Question

gA solution is prepared by adding 40 g of sugar in 100 g of water. Calculate the concentration in terms of mass by mass percentage of solution.

Answer 1

mass of solute (sugar)= 40 grams

mass of solution= mass of water + mass of sugar = 100 +40 = 140 gm

%( m/m)= (  mass of solute / mass of solution )x 100

             =(40/140) x 100= 28.57%

Answer 2

We have,

solute = 40g

solvent = 100g

So, solution =( 40 + 100) g

= 140 g

Now,

Percentage by mass =

(mass of solute / mass of solution) x 100%

= ( 40 / 140 ) x 100%

= ( 2 / 7 ) x 100%

= 200 / 7 %