Question

Dmitri needs 6 liters of a 16% solution of sulfuric acid for a research project in molecular biology. He has two supplies of sulfuric acid solution: one is an unlimited supply of the 12% solution and the other an unlimited supply of the 24% solution. How many liters of each solution should Dmitri use?

Answer 1

4 litres of 12% solution

2 litre of 24% solution

Explanation:

Let the 12% solution = l

Let the 24% solution = h

Dimitri needs a total of 6 litres of both :

l + h = 6 - - - - - - - - (1)

He needs a mixture of both volumes of both to give a 16% volume

12%l + 24%h = 16% * 6

0.12l + 0.24h = 0.96 ----(2)

From (1)

l + h = 6;

l = 6 - h

Substitute l =6-h into (2)

0.12(6 - h) + 0.24h = 0.96

0.72 - 0.12h + 0.24h = 0.96

0.72 + 0.12h = 0.96

0.12h = 0.96 - 0.72

0.12h = 0.24

h = 0.24 / 0.12

h = 2

From ;

l = 6 - h

l = 6 - 2

l = 4