# Density question

## Homework Statement

The density of a solution of ferric chloride is 1.058g/cc, and it is 7.00 percent by mass. What volume of the soltion (in mL) do you need to supply 34.0g of ferric chloride?

D=m/v

## The Attempt at a Solution

Not sure where to begin. I dont understand the statement, " and it is 7 percent by mass". Does this mean i ned to multiply 34*0.07? then just calculate the volume by rearranging the density formula?

It means that 100 g of the solution contains 7 g of ferric chloride.

Where do I even begin on this question?

You know the absolute mass of ferric chloride you need to supply.

You know the mass percentage of it in the solution => you know the mass of the solution containing the required amount of ferric chloride.

Can you see what happens next?

muultiply mass by mass percentage?

Chestermiller
Mentor
You do understand that the solution is partly water and partly ferric chloride, right?

If, as voko pointed out, 100 gm of the solution contains 7 gm of ferric chloride, how many grams of solution contain 34 grams of ferric chloride?