chemistry
posted by roshni .
how much sodium chloride and how much water would you need to prepared a 5.00kg of an aqueous solution that is 10.0% NaCl by mass?

%NaCl = (mass NaCl/100 g soln)*100
(x g NaCl/5,000 g soln)*100 = 10
Solve for x. 
I suppose I answered only half the question. I solved for x to obtain 500 g NaCl but you need to confirm that.
Then 5,000 g H2O  500 g NaCl = 4.5 kg.
Check it to make sure that's a 1% solution.
(500 g NaCl/4500 gH2O+500 gNaCl)*100 = ??%
(500/5,000)*100 = (50000/5000) = 10%
check out. Check me out on that.