Electrolytic Refining

Q.

Explain the structure of an electrolytic cell.

Q.

Electrolysis is used in the purification of metals. Name the

(i) anode (ii) cathode (iii) electrolyte, you would use to get pure copper from a piece of impured copper.

Q.

Local action in the simple voltaic cells is caused due to impurities in

1. zinc plate

2. copper

3. dil. sulphuric acid

4. all of above

Q.

Ammonia is heated with black metallic oxide X to give reddish brown metal Y. What is X and Y?

1. CuO and Pb

2. PbO and Pb

3. PbO and Cu

4. CuO and Cu

Q.

Answer the following questions with respect to the electrolytic process in the extraction of aluminum.

1. Identify the components of the electrolyte other than pure alumina and the role played by each.
2. Explain why powdered coke is sprinkled over the electrolytic mixture.

Q. Which among the following metals are least reactive in nature?

1. Gold
2. Silver
3. Copper
4. Lead
5. Mercury
6. Sodium
7. Potassium
8. Calcium

Q.

Question 36
Which one of the following figures correctly describes the process of electrolytic refining?

Q. Q 3. What happens when:
(a) Copper sulphate solution is electrolysed by using copper electrodes
(b) A concentrated volatile acid is treated with a non-metal
(c) A concentrated dilute volatile acid is treated with metallic carbonate.

Q. 1mole of H2 and 4moles of O2 effuse through orifice and at same temperature, then which is correct percentage of effuse volume of H2 and O2. (Assume they do not react) H2. O2 1). 50%. 50% 2). 60%. 40% 3). 30 %. 70% 4). 10 %. 90%

Q. Standard reduction electrode potential of lead suggests that it is reactive metal but it appears more noble (unreactive). It is due to :

1. surface coating of oxide
2. none of the above
3. both (A) and (B)
4. high over potential of reduction of $H^{+}$ to $H_2$

Q. is it correct to say that if electrode potl is -ve then oxidation takes place easily and reduction if its +ve electrode potl? -electrochemistry