Question

answer both the question asap plss..

Answer 1

7.(i)    the HCl gas when passed over dry litmus paper, nothing is observed as the h+ ion is not evolved in dry paper but when passed over wet litmus paper the color of paper changes to red color because h+ ion is evolved in presence of water.

equation: H₂SO₄ + 2NaCl = NA₂SO₄ + 2HCl

(ii)    we can add base to the solution to increase the number.

                                          (OR)

(i)  Na₂CO₃    sodium carbonate

(ii) NaHCO₃ (heat) → Na₂CO₃ + CO₂ + H₂O

(iii) uses:      a. used for manufacturing glass, soap and paper.

                   b. used for removing permanent hardness of water