Question

cample 2.1 A solution contains 40 g of
common salt in 320 g of water.
Calculate the concentration in terms of
mass by mass percentage of the
solution.
$\cot( \tan(\pi) )$
​

Answer 1

$\sf\underline{ \large{Solution- }}$

Here it is given that,

• Mass of solute (salt) = 40 g
• Mass of solvent (water) = 320 g

➢ We have to calculate the concentration in terms of mass by mass percentage of the solution.

Now,

Mass of solution :

• Mass of solute + Mass of solvent.

⟹ 40 g + 320 g

⟹ 360 g

Then,

Mass by mass percentage of solution =

$\sf \implies \boxed{ \rm \dfrac{Mass \: of \: solute}{Mass \: of \: solution} \times 100}$

$\sf \implies { \dfrac{40}{360} \times 100}$

$\sf \implies { \dfrac{1}{9} \times 100}$

$\sf \implies \dfrac{100}{9} = \boxed{ \rm \bf11.1 \%}$

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Two more methods of expressing the concentration of a solution :

Mass by volume percentage of solution =

$\sf \implies { \rm \dfrac{Mass \: of \: solute}{Volume \: of \: solution} \times 100}$

Volume by volume percentage of solution =

$\sf \implies { \rm \dfrac{Volume \: of \: solute}{Volume \: of \: solution} \times 100}$