Question

Match the following
$\begin{array}{cccc}& \text{Column I}& & \text{Column II}\\ & \text{(Method of preparation)}& & \text{(Type of sol)}\\ \text{a}& \text{Electrodispersion}& \text{p}& \text{Mercury sol}\\ \text{b}& \text{Mechanical dispersion}& \text{q}& \text{Hydrosol of gold}\\ \text{c}& \text{Ultrasonic method}& \text{r}& \text{Graphite sol}\\ \text{d}& \text{Peptisation}& \text{s}& \text{AgI sol}\end{array}$

• A. $a\to q$; $b\to r$; $c\to p$; $d\to s$
• B. $a\to q$; $b\to r$; $c\to s$; $d\to p$
• C. $a\to r$; $b\to q$; $c\to p$; $d\to s$
• D. $a\to r$; $b\to s$; $c\to p$; $d\to q$

Answer 1

The correct option is A $a\to q$; $b\to r$; $c\to p$; $d\to s$

$\left(a\right)$ Bredig's arc method or electrodispersion method is used for the preparation of colloidal sol of gold, silver and platinum.

$\left(b\right)$ In mechanical dispersion method, the substance is first ground to coarse particles and is used for preparation of graphite sol.

$\left(c\right)$ The sound waves of high frequency are used in ultrasonic method and this method is used for preparation of sol of mercury, sulphides and oxides of metals.

$\left(d\right)$ Peptisation is a process of converting a freshly prepared precipitate into colloidal form by the addition of a suitable electrolyte. $KI$ and $AgN{O}_3$ solutions are used for the peptisation of $AgI$ precipitate.