Which of the following bonds are polar: (a) P—O; (b) S—F; (c) Br—Br; (d) O—Cl? Which is the more electronegative atom in each polar bond?

The carbonate anion, CO32- , is a resonance hybrid. Draw all of the important resonance structures for this molecule. If an atom has a nonzero formal charge, be sure the formal charge is shown clearly in the structure. Use the resonance structures to calculate the average formal charge on each O atom (which are all equivalent in the "true" structure). [Note: all of the important contributing resonance structures have octets around each atom that desires an octet.]

What possible error(s) exist in the Lewis structure (assume we are trying to represent the best possible Lewis structure for the NO₂S ion knowing N is the central atom in this polyatomic ion)? [:ö==S: N= CO :O: The best structure would have double bond and two lone pairs on each oxygen atom and a single bond with three lone pairs on the sulfur. There are no errors. This is the best possible structure. The Lewis structure above does not minimize formal charges, thus is the not the best possible structure. The nitrogen atom has an expanded octet, and this structure is impossible. The Lewis structure contains the wrong number of electrons, thus this structure is impossible.

Chloral, Cl3C—CH=O, reacts with water to form the sedative and hypnotic agent chloral hydrate, Cl3C—CH(OH)2. Draw Lewis structures for these substances, and describe the change in molecular shape, if any, that occurs around each of the carbon atoms during the reaction.

Keeping in mind that some elements violate the octet rule, draw a Lewis structure for each compound: (a) BCl 3; (b) SO 3.

Fructose, C6H1206(S), consists of 5 C-C single bonds, 7 C-O bonds, 7 C-H bonds, and 5 O-H bonds with average bond energies of 348 kJ/mol, 360 kJ/mol, 412 kJ/mol, and 463 kJ/mol respectively. The bond energy for C=O is 799 kJ/mol and O=O is 498 kJ/mol. The molar mass of fructose is 180.12 g/mol. Estimate the change in enthalpy if 2.56 g of fructose undergoes complete combustion at standard temperature and pressure.

2) Build C6H6 as a ring. What do you notice about the placement of the bonds? This is an example of resonance. What is a resonant Lewis structure?

Consider the following ions: NO2−NO2−, CO32−CO32−, and ClO4−ClO4−. For each of these, you should use a Lewis structure that satisfies the octet rule. Which of these ions will exhibit resonance among multiple equivalent Lewis structures that satisfy the octet rule?

Estimate the enthalpy change for the reaction:                                2CO + O2 ⟶2CO2 given the following bond energies.              BE(C O) = 1074 kJ/mol              BE(O=O) = 499 kJ/mol              BE(C=O) = 802 kJ/mol Hint: You need to draw the Lewis Structures of the compounds to know the bonds present. Group of answer choices +2380 kJ/mol -561 kJ/mol +744 kJ/mol +1949 kJ/mol -744 kJ/mol