Molality is defined as the number of moles of solute present in one kilogram of solvent. It is expressed in mol/kg. On the other hand, molarity is defined as the number of moles of solute present in one liter of solution. It is expressed in mol/L.



To calculate the mass of 0.50 molal glucose solution required to obtain 0.15 mole glucose, we need to use the following formula:

Molality = Number of moles of solute / Mass of solvent in kg

We know the molality (0.50 molal) and the number of moles of solute (0.15 mole). We need to calculate the mass of solvent in kg.

Rearranging the formula, we get:

Mass of solvent in kg = Number of moles of solute / Molality

Substituting the values, we get:

Mass of solvent in kg = 0.15 mole / 0.50 mol/kg

Mass of solvent in kg = 0.30 kg

This means that we need 0.30 kg of solvent to prepare a 0.50 molal glucose solution containing 0.15 mole glucose.



To calculate the mass of solution, we need to add the mass of solute (glucose) and the mass of solvent (water).

The molar mass of glucose is 180.16 g/mol. Therefore, the mass of 0.15 mole glucose is:

Mass of glucose = Number of moles of solute x Molar mass

Mass of glucose = 0.15 mole x 180.16 g/mol

Mass of glucose = 27.02 g

The mass of solvent is 0.30 kg or 300 g.

Therefore, the mass of solution required is:

Mass of solution = Mass of solute + Mass of solvent

Mass of solution = 27.02 g + 300 g

Mass of solution = 327.02 g

Therefore, we need 327.02 g of 0.50 molal glucose solution to obtain 0.15 mole glucose.