Question

A solution is prepared by dissolving 50 g of glucose in 400 g of water. Calculate the concentration of the solution.

Answer 1

A solution comprises two parts i.e.; solute and solvent

• Solute: The component of the solution to be dissolved or the component present in the solution in a lesser quantity.
• Solvent: The component of the solution that dissolves or the component present in the solution in a larger quantity.
• Here, Glucose $\left({\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6\right)$ is the solute and the solvent is Water $\left({\mathrm{H}}_2\mathrm{O}\right)$.

Step-1: Calculate the mass of solution

Given, Mass of the glucose (solute)= $50\mathrm{g}$

Also given, Mass of water (solvent)= $400\mathrm{g}$

• Mass of the solution= Mass of the solute+ Mass of the solvent
• Mass of the solution= $50+400=450\mathrm{g}$

Step-2: Calculate the mass percentage $(\mathrm{m}/\mathrm{m})$ of the solution

Formula to be used:

$\mathrm{Concentration}\mathrm{in}(\mathrm{m}/\mathrm{m})\%=\frac{\mathrm{Mass}\mathrm{of}\mathrm{the}\mathrm{solute}\left(\mathrm{g}\right)}{\mathrm{Mass}\mathrm{of}\mathrm{the}\mathrm{solution}\left(\mathrm{g}\right)}\times 100$

• $\mathrm{m}/\mathrm{m}$ represents mass by mass. It is a way to represent the concentration of the solution.
• It is defined as the mass of the solute in $\mathrm{g}$ dissolved in per $100\mathrm{g}$ of the solution.

Given, Mass of the glucose (solute)= $50\mathrm{g}$

Also given, Mass of solution= $450\mathrm{g}$ (calculated in Step-1)

Substituting the given values in the above formula

• Concentration of the glucose solution $(\mathrm{m}/\mathrm{m})\%=\frac{50}{450}\times 100$
• Concentration of the glucose solution $(\mathrm{m}/\mathrm{m})\%=\frac{5000}{450}$
• Concentration of the glucose solution $(\mathrm{m}/\mathrm{m})\%=11.11\%(\mathrm{m}/\mathrm{m})$