How many ml of a 2% solution will 20 ml of a 10% solution make?

since 10% is five times as concentrated as 2%, each ml of 10% will make 5ml of 2%.

So, 20ml @ 10% = 100ml @ 2%

To find the answer, we need to understand how to calculate the volume of solution needed.

The concentration of a solution is expressed as a percentage, which refers to the amount of solute (the substance being dissolved) in a given volume of solution.

In this case, we have a 10% solution and we want to know how much 2% solution we can make from it.

The formula to calculate the volume of a solution is:

(C1)(V1) = (C2)(V2)

Where:
C1 = concentration of the initial solution
V1 = volume of the initial solution
C2 = concentration of the final solution
V2 = volume of the final solution

Let's use this formula to find the answer:

Given:
C1 = 10% = 0.1
V1 = 20 ml
C2 = 2% = 0.02

Substituting into the formula:

(0.1)(20 ml) = (0.02)(V2)

Simplifying the equation:

2 ml = 0.02(V2)

To solve for V2, divide both sides of the equation by 0.02:

V2 = 2 ml / 0.02 = 100 ml

Therefore, 20 ml of a 10% solution will make 100 ml of a 2% solution.