SOLUTION: I need to make a solution of 20% alcohol. I have on hand 98% alcohol. What is the ratio of 98% alcohol and sterile water to make 20% alcohol?

Question 636030: I need to make a solution of 20% alcohol. I have on hand 98% alcohol. What is the ratio of 98% alcohol and sterile water to make 20% alcohol?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
make a solution of 20% alcohol. I have on hand 98% alcohol.
What is the ratio of 98% alcohol and sterile water to make 20% alcohol?
:
Decide how much of the 20% solution you require, let's say 10 liters
Let w = amt of water required
then
(10-w) = amt of 98% alcohol required
:
.98(10-w) = .20w
9.8 - .98w = .20w
9.8 = .20w + .98w
9.8 = 1.18w
w = 9.8/1.18
w ~ 8.3 liters of water
and
10 - 8.3 = 1.7 liters of the 98% solution
:
if you need a ratio; water: 98% alcohol:
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