Date | May 2018 | Marks available | 1 | Reference code | 18M.3.hl.TZ1.13 |
Level | HL | Paper | 3 | Time zone | TZ1 |
Command term | State | Question number | 13 | Adapted from | N/A |
Question
One suggestion for the reduction of carbon footprints is the use of biofuels, such as vegetable oils, as a substitute for petroleum based fuels.
Outline the major technical problem affecting the direct use of vegetable oils as fuels in internal combustion engines and the chemical conversion that has overcome this.
State the formula of a fuel that might be produced from the vegetable oil whose formula is shown.
Markscheme
viscosity «of vegetable oils is too high»
transesterification
OR
«conversion into» alkyl/methyl/ethyl esters
[2 marks]
R–CO–O–CH3 / RCOOMe
OR
R–CO–O–C2H5 / RCOOEt
[1 mark]