JEE Main 2026 Chemistry question
What is the mole fraction of water in 10% by weight (w/w) of aqueous urea solution? [Given: Molar mass of H, O, C and N are 1, 16, 12 and 14 g mol⁻¹ respectively.]
Answer: (D)
Solution
10 g urea (M=60) in 100 g solution = 90 g water. Moles urea=0.1667, moles water=5. Mole fraction water = 5/5.1667 ≈ 0.967.