# Question #48627

##### 1 Answer

#### Explanation:

The idea here is that you need to convert the *volume* of the sample to *mass* by using the solution's known **density**.

Notice that the density of the solution is expressed in *grams per milliliter*, *liters*.

In order to be able to use the density to find the mass of the solution, you must convert the volume of the sample to milliliters. You can convert *liters* to *milliliters* by using the conversion factor

#color(blue)(ul(color(black)("1 L" = 10^3"mL")))#

In your case, the sample will have a volume of

#2.50 color(red)(cancel(color(black)("L"))) * (10^3"mL")/(1color(red)(cancel(color(black)("L")))) = 2.50 * 10^3"mL"#

Now, the density of the solution tells you the mass of **unit of volume** of solution. More specifically, a density of **every**

This means that your sample will have a mass of

#2.50 * 10^3 color(red)(cancel(color(black)("mL"))) * "1.149 g"/(1color(red)(cancel(color(black)("mL")))) = "2872.5 g"#

In order to find the mass of iron(III) chloride present in this sample, you must use the fact that the solution is **by mass**.

This means that **every**

#2872.5 color(red)(cancel(color(black)("g solution"))) * "11 g Fe Cl"_3/(100color(red)(cancel(color(black)("g solution")))) = color(darkgreen)(ul(color(black)("316 g FeCl"_3)))#

I'll leave the answer rounded to three **sig figs**, but keep in mind that you only have two significant figures for the percent concentration of the solution.