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?

1 Answer
Mar 3, 2017


#"12% sugar"#


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.