Question

Solutions $A$ , $B$ , $C$ and $D$ are respectively $0.1\, M$ glucose, $0.05 \,M\, NaCl$ , $0.05 \,M\, BaCl_2$ and $0.1\, M\,AlCl_3$ . Which one of the following pairs is isotonic ?

• A. $A$ and $B$
• B. $B$ and $C$
• C. $A$ and $D$
• D. $A$ and $C$

Answer 1

Answer: (A)

$A$ and $B$

Answer 2

Isotonic solutions have same molar concentration of solute particles in solution. Molar concentration of particles in solution are $0.1 M$ in glucose, $2 \times 0.05 M$ in $NaCl , 3 \times 0.05$ in $BaCl _{2}$ and $4 \times 0.1$ in $AlCl _{3} .$ Therefore, $0.1 M$ glucose and $0.05 \,M \,NaCl$ solutions are isotonic.