Kool Aid Lab

Kool-Aid Lab

Objective:                       

This activity reviews stoichiometry and solutions by making different concentrations of a Kool-Aid solution. There are many ways to calculate the concentration of a substance including: molarity (M), parts per million (ppm), percent composition (% comp), and grams per liter (g/L).

In chemistry, concentration is usually measured by the number of moles of substance dissolved in a liter of liquid. This is called molarity and is expressed as M (formula: molarity = moles/volume).

Pre-lab Questions:

1.   Calculate the molar mass of Kool-Aid. Assume the solute is pure table sugar, called sucrose.  Its chemical formula is C₁₂H₂₂O₁₁.

2.   What mass of Kool-Aid is needed to make a 1.0-M solution from 100 mL?

3.   What mass of Kool-Aid is needed to make a 0.5-M solution from 100 mL?

4.   What mass of Kool-Aid is needed to make a 0.2-M solution from 100 mL?

Purpose:

Apply your knowledge to calculate grams of Kool-Aid powder required to make three different solutions of Kool-Aid (C₁₂H₂₂O₁₁) with the following concentrations: 0.2 M, 0.5 M and 1.0 M. Determine the concentration (molarity) of properly prepared Kool-Aid through a taste test.

1. Hypothesis

Make an educated guess: Which of the 3 solutions will provide the best tasting drink?

2. Procedure

Part I:

1.  Create a data table to record the amount of Kool-Aid used (in grams), color, and taste ranking. Also create a data table to hold the data collected throughout this experiment.

	Grams used	Color	Taste ranking
control
0.2 M
0.5 M
1.0 M

2.  Select your taster(s). Taste the Kool-Aid and rank on a scale of 1–5 (1 = gross and 5 = amazing taste).

3.  Mix the Kool-Aid (C₁₂H₂₂O₁₁) exactly following the directions for one serving size.  

Part II:

	Observations	Saturation?
Control
0.2 M
0.5 M
1.0 M

1.  Record your observations: (ex. looked like? Taste? Which seems more concentrated, saturated, supersaturated, unsaturated?)

3. Analysis

(Reminder: 1 gram H₂0 = 1 mL; 1 L = 1,000 mL)

1.  A chemist makes two Kool-Aid solutions with varying concentrations.  The chemist makes solution A by dissolving 50.0 g of sugar in 400.0 mL of water.  She then makes solution B by dissolving 50.0 g of sugar in 200.0 mL of water.  What can be said about the solution’s concentrations? (use at least three of the following terms in your explanation: saturated, dilute, supersaturated, homogeneous, unsaturated, solvent, solute, solution)

2. If you were working for the Kool-Aid company, which concentration would you recommend to customers? Explain why, using evidence and reasoning to support your claim.

3. If 104 grams of Kool-Aid was dissolved in enough water to make 3.60 L of solution, what would be the Molarity?

4. Bryan loves Kool-Aid. He makes a super-concentrated solution of Kool-Aid by heating water to boiling and then dissolving Kool-Aid until no more would dissolve. After cooling, he notices that there is a bunch of Kool-Aid powder on the bottom of his solution.  What happened? Explain your answer.