Chemistry
Give a chemical test to distinguish between:
(a) dilute sulphuric acid and dilute hydrochloric acid (using lead nitrate solution).
(b) dilute sulphuric acid and concentrated sulphuric acid.
Answer
(a) When dil sulphuric acid is reacted with lead nitrate it produces a white ppt. of lead sulphate which remains insoluble even on heating.
Pb(NO3)2 + H2SO4 (dil) ⟶ 2HNO3 + PbSO4 ↓ [white ppt. formed]
When dil hydrochloric acid is reacted with lead nitrate, a white ppt. of lead chloride is formed which dissolves on heating.
Pb(NO3)2 + 2HCl ⟶ 2HNO3 + PbCl2 ↓ [white ppt. formed]
(b) Dilute sulphuric acid when reacted with zinc produces Hydrogen gas which burns with a pop sound.
Zn + H2SO4 [dil.] ⟶ ZnSO4 + H2 ↑
Concentrated sulphuric acid when reacted with zinc produces SO2 gas which turns acidified potassium dichromate paper green.
Zn + 2H2SO4 [conc.] ⟶ ZnSO4 + 2H2O + SO2 ↑
Related Questions
In the manufacture of sulphuric acid by the Contact process, give the equations for the conversion of sulphur trioxide to sulphuric acid.
Give a balanced equation for the conversion of zinc oxide to zinc sulphate.
What property of conc. H2SO4 is made use of in each of the following cases? Give an equation for the reaction in each case:
(a) in the production of HCl gas when it reacts with a chloride,
(b) in the preparation of CO from HCOOH.
(c) as a source of hydrogen by diluting it and adding a strip of magnesium.
(d) in the preparation of sulphur dioxide by warming a mixture of conc. sulphuric acid and copper-turnings.
(e) hydrogen chloride gas is passed through concentrated sulphuric acid.
(f) it's reaction with (i) Ethanol (ii) Carbon.
(a) Which property of sulphuric acid accounts for it's use as a dehydrating agent?
(b) Concentrated sulphuric acid is both an oxidizing agent and a non-volatile acid. Write one equation each to illustrate the above mentioned properties of sulphuric acid.