Which of the following represents 1.0 m aqueous solution of glucose (…

The correct answer is Option (2) → 180 g of glucose dissolved in 1 kg of water.

Molality uses the mass of the solvent in kg, so it does not change with temperature. Molarity (M), in contrast, is moles of solute per litre of solution, and it changes with temperature because volume does.

Molar mass of glucose, \( \ce{C6H12O6} \):

    \( \displaystyle 6\times12+12\times1+6\times16=180\ \mathrm{g\,mol^{-1}} \)

So 180 g of glucose is 1 mol, and 1 mol in 1 kg of water is

    \( \displaystyle m=\frac{1\ \mathrm{mol}}{1\ \mathrm{kg}}=1.0\ \mathrm{mol\,kg^{-1}} \)

This is a 1.0 m solution.

NCERT (2026-27 edition):
Molality