Alcohol Solution Question

Question

You need a 30% alcohol solution. On hand, you have a 45 mL of a 10% alcohol mixture. You also have 45% alcohol mixture. How much of the 45% mixture will you need to add to obtain the desired solution?

You will need

 mL of the 45% solution

Answer 1

First let x be the amount of 45% alcohol solution

A 30% alcohol solution will contain 30mL of alcohol for every 100mL of solution. So this creates a desired ratio.

So the amount of alcohol in the final solution / the volume of the final solution = 30%

The amount of alcohol in the final solution is:

the amount of alcohol in the 45% mixture + the amount of alcohol in the 10% mixture

= x * 45% + 45 * 10% = 0.45x + 4.5

The volume of the final solution is:

the volume of the 45% solution + the volume of the 10% solution = x + 45

Therefore, (0.45x + 4.5)/ (x + 45) = 30%

Do you think you solve the rest?