Application of Electrolysis

Q.

What is the function of the salt bridge in an electrochemical cell?

Q. Explain, why during the electrolysis of copper sulphate using copper electrodes, the colour of solution does not fade.

Q.

The standard reduction potentials, $E^{\circ }$, for the half-reactions are as $Zn=Z{n}^{2+}+2e$, $E^{\circ }$= + 0.76 V and $Fe=F{e}^{2+}+2e$, $E^{\circ }$ = + 0.41 V. The e.m.f. for the cell reaction, $F{e}^{2+}+Zn=Z{n}^{2+}+Fe$ is

1. - 0.35 V

2. + 0.35 V

3. - 1.17 V

4. + 1.17 V

Q. $4.5g$ of aluminum (at. mass 27amu) is deposited at cathode from $A{l}^{3+}$ solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from $H+$ ions in solution by the same quantity of electric charge will be

1. 11.2 L
2. 22.4 L
3. 44.8 L
4. 5.6 L

Q.

During electrolysis of brine, a gas ‘G’ is liberated at anode. When this gas ‘G’ is passed through slaked lime, a compound ‘C’ is formed, which is used for disinfecting drinking water.

(iii) What is common name of compound ‘C’? Give its chemical name.

Q.

Electrolysis of water is exothermic or endothermic reaction.

Q.

Explain why zinc metal can displace copper from Copper sulphate solution but copper cannot displace Zinc sulphate solution.

Q.

Faradays laws of electrolysis are related to the?

Q.

What is an active electrode? Explain with the help of an example

Q.

Decomposition of vegetable matter, is an example of

Q.

Write a short note on anodizing. (1m)

Q.

(a) State observation at the anode when aqueous copper sulphate solution is electrolysed using copper electrodes.

(b) During electrolysis of molten lead bromide, graphite anode is preferred to other electrodes. Give reason.

(c) Electrolysis of molten lead bromide is considered to be a redox reaction. Give reason.

Q.

(a) Copy and complete the following table which refers to two practical applications of electrolysis

$\begin{array}{cccc}& Anode& Electrolyte& Cathode\\ \left(i\right)Silverplating& & Solutionof& \\ ofaspoon& & potassium& \\ & & argentocyanide& \\ \left(ii\right)Purification& & & \\ Ofcopper& & & \\ \left(iii\right)Extraction& & & \\ Ofsodium& & & \end{array}$

(b) Write equations of reactions taking place at anode for Q.2(a).

Q. The following questions refer to the electrolysis of copper sulphate solution with copper electrodes:
(a) Compare the change in mass of the anode.
(b) What is seen to happen to the colour of the copper sulphate solution if platinum electrodes are used? Explain this observation.
(c) What is the practical application of the electrolysis of copper sulphate solution? Briefly, describe one such application.

Q. Is redox reaction exothermic or endothermic reaction?

Q.

Which metal cannot be extracted by hydrometallurgy, copper or zinc ?

Q. State what happen when a concentrated solution of sodium chloride is electrolysed . Explain briefly?

Q.

Is dissolving salt in water a redox reaction?

Q.

Which of the following is/are applications of electrolysis?

1. Extraction of Metals

2. Electrorefining of metals

3. Alloy creation of metals

4. Electroplating

Q. State your observations for the following electrolytic reactions:
(a) Solid copper sulphate is electrolysed between platinum electrodes.
(b) Aqueous copper sulphate is electrolysed between platinum electrodes.
(c) Aqueous copper sulphate is electrolysed between copper electrodes.

Q.

Which of the following reaction takes place at the cathode during electrolysis of molten magnesium chloride?

1. Mg → Mg²⁺ + 2e^-

2. 2Cl^- → Cl₂ + 2e^-

3. Mg²⁺ + 2e^- → Mg

4. Cl₂ + 2e^- → 2Cl^-

Q.

The following questions refer to the electrolysis of CuSO₄ solution with copper electrodes.
(i) What is the change in the mass of cathode and anode?
(ii) What will happen to the colour of the electrolyte if platinum electrodes are used? Explain.
(iii) Briefly, describe one practical application of electrolysis of CuSO₄ solution.

Q. During electrolytic refining of metals, anode is made of the pure metal whereas the cathode is made of the impure metal.

Q. Choose the correct answer:
During the electrolysis of molten lead bromide, which of the following takes place?
(a) Bromine is released at the cathode
(b) Lead is deposited at the anode
(c) Bromine ions gain electrons
(d) Lead is deposited at the cathode

Q. Which of the following metals can replace copper from $CuS{O}_4$?

1. Magnesium
2. Sodium
3. Gold
4. Iron

Q. The main applications of electrolysis are:

1. electroplating
2. electrorefining
3. extraction of metals
4. All of the above

Q.

How electrolysis helps in removing impurities of metal under cuso4 solution?

And after the process the impurities settle under the anode. How , why

Q. (a) What kind of particles will be found in a liquid compound which is a non-electrolyte?
(b) If HX is a weak acid, what particles will be present in its dilute solution apart from those of water?
(c) Cations are formed by __________ (loss/gain) of electrons and anions are formed by ________ (loss/gain) of electrons.
(Choose the correct words to fill in the blanks.)
(d) What ions must be present in a solution used for electroplating a particular metal?
(e) Explain, how electrolysis is an example of redox reaction.

Q.

What is the difference between extraction of metals and refining of metals?

Q.

Mention differences between electrolytic reduction and carbon reduction methods.