Chemistry
How will the action of dilute hydrochloric acid enable you to distinguish between the following?
(a) Sodium carbonate and sodium sulphite
(b) Sodium thiosulphate and sodium sulphite.
Answer
(a) When Sodium carbonate is treated with dil. HCl, odourless carbon dioxide gas is produced.
Na2CO3 + 2HCl ⟶ 2NaCl + H2O + CO2 ↑
However, when sodium sulphite is treated with dil.HCl, sulphur dioxide gas with a suffocating odour (burning smell) is produced.
Na2SO3 + 2HCl ⟶ 2NaCl + H2O + SO2 ↑
(b) When sodium thiosulphate is treated with dil. HCl it produces sulphur dioxide gas and yellow sulphur precipitates.
Na2S2O3 + 2HCl ⟶ 2NaCl + S + H2O + SO2 ↑
However, S is not produced when sodium sulphite is treated with dil.HCl.
Na2SO3 + 2HCl ⟶ 2NaCl + H2O + SO2 ↑
Related Questions
MnO2, PbO2 and red lead react with conc. HCl acid liberates Cl2.
What is the common property being shown by these metal oxides?
Complete and balance the following reactions, state whether dilute or conc. acid is used.
(a) NH4OH + HCl ⟶
(b) NaHSO3 + HCl ⟶
(c) Pb(NO3)2 + HCl ⟶
(d) Pb3O4 + HCl ⟶
Write an equation for the reactions of hydrochloric acid on :
(a) silver nitrate solution
(b) magnesium foil
(c) caustic soda solution
(d) zinc carbonate
(e) manganese (IV) oxide
(f) copper oxide
Explain why
(a) anhydrous HCl is a poor conductor while aqueous HCl is an excellent conductor.
(b) when the stopper of a bottle full of hydrogen chloride gas is opened there are fumes in the air.
(c) a solution of hydrogen chloride in water turns blue litmus red and conducts electricity, while a solution of the same gas in toluene
(i) has no effect on litmus, and
(ii) does not conduct electricity.
(d) dry hydrogen chloride gas does not affect a dry strip of blue litmus paper, but it turns red in the presence of a drop of water.
(e) dilute hydrochloric acid cannot be concentrated by boiling beyond 22.2%.