41.

(i)Calculate the solubility of AgCl in 0.2 M solution of sodium chloride. 

K_sp of AgCl = 1.2 x 10^–10

(ii) A current of 10 A is passed for 80 min. and 27 seconds through a cell containing dilute sulphuric acid.

1.    How many moles of oxygen gas will be liberated at the anode ?

2.    Calculate the amount of zinc deposited at the cathode when another cell containing ZnSO₄ solullon is connected in series (Zn = 65).

(iii) Calculate:

E_cell  at 25°C for the reaction

Zn + Cu²⁺ (0.20 M) → Zn²* (0.50M) + Cu

Given :

E° (Zn²⁺/Zn) = – 0.76 volt E°(Cu²⁺/Cu) = 0.34 volt

Copper pyrites is an ore of copper.    

(i) Describe the process by which copper pyrites is concentrated.

(ii) Describe all the steps, with equations, to convert the concentrated ore to blister copper.

(iii) Describe the process of conversion of blister copper to pure copper.

(i) How is iodine manufactured from sea weeds ?   

(ii) How is hydrogen peroxide prepared in the laboratory ?

(iii) Give a balanced equation for a reaction in which hydrogen peroxide acts as a reducing agent and one in which it acts as an oxidizing agent.