Exercise | Q 3.4 | Page 46

# Answer the following.

## The osmotic pressure of CaCl2 and urea solutions of the same concentration at the same temperature are respectively 0.605 atm and 0.245 atm, calculate van’t Hoff factor for CaCl2.

### Solution:

**Given:** Osmotic pressure of CaCl2 solution = 0.605 atm

Osmotic pressure of urea solution = 0.245 atm

**To find:** The value of van’t Hoff factor

**Formulae:** π = MRT, π = iMRT

**Calculation:** For urea solution

π = MRT

0.245 atm = MRT ....(i)

For CaCl_{2} solution

π = iMRT

0.602 atm = iMRT ....(ii)

From equations (i) and (ii),

∴ i = 2.47

The value of van’t Hoff factor is 2.47.