a. When thin copper leaves are thrown in a jar of chlorine they catch fire and form cupric chloride.

Cu (Copper) + Cl₂ (Chlorine) → CuCl₂ (Cupric chloride)

b. 1. Due to greater electronegativity of O than S, H₂O undergoes extensive intermolecular H-bonding. As a result, H₂O exists as an associated molecule in which each O is tetrahedrally surrounded by four water molecules. Large amount of energy is required to break these H-bonds. Therefore, H₂O is a liquid at room temperature. 

2. In contrast, H₂S does not undergo H-bonding. It exists as discrete molecules which are held together by weak van der Waals forces of attraction. To break these forces of attraction, only a small amount of energy is required. Therefore, H₂S is a gas at room temperature.

c. Given: C = 0.02 M , k = 2.428 x 10^-3  Ω^-1 cm^-1 

To find: Molar conductivity 

Formula: Molar conductivity = \(\frac{1000k}{C}\) 

Calculation: Molar conductivity = \(\frac{1000k}{C}\) = \(\frac{1000\times2.428\times10^{-3}}{0.02}\)

= 121.4 Ω^-1 cm² mol^-1

d. Henry’s law relates solubility of a gas with external pressure. The law states that, “the solubility of a gas in liquid at constant temperature is proportional to the pressure of the gas above the solution”.