(b) The Lewis structures for IFs and XeF4 are shown below. :F.:F: F: (i) What is the molecular geometry (shape) of the IFs molecule? (ii) (iii) ABSE square pyramidal What is the molecular geometry (shape) of the XeF4 molecule? AB4E2 Square planar Both IFs and XeF4 contain polar bonds, but only one is a polar molecule. Which of the substances is a polar molecule, and which of the substances is a non-polar molecule? Justify your decision. Filter (pa) Honkbas (po) od (iv) voled svaro orb no word? Which of the substances would more likely be soluble in water? Justify your decision based on intermolecular forces. (v) Both IFs and XeF4 are gases at room conditions. Which of the two compounds would you expect to behave more ideally (like an ideal gas)? Justify your decision. 004 0001 COST 003

(a) Use the VSEPR theory to predict the structure of the NNO molecule. (b) The substance NNO has a small dipole moment. Which end of the molecule is more likely to be the positive end, based only on electronegativity?

For each of the following molecules, complete the Lewis structure and use the VSEPR model to determine the bond angles around each central atom. Note that the drawings are only skeleton structures and may depict the angles incorrectly.

Define formal charge and explain how to calculate it. What is the purpose of the formal charge? Organic compounds are composed mostly of carbon and hydrogen but also may have oxygen, nitrogen, and/or halogens in the formula. Formal charge arguments work very well for organic compounds when drawing the best Lewis structure. How do C, H, N, O, and Cl satisfy the octet rule in organic compounds so as to have a formula charge of zero?

A stable triatomic molecule can be formed that contains one atom each of nitrogen, sulfur, and fluorine. Three bonding structures are possible, depending on which is the central atom: NSF, SNF, and SFN. (a) Write a Lewis diagram for each of these molecules, indicating the formal charge on each atom. (b) Often, the structure with the least separation of formal charge is the most stable. Is this statement consistent with the observed structure for this molecule—namely, NSF, which has a central sulfur atom? (c) Does consideration of the electronegativities of N, S, and F from Figure 3.18 help rationalize this observed structure? Explain.

7.47 Which of the species listed has a Lewis structure with only one lone pair of electrons? F2 , CO32 , CH4 , PH3

The compound whose molecles contain one atom of C and one of O is named carbon monoxide rather than oxygen monocarbide. Why is this the case?

What is meant by a chemical bond? Why do atoms form bonds with each other? Why do some elements exist as molecules in nature instead of as free atoms?

9.77 When a reaction is exothermic, is the sum of bond energies of products or of reactants greater?

What aspect of the following Lewis structure indicates that the concept of coordinate covalency is needed to explain the bonding in the molecule?