lalania1 wrote:
A chemical supply company has 60 liters of a 40% HNO3 solution. How many liters of pure undiluted HNO3 must the chemists add so that the resultant solution is a 50% solution?
A) 12
B) 15
C) 20
D) 24
E) 30
We can lert n = the amount of pure undiluted HNO3 to be added and create the equation:
(0.4 x 60 + n)/(60 + n) = 1/2
2(24 + n) = 60 + n
48 + 2n = 60 + n
n = 12
Answer: A
