Electrolysis

Which metal could not be used for electroplating using an aqueous solution?

• chromium

• copper

• silver

• sodium

The diagram shows a failed attempt to copper-plate a pan.

Which can be done to plate the pan with copper?

• Cool the copper sulfate solution in an ice bath

• Heat the copper sulfate solution to boiling point

• Increase the voltage from 2V to 6V

• Make the pan the cathode and the copper the anode

Tags

NGSS.HS-PS2-5

A student wishes to electroplate an object with copper.

Which row is correct?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-5

Four substances are electrolysed. The substances are concentrated aqueous sodium chloride, concentrated hydrochloric acid, molten lead (II) bromide and molten sodium oxide.

Which statement about these electrolysis reactions is correct?

• A colourless gas is formed at the anode when motlen sodium oxide is electrolysed

• A green gas is formed at the cathode when concentrated hydrochloric acid is electrolysed

• A metal is formed at the anode when molten lead (II) bromide is electrolysed

• A metal is formed at the cathode when concentrated sodium chloride is electrolysed

Four solutions are separately electrolysed.

In which two experiments is a colourless gas evolved at the anode?

• 1 and 2

• 1 and 4

• 2 and 3

• 3 and 4

The diagram shows the electrolysis of concentrated hydrochloric acid and concentrated aqueous sodium chloride using carbon electrodes.

At which electrode(s) is hydrogen produced?

• electrode 1 only

• electrodes 1 and 3

• electrode 2 only

• electrodes 2 and 4

What are the electrode products when molten silver iodide is electrolysed between inert electrodes?

• A

• B

• C

• D

The diagram shows the electroplating of a steel object.

A student made the following statements.

1. The object turns a reddish-brown colour.

2. The copper sulfate solution changes to a paler blue colour.

3. The copper electrode becomes smaller.

Which statements are correct?

• 1,2 and 3

• 1 and 2 only

• 1 and 3 only

• 2 and 3 only

Tags

NGSS.HS-PS1-2

Which products are formed at the electrodes when a concentrated solution of sodium chloride is electrolysed?

• A

• B

• C

• D

In the electrolysis shown, chlorine is produced at W and sodium at X.

• A

• B

• C

• D