Question 1033433
If the water is pure, then it is 100% water. We start out with an 87% acid solution, so:
4.5(.87)+ X(1.0)=.64(4.5+X)
3.915+X=2.88+.64X
1.035=.64X
X=1.035/.64=1.6172 liters of pure water needed to add to the mixture to make it 64% acid!!!!