The following is a list of metals : Na, Mg, Al, Zn, Fe, Pb, Cu and Au. Name an ore of one of the

Question

(i) The following is a list of metals : Na, Mg, Al, Zn, Fe, Pb, Cu and Au. Name an ore of one of the above metals and state, how the metal is produced from it commercially by the process of: 

(a) Electrolysis of the molten ore 

(b) Reduction by coke 

(c) Roasting followed by reduction 

(d) Metal found in native state 

(ii) How would you prove that the alloy solder contains lead ?

Answer 1

 (i) (a) Aluminium-Bauxite. 

(b) Iron—Hematite. 

(c) Lead—Galena. 

(d) Gold. 

(ii) Take the given sample of solder and dissolve it in concentrated nitric acid. Dilute the solution with water and add dilute hydrochloric acid. A white precipitate of lead chloride is obtained, which is soluble in hot water. To this solution add potassium chromate solution, a golden yellow precipitate, confirms the presence of lead. 

Pb + 4HNO₃ ⟶ Pb(NO₃ )₂ + 2H₂O + 2NO₂ 

Lead present in solder is confirmed as below :