1. Which of the following species has the longest N—O bond? NO3 NO+ NO2− H2NOH

Best Lewis Formula and Molecular Geometry A student writes the Lewis electron-dot formula for the carbonate anion, CO32, as a Does this Lewis formula obey the octet rule? Explain. What are the formal charges on the atoms? Try describing the bonding for this formula in valence bond terms. Do you have any difficulty doing this? b Does this Lewis formula give a reasonable description of the electron structure, or is there a better one? If there is a better Lewis formula, write it down and explain why it is better. c The same student writes the following resonance description for CO2: Is there something wrong with this description? (What would you predict as the geometries of these formulas?) d Is one or the other formula a better description? Could a value for the dipole moment help you decide? e Can you write a Lewis formula that gives an even better description of CO2? Explain your answer.

a Carbonyl fluoride, COF2, is an extremely poisonous gas used in organofluorine synthesis. Give the valence bond description of the carbonyl fluoride molecule. (Both fluorine atoms are attached to the carbon atom.) b Nitrogen, N2, makes up about 80% of the earths atmosphere. Give the valence bond description of this molecule.

Formamide, HC(O)NH2, is prepared at high pressures from carbon monoxide and ammonia, and serves as an industrial solvent (the parentheses around the O indicate that it is bonded only to the carbon atom and that the carbon atom is also bonded to the H and the N atoms). Two resonance forms (one with formal charges) can be written for formamide. Write both resonance structures, and predict the bond angles about the carbon and nitrogen atoms for each resonance form. Are they the same? Describe how the experimental determination of the HNH bond angle could be used to indicate which resonance form is more important.

Put the following three molecules in order of increasing H-X-H bond angle, where X is the central atom. CH4 H2S PH3 A. CH4 < H2S < PH3 B. H2S < PH3 < CH4 C. CH4 < PH3 < H2S D. H2S < CH4 < PH3 E. PH3 < CH4 < H2S く く

10. Molecular Chlorine, Oxygen and Nitrogen- Draw the Lewis dot structures and structural formulas Molecule Lewis Dot Structure Structural Formula Chlorine Отудеn Nitrogen Do these molecules have an interior atom? What is their molecular shape? How many sigma and pi bonds does each molecule have? Number of Sigma Bonds Number of PI Bonds Chlorine Охудев Nitrogen

The formula SbCl5^2- what is the 3D Lewis structure with bond angles and all dipole moments? what is the least electronegative element? What is the number of electron regions surrounding the central atom ? is it octet exceeded? what is the genereral formula? Is it polar or non polar molecule? what is the molecular geometry? what is the electron pair geometry?

The caffeine molecule is shown below. Indicate the electron geometry AND the molecular shape around each of the indicated atoms (six answers in total). Be aware that the angles may not be drawn correctly in this Lewis structure.

A. What is the electron-pair geometry for B in BF4-?fill in the blank 1    There are  lone pair(s) around the central atom, so the geometry of BF4- is ________. B. What is the electron-pair geometry for Se in SeF6?fill in the blank 4    There are  lone pair(s) around the central atom, so the geometry of SeF6 is _________.