Question

An amorphous solid $(X)$ burns in air to form a gas $(Y)$ which turns lime water milky. This gas decolourises aqueous solution of acidified $KMnO_4$. Gas $(Y)$ reacts with oxygen to give another gas $(Z)$ which is responsible for acid rain. $X$, $Y$ and $Z$ are

• A. a
• B. b
• C. c
• D. d

Answer 1

The Correct Option is B

$\underset{\text{(X)}}{ {S}} {+ \,O2 ->}$ $\underset{\text{(Y)}}{ {SO2}}$ $\underset{\text{(Y)}}{ {SO2}}+ {Ca(OH)2 ->}$$\underset{\text{white ppt.}}{ {CaSO3 v}}+ {H2O}$ $\underset{\text{Purple}}{ {2KMnO4}}+$$\underset{\text{(Y)}}{ {5SO2}}+$$ {2H2O \to K2SO4 +}$$\underset{\text{Colourless}}{ {2MnSO4}}+ {2H2SO4}$ $\underset{\text{(Y)}}{ {2SO2}}+ {O2 ->}$ $\underset{\text{(Z)}}{ {2SO3}}$ $\underset{\text{(Z)}}{ {SO_3}}$$ {+\,H2O \to H2SO4}$ (responsible for acid rain)