Question

Consider the following solutions :

$A=0.1M$ glucose, $B=0.05MNaCl$
$C=0.05MBaC{l}_2,D=0.1MAlC{l}_3$

Which of the following pairs is isotonic?

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

Answer 1

The correct option is A $A$ and $B$

Isotonic solutions have the same molar concentration of solute particles in solution.

Molar concentration of particles in solution are :

$\left(a\right)=0.1M$ in glucose (only one particle is there in solution)

$\left(b\right)=2\times 0.05=0.1M$ in $NaCl$ (two particles $N{a}^{+},C{l}^{-}$ are there in solution)

$\left(c\right)=3\times 0.05=0.15M$ in $BaC{l}_2$ (Three particles $B{a}^{2+},2C{l}^{-}$ are there in solution)

$\left(d\right)=4\times 0.1=0.4M$ in $AlC{l}_3$ (Four particles $A{l}^{3+},3C{l}^{-}$ are there in solution)

Hence, $0.1M$ glucose and $0.05MNaCl$ solutions are isotonic.

Therefore, option A is correct.