Class 10 FRANK Solutions Chemistry Chapter 8 - Study of Compounds-I: Hydrogen Chloride
What is aqua regia? What happens when silver nitrate solution is added to dilute HCl? Discover the answers in our Frank Solutions for ICSE Class 10 Chemistry Chapter 8 Study of Compounds-I: Hydrogen Chloride. Also, learn the steps for preparing hydrochloric acid in a laboratory.
With our ICSE Class 10 Chemistry textbook solutions, learn the properties and uses of hydrochloric acid in detail. Revise more to score more. Now, enjoy anytime access to various TopperLearning resources such as concept videos, online tests and more for thorough Chemistry revision.
Study of Compounds-I: Hydrogen Chloride Exercise 198
Study of Compounds-I: Hydrogen Chloride Exercise 199
Study of Compounds-I: Hydrogen Chloride Exercise 200
(i) Diffused sunlight
(iv) HCl gas is collected by the downward displacement of air.
Study of Compounds-I: Hydrogen Chloride Exercise 201
Study of Compounds-I: Hydrogen Chloride Exercise 202
Study of Compounds-I: Hydrogen Chloride Exercise 203
Aqua regia is a mixture of concentrated hydrochloric acid [3 parts] and concentrated nitric acid [1 part].
Study of Compounds-I: Hydrogen Chloride Exercise 204
(i) A = conc. H2SO4 B = NaCl
(iii) When a rod dipped in ammonium hydroxide is brought near the mouth of the gas jar, dense white fumes of ammonium chloride are produced.
(iv) Hydrogen chloride is denser than air.
Silver nitrate solution will give a white ppt. when added to dil. hydrochloric acid, and no change will be observed when it is added to dil. nitric acid.
Being highly soluble in water, hydrogen chloride gas is dried by conc. sulphuric acid.
(i) Diagram to show the arrangement used for the absorption of HCl gas in water:
(ii) Such an arrangement is necessary to prevent back suction of water into the apparatus, and it provides a large surface area for dissolution of hydrogen chloride gas.
(iii) Balanced chemical equations for the laboratory preparation of HCl gas:
(i) Add silver nitrate solution to both solutions. Sodium chloride will form a curdy white ppt., whereas sodium nitrate will not undergo any reaction.
(ii) Hydrogen chloride gas gives thick white fumes of ammonium chloride when a glass rod dipped in ammonia solution is held near the vapours of the acid, whereas no white fumes are observed in case of hydrogen sulphide gas.
(iii) Ethene gas decolourises the purple colour of KMnO4, whereas ethane does not decolourise KMnO4 solution.
(iv) Calcium nitrate forms no ppt. even with addition of excess of NH4OH, whereas zinc nitrate forms a white gelatinous ppt. which dissolves in excess of NH4OH.
(v) Carbon dioxide gas has no effect on acidified KMnO4 or K2Cr2O7, but sulphur dioxide turns potassium permanganate from pink to colourless.
(i) The gas is HCl (hydrogen chloride) gas.
(ii) Extreme solubility of hydrogen chloride gas is demonstrated by the fountain experiment.
(iii) Ammonia gas is another gas which has the same property which can be demonstrated through this experiment.
Study of Compounds-I: Hydrogen Chloride Exercise 205
(i) Equation for the laboratory preparation of hydrogen chloride gas:
Although it is a reversible reaction, it goes to completion as hydrogen chloride continuously escapes as a gas.
The reaction can occur up to the stage of the formation of sodium sulphate on heating above 200°C.
(ii) The drying agent used in the laboratory preparation of hydrochloric acid is conc. sulphuric acid.
The other drying agents such as phosphorus pentoxide (P2O5) and quick lime (CaO) cannot be used because they react with hydrogen chloride.
2P2O5 + 3HCl → POCl3 + 3HPO3
CaO + 2HCl → POCl3 + 3HPO3
(iii) A safety precaution which should be taken during the preparation of hydrochloric acid:
Always wear chemical splash goggles, chemical-
resistant gloves and a chemical-resistant apron in the
laboratory during the preparation of hydrochloric
(a) HCl turns blue litmus red
(i) When dil. HCl is added to lead nitrate solution and heated, it forms a white precipitate of lead chloride.
Pb(NO3)2 + 2HCl → PbCl2 + 2HNO3
(ii) Dil. HCl reacts with thiosulphate to produce sulphur dioxide, and yellow sulphur is precipitated.
Na2S2O3 + 2HCl → 2NaCl + H2O + SO2 + S ↓
(iii) When dilute hydrochloric acid is added to copper carbonate, it decomposes to give copper chloride.
CuCO3 + 2HCl → CuCl2 + H2O + CO2↑
Dilute hydrochloric acid decomposes iron(II) sulphide to produce iron(II) chloride and hydrogen sulphide having rotten egg smell.
FeS + 2HCl → FeCl2 + H2S
Sulphuric acid precipitates the insoluble sulphate from lead nitrate solution.
Lead nitrate reacts with hydrochloric acid to give a white ppt. of lead chloride.