sir molarity M = n/V.

yaha question m 2% urea kaha to h but ye specify nahi kiya h ki % concentration W/W k form m h ya W/V k form m.

aise situation m apne W/W as default maane ko kaha tha; that means question reads 2g Urea dissolved in 100g solution and not in 100 mL solution.

so i request u to either specify 2% W/V in the question or add value of density in the question.