AP EAPCET 04-Jul-2022 Shift 2 Paper

(a) 4%w∕V solution means 100‌mL of solution contains 4g of non-volatile solute.
Molar mass of solute =120gmol−1
Moles, ˙ns=‌

4

120

=‌

1

30

‌mol
x%(‌

w

V

) so mass of urea is xg.
Molar mass of urea =60gmol−1
Using formula, number of moles =‌

‌ Mass ‌

‌ Molar mass ‌

Moles, nv=‌

x

60

‌mol
For isotonic solution,
πs=πU
‌Co=Cs
‌nv=ns
‌‌

x

60

=‌

1

30

‌x=2
∴2%(w∕V) solution of urea is isotonic with 4% (w∕V) solution of non-volatile solute.