Question

What mass of water should be added to 15g of salt to obtain 15% salt solution

Answer 1

let rhe mass of H20 added be y g

now as the solution is 15 %

hence 15 = 15 x 100 /Wt of solution

hence 15 = 15 x100/ 15+ y

= y+ 15 = 100

y = 85

I have used the following ideas

1) Wt of solution = Wt of solutes + Wt of solvent = 15 + y

2) X per cent solution means

X = wt of solutes x 100/ wt of solution

Answer 2

Answer:

Expl15 = 15 x 100 /Wt of solution

hence 15 = 15 x100/ 15+ y

= y+ 15 = 100

y = 85