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IGCSE Chemistry Extended11.5.4—Test to distinguish between saturatedTopic Practice

11.5.4—Test to distinguish between saturated

• Describe test to distinguish between saturated and unsaturated hydrocarbons by their reaction with aqueous bromine

Question 2(a)(ii)

[Maximum number: 2]

Cyclopropane is a colourless gas.
Cyclopropane reacts with bromine at room temperature. The chemical equation for the reaction is shown.

Question image

What colour change, if any, would you see when cyclopropane is bubbled into aqueous bromine?
initial colour
final colour

Question 3(f)(ii)

[Maximum number: 2]

Fluorine is a Group VII element. Fluorine forms compounds with metals and non-metals.

Tetrafluoroethene is an unsaturated compound with the formula C2 F4\mathrm{C}_{2} \mathrm{~F}_{4}. Tetrafluoroethene is the monomer used to make the polymer poly(tetrafluoroethene).

Describe a test to show that tetrafluoroethene is unsaturated.
test
observations

Question 31

[Maximum number: 1]

Which compound rapidly decolourises aqueous bromine?

A

propane

B

propanoic acid

C

propanol

D

propene

Question 36

[Maximum number: 1]

Which statements about propene are correct?
1 Propene contains only single bonds.
2 Propene decolourises bromine water.
3 Propene is obtained by cracking.
4 Propene is a hydrocarbon.

A

1 and 4

B

2, 3 and 4

C

2 and 4 only

D

4 only

Question 37

[Maximum number: 1]

Some properties of colourless liquid L are listed.
- It boils at 65∘C65^{\circ} \mathrm{C}.
- When added to water, two layers form which do not mix.
- It does not react with sodium carbonate.
- It has no effect on bromine water.

What is L ?

A

ethanol

B

hexane

C

hexene

D

ethanoic acid

Question 38

[Maximum number: 1]

Which statements about unsaturated hydrocarbons are correct?
1 They contain both single and double bonds.
2 They turn aqueous bromine from colourless to brown.
3 They can be manufactured by cracking.

A

1 and 2 only

B

1 and 3 only

C

2 and 3 only

D

1, 2 and 3

Question 39

[Maximum number: 1]

Which statement about unsaturated hydrocarbons is correct?

A

CH3CH2CH=CHCH3\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CHCH}_{3} is an unsaturated hydrocarbon.

B

Ethene has more hydrogen atoms per molecule than ethane.

C

Unsaturated hydrocarbons have double bonds between carbon and hydrogen atoms.

D

Unsaturated hydrocarbons turn aqueous bromine from colourless to brown.

Question 5(b)(iii)

[Maximum number: 2]

Cracking is used to convert long chain alkanes into shorter chain alkanes and alkenes. Alkenes are unsaturated compounds.

Decane, C10H22\mathrm{C}_{10} \mathrm{H}_{22}, can be cracked to give propene and one other product.

Describe a test to show that propene is an unsaturated compound.
test
result

Question 4(b)(iii)

[Maximum number: 2]

Alkenes and alkanes are homologous series of compounds containing carbon and hydrogen atoms.

Alkenes take part in addition reactions.

Describe the colour change seen when propene is added to aqueous bromine. from to

Question 5(b)

[Maximum number: 2]

The table shows the names or structures of organic compounds P to U.

Table

Describe the test for an unsaturated hydrocarbon.
test
observations

0 selected