Question

What is the weight of the ethyl alcohol that exactly fills a 200.0 mL container?

The density of ethyl alcohol is 0.789 g/mL.

Answer 1

`158g`

Explanation:

To calculate the "weight" (mass) of ethyl alcohol, we have to use this formula:

- Density will have units of `g/(mL)` when dealing with a liquid or units of `g/(cm^3)` when dealing with a solid.

• The mass has units of grams, `g`.

• The volume will have units of `mL` or `cm^3`

We are given the density and volume, both of which have good units so all we have to do is rearrange the equation to solve for the mass:

`densityxxvolume=(mass)/(cancel"volume")xxcancel"volume"`

`color(green)("Density")` `xx` `color(green)("Volume = Mass")`

`(0.789g)/cancel"mL"xx200.0cancel"mL"`

Thus, ethyl alcohol weighs 158g.