Chapter 9.5, Problem 13P

To determine

To find: The grams of water that must be added to reduce the acidity by $25\%$ .

Answer to Problem 13P

The grams of water that must be added to reduce the acidity by $25\%$ is $120\text{gm}$ .

Explanation of Solution

Given information:

Amount of acid solution is $1000\text{gm}$ with $40\%$ acid.

Calculation:

Assume that amount of water added is $x$ .

The given problem can be written in the form of equation as,

  $\begin{array}{l}\left(1000\right)\left(\frac{40}{100}\right)=x+\left(\frac{25}{100}\right)\left(1000+x\right)\\ 400=x+250+0.25x\\ 1.25x=150\\ x=120\text{gm}\end{array}$

Therefore, the grams of water that must be added to reduce the acidity by $25\%$ is $120\text{gm}$ .