IGCSE Coordinated Chemistry Workout 12

The graph shows the changes in temperature when a substance is cooled. Which describes the processes occurring at X and Y?

• X is boiling and Y is melting

• X is condensing and Y is freezing

• X is freezing and Y is condensing

• X is melting and Y is boiling

Which trends in physical properties are correct for the alkali metals down Group I?

• A

• B

• C

• D

Large hydrocarbons can be ..….1…... to make smaller, more useful molecules. Small hydrocarbon molecules can be …...2…... to make long molecules. Which words correctly complete gaps 1 and 2?

• A

• B

• C

• D

What is made when amino acids join together in a large chain?

• cellulose

• glucose

• protein

• starch

Some properties of three substances are shown. What are the structures of W, X and Y?

• W is giant covalent; X is giant ionic; Y is simple molecular

• W is giant ionic; X is giant covalent; Y is simple molecular

• W is giant ionic; X is simple covalent; Y is giant covalent

• W is simple molecular; X is giant ionic; Y is giant covalent

How is carbon (coke) used in the extraction of iron from iron oxide?

• as an anode

• as a cathode

• as an oxidising agent

• as a reducing agent

Electrolysis of sodium chloride is used to obtain chlorine.

In what form is sodium chloride electrolysed and at which electrode is the chlorine obtained?

• an aqueous solution of sodium chloride and chlorine is formed at the anode

• an aqueous solution of sodium chloride and chlorine is formed at the cathode

• solid sodium chloride and chlorine is formed at the anode

• solid sodium chloride and chlorine is formed at the cathode

A solution is tested by adding acidified silver nitrate solution. Which ion causes the white precipitate to form?

• chloride ions, Cl⁻

• copper ions, Cu²⁺

• hydroxide ions, OH⁻

• sodium ions, Na⁺

Which statements about a positive test for a nitrate ion are correct?

1 Aluminium is used.

2 The nitrate ion is reduced to ammonia.

3 Ammonia turns damp litmus paper red.

• 1, 2 and 3

• 1 and 2 only

• 1 and 3 only

• 2 and 3 only

The diagram shows part of the Periodic Table.

Which element has atoms containing three electrons in the outer shell?

• A

• B

• C

• D