Q.) The effect of gas formed by heating sulphur
powder on litmus paper is:
(a) It turns both dry blue litmus paper and moist blue litmus paper red.
(b) It turns dry blue litmus paper red but has no effect on moist blue litmus paper.
(c) It has no effect on dry blue litmus paper but turns moist blue litmus paper red.
(d) It has no effect on both dry blue litmus paper and moist blue litmus paper.
Ans: (c) It has no effect on dry blue litmus paper but turns moist blue litmus paper red.
Explanation: When sulphur powder is heated, it forms sulphur dioxide gas, which is acidic in nature. However, it shows acidic behaviour only in presence of water. Therefore, it has no effect on dry blue litmus paper, but turns moist blue litmus paper red.
