Q114 / 200 · MHT CET - Medical 2026 (22 April Shift 1) · Chemistry
What is the molality of an aqueous solution containing 6 % glucose by mass ? ( Molar mass of glucose = 180 g/mol )
- A$0.15$ m
- B$0.25$ m
- Correct answerC$0.35$ m
- D$0.45$ m
Solution
Let the mass of the solution be $100$ g.
Mass of glucose (solute) = $6$ g
Mass of water (solvent) = $100 - 6 = 94$ g = $0.094$ kg
Molar mass of glucose = $180$ g/mol
Moles of glucose = $\dfrac{6}{180} = \dfrac{1}{30}$ mol
Molality ($m$) = $\dfrac{\text{Moles of solute}}{\text{Mass of solvent in kg}}$
$m = \dfrac{1/30}{0.094} = \dfrac{1}{2.82} \approx 0.35$ m
Answer: $0.35$ m
Mass of glucose (solute) = $6$ g
Mass of water (solvent) = $100 - 6 = 94$ g = $0.094$ kg
Molar mass of glucose = $180$ g/mol
Moles of glucose = $\dfrac{6}{180} = \dfrac{1}{30}$ mol
Molality ($m$) = $\dfrac{\text{Moles of solute}}{\text{Mass of solvent in kg}}$
$m = \dfrac{1/30}{0.094} = \dfrac{1}{2.82} \approx 0.35$ m
Answer: $0.35$ m
Hence, the correct answer is option: 'C'.