DP Chemistry (last assessment 2024)
Question 19M.3.hl.TZ1.b
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.hl.TZ1.b |
| Level | hl | Paper | 3 | Time zone | TZ1 |
| Command term | Deduce | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
19M.3.hl.TZ1.b
The main fatty acid composition of cocoa butter and coconut oil is detailed below.
Fats contain triglycerides that are esters of glycerol and fatty acids. Deduce an equation for the acid hydrolysis of the following triglyceride.
[2]
Markscheme
correct products [✔]
correctly balanced [✔]
Examiners report
Quite a few candidates had no idea how to write an equation for the acid hydrolysis of a given triglyceride. Many struggled with the structure or molecular formula of glycerol. Some created products of (R-O-CO-OH)3 and alkanes, even though the question told them that triglycerides are esters of glycerol and fatty acids. Some got the products almost correct but wrote O-H-CO-R for the fatty acid so failed to score the first mark. Some forgot to balance the equation.
