KnowledgeBoat Logo
|

Chemistry

Give a chemical test to distinguish between :

(i) Sodium chloride soln. and sodium nitrate soln.

(ii) Hydrogen chloride gas and hydrogen sulphide gas.

(iii) Calcium nitrate soln. and zinc nitrate soln.

(iv) Carbon dioxide gas and sulphur dioxide gas.

Practical Chemistry

3 Likes

Answer

(i) 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 ↓ [white ppt.] + NaNO3

NaNO3 + AgNO3 ⟶ no white ppt.

(ii) Hydrogen sulphide gas turns moist lead acetate paper silvery black or black whereas, no change is observed in case of HCl gas.

Pb(CH3COO)2 [colourless] + H2S ⟶ PbS [black] + 2CH3COOH

(iii) When NaOH is added to the given soln., Zn(NO3)2 reacts to form a gelatinous white ppt. which dissolves in excess of NaOH whereas, Ca(NO3)2 forms a milky white ppt. which is insoluble in excess of NaOH. Hence, the two can be distinguished.

(iv) Carbon dioxide gas has no effect on acidified potassium permanganate (KMnO4) and acidified potassium dichromate (K2Cr2O7) solution whereas sulphur dioxide gas turns acidified potassium permanganate from pink to clear colourless and acidified potassium dichromate from orange to clear green.

2KMnO4 + 2H2O + 5SO2 ⟶ K2SO4 + 2MnSO4 + 2H2SO4

K2Cr2O7 + H2SO4 + 3SO2 ⟶ K2SO4 + Cr2(SO4)3 + H2O

Answered By

3 Likes


Related Questions