GCSE Chemistry

Question 1

What is cracking an example of

Answer 1

Thermal decomposition

Question 2

What is combustion

Answer 2

Combustion is an oxidation chemical reaction where energy is released from fuels.

Question 3

What is the process called when the chemicals in crude oil are separated into useful fractions

Answer 3

Fractional Distillation

Question 4

What is viscosity

Answer 4

The lack of fluidity a substance has

Question 5

Compounds that contain only carbon and hydrogen atoms are called

Answer 5

Hydrocarbons

Question 6

What is a mixture

Answer 6

A mixture consists of two or more elements or compounds that are not chemically bonded together.

Question 7

What is crude oil

Answer 7

A mixture of hydrocarbons

Question 8

Crude oil is a thick, smelly dark brown liquid. Before it can be used it must be separated into ___________.

Answer 8

Fractions

Question 9

Distillation can be used to separate a pure liquid from a mixture of liquids with different ___________.

Answer 9

Boiling points

Question 10

Different hydrocarbons in crude oil have different boiling points, so they can be separated by fractional ___________.

Answer 10

Distillation

Question 11

The fractioning column is ________ at the bottom and __________ at the top.

Answer 11

Hot/cool

Question 12

Small hydrocarbons with only a few carbon atoms have _________ boiling points.

Answer 12

Low

Question 13

_______________ hydrocarbons containing __________ carbon atoms have high boiling points.

Answer 13

Large/many

Question 14

_________ hydrocarbons travel further up the fractionating column before they condense because they have _______ boiling points.

Answer 14

Smaller/lower

Question 15

Substances with _____ boiling points condense near the bottom of the fractionating column.

Answer 15

High

Question 16

Bigger hydrocarbon molecules are _______ viscous than small molecules.

Answer 16

More

Question 17

Bigger hydrocarbon molecules are _______ volatile than small molecules.

Answer 17

Less

Question 18

Bigger hydrocarbon molecules are _______ flammable than small molecules.

Answer 18

Less

Question 19

Why can shorter-carbon fractions evaporate much more easily than longer ones

Answer 19

Lower boiling point

Question 20

What do the weak bonds (intermolecular forces) between the molecules have to be for the hydrocarbon to boil

Answer 20

They have to be broken

Question 21

How many carbon atoms in methane

Answer 21

1

Question 22

How many carbon atoms in ethane

Answer 22

2

Question 23

How many carbon atoms in propane

Answer 23

3

Question 24

How many carbon atoms in butane

Answer 24

4

Question 25

Where is crude oil found

Answer 25

In rocks