# Question #5d2fc

##### 1 Answer

#### Answer:

#### Explanation:

Think about what the density of a substance tells you.

As you know, the density of a substance is defined as the mass of **one unit of volume** of that substance.

#color(blue)("density" = "mass"/"unit of volume"#

In your case, the volume is given in *milliliters*, and the density in *grams per milliliter*, so **one unit of volume** will be equal to

A density of **for every**

So, you can say that

#"1 mL " -> " 0.79 g"#

#"2 mL " -> " 0.79 g" + "0.79 g"#

#"3 mL " -> " 0.79 g" + "0.79 g" + "0.79 g"#

#vdots#

and so on. In your case ,the sample of ethanol is said to have a volume of

#53 color(red)(cancel(color(black)("mL"))) * overbrace("0.79 g"/(1color(red)(cancel(color(black)("mL")))))^(color(purple)("given density")) = "41.87 g"#

Rounded to two sig figs, the answer will be

#m = color(green)("42 g")#