Question

In what mass of water must 25 g of cuso4.5h2o be dissolved to obtain an 8 percent solution of cuso4?

Answer 1

we know that
mass of solute/mass of solution*100=mass % of solution
therefore
here we  also know that mass of solution is mass of solute+mass of solvent

Here mass of solute=25g
mass of solution=25g+ mass of solvent(i.e. water) 
suppose mass of water is x
25/25+x*100=8
on solving we get the answer of x=287.5g and total mass of solution is 312.5 in order to obtain solution of cuso with 25g of cuso4.5h20