Question

1. Which one of the following is most likely to be an ionic compound? A) CaCl2 B) CO2 C) CS2 D) SO2 E) OF2

2. Which one of the following ionic solids would have the largest lattice energy? A) NaCl B) NaF C) CaBr2 D) CsI E) CaCl2

3. Calculate the energy change for the reaction K(g) + I(g) → K+(g) + I – (g) given the following ionization energy (IE) and electron affinity (EA) values.

IE

K: 419 kJ/mol

I: 1,010 kJ/mol

A) –124 kJ/mol B) –715 kJ/mol C) 715 kJ/mol

EA

48 kJ/mol

295 kJ/mol

D) 1429 kJ/mol E) None of these

4. Which one of the following is most likely to be a covalent compound? A) KF B) CaCl2 C) SF4 D) Al2O3 E) CaSO4

5. The number of lone electron pairs in the CO32– ion is ___.

A) 4 B) 5 C) 6 D) 7 E) 8

6. A polar covalent bond would form in which one of the following pairs of atoms?

A) Cl  Cl B) Si  Si C) Ca  Cl D) Cr  Br E) P  Cl

7. The bond in which one of the following pairs of atoms would be the most polar?

A) B  C B) C  N C) C  O D) Si  O E) C  C

8. The total number of bonding electrons in a molecule of formaldehyde (H2CO) is

A) 3 B) 4 C) 6 D) 8 E) 18

9. Assuming the octet rule is obeyed, how many covalent bonds will a nitrogen atom form to give a formal charge of zero?

A) 0 B) 1 C) 2 D) 3 E) 4

10. The number of resonance structures for the sulfur dioxide molecule that satisfy the octet rule is

A) 1 B) 2 C) 3 D) 4 E) None of these

11. Which of the following substances will display an incomplete octet in its Lewis structure?

A) CO2 B) Cl2 C) ICl D) NO E) SO2

12. What is total number of lone pairs in the best Lewis structure for SOF4 that exceeds the octet rule (S is the central atom)?

A) 0 B) 2 C) 14 D) 16 E) 18

13. Use bond energies to estimate the enthalpy change for the reaction of one mole of CH4 with chlorine gas to give CH3Cl and hydrogen chloride.

BE(C–H) = 414 kJ/mol BE(C–Cl) = 326 kJ/mol BE(H–Cl) = 432 kJ/mol BE(Cl–Cl) = 243 kJ/mol

A) –101 kJ/mol B) –106 kJ/mol C) +331 kJ/mol

D) +106 kJ/mol E) +101 kJ/mol

Answer 1