Electrolysis

Question 1

Explain the term electrolysis.

Answer 1

The breaking down or decomposition of compounds.

Question 2

Describe the test for oxygen.

Answer 2

Take a glowing splint and place it in a sample of gas, if it re-ignites the splint, the gas is oxygen.

Question 3

Describe the test for chlorine gas.

Answer 3

You use (damp) blue litmus paper, the water will dissolve the chlorine, if the paper bleaches, then chlorine is present.

Question 4

Describe the test for hydrogen.

Answer 4

Light a splint and put it in the test tube, if hydrogen is present a squeaky pop will happen.

Question 5

What is produced at the anode and a cathode during the electrolysis of brine.

Answer 5

Chlorine is produced at the anode and hydrogen is produced at the cathode.

Question 6

What charge do ions attract to the cathode electrode have?

Answer 6

Positive

Question 7

Compare the processes of oxidation and reduction.

Answer 7

Oxidation involves the loss of electrons, reduction involves gaining electrons.

Question 8

Explain why when solid lead bromide is melted it results in bromine gas being produced at the anode.

Answer 8

Ions cannot move in solid, ions free to move in a molten liquid, br ions move to the anode to form bromine molecules.

Question 9

Define the term electrolyte.

Answer 9

Solution containing ions.

Question 10

Write the half equations to show what produced at the anode and cathode when the electrolysis of copper sulfate solution is carried out.

Answer 10

Cathode: Cu2+ + 2e-→Cu; 1 Anode: 4OH-→4e- + 2H2O + O2