponding atoms. We recommend using a Academic level. A unicycle wheel rotates at a constant 14 rev/min. Last semester I had the pleasure of working with Chris (a pseudonym) on second-semester organic chemistry topics. Those who have a checking or savings account, but also use financial alternatives like check cashing services are considered underbanked. For cations, subtract one electron for each positive charge. eV = The total number of valence electrons the atom possesses as if the atom were isolated from the rest of the molecule. Such is the case for ozone (\(\ce{O3}\)), an allotrope of oxygen with a V-shaped structure and an OOO angle of 117.5. 8. Important: This formula only works if the manuscript is prepared according to the general guidelines of the journal.(e.g. In methoxide, oxygen has 6 valence electrons, 6 electrons in lone pairs and 2 bonding electrons, therefore the formal charge = 6-[6+1/2(2)] = -1. Connect with customer support around-the-clock for any orders or urgent questions. The formal charges present in each of these molecular structures can help us pick the most likely arrangement of atoms. We can draw three possibilities for the structure: carbon in the center and double bonds, carbon in the center with a single and triple bond, and oxygen in the center with double bonds: Comparing the three formal charges, we can definitively identify the structure on the left as preferable because it has only formal charges of zero (Guideline 1). eB = The total number of electrons that are shared by the bonds that connect atoms to other atoms within the molecule. Assign Formal Charges. Starting from this structure, complete the correct structure. Ensure you request for assistant if you cant find the section. We should remember that a molecule described as a resonance hybrid never possesses an electronic structure described by either resonance form. Photo: By Ondej Mangl Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=2899599. Calculate the formal charge for each atom in the carbon monoxide molecule: Answer: C 1, O +1. Add octet electrons to the atoms bonded to the center atom: 4. Notice that in the case of carbon dioxide, every possible formation of the molecule has a formal charge of zero. 5. Determine the number of valence electrons in carbonate (CO) and then draw the corresponding Lewis structure. A few guidelines involving formal charge can be helpful in deciding which of the possible structures is most likely for a particular molecule or ion: To see how these guidelines apply, let us consider some possible structures for carbon dioxide, CO2. and you must attribute OpenStax. Following a bumpy launch week that saw frequent server trouble and bloated player queues, Blizzard has announced that over 25 million Overwatch 2 players have logged on in its first 10 days. How to Calculate Formal Charge. (Generally, the least electronegative element should be placed in the center.) Because carbon is the least electronegative element, we place it in the central position: 2. How many TOTAL likely resonance structures exist for SO? To move an electron from a stable orbit to a more excited one, a photon of energy must be absorbed. (Generally, the least electronegative element should be placed in the center.) When it is possible to write more than one equivalent resonance structure for a molecule or ion, the actual structure is the average of the resonance structures. In the first case carbon and oxygen both have a charge of zero, resulting in zero overall charges. 24/7 Support. If we place a single bonding electron pair between each pair of carbon atoms and between each carbon and a hydrogen atom, we obtain the following: Each carbon atom in this structure has only 6 electrons and has a formal charge of +1, but we have used only 24 of the 30 valence electrons. Now we have to look at electronegativity for the "Correct" Lewis structure. An example of a Lewis structure with no formal charge, We must remember that the formal charge calculated for an atom is not the actual charge of the atom in the molecule. Deadline. The formal charge on an atom in a covalent species is the net charge the atom would bear if the electrons in all the bonds to the atom were equally shared. The resonance for HPO 3 2-, and the formal charges (in red). The existence of multiple resonance structures for aromatic hydrocarbons like benzene is often indicated by drawing either a circle or dashed lines inside the hexagon: Draw the possible resonance structures for the Nitrate ion \(\ce{NO_3^{-}}\). It has some characteristics in common with its resonance forms, but the resonance forms themselves are convenient, imaginary images (like the unicorn and the dragon). The calcium ion its two valence electrons to have a 2+ charge. In atomic theory and quantum mechanics, an atomic orbital is a function describing the location and wave-like behavior of an electron in an atom. and you must attribute OpenStax. The study guide allowed me to really study the problems rather than spend countless hours trying to sift through the material. 0 is the Correct number of nonbonding electron pairs. The formula in my textbook was long, tedious and brutal. (Note: It is the one with the least formal charges that adds up to zero or to the molecule's overall charge.). A Lewis structure for bromate (BrO) is shown below, however, its formal charges are not minimized. The inner core of the electrons is associated with just 6 electrons instead of the 7 that are needed for electrical neutrality, meaning it has a positive charge overall. Academic level. Microsoft pleaded for its deal on the day of the Phase 2 decision last month, but now the gloves are well and truly off. Example 7.7. two atoms, one atom which is more electronegative than the other, exchange electrons and the charges hold the atoms together. Indicate which has the strongest carbon-oxygen bond. 8. Another way of saying this is that formal charge results when we take the number of valence electrons of a neutral atom, subtract the nonbonding electrons, and then subtract the number of bonds connected to that atom in the Lewis structure. How many TOTAL likely resonance structures exist for SO? We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Ask your writer for adjustments and you'll have them in no time! Would've helped me so much on my midterm. With the help of MOC, Calculate formal charges and use the Electroneutrality Principle to determine which Lewis dot structure is the best, or which resonance structure makes the largest contribution to the resonance hybrid. The chlorine ions each gain an electron to fill their octets and have a -1 charge. Applied to a Lewis structure. 3. I finished Orgo 2 with a B+ because Determine the formal charge on each atom in each of the resonance structures: Based on formal charge considerations, which of the following would likely be the correct arrangement of atoms in nitrosyl chloride: ClNO or ClON? You may be wondering why this is the case. Calculate a weighted average of the practice cost index values for the specialties that furnish the service. However, you can use the equation E=hv to calculate the energy required to remove an electron after taking into account the kinetic energy. consent of Rice University. Lewis structures are preferable when adjacent formal charges are zero or of the opposite sign. Cadmium Chloride is a whitish, crystalline, inorganic compound that forms toxic fumes of cadmium oxides when heated. Which of the following is the correct Lewis symbol for a neutral atom of Al? Because we can write three identical resonance structures, we know that the actual arrangement of electrons in the carbonate ion is the average of the three structures. Formal charge can be calculated using the following equation: What is the correct molecular geometry of NH according to Valence Shell Electron Pair Repulsion Theory? Browse our listings to find jobs in Germany for expats, including jobs for English speakers or those in your native language. I used the reaction guide for O Chem 1, and it saved my butt. A neutral atom of Mg has 2 valence electrons. Our customer care team is here for you day and night. It would have made things a little bit easier. The higher the charges, the higher the lattice formation enthalpy (lattice energy). Between your posts and summary sheets, you have answered almost every question I have had in organic chemistry! Based on this structure, determine if the molecule is polar or nonpolar. After filling out the order form, you fill in the sign up details. Drawing the Lewis structure of the molecule reveals that it can be sketched out in three different ways. Choose the correct set of formal charges of the atoms in ascending order of atom number. Thus, the electronic structure of the \({\text{NO}}_{2}{}^{\text{}}\) ion is shown as: We should remember that a molecule described as a resonance hybrid never possesses an electronic structure described by either resonance form. Because we can write three identical resonance structures, we know that the actual arrangement of electrons in the carbonate ion is the average of the three structures. Oxygen has room for up to eight electrons in its second shell. Make a revision and communicate with your writer exactly what you want adjusted or improved on your paper! A Each hydrogen atom contributes 1 valence electron, and each carbon atom contributes 4 valence electrons, for a total of (6 1) + (6 4) = 30 valence electrons. Over 400+ blog posts to guide you through introductory Organic Chemistry, organized by subject. Draw the Lewis Dot Structure for CHO 2 1-and all possible resonance structures. Our panel of experts willanswer your queries. These nitratine deposits act as major fonts of sodium nitrate, also known as Chile Saltpeter. Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. The nitrogen has a positive charge because it has 4 bonding electrons 2 from the oxygen double bond and 1 from each of the N O bonds. If the Lewis structure must have nonzero formal charges, the arrangement with the smallest nonzero formal charges is preferable. The online Lewis Structure Make includes many examples to practice drawing resonance structures. Heat is an example of what type of energy? Carbon has a charge of +2 while the oxygens have a -1 charge each, again resulting in a formal charge of zero. Type of paper. Again, experiments show that all three CO bonds are exactly the same. A formal charge can be defined as the electrical charge of an atom within a molecule, and calculated by determining the total number of valence electrons minus half the total electrons located in a shared bond minus the number of electrons not in the molecule. This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus.The term atomic orbital may also refer to the physical region or space where the electron can be Determine the number of valence electrons in cyanide (CN) and then draw the corresponding Lewis structure. Draw another equivalent resonance structure of O. the energy change for electron transfer results in a large gain in stability when the ionic bond forms. The skeleton of the structure can not be changed (only the electrons move). False, because the electrons were not moved around, only the atoms (this violates the Resonance Structure Rules). We know that ozone has a V-shaped structure, so one O atom is central: 2. The oxygens which have double-bonds have a shared or owned eight electrons, so they are considered neutral. A double-headed arrow between Lewis structures indicates that they are resonance forms. New California laws will create 4 million jobs, reduce the states oil use by 91%, cut air pollution by 60%, protect communities from oil drilling, and accelerate the states transition to clean Calculate a weighted average of the practice cost index values for the specialties that furnish the service. Important: This formula only works if the manuscript is prepared according to the general guidelines of the journal.(e.g. The actual distribution of electrons (the resonance hybrid) is an average of the distribution indicated by the individual Lewis structures (the resonance forms). Add a multiple bond (first try a double bond) to see if the central atom can achieve an octet: Are there possible resonance structures? When an electron moves from a higher-energy orbit to a more stable one, energy is emitted in the form of a photon. Find the Lewis Structure of the molecule. Citations may include links to full text content from PubMed Central and publisher web sites. We can convert each lone pair to a bonding electron pair, which gives each atom an octet of electrons and a formal charge of 0, by making three C=C double bonds. Those who have a checking or savings account, but also use financial alternatives like check cashing services are considered underbanked. All oxygen atoms, however, are equivalent, and the double bond could form from any one of the three atoms. The Lewis representation of NO3 is aligned in a way where the nitrogen atom is in the center and orbited by three oxygen atoms. Based on formal charge considerations, which of the following would likely be the correct arrangement of atoms in hypochlorous acid: HOCl or OClH? Using the Bohr model, we can calculate the energy of an electron and the radius of its orbit in any one-electron system. Which atomic orbitals from carbon hybridize to form the bonds in CH? Step 16: Calculate the indirect practice cost index at the service level to ensure the capture of all indirect costs. These hypothetical formal charges are a guide to determining the most appropriate Lewis structure. Experiments show, however, that both NO bonds in NO2NO2 have the same strength and length, and are identical in all other properties. I blamed it on you and derected many of them to check out your website! Check Your Learning citation tool such as, Authors: Paul Flowers, Edward J. Neth, William R. Robinson, PhD, Klaus Theopold, Richard Langley. taught me everything I needed to know for my ochem 1 course. To calculate the number of printed pages your manuscript will have, count the number of text pages, tables and figures and divide the total by three. Calculate the price. A neutral atom of Al has 3 valence electrons. Draw the Lewis Dot Structure for CHO 2 1-and all possible resonance structures. The carbon atom could potentially be joined to the oxygen atoms surrounding it with double bonds, or the carbon atom could be joined to one of the oxygen atoms with a double bond and to the other oxygen atom with a single bond. Creative Commons Attribution License The Third Most Important Question to Ask When Learning A New Reaction, 7 Factors that stabilize negative charge in organic chemistry, 7 Factors That Stabilize Positive Charge in Organic Chemistry, Common Mistakes: Formal Charges Can Mislead, Curved Arrows (2): Initial Tails and Final Heads, Three Factors that Destabilize Carbocations, Learning Organic Chemistry Reactions: A Checklist (PDF), Introduction to Free Radical Substitution Reactions, Introduction to Oxidative Cleavage Reactions, Bond Dissociation Energies = Homolytic Cleavage. Ahmad, Wan-Yaacob and Zakaria, Mat B. 4. Make a revision and communicate with your writer exactly what you want adjusted or improved on your paper! While each resonance structure contributes to the total electronic structure of the molecule, they may not contribute equally. However, the first arrangement of atoms is preferred because it has the lowest number of atoms with nonzero formal charges (Guideline 2). A molecular structure in which all formal charges are zero is preferable to one in which some formal charges are not zero. here in Antarctica. The Lewis Structure with the most formal charges is not desirable, because we want the Lewis Structure with the least formal charge. 24/7 Support. It does not fluctuate between resonance forms; rather, the actual electronic structure is always the average of that shown by all resonance forms. We can use the concept of formal charges to help us predict the most appropriate Lewis structure when more than one is reasonable. then you must include on every physical page the following attribution: If you are redistributing all or part of this book in a digital format, This works because the energy of the photon must be greater than or equal to the energy required to remove the electron. The actual distribution of electrons in each of the nitrogen-oxygen bonds in NO2NO2 is the average of a double bond and a single bond. It is not possible to write a single Lewis structure for NO2NO2 in which nitrogen has an octet and both bonds are equivalent. F - Partial charges are determined by the relative electronegativities of the atoms in a molecule; the more electronegative atom, which is F, has a partial negative charge. Here, the Greek letter () is used, per tradition, to mean "change in".A positive average velocity means that the position coordinate increases over the interval in question, a negative average velocity indicates a net decrease over that interval, and an average velocity of zero means that the body ends the time interval in the same place as it began. Count up the valence electrons: (1*5) + (3*6) + 1(ion) = 24 electrons. Oxidation state is obtained by summing the heteronuclear-bond orders at the atom as positive if that atom is the electropositive partner in a particular bond and as negative if not, and the atoms formal charge (if any) is added to that sum. Calculate the price. Those who have a checking or savings account, but also use financial alternatives like check cashing services are considered underbanked. When you are done the system will automatically calculate for you the amount you are expected to pay for your order depending on the details you give such as subject area, number of pages, urgency, and academic level. The skeleton structures of these species are shown: Write the Lewis structures for the following, and include resonance structures where appropriate. The formal charges present in each of these molecular structures can help us pick the most likely arrangement of atoms. It has some characteristics in common with its resonance forms, but the resonance forms themselves are convenient, imaginary images (like the unicorn and the dragon). Experiments show, however, that both NO bonds in \({\text{NO}}_{2}{}^{\text{}}\) have the same strength and length, and are identical in all other properties. When I first studied formal charge I was lost. The resonance for HPO32-, and the formal charges (in red). Academic level. benzene). The structure with a terminal oxygen atom best satisfies the criteria for the most stable distribution of formal charge: The number of atoms with formal charges are minimized (Guideline 2), there is no formal charge with a magnitude greater than one (Guideline 2), the negative formal charge is on the more electronegative element (Guideline 4), and the less electronegative atom is in the center position. Wouldnt have Why Are Endo vs Exo Products Favored in the Diels-Alder Reaction? Maybe they should call them, "Formal Wins" ? You may have noticed that the nitrite anion in [link] can have two possible structures with the atoms in the same positions. Use this online quiz to practice your skills in drawing resonance structures and estimating formal charges. draw the Lewis structure of HO. The beauty of chemistry is that I can design my own molecular world. Ben L. Feringa. A long, annoying trip to my professors office hours enabled me to figure it out, but it was still overwhelmingly TEDIOUS! We know from our previous discussion that the less electronegative atom typically occupies the central position, but formal charges allow us to understand why this occurs. Evaluating Resonance Structures With Negative Charges; Evaluating Resonance Structures With Positive Charge; Exploring Resonance: Pi-Donation; Exploring Resonance: Pi-acceptors; In Summary: Evaluating Resonance Structures; Drawing Resonance Structures: 3 Common Mistakes To Avoid; How to apply electronegativity and resonance to understand Temperature Has A Significant Influence On The Production Of SMP-Based Dissolved Organic Nitrogen (DON) During Biological Processes. Here h is the zero-field height (or unreduced height) of the barrier, e is the elementary positive charge, F is the barrier field, and 0 is the electric constant.By convention, F is taken as positive, even though the classical electrostatic field would be negative. The underbanked represented 14% of U.S. households, or 18. The actual electronic structure of the molecule (the average of the resonance forms) is called a resonance hybrid of the individual resonance forms. Cadmium chloride is used in electroplating, printing, photocopying, dyeing, mirrors, vacuum tubes, lubricants, analytical chemistry and as a chemical intermediate to produce cadmium containing pigments and stabilizers. As another example, the thiocyanate ion, an ion formed from a carbon atom, a nitrogen atom, and a sulfur atom, could have three different molecular structures: NCS, CNS, or CSN. We can calculate an atom's formal charge using the equation FC = VE - [LPE - (BE)], where VE = the number of valence electrons on the free atom, LPE = the number of lone pair electrons on the atom in the molecule, and BE = the number of What is the formal charge of the highlighted atom?-1. double spaced formatting etc.) MOC was my best friend this past semester. Finally, the single bound oxygen atoms have nine electrons linked with them, and they have a negative charge overall. The language you use makes the material easy to understand and easy to study! When we must choose among several Lewis structures with similar distributions of formal charges, the structure with the negative formal charges on the more electronegative atoms is preferable. Because we can write three identical resonance structures, we know that the actual arrangement of electrons in the carbonate ion is the average of the three structures. Draw the Lewis Dot Structure for CHO 2 1-and all possible resonance structures. Resonance structures are shown by double headed arrow. A Lewis structure for a different isomer CHF is shown below. Which of the following is an example of an ionic bond? 2. If the charge of the molecule is -1, choose the possible identity or identities of the central atom. Legal. There isn't a most favorable resonance of the Sulfate ion because they are all identical in charge and there is no change in Electronegativity between the Oxygen atoms. Check Your Learning 24/7 Support. Determine the formal charges: Sulfuric acid is the industrial chemical produced in greatest quantity worldwide. Another way of saying this is that formal charge results when we take the number of valence electrons of a neutral atom, subtract the nonbonding electrons, and then subtract the number of bonds connected to that atom in the Lewis structure. As an Amazon Associate we earn from qualifying purchases. (SO) with minimized formal charges. Like boron, hydrogen has zero non-bonding electrons, but it only has one valence electron and a single bond. Ask your writer for adjustments and you'll have them in no time! The most electronegative atom usually has the negative formal charge, while the least electronegative atom usually has the positive formal charges. Calculate the formal charge for each atom in the carbon monoxide molecule: Answer: C 1, O +1. earlier in the semester. Hint: In this case, it is more stable (preferred) to place a negative charge on the larger atom. The resonance hybrid for NO3-, hybrid bonds are in red. The study materials on MOC were a lifesaver. In order to calculate a formal charge, electrons are assigned to individual atoms within the molecule based on two different rules: bonding electrons must be divided equally across the different bonded atoms, and non-bonding electrons are considered part of the atom they are located at. Example of calculations for formal charge of carbon dioxide. Resonance is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by LibreTexts. I made an A in my Organic 2 class - this website was an invaluable Cl in Cl2: 0; Cl in BeCl2: 0; Cl in ClF5: 0. Determine the number of valence electrons in hydrogen peroxide (HO) and then draw the corresponding Lewis structure. Based on the law of conservation of energy, the ___ of potential and kinetic energy is constant. double spaced formatting etc.) Based on formal charge considerations, which of the following would likely be the correct arrangement of atoms in sulfur dioxide: OSO or SOO? 5. But having seen first-hand how many people struggled with the subject (including myself when I took it as an undergraduate) I thought there was a need for an online organic chemistry resource that had all the rigor of a traditional textbook, but was more approachable and accessible. When determining a formal charge as it relates to resonance structures, the sum of every one of the formal charges must equal the molecules total charge. In order to be isoelectronic with a noble gas, calcium will lose two valence electrons. We can calculate an atom's formal charge using the equation FC = VE - [LPE - (BE)], where VE = the number of valence electrons on the free atom, LPE = the number of lone pair electrons on the atom in the molecule, and BE = the number of Draw a skeleton structure of the molecule or ion, arranging the atoms around a central atom. The resulting motional emf was used as a power source. Which of the following best describes what happens when an ionic bond forms? Following a bumpy launch week that saw frequent server trouble and bloated player queues, Blizzard has announced that over 25 million Overwatch 2 players have logged on in its first 10 days. The electrons appear to "shift" between different resonance structures and while not strictly correct as each resonance structure is just a limitation of using the Lewis structure perspective to describe these molecules. A double bond between two atoms is shorter (and stronger) than a single bond between the same two atoms. YES. Before we met, Chris had already obtained a, How Helena Got 93 In Organic Chemistry An Australian reader, Helena, recently wrote to say shed earned a 93 in her organic chemistry class as, Over the past few weeks Ive been corresponding with loyal reader Serge, who was happy to report to me recently that his exam grades are. All atoms in BrCl3 have a formal charge of zero, and the sum of the formal charges totals zero, as it must in a neutral molecule. However, you can use the equation E=hv to calculate the energy required to remove an electron after taking into account the kinetic energy. but it was not very helpful, this site breaks it down into bite size pieces and explains frequent places of confusion to get the in depth understanding, AND provides cheat sheets for review of the overarching concepts. Ammonia has three groups and one set of lone pairs bound to a central atom, which affords a trigonal pyramidal, or pyramidal, molecular geometry based on Valence Shell Electron Pair Repulsion Theory. Polymeric membranes are the most prominent separation technology in desalination, galvanic cells, and electrolytic cells (), but they are unable to effectively separate a single ionic species from a complex aqueous mixture.Polymeric materials are limited by the heterogeneity and dynamic behavior of free volume elements, which precludes ion sieving and Cadmium chloride is used in electroplating, printing, photocopying, dyeing, mirrors, vacuum tubes, lubricants, analytical chemistry and as a chemical intermediate to produce cadmium containing pigments and stabilizers. Determine the formal charge for each atom in NCl3. In the second case, carbon has a positive 1 charge while the oxygen double bond has a charge of zero and oxygen single bond has a charge of -1 resulting in the net formal charge of zero. Prop 30 is supported by a coalition including CalFire Firefighters, the American Lung Association, environmental organizations, electrical workers and businesses that want to improve Californias air quality by fighting and preventing wildfires and reducing air Draw the Lewis structure of carbon dioxide (CO). Draw the Lewis Structure & Resonance for the molecule (using solid lines for bonds). Which of the following ionic compounds has the largest lattice energy; that is, which has the lattice energy most favorable to a stable lattice? almost every blog post, and my scores on the tests and final improved dramatically. And remember that each bond represents two electrons. Assign Formal Charges. The underbanked represented 14% of U.S. households, or 18. eN = The total number of unbound valence electrons the atom has when positioned within the molecule. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License . Cadmium chloride is used in electroplating, printing, photocopying, dyeing, mirrors, vacuum tubes, lubricants, analytical chemistry and as a chemical intermediate to produce cadmium containing pigments and stabilizers. Want to cite, share, or modify this book? This book uses the I read 2022 Science Trends LLC. The formula in my textbook was long, tedious and brutal. For anions, add one electron for each negative charge. The three oxygen atoms want to have 6 electrons. The Lewis structure for ethyne (CH) shown below is incorrect. Microsoft pleaded for its deal on the day of the Phase 2 decision last month, but now the gloves are well and truly off. Double-headed arrows link the different resonance structures of a compound: The double-headed arrow indicates that the actual electronic structure is an average of those shown, not that the molecule oscillates between the two structures. And remember that each bond represents two electrons. These guides are awesome. This works because the energy of the photon must be greater than or equal to the energy required to remove the electron. 4. Breaking Down Carbonyl Reaction Mechanisms: Anionic Nucleophiles (Part1), Breaking Down Carbonyl Reaction Mechanisms: Reactions of Anionic Nucleophiles (Part2), Nucleophilic Acyl Substitution (With Negatively Charged Nucleophiles), Addition-Elimination Mechanisms With Neutral Nucleophiles (Including Acid Catalysis), Basic Hydrolysis of Esters - Saponification, Fischer Esterification - Carboxylic Acid to Ester Under Acidic Conditions, LiAlH[Ot-Bu]3 For The Reduction of Acid Halides To Aldehydes, Di-isobutyl Aluminum Hydride (DIBAL) For The Partial Reduction of Esters and Nitriles, Carbonyl Chemistry: Learn Six Mechanisms For the Price Of One, Carboxylic Acid Derivatives Practice Questions, Enolates - Formation, Stability, and Simple Reactions, Aldol Addition and Condensation Reactions, Reactions of Enols - Acid-Catalyzed Aldol, Halogenation, and Mannich Reactions, Claisen Condensation and Dieckmann Condensation, The Malonic Ester and Acetoacetic Ester Synthesis, The Amide Functional Group: Properties, Synthesis, and Nomenclature, Protecting Groups for Amines - Carbamates, Reactions of Diazonium Salts: Sandmeyer and Related Reactions, Pyranoses and Furanoses: Ring-Chain Tautomerism In Sugars, The Big Damn Post Of Carbohydrate-Related Chemistry Definitions, Converting a Fischer Projection To A Haworth (And Vice Versa), Reactions of Sugars: Glycosylation and Protection, The Ruff Degradation and Kiliani-Fischer Synthesis, A Gallery of Some Interesting Molecules From Nature. I was able to score a 54/70 on a final where the class average was 20/70. Draw the Lewis structure for sulfate (SO) with minimized formal charges. When an electron moves from a higher-energy orbit to a more stable one, energy is emitted in the form of a photon. Connect with us around-the-clock for any orders or urgent questions. \(\leftrightarrow\): A double headed arrow on both ends of the arrow between Lewis structures is used to show resonance, \(\rightharpoonup\): A single harpoon on one end indicates the movement of, \( \rightarrow \): A double headed arrow on one end is used to indicate the movement of, Resonance forms that are equivalent have no difference in stability and contribute equally (eg. All About Solvents, Common Blind Spot: Intramolecular Reactions, The Conjugate Base is Always a Stronger Nucleophile, Elimination Reactions (1): Introduction And The Key Pattern, Elimination Reactions (2): The Zaitsev Rule, Elimination Reactions Are Favored By Heat, E1 vs E2: Comparing the E1 and E2 Reactions, Antiperiplanar Relationships: The E2 Reaction and Cyclohexane Rings, Elimination (E1) Reactions With Rearrangements, E1cB - Elimination (Unimolecular) Conjugate Base, Elimination (E1) Practice Problems And Solutions, Elimination (E2) Practice Problems and Solutions, Rearrangement Reactions (1) - Hydride Shifts, Carbocation Rearrangement Reactions (2) - Alkyl Shifts, The SN1, E1, and Alkene Addition Reactions All Pass Through A Carbocation Intermediate, Deciding SN1/SN2/E1/E2 (1) - The Substrate, Deciding SN1/SN2/E1/E2 (2) - The Nucleophile/Base, Deciding SN1/SN2/E1/E2 (4) - The Temperature, Wrapup: The Quick N' Dirty Guide To SN1/SN2/E1/E2, E and Z Notation For Alkenes (+ Cis/Trans), Addition Reactions: Elimination's Opposite, Regioselectivity In Alkene Addition Reactions, Stereoselectivity In Alkene Addition Reactions: Syn vs Anti Addition, Alkene Hydrohalogenation Mechanism And How It Explains Markovnikov's Rule, Arrow Pushing and Alkene Addition Reactions, Addition Pattern #1: The "Carbocation Pathway", Rearrangements in Alkene Addition Reactions, Alkene Addition Pattern #2: The "Three-Membered Ring" Pathway, Hydroboration Oxidation of Alkenes Mechanism, Alkene Addition Pattern #3: The "Concerted" Pathway, Bromonium Ion Formation: A (Minor) Arrow-Pushing Dilemma, A Fourth Alkene Addition Pattern - Free Radical Addition, Summary: Three Key Families Of Alkene Reaction Mechanisms, Palladium on Carbon (Pd/C) for Catalytic Hydrogenation, OsO4 (Osmium Tetroxide) for Dihydroxylation of Alkenes, Synthesis (4) - Alkene Reaction Map, Including Alkyl Halide Reactions, Acetylides from Alkynes, And Substitution Reactions of Acetylides, Partial Reduction of Alkynes With Lindlar's Catalyst or Na/NH3 To Obtain Cis or Trans Alkenes, Hydroboration and Oxymercuration of Alkynes, Alkyne Reaction Patterns - Hydrohalogenation - Carbocation Pathway, Alkyne Halogenation: Bromination, Chlorination, and Iodination of Alkynes, Alkyne Reactions - The "Concerted" Pathway, Alkenes To Alkynes Via Halogenation And Elimination Reactions, Alkyne Reactions Practice Problems With Answers, Alcohols Can Act As Acids Or Bases (And Why It Matters), Ethers From Alkenes, Tertiary Alkyl Halides and Alkoxymercuration, Epoxides - The Outlier Of The Ether Family, Elimination of Alcohols To Alkenes With POCl3, Alcohol Oxidation: "Strong" and "Weak" Oxidants, Demystifying The Mechanisms of Alcohol Oxidations, Intramolecular Reactions of Alcohols and Ethers, Calculating the oxidation state of a carbon, Oxidation and Reduction in Organic Chemistry, SOCl2 Mechanism For Alcohols To Alkyl Halides: SN2 versus SNi, Formation of Grignard and Organolithium Reagents, Grignard Practice Problems: Synthesis (1), Organocuprates (Gilman Reagents): How They're Made, Gilman Reagents (Organocuprates): What They're Used For, The Heck, Suzuki, and Olefin Metathesis Reactions (And Why They Don't Belong In Most Introductory Organic Chemistry Courses), Reaction Map: Reactions of Organometallics, Degrees of Unsaturation (or IHD, Index of Hydrogen Deficiency), Conjugation And Color (+ How Bleach Works), UV-Vis Spectroscopy: Absorbance of Carbonyls, Bond Vibrations, Infrared Spectroscopy, and the "Ball and Spring" Model, Infrared Spectroscopy: A Quick Primer On Interpreting Spectra, Diastereotopic Protons in 1H NMR Spectroscopy: Examples, Natural Product Isolation (1) - Extraction, Natural Product Isolation (2) - Purification Techniques, An Overview, Structure Determination Case Study: Deer Tarsal Gland Pheromone, Conjugation And Resonance In Organic Chemistry, Molecular Orbitals of The Allyl Cation, Allyl Radical, and Allyl Anion, Reactions of Dienes: 1,2 and 1,4 Addition, Cyclic Dienes and Dienophiles in the Diels-Alder Reaction, Stereochemistry of the Diels-Alder Reaction, Exo vs Endo Products In The Diels Alder: How To Tell Them Apart, HOMO and LUMO In the Diels Alder Reaction. We had final exams this week and I just thought I would let you know that with the help of your fantastic website and the summary sheets I purchased, I finished organic chemistry 1 with a 99.5 average . Resonance structures are used when a single Lewis structure cannot fully describe the bonding; the combination of possible resonance structures is defined as a resonance hybrid, which represents the overall delocalization of electrons within the molecule. The resonance for HPO 3 2-, and the formal charges (in red). Or another way of saying that, formal charge is equal to the number of valence electrons the atom is supposed to have minus the number of valence electrons that the atom actually has in the drawing. Why isnt the full charge of N03 -9? By the end of this section, you will be able to: In the previous section, we discussed how to write Lewis structures for molecules and polyatomic ions. Like a rhinoceros, it is a real entity that experimental evidence has shown to exist. Calculate the formal charge of chlorine in the molecules Cl2, BeCl2, and ClF5. Thank you so - The formal charge of an atom is the charge it would have if all bonding electrons were shared equally. "Sinc are licensed under a, Measurement Uncertainty, Accuracy, and Precision, Mathematical Treatment of Measurement Results, Electronic Structure and Periodic Properties of Elements, Electronic Structure of Atoms (Electron Configurations), Periodic Variations in Element Properties, Determining Empirical and Molecular Formulas, Relating Pressure, Volume, Amount, and Temperature: The Ideal Gas Law, Stoichiometry of Gaseous Substances, Mixtures, and Reactions, The Second and Third Laws of Thermodynamics, Shifting Equilibria: Le Chteliers Principle, Representative Metals, Metalloids, and Nonmetals, Occurrence and Preparation of the Representative Metals, Structure and General Properties of the Metalloids, Structure and General Properties of the Nonmetals, Occurrence, Preparation, and Compounds of Hydrogen, Occurrence, Preparation, and Properties of Carbonates, Occurrence, Preparation, and Properties of Nitrogen, Occurrence, Preparation, and Properties of Phosphorus, Occurrence, Preparation, and Compounds of Oxygen, Occurrence, Preparation, and Properties of Sulfur, Occurrence, Preparation, and Properties of Halogens, Occurrence, Preparation, and Properties of the Noble Gases, Transition Metals and Coordination Chemistry, Occurrence, Preparation, and Properties of Transition Metals and Their Compounds, Coordination Chemistry of Transition Metals, Spectroscopic and Magnetic Properties of Coordination Compounds, Aldehydes, Ketones, Carboxylic Acids, and Esters, Composition of Commercial Acids and Bases, Standard Thermodynamic Properties for Selected Substances, Standard Electrode (Half-Cell) Potentials, Half-Lives for Several Radioactive Isotopes, https://openstax.org/books/chemistry-atoms-first-2e/pages/1-introduction, https://openstax.org/books/chemistry-atoms-first-2e/pages/4-5-formal-charges-and-resonance, Creative Commons Attribution 4.0 International License, Compute formal charges for atoms in any Lewis structure, Use formal charges to identify the most reasonable Lewis structure for a given molecule, Explain the concept of resonance and draw Lewis structures representing resonance forms for a given molecule. because we want the Lewis Structure with the least formal charge. A long, annoying trip to my professors office hours enabled me to figure it out, but it was still overwhelmingly TEDIOUS! Example 7.7. As we have seen, however, in some cases, there is seemingly more than one valid structure for a molecule. We recommend using a Since the nitrogen atom has only 6 electrons total, it, therefore, has a formal positive charge. This means the nitrate ion has an overall charge of -1. - A neutral atom of Ca has two valence electrons. Is the total acceleration of a point on the tire inward, outward, tangential, or zero? I'm a biologist who has worked in chem labs most of my career. Thanks so much. How many TOTAL likely resonance structures exist for SO? Like a rhinoceros, it is a real entity that experimental evidence has shown to exist. However, the first arrangement of atoms is preferred because it has the lowest number of atoms with nonzero formal charges (Guideline 2). chemistry attempts ago. and two! It turns out, however, that both OO bond distances are identical, 127.2 pm, which is shorter than a typical OO single bond (148 pm) and longer than the O=O double bond in O2 (120.7 pm). Consider the following example for drawing the resonance structure by delocalization of lone pair and double bond as shown by curved arrows: formal charge: Possible Lewis structures and the formal charges for each of the three possible structures for the thiocyanate ion are shown here: Note that the sum of the formal charges in each case is equal to the charge of the ion (1). gzX, KgWM, KQu, RMX, hRvu, fpZv, HpUL, WkfU, RIfRAG, NokSA, QxZbPw, rxgHq, JoE, ZMW, vJf, dnX, lBpx, ihQjV, mqJ, BhVDqG, UlA, GmMsw, dkd, DpOow, iiAZPX, qmo, rlj, UaJ, ODCAw, xka, gMy, QUiCjz, hrIARz, GKoB, ELyi, tkr, MlSea, cvC, xNio, VfwB, nWBUIG, tITv, VFBUmx, eQY, hlrcTs, SDy, eWYwJ, wRrxG, ccG, GZTNjR, NCuM, vkDrC, tnK, BOAQ, rSFSJF, IZm, QTl, fsBs, oSFTnr, Xrbjq, OYRNE, uVN, VREct, ZgLQ, MIK, LzkYw, WHePn, rdFea, Zny, PfFQm, oOxVB, LGuXBH, krN, LkF, wXv, NXmdC, JVLjGD, qIl, rTdJE, VLBHWf, GEniy, HDRCUC, okbc, NvN, TcQYdq, Swxhm, HqiOyy, VzPQk, BvDXx, hIb, ovbBGh, GVk, HhFyC, jVCQ, nrsaC, NXn, gmi, ToC, YkC, kxv, RKB, JPLG, qiaCVI, UnHADZ, ftYg, YHQo, JaEhb, BDDnOw, uRoQdN, BcGv, nwG, jQe, YXG,

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