Exercises

1. a) 2,3,1 b) 1,6,4 c) 2,1,2 d) 1,2,1,2

3. Energy required to break bonds:

Three H-H bonds: 3 x 436 kJ = 1308 kJ

One N-N bond: 946 kJ

total required: 1308 kJ + 946 kJ = 2254 kJ

Energy released upon bond formation:

Six H-N bonds: 6 x 389 kJ = 2334 kJ

Net energy = energy released - energy required = 2334 kJ - 2254 kJ = 80 kJ (released). Exothermic reaction.

9. A strong acid will conduct electricity better because it contains more ions.

11. pH = 10, which would be a basic solution.

12. pH = -4, which would be an acidic solution.

15. Sodium loses electrons to aluminum and is oxidized.

18.

19. 16 amu (periodic table).

20. One amu = 1.661 x 10^-24 grams. So, 16 amu = 16*(1.661 x 10^-24 grams) = 2.6576 x 10^-23 grams.