Question

If 200g of 25% sulphuric acid solution was added to 300g of 40% sulphuric acid solution. Find the concentration of acid in the mixture.

Answer 1

Hint: In order to solve this question find the total amount of acid. This will give us a clear picture of what our approach should be then simply find the concentration by doing simple mathematics.

Complete step-by-step answer:
We have given that,
200g of 25% sulphuric acid solution was added to 300g of 40% sulphuric acid solution.
And we have to find the concentration of acid in the mixture.
Now,
Amount of acid in the first solution = 25% of 200g
= ${\displaystyle \frac{25}{100}}\times 200$
= $50$g
Also in the same way,
Amount of acid in the second solution = 40% of 300g
=${\displaystyle \frac{40}{100}}\times 300$
=$120$g
Now,
The total amount of acid $=50+120$
=$170$g
Now, we have to calculate the required concentration
The required concentration =${\displaystyle \frac{170}{\left(200+300\right)}}\times 100$
 =$34\mathrm{\%}$
Thus the concentration of acid in the mixture is 34%.

Note: Whenever we face such types of questions the key concept is that we should write what is given to us then, convert the statements into equations, like we did in this question. Here, we write what is given to us then we simply convert the statements into equations and then we find the total amount of acid. Thus we get our desired answer.