# Question #fdee5

##### 1 Answer

#### Explanation:

As you know, the **density** of a substance tells you the mass of exactly **unit of volume** of that substance.

In your case, you know that mercury has a density equal to *unit of volume*, will have a mass of

Now, notice that the volume of the sample is given in *liters*. This means that the first thing that you have to do here is to convert the volume of the sample to *milliliters* because that is the unit of volume given for the *density* of mercury.

Use the fact that

#"1 L" = 10^3color(white)(.)"mL"#

to get

#3.78 color(red)(cancel(color(black)("L"))) * (10^3color(white)(.)"mL")/(1color(red)(cancel(color(black)("L")))) = 3.78 * 10^3color(white)(.)"mL"#

To find the mass of the sample, you need to use the density of mercury as a **conversion factor**.

Since you *have* volume and you *need* mass, set up the mass of **numerator** and the **denominator**.

You will end up with

#3.78 * 10^3 color(red)(cancel(color(black)("mL"))) * "13.6 g"/(1color(red)(cancel(color(black)("mL")))) = color(darkgreen)(ul(color(black)(5.41 * 10^4color(white)(.)"g")))#

The answer is rounded to three **sig figs**.

If you want, you can convert this to *kilograms*

#5.41 * 10 * color(blue)(cancel(color(black)(10^3))) color(red)(cancel(color(black)("g"))) * "1 kg"/(color(blue)(cancel(color(black)(10^3)))color(red)(cancel(color(black)("g")))) = color(darkgreen)(ul(color(black)("54.1 kg")))#