Question

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?

Answer 1

`"12% sugar"`

Explanation:

We use percent composition as a measure of how many grams of a given substance are present in exactly `"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 `"100 g"` of beverage.

Now, you know that you have `"30 g"` of sugar in `"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 `"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

`color(darkgreen)(ul(color(black)("% 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.