$ \begin{aligned} & \begin{array}{|l|l|l|l|} \hline & \text{List-I} & & \text{List-II} \\ \hline &…

$ \begin{aligned} & \begin{array}{|l|l|l|l|} \hline & \text{List-I} & & \text{List-II} \\ \hline & \text{(Colloid Preparation Method)} & & \text{(Chemical Reaction)} \\ \hline \text{(a)} & \text{Hydrolysis} & \text{(i)} & 2 \mathrm{AuCl}_3+3 \mathrm{HCHO}+3 \mathrm{H}_2 \mathrm{O} \rightarrow \\ & & & 2 \mathrm{Au}(\mathrm{sol})+3 \mathrm{HCOOH}+6 \mathrm{HCl} \\ \hline \text{(b)} & \text{Reduction} & \text{(ii)} & \mathrm{As}_2 \mathrm{O}_3+3 \mathrm{H}_2 \mathrm{S} \rightarrow \mathrm{As}_2 \mathrm{S}_3(\mathrm{sol})+3 \mathrm{H}_2 \mathrm{O} \\ \hline \text{(c)} & \text{Oxidation} & \text{(iii)} & \mathrm{SO}_2+2 \mathrm{H}_2 \mathrm{S} \rightarrow 3 \mathrm{S}(\mathrm{sol})+2 \mathrm{H}_2 \mathrm{O} \\ \hline \text{(d)} & \text{Double Decomposition} & \text{(iv)} & \mathrm{FeCl}_3+3 \mathrm{H}_2 \mathrm{O} \rightarrow \mathrm{Fe}(\mathrm{OH})_3(\mathrm{sol})+3 \mathrm{HCl} \\ \hline \end{array} \end{aligned}$ Choose the most appropriate answer from the options given below:
  1. $(a)-(i), (b)-(iii), (c)-(ii), (d)-(iv)$
  2. $(a)-(iv), (b)-(i), (c)-(iii), (d)-(ii)$
  3. $(a)-(i), (b)-(ii), (c)-(iv), (d)-(iii)$
  4. $(a)-(iv), (b)-(ii), (c)-(iii), (d)-(i)$

Solution

Colloid preparation by Hydrolysis reaction: (no change in oxidation number.) $FeCl_{3} + 3H_{2}O \rightarrow Fe(OH)_{3} (sol) + 3HCl$ Gold sol is prepared by reduction reaction: $2AuCl_{3} + 3HCHO + 3H_{2}O \rightarrow 2Au (sol) + 3HCOOH + 6HCl$ Preparation of sulphur sol: (oxidation) $SO_{2} + 2H_{2}S \rightarrow 3S (sol) + 2H_{2}O$ Preparation of colloid by double decomposition reaction: $As_{2}O_{3} + 3H_{2}S \rightarrow As_{2}S_{3} (sol) + 3H_{2}O$

Asked in: MHT CET Full Test 2

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