Electrolysis half equations

This lesson will focus on writing half equations for the reactions at each electrode during electrolysis.

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Quiz:

Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Q1.(Revision) What ions do alkalis release in solution?

H⁺ Na⁺ OH⁻ O²⁻

1/7

Q2.(Revision) What method is used to extracted aluminium from its ore?

Heating with carbon Distillation Electrolysis Crystallisation

2/7

Q3.What state symbol would be used to represent a solution?

(L) (l) (AQ) (aq)

3/7

Q4.What will form at the cathode during the electrolysis sodium chloride solution?

chlorine oxygen hydrogen copper

4/7

Q5.What is the correct test for hydrogen

A lit splint gives a squeaky pop Relights a glowing splint Passed through limewater and limewater turns cloudy Damp blue litmus turns red the bleaches

5/7

Q6.A students tests for the gas produced at the anode during the electrolysis of an ionic compound solution. The test shows damp blue litmus turning red then bleaching. Which gas have they identified?

Oxygen Carbon dioxide Chlorine Hydrogen

6/7

Q7.A student tests the hypothesis that 'The volume of gas produced during electrolysis increases with time'. Which of these is the dependent variable for this reaction?

Volume of gas Time electrolysis is carried out for Concentration of solution Temperature of solution

7/7

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Q1.(Revision) What ions do alkalis release in solution?

H⁺ Na⁺ OH⁻ O²⁻

1/7

Q2.(Revision) What method is used to extracted aluminium from its ore?

Heating with carbon Distillation Electrolysis Crystallisation

2/7

Q3.What state symbol would be used to represent a solution?

(L) (l) (AQ) (aq)

3/7

Q4.What will form at the cathode during the electrolysis sodium chloride solution?

chlorine oxygen hydrogen copper

4/7

Q5.What is the correct test for hydrogen

A lit splint gives a squeaky pop Relights a glowing splint Passed through limewater and limewater turns cloudy Damp blue litmus turns red the bleaches

5/7

Q6.A students tests for the gas produced at the anode during the electrolysis of an ionic compound solution. The test shows damp blue litmus turning red then bleaching. Which gas have they identified?

Oxygen Carbon dioxide Chlorine Hydrogen

6/7

Q7.A student tests the hypothesis that 'The volume of gas produced during electrolysis increases with time'. Which of these is the dependent variable for this reaction?

Volume of gas Time electrolysis is carried out for Concentration of solution Temperature of solution

7/7

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This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Electrolysis Half Equations HT

This quiz will assess your learning on this lesson and other lessons in this unit.

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Q1.(Revision) What is the correct definition of a strong acid?

Partially ionises in solution Fully ionises in solution A large number of acid particles per volume of water A small number of acid particles per volume of water

1/7

Q2.If the pH of an acid with a concentration of 0.05 mol/dm³ is 3, what will be the pH if its concentration is 0.005mol/dm³?

1 5 3 7

2/7

Q3.What is the charge on the cathode?

positive negative

3/7

Q4.What do negative non-metal ions do when they reach the anode?

Lose electrons to form ions Lose electrons to form atoms Gain electrons to form ions Gain electrons to form atoms

4/7

Q5.What would be the correct products at the anode and cathode in the electrolysis of magnesium bromide solution?

Anode = oxygen cathode = magnesium Anode = oxygen cathode = hydrogen Anode = bromine cathode = magnesium Anode = bromine cathode = hydrogen

5/7

Q6.Does this half equation show oxidation or reduction?

Oxidation Reduction

6/7

Q7.What number needs to be placed in front of OH⁻ to correctly balance this equation?

1 2 3 4

7/7

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Electrolysis Half Equations HT

This quiz will assess your learning on this lesson and other lessons in this unit.

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Q1.(Revision) What is the correct definition of a strong acid?

Partially ionises in solution Fully ionises in solution A large number of acid particles per volume of water A small number of acid particles per volume of water

1/7

Q2.If the pH of an acid with a concentration of 0.05 mol/dm³ is 3, what will be the pH if its concentration is 0.005mol/dm³?

1 5 3 7

2/7

Q3.What is the charge on the cathode?

positive negative

3/7

Q4.What do negative non-metal ions do when they reach the anode?

Lose electrons to form ions Lose electrons to form atoms Gain electrons to form ions Gain electrons to form atoms

4/7

Q5.What would be the correct products at the anode and cathode in the electrolysis of magnesium bromide solution?

Anode = oxygen cathode = magnesium Anode = oxygen cathode = hydrogen Anode = bromine cathode = magnesium Anode = bromine cathode = hydrogen

5/7

Q6.Does this half equation show oxidation or reduction?

Oxidation Reduction

6/7

Q7.What number needs to be placed in front of OH⁻ to correctly balance this equation?

1 2 3 4

7/7

Lesson summary: Electrolysis half equations

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