http://i67.tinypic.com/6ifurd.jpg - Question 32 why is the answer (b)..?

32)
Calcium ions (Ca²⁺) form a white precipitate of calcium hydroxide (Ca(OH)₂) when reacting with aqueous solution. However, calcium ions do not form precipitate with aqueous ammonia (NH₃) because ammonia is a weak base in which the concentration of hydroxide ions (OH⁻) is low. On the other hands, lead(II) hydroxide (Pb(OH)₂) is formed with lead(II) ions (Pb²⁺) react with either aqueous sodium hydroxide or ammonia. Hence, the unknown solution contains calcium ion, but no lead(II) ions.

Chloride ions (Cl⁻) react with acidified silver nitrate solution (AgNO₃) to form a white precipitate of silver chloride (AgCl). On the other hand, silver sulfate (Ag₂SO₄) precipitate may not be formed with sulfate ions (SO₄²⁻) mixed with silver nitrate solution because silver sulfate is sparingly soluble in water. Hence, the unknown solution contains rather chloride ions than sulfate ions.

The answer is : (B) Calcium and chloride