DP Chemistry (last assessment 2024)
Question 19N.3.sl.TZ0.9a
| Date | November 2019 | Marks available | [Maximum mark: 1] | Reference code | 19N.3.sl.TZ0.9a |
| Level | sl | Paper | 3 | Time zone | TZ0 |
| Command term | Calculate | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 1]
19N.3.sl.TZ0.9a
Stearic acid (Mr = 284.47) and oleic acid (Mr = 282.46) have the same number of carbon atoms. The structures of both lipids are shown in section 34 of the data booklet.
(a)
The iodine number is the number of grams of iodine which reacts with 100 g of fat. Calculate the iodine number of oleic acid.
[1]
Markscheme
«one C=C bond»
«1 mole iodine : 1 mole oleic acid»
« =» 89.85 «g of I2» ✔
NOTE: Accept “90 «g of I2»”.
