Problema Solution
A chemistry experiment calls for a 40% hydrochloric acid solution. If the lab supply room has only 60% and 10% hydrochloric acid solutions, how much of each should be mixed to obtain 12 liters of the 40% acid solution?
Answer provided by our tutors
let
x = liters of the 60% hydrochloric acid solution, x>0
y = liters of the 10% hydrochloric acid solution, y>0
the total mixture will be 12 liters of 40% solutions thus
x + y = 12
60% of x + 10% of y = 40% of 12 that is
0.60x + 0.10y = 0.40*12
by solving the system of equations
x + y = 12
0.60x + 0.10y = 0.40*12
we find
x = 7.2 liters
y = 4.8 liters
7.2 liters of 60% hydrochloric acid solution should be mixed with 4.8 liters of 10% hydrochloric acid solution to obratin 12 liters of the 40% acid solution.