| Date | November 2016 | Marks available | 2 | Reference code | 16N.3.sl.TZ0.14 |
| Level | SL | Paper | 3 | Time zone | TZ0 |
| Command term | State | Question number | 14 | Adapted from | N/A |
Question
Biofuels are renewable energy sources derived mainly from plants.
State the equation for the complete transesterification of the triglyceride given below with methanol.
[2]
a.
Outline why the fuel produced by the reaction in (a) is more suitable for use in diesel engines than vegetable oils.
[1]
b.
Markscheme
methyl ester formula AND glycerol formula
correct balancing
Award M2 only if M1 is correct.
a.
«methyl esters have» low«er» viscosity/surface tensions
OR
«methyl esters have» high«er» volatility
OR
«combustion of vegetable oils» produces carbon deposits in engine/reduces engine life
Accept converse arguments.
b.
Examiners report
[N/A]
a.
[N/A]
b.
