Density - a Physical Property Physical Properties Elmhurst College Diet vs. Reg. Coke Density of Ice Density of Gold Chemistry Department Density of Liquids Density of Gases Virtual ChemBook

Which is more dense - COKE or DIET COKE?

 DENSITY is defined in a qualitative manner as the measure of the relative "heaviness" of objects with a constant volume. Both cans say 12 fl. oz. (fluid onces) or 355 mL. So they appear to be the same size and weight so should have the same density. Density Comparison to Water: In chemistry, the density of many substances is compared to the density of water. Does an object float on water or sink in the water? Put both cans into a large container of water to observe the behavior of each in water. Look at the graphic on the right. Which type of Coke is floating? Sinking?

 Comparison of: Classic Coke Diet Coke 355 mL 355 mL Water = 355 g Water = 355 g Sugar = 39 g Sugar = 0 g Nutra Sweet = 0 g Nutra Sweet = 0.1g Tot. Wgt. = 394 g Tot. Wgt. = 355.1 g

Mathematical Definition of Density

The formal definition of density is mass per unit volume. Usually the density is expressed in grams per mL or cc. Mathematically a "per" statement is translated as a division. cc is a cubic centimeter and is equal to a mL Therefore,

 Density = mass = g/mL volume

Example: Calculate the density in g/mL of Classic Coke if a 355 mL can weighs 394 g.

Solution:
Apply the definition:

 Density = 394 g = 1.11 g/mL 355 mL

Example: Calculate the density in g/mL of Diet Coke if a 355 mL can weighs 355.1 g.

Solution:
Apply the definition:

 Density = 355.1 g = 1.00 g/mL 355 mL

The above calculations make the asumption that the weight of the aluminum can is constant.