Question

A solution contains 5g of common salt in 20g of water.caluculate mass by mass%

Answer 1

Concentration of the solution by mass by mass percentage= mass of solute /
mass of solution*100
mass of solute = 5g (common salt)
mass of solution = mass of solute (common salt)+ mass of solvent( water)
= 5g + 20g
= 25g
therefore, concentration of solution=
mass of solute /
mass of solution*100
= 5/25*100
= 20 %

Answer 2

mass of solute=5g
mass of solvent(water)=20g
mass of solution=mass of solute +mass of solvent
=5g+20g
=25g
mass by mass percentage of a solution =mass of solute /mass of solution ×100
5/25×100
=20%