Question

a chemist mixes 4 liters of one acid solution with 10 liters of a 40% solution, resulting in a 30% acid solution. what is the value of x, the acid concentration of the forst solution?

Answer 1

We can use the familiar formula

C(V1+V2)=C1*V1+C2*V2

For the particular problem, we have

C1=unknown

V1=4 L

C2=40%

V2=10 L

C=30%

Substitute in equation

0.30*(4+10) = C1*4+0.40*10

Simplify: 4.2=4C1=4

Solve for C1

C1=(4.2-4)/4 = 0.2/4 = 5%