If a steady current of 2 amperes was passed through an aqueous solution of iron (II) sulphate for 15 minutes, the mass of iron deposited at the cathode will be.

1. 30g.
2. 56g.
3. 0.54g.
4. 28g.
5. 0.52g.

If a stead current of 2 amperes was passed through an aqueous solution of iron (II) sulphate for 15 minutes, then the mass of iron deposited at the cathode will be:

1. 54 g.
2. 56 g.
3. 0.54 g.
4. 28 g.
5. 0.52 g.

 Aqueous sugar solution is a poor conductor of electricity because

1.  water and sugar are covalent compounds
2.  water is a non­electrolyte
3.  sugar is a non­electrolyte
4.  sugar is covalent when in liquid form
5.  sugar dissolves completely in water.

   The charge of one mole of electrons is represented by the term

1.   one ampere
2. one coulomb
3. one volt
4. one faraday E
5. one gram.

A current of 0.2 A was passed through an electrolyte for 16 minutes and 40 seconds. What is the quantity of electricity produced in coulombs?

1. 2000 C
2. 1000 C
3. 200 C
4. 0.20 C
5. 7686 C.

How long must a current of 4.00 A be applied to a solution of Cu₍²_a⁺_q) to produce 2.0 grams of copper metal?

1. 2.4x10²s
2. 1.5x10³s
3. 7.6x10²s
4. 3.8x10²s
5. 12x10⁴s

 Among the factors that determine the ions to be discharged at electrodes when salt solutions are electrolysed are their

1.  non metallic nature
2.  relative concentrations in the solution
3.  relative ionic masses
4.  electronic configuration
5.  position in the periodic table.

6. A Form Three student prepared an experiment to prepare a gas in the laboratory by decomposing a compound using electricity. A steady current was allowed to flow through the solution for 3 hours. At s.t.p 4.12 dm³ of the gas which relighted the glowing splint was produced.

(a) What terminology is used to refer to such experimental set up?

(b) Work out the current flowing in the circuit.

Copper obtained from copper pyrites (CuFeS2) is impure for electrical wiring and has to be purified by electrolysis.

(i) Name the electrolyte and the electrodes used during electrolysis.

(ii) Write the observations that can be made during the electrolysis.

   State three industrial application of electrolysis.

How long a current of 5A should be passed through a solution of silver chloride in order to deposit 3.24 g of silver metal at the cathode? Given that, the electrochemical equivalent of silver = 1.118 x 10^-3 ge^-1 .

(i) Draw a labeled diagram of a simple electrolytic cell which show how copper is purified.

(ii) Write balanced ionic equations to show the electrode reactions which occur when copper is purified.

0.48g of a metal, M was placed in a test tube and hot copper (II) sulphate solution was added to it and stirred until the reaction stopped. The metal (M) displaced copper from copper (II) sulphate solution. Copper was filtered, washed with water, dried at 100⁰ C _ and the mass found to be 1.27g. Given that, the balanced chemical reaction that occurred is M _(s)  + CuSO  _4(aq)  MSO  _4(aq)  + Cu  _(s) 

(a) Calculate;

1. The number of moles of copper that were formed and the number of moles of M that were used in the reaction.

2. The relative atomic mass of M and hence identify metal M.

(b) State the appearance of the metal formed (Cu).

(c) With ionic equations, explain why the reaction can be considered to involve both oxidation and reduction.

Assume that you are a chemist in a chemical plant that deals with the production of chlorine gas You want to produce 100 litres of chlorine gas per hour so that you can reach the company’s goal of producing 2400 litres every day. What current of electricity will you allow to flow per hour?

 A current of 0.5 A were made to flow through silver voltameter for 30 minutes. Calculate the mass of silver deposited and the equivalent weight of silver.

A solution of sodium hydroxide was electrolysed using platinum electrodes. Write the reactions which took place at the electrodes and give a reason why the solution becomes alkaline.

Electric current was passed through a solution of sodium hydroxide using platinum electrodes. Draw a labelled electrolytic cell for this electrolysis. Indicate the directions of the movement of ions. 

14.     How electrolysis is applied in industries? Describe by giving six points.  (15 marks

9.A Form Three student conducted an experiment to prepare a gas in the laboratory by decomposing a certain compound using electricity. She allowed a steady electric current to flow through the solution for 3 hours at s.t.p. If the volume of the gas obtained was 4.12 dm³ and the gas relighted a glowing splint;

(a)name the gas that was produced.

(b)calculate the electric current that was flowing in the solution. (7 marks)