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
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 ⟶
State the composition of aqua regia. State which component is the oxidizing agent in aqua regia.
MnO2, PbO2 and red lead react with conc. HCl acid liberates Cl2.
What is the common property being shown by these metal oxides?
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