Question

Calcium chloride is used as a de-icer on the roads in winter. it has a density of 2.50g/cm^3. What is the mass of 15.00 cm^3 of this substance?

Answer 1

`"37.5 g"`

Explanation:

Take a look at what information the problem provides you with.

Notice that you are given density, expressed in grams per cubic centimeter, and volume, expressed in cubic centimeters.

As you know, density is defined as mass per unit of volume

`color(blue)("densitgy" = "mass"/"volume")`

In your case, a density of `"2.50 g/cm"^3` tells you that each `"cm"^3` of calcium chloride, `"CaCl"_2`, has a mass of `"2.50 g"`.

Well, if `"1 cm"^3` of calcium chloride has a mass of `"2.50 g"`, do you expect the mass of `"15 cm"^3` to be bigger or smaller?

`15.00color(red)(cancel(color(black)("cm"^3))) * "2.50 g"/(1color(red)(cancel(color(black)("cm"^3)))) = color(green)("37.5 g")`