# A flask was weighed dry and then filled with water. If the masses of the empty flask and filled flask were 56.12 g and 87.39 g, respectively, and the density of water is 0.9976 g/#cm^3#, how would you calculate the volume of the flask in #cm^3#?

##### 1 Answer

#### Explanation:

The idea here is that you can sue the mass of the *empty flask* and the mass of the *filled flask* to find the **mass of water** that can be pouted into the flask.

Once you know this, you can use the **density** of water to find the volume of water, which is of course equivalent to the volume of the flask.

So, you know that you make two measurements and find

#"56.12 g " -># the mass of theempty flask

#"87.39 g " -># the mass of thefilled flask

The **difference** between these two values will be the mass of the added water

#m_"water" = "87.39 g" - "56.12 g" = "31.27 g"#

Now, the density of the water is equal to **every cubic centimeter** of water at the temperature you're performing the experiment has a mass of

You can thus use the density of water as a **conversion factor** to find the volume of

#31.27 color(red)(cancel(color(black)("g"))) * overbrace("1 cm"^3/(0.9976color(red)(cancel(color(black)("g")))))^(color(blue)("the given density")) = color(green)(|bar(ul(color(white)(a/a)color(black)("31.45 cm"^(3))color(white)(a/a)|)))#

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

So, your flask can hold a volume of