Ethanol burns in air

4 marks · Normal

Ethanol is used in spirit burners for heating in a laboratory.

(a)

Draw the displayed formula of ethanol.

[2 marks]

(b)

Complete the following word equation for the combustion of ethanol: ethanol + _____ → carbon dioxide + _____

[2 marks]

Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.

Show answer

(a) Displayed formula must show CH3–CH2–O–H, with all bonds including O–H clearly shown. · must show All bonds, correct attachments, three C–H, two C–H, C–C, C–O, O–H bonds.

(b) oxygen; water · must show oxygen; water

Show mark scheme and worked solution

Marking points

D1 (a) · 2 marks · Correct displayed formula for ethanol: all atoms and bonds, especially O–H bond.

B1 (b) · 1 mark · Completes equation with 'oxygen'.

B2 (b) · 1 mark · Completes equation with 'water'.

Worked solution

a) The displayed formula of ethanol shows:

H H | | H–C–C–O–H | | H H

It must show each bond, with the –OH group on the second carbon.

b) The completed word equation is:

ethanol + oxygen → carbon dioxide + water