Determining the Molarity of a Saturated Solution
Purpose: The purpose is to determine the molarity of a asaturated solution at room
temperature.
Background:
In this experiment you will be given a sample of a known solute. Design an experiment
to determine the molarity of a saturated solution. Molarity (M) is a unit used to indicate
the concentration of a solution.
Procedure
NOTE: Consult safety information and obtain teacher approval before beginning the
experiment. Design a procedure to prepare a saturated solution and calculate the molarity
of the saturated solution. You will be limited to 75 grams of solute. You may use any
materials at your lab station and you may request additional materials.
Safety Information
After reviewing your procedure, the instructor will discuss any safety precautions that are
specific to your experiment.
Questions for further thought
1. Calculate the molarity of a solution that contains 17.54 g of KCl in 2.00 L of
solution.
2. What mass of glucose (C6H12O6) would be required to prepare 2.00 L of a 1.50 M
solution?
3. What is the relationship between temperature and the molarity of a saturated NaCl
solution?
4. Phosphoric acid is usually obtained as an 87.0% (by mass) phosphoric acid
solution. If it is 13.0 M, what is the density of this solution? What is its molality?
5. An aqueous solution of hydrofluoric acid is 30.0% HF, by mass, and has a density
of 1.101 g cm-3. What are the molality and molarity of HF in this solution?
Prelab questions
1. What is the equation for molarity?
2. If you prepared a saturated potassium nitrate solution at room temperature and
then raised the temperature 20 degrees Celsius, would you expect the solution to
remain saturated? Explain your answer.
3. If a saturated glucose (C6H12O6) solution had a molarity of 3.28 M, calculate the
grams of glucose that would be present in 100 mL of the saturated solution.
Determining the Molality of a Saturated Solution
Purpose: The purpose is to determine the molality of a saturated solution at room
temperature.
Background:
In this experiment, you will be given a sample of a known solute. Design an
experiment to determine the molality of a saturated solution. Molality is a unit used
to indicate the concentration of a solution.
Procedure:
NOTE: Consuslt safety information and obtain teacher approval before beginning the
experiment. Design an experiment to prepare a saturated solution of a given solute
and calculate the molality of the saturated solution. You will be limited to 75 g of
solute. You may use any materials at your lab station and you may request additional
materials.
Safety Information:
After reviewing your procedure, the instructor will discuss any safety rpecautions that
are specific to your experiment.
Questions for Further Thought
1. Calculate the molality of a solution that contains 20.00 g of KCl dissolved in 300
g of water.
2. What mass of glucose (C6H12O6) would be required to prepare a 3.00 m solution
in 2.50 kg of water?
3. What is the relationship between temperature and the molality of a saturated NaCl
solution?
4. Phosphoric acid is usually obtained as an 87.0% (by mass) phosphoric acid
solution. If it is 13.0 M, what is the density of this solution? What is its molality?
5. An aqueous solution of hydrofluoric acid is 30.0% HF, by mass, and has a density
of 1.101 g cm-3. What are the molality and molarity of HF in this solution?
Prelab questions
1. What is the equation for molality?
2. If you prepared a saturated potassium nitrate solution at room temperature and
then raised the temperature 20 degrees Celsius, would you expect the solution to
remain saturated? Explain your answer.
3. If a saturated glucose (C6H12O6) solution had a molality of 3.28 m, calculate the
grams of glucose that would have to be added to 100 mL of water.