# The label on an Ocean Spray Cran-Raspberry drink lists 30 g of sugar in 240 mL of drink. I weighed 240 mL of drink and found its mass to be 251 g. What is the percent composition of sugar in the drink?

Mar 3, 2017

$\text{12% sugar}$

#### Explanation:

We use percent composition as a measure of how many grams of a given substance are present in exactly $\text{100 g}$ of a compound or a mixture.

In this case, the percent composition of sugar in the beverage will tell you how many grams of sugar you get for every $\text{100 g}$ of beverage.

Now, you know that you have $\text{30 g}$ of sugar in $\text{251 g}$ of beverage. This is the known composition of the drink. You can use this composition to determine the mass of sugar present in $\text{100 g}$ of beverage.

100 color(red)(cancel(color(black)("g drink"))) * "30 g sugar"/(251color(red)(cancel(color(black)("g drink")))) = "11.95 g sugar"

This means that the percent composition of sugar in the drink will be

$\textcolor{\mathrm{da} r k g r e e n}{\underline{\textcolor{b l a c k}{\text{% sugar = 12%}}}}$

I'll leave the answer rounded to two sig figs, but keep in mind that you only have one significant figure for the mass of sugar.