1. Sugar Content Analysis
Beverage Density Lab
Sugar Content Analysis

2. Introduction
The density of a pure substance is a characteristic physical property that
can be used to identify the substance. Density is defined as the ratio of mass
per unit volume. It is an “intensive” property; that is, it does not depend on
the amount of the substance.
The density of any material is determined by measuring its mass and volume
and then dividing the mass by the volume. The mass of a substance can be
measured directly using a balance. The volume of a liquid can also be measured
directly using special laboratory glassware, such as a graduated cylinder, a buret,
or a pipet. In this experiment, liquid volumes will be measured using a pipet. A
pipet is designed to deliver an accurate and precise volume of liquid to another
container.

3. The density of a solution depends on its concentration, that is, how
much solute (solid) is dissolved in the solvent (liquid). The higher the
concentration of solute, the greater the density of the solution. A con-
venient way to express concentration is in units of weight percent, which corresponds to the number of grams of solute that are present in 100 g
of solution. A 20% salt solution is prepared by dissolving 20 g of sodium
chloride in 80 g of water. (Notice that the final mass of the solution is 100 grams.) If the density of a solution is plotted on a graph against the concentration of solute, a regular pattern is evident. Density is directly proportional to concentration. A 20% salt solution, for example, has a greater density than a 10% salt solution. If the densities of several solutions on known concentrations are determined experimentally, a calibration curve (graph) can be constructed that shows a straight-line relationship between the density of a solution and the concentration
of solute. The calibration curve can then be used to find the concentration of solute in an unknown solution.

4. Experiment Overview
The purpose of this experiment is to determine the percent sugar content
in beverages. The density of five sugar “reference” solutions will be measured
in Part A. The reference solutions contain known amounts of sugar (0-20%)
and have been dyed with food coloring to make it easier to tell them apart.
0% sugar = clear
5% sugar = yellow
10% sugar = green
15% sugar = blue
20% sugar = purple
Their densities will be plotted on a graph to obtain a calibration curve of
density versus percent sugar concentration. In part B, the densities of two
beverages will also be determined and the calibration curve used to find
how much sugar they contain. The results will be compared against the
information provided on the nutrition labels for these beverages.

5. Pre-Lab Questions
1. If the following mass and volume data are used to calculate the density of
solution, how many significant figures are allowed in the calculated density?
Mass of solution = g; volume of solution = 8.27 mL.
2. Calculate the density of the solution described in Question #1.
3. According to its nutritional label, orange soda contains 49 g of sugar per 355 mL
serving. If the density of the beverage is g/mL, what is the percent sugar
concentration in orange soda?
Hint: This is a 2-step problem.
First, use the density to convert the 355 mL serving size to grams.
Then calculate percent sugar in the beverage.

6. Solution Mass, g Sample Volume, mL Density, g/mL 0% Sugar 9.95 g 10.00
Data Table A: Density of Reference Solutions
Solution
Mass, g
Sample Volume, mL
Density, g/mL
0% Sugar
9.95 g
10.00
0.995
5% Sugar
10.14 g
1.014
10% Sugar
10.34 g
1.034
15% Sugar
10.53 g
1.053
20% Sugar
10.73 g
1.073

7. Density vs. Percent Sucrose
Calibration Curve
1.08
1.07
1.06
1.05
1.04
Density (g/mL)
1.03
1.02
1.01
1.00
0.99
Percent Sucrose

8. Beverage Mass, g Sample Volume, mL Density, g/mL Powerade 10.27 g
Data Table B: Beverage Densities
Beverage
Mass, g
Sample Volume, mL
Density, g/mL
Powerade
10.27 g
10.00
1.027
Lemon-lime soda
10.35 g
1.035
Cola
10.38 g
1.038
Apple juice
10.42 g
1.042
Grape juice
10.59 g
1.059

9. Nutrition Facts The relevant information on this label is the grams
Serving Size: 1 Can (355 mL)
Amounts Per Serving
Calories 150
% Daily Value*
Total Fat 0 g %
Sodium 55 mg %
Total Carb. 40 g %
Sugars 40 g
Protein 0 g %
* Percent Daily Values are bases on a 2,000
calorie diet.
The relevant information
on this label is the grams
of sugars, NOT the Percent
Daily Value.
This soda contains 40 g of
sugar per 355 mL of beverage.

10. from calibration curve
Data Table C: Results Table
Beverage
Measured
density, g/mL
Percent sugar
(experimental)
Amount of sugar
(Nutrition label)
(calculated from
Nutrition label)
Percent
error
Powerade
1.027
8.3%
15 g/240 mL
6.1%
*36%
Lemon-lime soda
1.035
10.3%
38 g/355 mL
10% 3%
Cola
1.038
11.1%
42 g/355 mL
11% 1%
Apple juice
1.042
12.1%
38 g/296 mL
12%
Grape juice
1.059
16.5%
40 g/240 mL
16%
*Powerade contains a large amount of salt (electrolytes)

11. Pre-Lab Questions
1. If the following mass and volume data are used to calculate the density of
solution, how many significant figures are allowed in the calculated density?
Mass of solution = g; volume of solution = 8.27 mL.
2. Calculate the density of the solution described in Question #1.
3. According to its nutritional label, orange soda contains 49 g of sugar per 355 mL
serving. If the density of the beverage is g/mL, what is the percent sugar
concentration in orange soda?
Hint: This is a 2-step problem.
First, use the density to convert the 355 mL serving size to grams.
Then calculate percent sugar in the beverage.
(4 sig. figs.)
(3 sig. figs.)
(3 sig. figs.)
Density =
mass
volume
Density =
12.53 g
8.27 mL
Density =
1.52 g/mL
X g = 355 mL
1.043 g
1 mL
49 g
= 370 g
x 100% =
13%
370 g

12. need to convert to mass first (using density) 355 mL 42 g x 100% = 12%
Data Table C: Results Table
Beverage
Measured
density, g/mL
Percent sugar
(experimental)
Amount of sugar
(Nutrition label)
(calculated from
Nutrition label)
Percent
error
Powerade
1.027
8.3%
15 g/240 mL
6.1%
*36%
Lemon-lime soda
1.035
10.3%
38 g/355 mL
10% 3%
Cola
1.038
11.1%
42 g/355 mL
11% 1%
Apple juice
1.042
12.1%
38 g/296 mL
12%
Grape juice
1.059
16.5%
40 g/240 mL
16%
DO NOT use volume…
need to convert to mass first (using density)
355 mL
42 g
x 100% =
12%
1.038 g
1 mL
42 g
X g = 355 mL
= 338 g
x 100% =
11%
368 g

13. Teacher Notes
Printable
copy of
LAB
Have students make standard reference samples of 5%, 10%, 15%, 20% sugar
Use balances that have more than 0.0 g precision
Students should use 10 mL pipets for references
Teacher may want to set-up buret with beverage samples
Scales not working properly and pipet bulbs that don’t work were largest problem with this lab.
Have students place dirty pipets in bucket of soapy water at end of lab
DO NOT ALLOW students to pour samples back into containers
Having students mix reference standards will cement the idea of percent composition in the minds of your students. It will however take ~15 minutes additional time.
If you have enough time:
DAY 1: Go over pre-lab with students, have students mix standard reference solutions and practice pipeting with water.
Allow students to pipet water onto an electronic balance to show that mL of water does weigh grams.
DAY 2: Perform the lab, having the students make a calibration curve with reference solutions they have made and collect data using the different beverages.
To complete lab in one day. Teacher should have reference solutions mixed.
Be sure to demonstrate how to use a pipet properly with students.
Some teachers prefer to fill burets with the solutions and have students rotate around to sample each solution.
A final note: sugar solutions will mold within a week. Do not mix solutions too far ahead of time and dispose of all solutions when done. Do not save standards.

14. Aspartame
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