When substance X is electrolysed, the amount of gases P and Q formed is shown.

What is substance X?

• concentrated aqueous sodium chloride

• concentrated hydrochloric acid

• dilute sulfuric acid

• molten lead(II) bromide

What are the products at the electrodes when dilute sulfuric acid is electrolysed using inert electrodes?

• A

• B

• C

• D

Electricity is passed separately through concentrated hydrochloric acid, concentrated aqueous

sodium chloride and dilute sulfuric acid.

In which rows are the electrolysis products correctly named?

• 1, 2 and 3

• 1 and 2 only

• 1 and 3 only

• 2 and 3 only

Which row describes the electrolysis of molten potassium bromide?

• A

• B

• C

• D

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

Copper and hydrogen can each be formed by electrolysis.

At which electrodes are these elements formed?

• A

• B

• C

• D

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

Which action will plate the pan with copper?

• cooling the copper sulfate solution in an ice bath

• heating the copper sulfate solution to boiling point

• increasing the voltage from 3V to 6V

• making the pan the cathode and the copper the anode

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

NGSS.HS-PS1-4

An object is electroplated with silver using an aqueous silver salt as the electrolyte.

Which set of conditions is used?ZA

• A

• B

• C

• D