C9 - Crude Oil And Fuels

Question 1

Most of the compounds in crude oil are….

Answer 1

hydrocarbons

Question 2

D. Alkane?

Answer 2

saturated hydrocarbon

Question 3

General formula for alkanes?

Answer 3

C(n)H(2n+2)

Question 4

Saturated hydrocarbon?

Answer 4

all carbon-carbon bonds are single covalent

Question 5

D. Fractions?

Answer 5

Hydrocarbons with similar boiling points, separated from crude oil

Question 6

Why is crude oil not very useful on its own?

Answer 6

too many substances in it, all with different boiling points

Question 7

What type of hydrocarbon molecules tend to be the most useful?

Answer 7

short-chain

Question 8

Properties of short-chain hydrocarbons?

Answer 8

very flammable, burn well

Question 9

As the size of the hydrocarbon molecule gets larger…

boiling point, volatility, viscosity, flammability

Answer 9

• boiling point increases
• volatility decreases
• viscosity increases
• flammability decreases

Question 10

D. Volatility?

Answer 10

the tendency to turn into gas

Question 11

Properties of each fraction depend on?

Answer 11

size of the molecule

Question 12

Products of the complete combustion of a hydrocarbon?

Answer 12

Carbon dioxide and water

Question 13

How to test for water?

Answer 13

• anhydrous copper sulphate powder goes white to blue

- blue cobalt chloride paper goes pink

Question 14

Products of incomplete combustion?

Answer 14

carbon monoxide

Question 15

Positive test for unsaturated hydrocarbons?

Answer 15

turns orange bromine water colourless

Question 16

D. Cracking?

Answer 16

the breaking of large less useful hydrocarbon molecules into smaller more useful molecules

Question 17

Process of cracking?

Answer 17

oil is vaporised and passed over a hot catalyst OR mixed with steam and heated to very high temp