Question

Compartments $A$ and $B$ have the following combinations solution.

	$A$	$B$
I	0.1 M $KCl$	0.2 M $KCl$
II	$0.1\%$ (m/V) $NaCl$	$10\%$ (m/V) $NaCl$
III	$18g{L}^{-1}$ glucose	$34.2g{L}^{-1}$ sucrose
IV	$20\%$ (m/V) glucose	$10\%$ (m/V) glucose

Indicate the number of solutions which is/are isotonic.

• A. I only
• B. III only
• C. IV only
• D. II only

Answer 1

The correct option is B III only

Isotonic solution has the same molarity.

Molarity of 18 g glucose $=\frac{18}{180\times 1}=0.1M$
Molarity of 34.2 g sucrose $=\frac{34.2}{342\times 1}=0.1M$
The concentration of $18g{L}^{-1}$ glucose is same to $34.2g{L}^{-1}$ sucrose.