CHEM TOPIC 7

Question 1

Define ‘hydrocarbon’

Answer 1

Molecules made up of carbon and hydrogen atoms only

Question 2

formula for alkanes

Answer 2

CnH2n+2

Question 3

Alkene formula

Answer 3

CnH2n

Question 4

test for alkenes

Answer 4

• bromine water
• orange to colourless

Question 5

How is crude oil separated into fractions? (4 marks)
4 points

Answer 5

• The crude oil is heated
• some of the hydrocarbons vaporise
• the column has a temperature gradient
• so the hydrocarbons/ fractions consense at different temperatures/ heights in the column.

Question 6

what is the test used for hydrogen gas.
a …. splint

Answer 6

BURNING

Question 7

Crude oil is formed by the…

Answer 7

decomposition of plankton

Question 8

what industry uses hydrocarbons from crude oil

Answer 8

petrochemical industry

Question 9

crude oil can be used by petrochemical industry to make new compounds like…. x4

Answer 9

• polymers
• lubricants
• detergents
• solvents

Question 10

2 types of cracking

Answer 10

• steam cracking
• catalytic cracking

Question 11

cracking is a ….. ….. reaction

Answer 11

thermal decomposition