Question

Q21. Use the following information to answer the next question. Ritu took some sulphur in a spatula and heated it. She collected the gas evolved in a gas jar. Later, she dipped a dry blue litmus paper and a moist blue litmus paper in it. Which table lists the effect of the evolved gas on the dry and moist blue litmus papers? A : Dry blue litmus paper Moist blue litmus paper Change in colour Change in colour B : Dry blue litmus paper Moist blue litmus paper Change in colour No change in colour C : Dry blue litmus paper Moist blue litmus paper No change in colour Change in colour D : Dry blue litmus paper Moist blue litmus paper No change in colour No change in colour View Graph View Solutions With dry litmus paper, sulphur dioxide gas does not produce a change in colour. With moist litmus paper, sulphur dioxide gas first reacts with water to form sulphurous acid. This sulphurous acid causes a change in colour of the litmus. Hence, the colour of blue litmus will change to red. The correct answer is C. This Question is there in the MCQTest of Chapter metals and non-metals. Why Sulphur dioxide does not change blue litmus paper red ?

Answer 1

as sulphur di oxide is acidic in nature.