Question

A solution contains 20g of solute in 180g of solvent. If the solvent is water, what is the concentration of the solution in terms of mass by mass percentage

A. 11.%

B. 22.2%

C. 10%

D. 20%

Please show working

Answer 1

Concentration of a solution:

$m/m\space=\frac{mass\space of \space solute}{mass\space of\space solution}×100$

Mass of solutions=mass of solute + mass of solvent =20g+180g = 200g

$m/m\space=\frac{20}{200}×100=10$