Name the sulphide ore of Copper. Describe how pure copper is extracted from this ore.

Calculate the emf and △G^o for the cell reaction at 25^oC:

Zn(s)|Zn²⁺(aq) ||Cd²⁺ (aq)| Cd(s)

Zn²⁺(aq) = (0.1 M)

Cd²⁺ (aq) = (0.01 m)

Given E^o Zn²⁺/Zn = -0.763 and E^o Cd²⁺/Cd = -0.403 V

Define the following terms :

(1) Equivalent conductivity

(2) Corrosion of metals

The specific conductivity of a solution containing 5 g of anhydrous BaCl₂ (mol. wt = 208) in 1000 cm³ of a solution is found to be 0.0058 ohm^–1cm^–1. Calculate the molar and equivalent conductivity of the solution.

What is an electrochemical series? How is it useful in predicting whether a metal can liberate hydrogen from acid or not?

Explain why :

Nitrogen does not form pentahalides

Explain why :

 Helium is used for filling weather balloons.

Explain why :

ICl is more reactive than I₂

Draw the structures of the following :

(1) HClO₄

(2) H₃PO₃

50.

Explain why :

Mercury loses its meniscus in contact with ozone.