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Question Question 2(2018)
Give a chemical test to distinguish between following pairs of chemicals :
(i) Lead nitrate solution and zinc nitrate solution.
(ii) Sodium chloride solution and sodium nitrate solution
(i) When NaOH is added to each of the compounds, lead nitrate forms a chalky white precipitate of lead hydroxide [Pb(OH)2] whereas a gelatinous white precipitate of zinc hydroxide [Zn(OH)2] is formed in case of zinc nitrate.
(ii) Add silver nitrate soln. to the given solns., sodium chloride reacts to form a white ppt. which is soluble in NH4OH and insoluble in dil. HNO3. The other soln. is sodium nitrate.
NaCl + AgNO3 ⟶ AgCl + NaNO3
NaNO3 + AgNO3 ⟶ no white ppt.