5.7 Electrolysis Of Brine

Question 1

What ions are in brine?

Answer 1

• sodium/Na+
• chloride/Cl-
• hydrogen/H+
• hydroxide/OH-

Question 2

What is produced at the negative electrode in the electrolysis of brine?

Answer 2

Hydrogen

Question 3

What is produced at the positive electrode in the electrolysis of brine?

Answer 3

Chlorine

Question 4

What solution is left after the electrolysis of brine?

Answer 4

Sodium hydroxide

Question 5

Why is hydrogen when sodium chloride solution is electrolysed?

Answer 5

Sodium is more reactive than hydrogen so hydrogen is discharged in preference

Question 6

What pH is sodium hydroxide?

Answer 6

Strong alkali

Question 7

Name 5 uses of sodium hydroxide

Answer 7

• making soap
• making paper
• making bleach
• neutralising acids
• controlling pH

Question 8

Name 5 uses of chlorine

Answer 8

• kill bacteria in drinking water
• kill bacteria in swimming pools
• make bleach
• make disinfectants
• make plastics

Question 9

Name 2 uses of hydrogen

Answer 9

•make margarine

Question 10

Why is the electrolysis of brine an important industrial process?

Answer 10

It’s three products have many uses

Question 11

What is the half equation for the electrolysis of brine at the positive electrode?

Answer 11

2Cl- –> Cl2 + 2e-

Question 12

What is the half equation for the electrolysis of brine at the negative electrode?

Answer 12

2H+ + 2e- –> H2

Question 13

What is brine?

Answer 13

A solution of sodium chloride in water