Sunday, June 24, 2007
Chemistry Revision Answers
Below are the numerical answers for the revision questions I've given out on the Finland trip. Pls consult your chem tutors for the working steps if you're unable to figure them out, as well as for the questions which do not involve calculations.1. 20 cubic cm
2. 2.73 cubic dm
3. 62.5 cubic dm
4. 4 carbon atoms
5. 41.6 tonnes
6. 16 pairs
8c. -613 kJ per mol
9. -11957 kJ per mol
10. Spontaneous at 300K, not at 100K
11. -7.2 kJ per mol
12a. 33.3 kPa
b. Partial pressure of oxygen = 20 kPa
Partial pressure of nitrogen = 13.3 kPa
13. 3.60 cubic dm of butane required
14aiii. rate = k[A][B]
iv. rate constant = 60 cubic dm per mol per second
b. half life = 0.0231 s
15. half life = 6.93 s
16a. Question not complete, ignore
b. lattice energy is inversely proportionate to distance between ions, ionic radius increases from F to I, so distance increases, and LE decreases.
16a. Dative bond
b. 109.5 degrees around the nitrogen atom
18. +158 kJ per mol, halogen is fluorine
19. +55 kJ per mol
20. Rxn is spontaneous at low T.
21c. 11.3%
the music played{9:50 PM}