Question

6. A chemist wishes to make 5 liters of an 7% acid solution by mixing a 10% acid

solution and a 5% acid solution. How many liters of each solution the chemist have to
use? Make a table with relevant quantities and show all steps.

Answer 1

The chemist will mix 3 liters of the 5% acid solution and 2 liters of the 10% acid solution to get 5 liters of 7% acid solution

Explanation:

Here, we are interested in finding the number of liters of each solution the chemist have to make use;

Let the number of liters of the 5% acid solution be x while the number of liters of the 10% acid solution be y

Mathematically;

x + y = 5 •••••••••(i)

Also, let’s work with the percentages now

( x * 5%) + (y * 10%) = (5 * 7%)

0.05x + 0.1y = 0.35 ••••••••(ii)

From i , x = 5-y

Substitute this into ii

0.05(5 -y) + 0.1y = 0.35

0.25 - 0.05y + 0.1y = 0.35

0.25 + 0.05y = 0.35

0.05y = 0.35 -0.25

0.05y = 0.1

y = 0.1/0.05

y = 2

But x + y = 5

x + 2 = 5

x = 5-2

x = 3