Please, I need your help!How much water must be evaporated from 16oz of a 2% salt solution to make a 4% salt solution?

twice the concentration means half the volume, since the same amount of salt remains.

So, we lost half of 16 oz, or ?

by intuition, it must be 8 oz

or

the amount of salt must stay the same, so
.02(16) = .04(16-x)
.32 = .64 - .04x
.04x = -.32
x = 8

How much water must be evaporated from 260 gallons of 5% salt solution to produce an 8% salt

solution?

To find out how much water needs to be evaporated from the 2% salt solution to make a 4% salt solution, we can use the concept of the mass of salt in the solution.

Step 1: Understand the problem
We have 16 ounces of a 2% salt solution, which means that 2% of the solution is salt. We need to calculate the amount of water that needs to be evaporated to increase the salt concentration to 4%.

Step 2: Calculate the amount of salt in the original solution
To find out the amount of salt in the original 16-ounce solution, we can use the formula:

Mass of salt = (Salt concentration / 100) * Total volume of solution

In this case:
Mass of salt = (2 / 100) * 16 ounces.

Mass of salt = 0.02 * 16 ounces = 0.32 ounces.

Step 3: Calculate the final volume of the solution
Since we are evaporating only water, the mass of salt remains constant while the concentration increases. Therefore, we can use the following formula to calculate the final volume:

Final volume = (Initial mass of solution) / (Final concentration of salt / 100)

In this case:
Final volume = 16 ounces / (4 / 100) = 16 ounces / 0.04 = 400 ounces.

This means that the final solution should have a volume of 400 ounces.

Step 4: Calculate the amount of water to be evaporated
To find out the amount of water that needs to be evaporated, we can subtract the final volume from the initial volume.

Water to be evaporated = Initial volume - Final volume.

Water to be evaporated = 16 ounces - 400 ounces = -384 ounces.

However, we cannot have a negative volume, so the answer is not possible. Therefore, it is not possible to make a 4% salt solution from a 2% salt solution by evaporating water.