Question

Match the folllowing.

Answer 1

(A) Calcium hydroxide reacts with carbon dioxide to form white turbidity of calcium carbonate.
$C{O}_2+Ca(OH{)}_2⟶CaC{O}_3(whiteturbidity)+H_{2}O$
(B) When Zn reacts with mixture of NaOH and $S{O}_2$ rotten egg smell of hydrogen sulphide is obtained.
$Zn+2NaOH+S{O}_2⟶N{a}_{2}Zn{O}_2+H_{2}S\uparrow \left(rotteneggsmell\right)+O_2$
(C) Permanganate ion oxidizes sulphur dioxide to sulphate ions and itself is reduced to Mn(II) ions. This makes solution colorless.
$3S{O}_2+2Mn{O}_4^{-}+2H_{2}O⟶2Mn{O}_2+3S{O}_4^{2-}+4H^{+}$
Sulphur dioxide reacts with bromine water to form colourless solution.
$S{O}_2+B{r}_2+2H_{2}O=2HBr+H_{2}S{O}_4$
(D) When iodate ions react with sulphur dioxide in presence of starch, blue color of starch ioide complex is obtained.
$2I{O}_3^{-}+5S{O}_2+4H_{2}O⟶2HS{O}_4^{-}+3H_{2}S{O}_4+I_2$
In this reaction, iodate ion is reduced to iodine. The liberated iodine reacts with starch to form blue coloured starch iodide complex.