how many grams are contained in 500.g of a 25% solution of H2SO4?
25% by mass?
That means 25 g H2SO4/100 g solution.
So in 500 g soln there must be
25 g x (500/100) = ? g H2SO4
That means 25 g H2SO4/100 g solution.
So in 500 g soln there must be
25 g x (500/100) = ? g H2SO4