Exams › NEET › Chemistry

A solution is described as 1 molal, meaning it contains 1 mole of solute dissolved in 1 kilogram of solvent (water). Determine the mole fraction of the solute in this solution.

1. 1 / 1000
2. 1 / 18
3. 1 / 100
4. 1 / 10

Correct answer: 1 / 18

Solution

In a 1 molal solution, 1 mole of solute is dissolved in 1000 g (1 kg) of water. The molar mass of water is 18 g/mol, so the moles of water are 1000/18 = 55.56. The mole fraction of solute is calculated as 1 / (1 + 55.56) ≈ 1/18.

Related NEET Chemistry questions

• At \( 80^{\circ} \mathrm{C}, \) the vapour pressure of pure liquid \( A \) is 520 mmHg and that of pure liquid \( B \) is 1000 mmHg. If a mixture solution of \( A \) and \( B \) boils at \( 80^{\circ} \) and 1 atm pressure, the amount of \( A \) (mole percent) in the mixture is:
• A solution is prepared by adding 2 g of substance \( A \) to 18 g of water. The mass percent of the solute is:
• Which of the following solutions shows positive deviation from Raoult's law?
• Which of the following forms an ideal solution? This question has multiple correct options
• Which of the following will show a negative deviation from Raoult's law?
• An aqueous solution of methanol in water has vapour pressure:

⚔️ Practice NEET Chemistry free + battle 1v1 →