A salt solution of 15 litres contains 20% salt.How much water must you add to salt solution in order to dilute it 15% salt?
you want 3/4 the concentration, so you must have 4/3 the volume.
Or use the reliable c1v1 = c2v2
20%*15L = 15%*L
L =?
c1v1=c2v2
20%*15L=15%*L
20/100*15=15/100*L
3=3/20*L
L=3*20/3
L=20Ltrs
You must add 75 liters.
:)
To solve this problem, we need to calculate the amount of water that needs to be added to the salt solution.
Let's start by finding out how much salt is present in the original solution. We know that the original solution contains 20% salt. This means that for every 100 parts of the solution, 20 parts are salt.
So, the amount of salt in the original solution can be calculated as:
Salt in the original solution = 20/100 * 15 litres
Now, we need to dilute this solution to a concentration of 15% salt. This means that for every 100 parts of the diluted solution, 15 parts should be salt.
Let's assume that x litres of water need to be added to the original solution. So, the total volume of the diluted solution would be 15 + x litres.
Now, we can set up an equation to solve for x:
(20/100 * 15) / (15 + x) = 15/100
Simplifying the equation, we get:
(3/10) / (15 + x) = 3/20
Cross-multiplying, we get:
3(15 + x) = 3(20)
Simplifying further:
45 + 3x = 60
Subtracting 45 from both sides:
3x = 15
Dividing by 3:
x = 5
Therefore, you need to add 5 litres of water to the original solution in order to dilute it to a concentration of 15% salt.