Question

The volume of a colloidal particle, $V_c$ as compared to volume of 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. $\frac{V_c}{V_s}\approx 10$
• D. $\frac{V_c}{V_s}\approx {10}^{22}$

Answer 1

Answer: (B)

$\frac{V_c}{V_s}\approx {10}^3$

For a true solution diameter ranges from 1 to 10 angstrom for a colloidal solution the diameter ranges from 10 to 1000 angstrom.

$\frac{Vc}{Vs}=\frac{4/3\pi r_c^3}{4/3\pi r_s^3}=\frac{r_c^3}{r_s^3}$

$r_c=\frac{10}{2}=5$ angstorm

$r_s=\frac{1}{2}=0.5$ angstorm

$\frac{V_c}{V_s}=(\frac{5}{0.5}{)}^3={10}^3$

Hence option $B$ is correct.