Question

determining components of a mixture
a chemist mixes a 10% hydrogen peroxide solution with a 25% hydrogen peroxide solution to create 30 liters of a 15% hydrogen peroxide solution. how many liters of the 10% solution did the chemist use to make the 15% solution?
liters

Explanation:

Step1: Let the volume of 10% solution be $x$ liters.

Let the volume of 10% solution be $x$ liters. Then the volume of 25% solution is $(30 - x)$ liters.

Step2: Set up an equation based on the amount of hydrogen - peroxide.

The amount of hydrogen - peroxide in the 10% solution is $0.1x$, in the 25% solution is $0.25(30 - x)$, and in the 15% solution of 30 liters is $0.15\times30$. So, $0.1x+0.25(30 - x)=0.15\times30$.

Step3: Expand and simplify the equation.

$0.1x + 7.5-0.25x=4.5$. Combine like - terms: $0.1x-0.25x=4.5 - 7.5$. This gives $-0.15x=-3$.

Step4: Solve for $x$.

Divide both sides of the equation by $- 0.15$: $x=\frac{-3}{-0.15}=20$.

Answer:

20