SOLUTION: A pharmacist wants to make 18 ml of a 6% hydrogen peroxide solution. How many mls of 5% hydrogen peroxide must he mix with 7% hydrogen peroxide to make the desired solution?
Question 596472: A pharmacist wants to make 18 ml of a 6% hydrogen peroxide solution. How many mls of 5% hydrogen peroxide must he mix with 7% hydrogen peroxide to make the desired solution? Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website! Let = ml of 5% solution needed
Let = ml of 7% solution needed = ml of hydrogen peroxide in 5% solution = ml of hydrogen peroxide in 7% solution
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given:
(1)
(2)
--------------------------
(2)
(2)
(2)
Multiply both sides of (1) by and
subtract (1) from (2)
(2)
(1)
and, since
(1)
(1)
(1)
9 ml of 5% solution is needed
9 ml of 7% solution is needed
check:
(2)
(2)
(2)
(2)
(2)
(2)
OK
