Five ml of 8N nitric acid, 4.8ml of 5N hydrochloric acid and a certain volume of 17M sulphuric acid are mixed together and made upto 2 litre. Thirty ml of this acid mixture neutralise 42.9 ml of sodium carbonate solution containing one gram of Na₂CO₃.10H₂O in 100 ml of water. Calculate the amount in gram of the sulphate ions in solution.

The density of a 3 M Sodium thiosulphate solution (Na₂S₂O₃) is 1.25 g per ml. Calculate

(i) the percentage by weight of sodium thiosulphate,

(ii) the mole fraction of sodium thiosulphate and

(iii) the molalities of Na⁺ and $$S_2O_3^{-2}$$ ions

Complete and balance the following equation:

$$Cr_2O_7^{2-}$$ + C₂H₄O $$\to$$ C₂H₄O₂ + Cr³⁺

Complete and balance the following equation:

Zn + $$NO_3^- \to$$ Zn²⁺ + $$NH_4^+$$