The density of a 2 M aqueous solution of NaOH is 1.28 g/cm^3 . The molality of the solution is: [molecular mass of NaOH = 40 g/mol ] - CHEMISTRY MCQ NEET 2019 2026 | ExamTest.live

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The density of a 2 M aqueous solution of NaOH is 1.28 g/cm^{3} . The molality of the solution is: [molecular mass of NaOH = 40 g/mol]

Solution & Step-by-step Explanation

1. Let volume of solution be 1 L = 1000 cm^{3} .2. Mass of solution = V \times d = 1000 \times 1.28 = 1280 g .3. Moles of NaOH = 2 .4. Mass of solute (NaOH) = 2 \times 40 = 80 g .5. Mass of solvent (water) = 1280 - 80 = 1200 g = 1.2 kg .6. Molality m = \frac{moles of solute}{mass of solvent (kg)} = \frac{2}{1.2} = 1.666... \approx 1.67 m .

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The density of a 2 M aqueous solution of NaOH is 1.28 g/cm^{3} . The molality of the solution is: [molecular mass of NaOH = 40 g/mol]

1.20 m

1.56 m

1.67 m

1.32 m

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