Question

The order of osmotic pressure of three equimolar aqueous solutions of $CaCl_{2}, NaCl$ and $C_{6}H_{12}O_{6}$ (glucose) is

• A. $CaCl_{2} > \, NaCl > \, C_{6}H_{12}O_{6}$
• B. $NaCl >\, CaCl_{2} >\, C_{6}H_{12}O_{6}$
• C. $C_{6}H_{12}O_{6} >\, CaCl_{2} >\, NaCl$
• D. $C_{6}H_{12}O_{6} >\, NaCl > \,CaCl_{2}$

Answer 1

Answer: (A)

$CaCl_{2} > \, NaCl > \, C_{6}H_{12}O_{6}$

Answer 2

Osmotic pressure $(\pi) = iCRT$ For $CaCl_2$, $i = 3$ For $NaCl$, $i = 2$ For $C_6H_{12}O_6$, $i=1$ Greater is $i$ value, higher is the osmotic pressure. $\therefore$ Correct order is $CaCl_2 > NaCl > C_6H_{12}O_6$