General Rules of Electrolysis

Q.

In the activity of electrolysis of water, how to test the obtained gases present in the test tubes?

Q. In the electrolytic cell, flow of electrons is from:

1. cathode to anode in solution
2. anode to cathode through internal supply
3. cathode to anode through external supply
4. cathode to anode through internal supply

Q. Explain electrolysis of lead bromide.

Q. With reference to the electrolysis of acidulated water, answer the following:
(a) Why distill water is a non-electrolyte?
(b) What is the electrolytic cell called?
(c) State what you would observe at the (i) cathode (ii) anode.
(d) Summarize the electrode reactions.
(e) Why is the electrolysis of acidulated water considered as an example of catalysis?

Q. What happens when current is passed into the solution of an electrolyte?

1. Anions move towards anode and cations towards cathode
2. In some cases, anions move to cathode and cations stay in the solution
3. Anions move towards cathode and cations towards anode
4. No movement of ions take place

Q.

Strong electrolytes are those which

1. Dissolve readily in water

2. Completely dissociate into ions at all dilutions

3. Dissociate into ions at high dilution

4. Conduct electricity

Q.

What happens during the electrolysis of sodium chloride? explain in detail.

Q.

What is the color of anhydrous copper sulphate?

Q.

In which of the following state sodium chloride does not conduct electricity?

1. Solid state
2. Aqueous Solution
3. Molten state
4. Sodium chloride is not conductive in any state

Q.

Which kind of chemical reaction takes place when electric current is passed through fused lead Bromide?

Q. Electrolysis of acidified water produces a gas P at cathode and gas Q at anode. Identify the gases P and Q, and determine the ratio in which these gases are released at cathode and anode, respectively?

1. P: Hydrogen; Q: Oxygen; Ratio: 1:2
2. P: Oxygen; Q: Hydrogen; Ratio: 1:2
3. P: Oxygen; Q: Hydrogen; Ratio: 2:1
4. P: Hydrogen; Q: Oxygen; Ratio: 2:1

Q. Aqueous solution of nickel sulphate contains Ni²⁺ and SO₄²⁻ ions.
(a) Which ion moves towards the cathode?
(b) What is the product at the anode?

Q. Fill in the blanks:
(a) The metal plate through which current enters into an electrolyte is called _________. It has _________ of electrons.
(b) The metal plate through which _________ leaves from an electrolyte is called _________. It has ________ of electrons.
(c) The ions which discharge on the negative electrode during electrolysis _________ electrons. Thus, the ions are said to be _________.
(d) The ions which discharge on the positive electrode during electrolysis __________ electrons. Thus, the ions are said to be ________.
(e) Hydrogen and metallic ions are _________ because they __________ electrons.
(f) Non-metallic ions are __________ because they _________ electrons.

Q.

Why the Aluminum is extracted through an electrolytic process and not by using a reducing agent? Write the reaction taking place at anode and cathode during the electrolytic reduction of Alumina.

Q.

Acidified water is electrolysed using platinum electrodes. Give the electrode reactions.

Q. What should be the physical state of lead bromide if it is to conduct electricity?

Q. (a) A solution of silver nitrate is a good electrolyte but it is not used for electroplating an article with silver.
(b) Identify the following reactions as either oxidation or reduction:
(i) O + 2e⁻ $\stackrel{}{\to }$ O²⁻
(ii) K − e⁻ $\stackrel{}{\to }$ K⁺
(iii) Fe³⁺ + e⁻ $\stackrel{}{\to }$ Fe²⁺

Q.

Answer in one word: Name of the metallic ions that should be present in the electrolyte when an article made of copper is to be electroplated with silver.

Q. Write equations for the reactions taking place at cathode and at anode during the electrolysis of:

1. Acidified nickel sulphate solution with nickel electrode.
2. Acidulated water with inert electrode.

[2 marks]

Q.

What gases collect at the different electrodes in the electrolysis of acidulated water?

Q.

Explain why solid Sodium chloride does not pass electricity through it?

Q. State the chemical reactions that take place during the electrolysis of sodium chloride.
[2 Marks]

Q. (a) Write down the words or phrases from the brackets that will correctly fill in the blanks in the following sentences:
(b) Pure water consists entirely of _________ (ions/molecules).
(c) We can expect that pure water _________ (will/will not) normally conduct electricity.

Q. Select the correct statements regarding electric conduction.

1. Involves the transfer of molecules
2. Happens by the movement of electrons
3. Happens by the movement of ions
4. Does not involve the transfer of matter.

Q.

During electrolysis of an electrolyte, the number of ions produced is independent of the _______ .

1. temperature

2. nature of solvent

3. nature of the electrolyte

4. volume of the container

Q.

The process of separation of material by passing direct electric current through the solution is known as ____

1. Separation

2. Electrolysis

3. Segregation

4. Dissociation

Q. What happens when current is passed into the solution of an electrolyte?

1. Anions move towards anode and cations towards cathode
2. In some cases, anions move to cathode and cations stay in the solution
3. Anions move towards cathode and cations towards anode
4. No movement of ions take place

Q.

Define the term anode.

Q. The substance obtained at the anode during the electrolysis of water is:

1. water vapour
2. hydrogen
3. oxygen
4. dilute sulphuric acid

Q.

When an aqueous solution of sodium sulphate is electrolysed, on cathode we get:

1. Na

2. SO₂

3. SO₃

4. H₂