# Question #fc7d0

##### 1 Answer

#### Answer:

Use a couple of conversion factors to help you with that.

#### Explanation:

Density is defined as mass per unit of volume.

In your case, the density of mercury is given in *grams* per *mililiters*. In order to get the units to *pounds* per *cubic inch*, you will need to use a couple of conversion factors.

First, use the fact that **1 pound** is equivalent to **453.59237 grams**. To get from mililiters to cubic inches, you will use the fact that

To determine how much one cubic inch is, you can use

#"1 in"""^3 = "1 in" xx "1 in" xx "1 in"#

Now replace the inch with its equivalent in centimeters to get

#"1 in"""^3 = "2.54 cm" xx "2.54 cm" xx "2.54 cm" = "16.387064 cm"""^3#

So, your conversion will look like this

#13.6(color(red)(cancel(color(black)("g"))))/(1color(red)(cancel(color(black)("mL")))) * (1color(red)(cancel(color(black)("mL"))))/(1color(red)(cancel(color(black)("cm"^3)))) * "1 lb"/(453.59237color(red)(cancel(color(black)("g")))) * (16.387064color(red)(cancel(color(black)("cm"^3))))/("1 in"^3) = color(green)(0.491"lb"/"in"^3)#

The answer is rounded to three sig figs, the number of sig figs you have for the density in grams per mililiter.