# The volume of a colloidal particle, $V_c$ as compared to the volume of a solute particle, $V_s$ in a true solution could be

(a) $\frac{V_c}{V_s} \approx 10^{-3}$
(b) $\frac{V_c}{V_s} \approx 10^{3}$
(c) $\frac{V_c}{V_s} \approx 1$
(d) $\frac{V_c}{V_s} \approx 10^{23}$

Answer: $\frac{V_c}{V_s} \approx 10^{3}$
For a true solution, the diameter range is 1 to < 10 $\overset{\circ}{A}$, and for colloidal solution,diameter range is 10-1000 $\overset{\circ}{A}$.
Taking lower limits,
$\frac{V_c}{V_s} = \frac{4/3 \pi r^3_c}{4/3 \pi r^3_s} = (\frac{r_c}{r_s})^3$
We know, $r_c = \frac{10}{2} = 5 \overset{\circ}{A}$
$r_s = \frac{1}{2} = 0.5 \overset{\circ}{A}$
$\frac{V_c}{V_s} = (\frac{5}{0.5})^3 = \frac{10^3}{1} = 10^3$