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)

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.