Question

Plz, help me!

A 25L alkali solution has 15L of alkali. After addition of water, the solution becomes 30% alkaline. Fid the amount of water added.
this question is in my textbook the answer at the back is 25L water. but I need the steps.

Answer 1

25L

Explanation:

Since there is 15 alkali at first, there must be 25-15 = 10 water at first. Since there is 30% alkaline at last, there must be 100-30 = 70% water at last.

Let x = the amount of water added

Using this information we come up with the equation:

`(10+x)/(25+x)` =
`(70)/(100)` (10 + x is the amount of water at last, 25 + x is the total liquid, and 70/100 is the percentage of water at last)

using cross-multiply we get:

1000x + 100x = 70x + 1750

solving, we get x = 25