Hi Aman Bajpai !

Here is the solution of your numerical problem :-

Given that

given 0.25 molal,

Means in 1 kg of water(Solvent) 0.25 mole of Urea is present

Means in 1 kg of water(Solvent) 0.25 X 60 = 15 g of Urea is present

in Solution(1 kg of water + 15g urea) , 15 g of Urea is present

in 1015 g Solution, 15 g of Urea is present

in 1 g Solution, 15/1015 g of Urea is present

in 2500 g Solution, (2500X15)/1015 g of Urea is present

in 2500 g Solution, 36.9 g of Urea is present