Question

During an experiment, the students were asked to prepare a $10\%$ (Mass/Mass) solution of sugar in water. Ramesh dissolved $10\mathrm{g}$ of sugar in $100\mathrm{g}$ of water while Sarika prepared it by dissolving $10\mathrm{g}$ of sugar in water to make $100\mathrm{g}$ of the solution.

(a) Are the two solutions of the same concentration

(b) Compare the mass % of the two solutions.

Answer 1

Analyzing the both solution

Ramesh's solution

For Ramesh,

The mass of solute(sugar) =$10\mathrm{g}$

The mass of solvent(water) =$100\mathrm{g}$

Mass of solution $=$ mass of solute $+$ mass of solvent

So, Mass of solution $=10+100=110\mathrm{g}$

Mass$\%$ = $\frac{\mathrm{mass}\mathrm{of}\mathrm{solute}}{\mathrm{mass}\mathrm{of}\mathrm{solution}}\times 100$

$\mathrm{Mass}\%=\frac{10}{110}\times 100=9.09\%$

Sarika's solution

For Sarika,

The mass of Solute(sugar) =$10\mathrm{g}$

The mass of the solution =$100\mathrm{g}$

So, the mass of solvent in the case of Sarika = $100-10=90\mathrm{g}$

Mass$\%$ $=\frac{\mathrm{mass}\mathrm{of}\mathrm{solute}}{\mathrm{mass}\mathrm{of}\mathrm{solution}}\times 100$

$\mathrm{Mass}\%=\frac{10}{100}\times 100=10\%$

Part (a): Identifying is the concentration is the same for both solutions

The concentration of Ramesh's solution = 9.09%

The concentration of Sarika's solution = 10%

So, the concentration for both cases is different.

Part (b): Compare the mass %

The mass percentage of Ramesh's solution = 9.09%

The mass percentage of Sarika's solution = 10%

Therefore, the mass % in the case of Sarika is higher than Ramesh.