Question

HELP. Georgina wants to make a 42% citric acid solution. If she has 0.5 liters of water, how many liters of a 49% citric acid solution should she add?

Answer 1

Georgina should add 3 liters of 49% citric acid solution.

Explanation:

let x be the liters of 49% solution that Georgina should add. Then after she has added 0.5 liters of water, the total liters of solution she has will be

`x+0.5`

and 42% of this should be the solute:

`0.42(x+0.5)`

and since adding water does not add any solvent, this amount must come from the 49% citric acid solution; therefore

`0.42(x+0.5)=0.49x`

Solving for
`x` we get:

`\boxed{x= 3\:liters}`

This the amount of 49% citric acid solution Georgina must add.