Which of the following solutions does not flow in either direction, when separated by semipermeable…
Which of the following solutions does not flow in either direction, when separated by semipermeable membrane? (Molar mass: glucose $=180$, urea $=60$)
$18 \mathrm{~g} \mathrm{urea} \mathrm{dm}^{-3}$
$6 \mathrm{~g}$ urea $\mathrm{dm}^{-3}$ and $36 \mathrm{~g}$ glucose $\mathrm{dm}^{-3}$
$6 \mathrm{~g}$ urea dm${ }^{-3}$ and $24 \mathrm{~g}$ glucose $\mathrm{dm}^{-3}$
$12 \mathrm{~g}$ urea dm${ }^{-3}$ and $36 \mathrm{~g}$ glucose $\mathrm{dm}^{-3}$
Solution
$\begin{aligned}
& \mathrm{n}_{\text {urea }}=\frac{12}{60}=0.2 \text { and } \mathrm{n}_{\text {glucose }}=\frac{36}{180}=0.2 \\
& \text { Now, } \mathrm{n}_{\text {urea }}=\mathrm{n}_{\text {glucose }} \\
& \therefore \pi_{\text {urea }}=\pi_{\text {glucose }}
\end{aligned}$
Hence, if these solutions are separated by a semipermeable membrane, there is no flow of solvent in either direction.