The  concentration in terms of mass by mass percentage of the solution if a solution contains 40g of common salt in 320g of water is:

The concentration in terms of mass by mass percentage of the solution if a solution contains 40g of common salt in 320g of water is 11.1%.

Mass of solute(salt) = 40g

Mass of solvent(water) = 320g

$\mathit{mass\; of\; solution}=\mathit{mass\; of\; solute}+\mathit{mass\; of\; solvent}$

$\Rightarrow 40\mathit{g }+ 320g$

$\Rightarrow 360g$

$\mathit{mass }\%\mathit{ of\; the\; solution}= \frac{\mathit{mass\; of\; solute}}{\mathit{mass\; of\; solution }}\times 100$

$\Rightarrow \frac{40}{360}\times 100$

$\Rightarrow 11.1\%$