Question 613562
You need a 65% alcohol solution. On hand, you have a 525 mL of a 40% alcohol mixture. How much pure alcohol will you need to add to obtain the desired solution?
.
Let x = amount (mL) of pure alcohol added
then
x + .40(525) = .65(x+525)
x + .40(525) = .65(x+525)
x + 210 = .65x+341.25
.25x + 210 = 341.25
.25x = 131.25
x = 525 mL