Sugar, Sugar

See how sweet those "healthy" drinks really are

Estimate the amount of solute in a solution with a given concentration

Introduction

Nowadays, most people are aware of the high sugar content in soft drinks such as Coca-Cola, and some have turned to fruit drinks, energy drinks, and other beverages in order to be healthier. However, not all of those beverages are as healthy as they seem to be. The guiding question of this investigation is: How concentrated is sugar in popular brands of beverages and are the sugar concentrations in those beverages as low as they are said to be? To answer this question, the densities of solutions with known concentrations of sugar will be measured in addition to that of each beverage, in order to estimate the amount of sugar in each beverage.

Safety Equipment and Procedures:

  • Safety Glasses (To protect eyes)

  • Aprons (To protect clothing)

  • Do not taste or ingest the beverages (This could alter the quantities and could cause harm)

  • Use care when handling pipet and beakers (The equipment could break)

  • Do not spill liquids (Always keep the lab neat and tidy in order to avoid accidents)

  • Do not pour used beverages back into original container (This will alter the data)

  • Dispose of used beverages according to teacher’s instructions (Always follow the teacher’s instructions)

  • Clean up by thoroughly rinsing materials and drying with paper towels (This will keep the equipment clean and ready to use)

  • Wash hands thoroughly with soap and water before exiting the lab area (One might have hazardous substances on one's hands, so it’s always good to wash them thoroughly)

Equipment

  • Volumetric Pipet (10 mL)

  • Beakers

  • Cups (Labeled 0%, 5%,10%, 15%, Tea, Gatorade, Lemonade, Juice, Soft Drink)

  • Electronic Balance Scale

  • Graph Paper

  • Ruler

  • Paper Towels

  • 0% Sugar solution (Water)

  • 5% Sugar solution (Sugar and Water)

  • 10% Sugar solution (Sugar and Water)

  • 15% Sugar solution (Sugar and Water)

  • 20% Sugar solution (Sugar and Water)

  • Iced Tea

  • Lemonade

  • Gatorade

  • One of the following:

    • Apple Juice

    • Orange Juice

    • Grape Juice

    • Fruit Punch

  • One of the following:

    • Coca-Cola (De-carbonated)

    • Mountain Dew (De-carbonated)

    • Sprite (De-carbonated)

    • Fanta (De-carbonated)

Procedures

  1. Make a hypothesis as to how the liquids will rank in terms of sugar content using prior knowledge regarding the liquids chosen.

  2. Prepare the solutions before commencing the experiment (make sure the solutions are mixed properly)

    1. The 0% sugar solution will simply consist of pure water;

    2. The 5% sugar solution will consist of 5 g of sugar for every 100 mL of solution (95 mL of pure water);

    3. The 10% sugar solution will consist of 10 g of sugar for every 100 mL of solution (90 mL of pure water);

    4. The 15% sugar solution will consist of 15 g of sugar for every 100 mL of solution (85 mL of pure water)

    5. The 20% sugar solution will consist of 20 g of sugar for every 100 mL of solution (80 mL of pure water)

  3. Place the empty beaker on the balance scale and press “tare/zero” so that the scale reads 0 g.

  4. Use the volumetric pipet to draw up exactly 10 mL of the 0% sugar solution and empty it out in the beaker placed on the scale.

  5. Record the mass and volume of the liquid and use this information to calculate the density of the liquid. (Recall that Density=Mass/Volume)

  6. Empty out the 0% sugar solution into the sink.

  7. Thoroughly rinse the beaker and dry using paper towels.

  8. Remove any leftover liquid in the pipet or on the scale.

  9. Repeat steps 2-7 for each of the sugar solutions and beverages

  10. On a piece of graph paper, graph the sugar concentration of the 0% solution on the x-axis and the density of the 0% solution on the y-axis.

  11. Repeat step 10 for each of the sugar solutions.

  12. With the 5 plotted points for each of the sugar solutions, draw a line of best fit.

  13. Estimate the sugar concentration of each of the beverages by first finding the points on the line of best fit that corresponds to each of the beverages' density (y-value), then finding the x-values of each point, or the approximate sugar concentration for each corresponding beverage. Record each value.

  14. Find the nutritional label on each of the beverages, then calculate the sugar concentration by dividing the amount of sugar per serving by the serving size and then multiplying by 100. Record each value.

  15. Find the percent error in sugar concentration by dividing the difference between the empirical value (from graph) and the calculated value (from label) by the calculated value. Record the percent error for each beverage.