Exams › JEE Advanced › Chemistry

For a 100 molal aqueous solution, the mole fraction of the solute is approximately ___ x 10⁻² (rounded to the nearest integer). [H = 1.0 u, O = 16.0 u]

1. 64
2. 50
3. 36
4. 18

Correct answer: 64

Solution

With 100 mol solute and 1000/18 = 55.56 mol water, the solute mole fraction is 100/155.56 = 0.643, i.e. about 64 x 10⁻².

Related JEE Advanced Chemistry questions

• Which of the following contains the highest number of molecules?
• An organic compound with identical empirical and molecular formulas consists of 20% carbon, 6.7% hydrogen, 46.7% nitrogen, and the remainder as oxygen. When heated, it releases ammonia and leaves behind a solid residue. This residue produces a violet color when treated with an alkaline copper sulfate solution. Identify the compound.
• Which of the following statements accurately describe a hydrogen peroxide solution with a concentration of 17 g/L?
• The total energy needed to break all three P−H bonds in PH3(g) is 954 kJ mol⁻¹. What is the energy required to break a single P−H bond?
• Which of the following represents the balanced equation for the Calvin cycle in photosynthesis, showing the conversion of carbon dioxide into glucose?
• A substance H₂X with a molecular mass of 80 g is mixed into a liquid with a density of 0.4 g/ml. If the volume remains constant during dissolution, what is the molality of a solution with 3.2 molarity?

⚔️ Practice JEE Advanced Chemistry free + battle 1v1 →