30 g of glucose and 20 g common salt is dissolved in 500 mL of water to make a solution. Calculate the concentration of (a) glucose and (b) common salt in terms of mass by mass percentage of the solution.
(Density of water = 1 g/mL)

Explanation

Density of water = 1 g/mL
`therefore` Mass of water (solvent) = 500 g
Mass of solute (glucose) = 30 g
Mass of solute (common salt) = 20 g
Mass of solution = (30 + 20 + 500)g = 550 g
(a) Mass percentage of solution for glucose
= `("Mass of solute (glucose)")/("Mass of solution")xx100`
= `30/550xx100`
= 5.45%
(b) Mass percentage of solution for common salt
= `("Mass of solute (common salt)")/("Mass of solution")xx100`
= `20/550xx100`
= `3.64%`