As you come in,As you come in,

Pass up the Calories in a Chip Lab. Get paper, pencil, and calculator ready

for notes on calculations.

NOTE: Solubility Graph Quiz tomorrow!

Pass up the Calories in a Chip Lab. Get paper, pencil, and calculator ready

for notes on calculations.

NOTE: Solubility Graph Quiz tomorrow!

ConcentrationConcentration

Concentration - the amount of solute in a specific amount of solvent Molarity (M) Molality (m)

Molarity is the most common unit used to report the concentration of a solution in a laboratory setting.

Concentration - the amount of solute in a specific amount of solvent Molarity (M) Molality (m)

Molarity is the most common unit used to report the concentration of a solution in a laboratory setting.

MolarityMolarity

The number of moles of solute per liter of solution.

Write a mathematical equation to represent the definition of molarity.

Explain your equation. (A) Agree or disagree. (B)

The number of moles of solute per liter of solution.

Write a mathematical equation to represent the definition of molarity.

Explain your equation. (A) Agree or disagree. (B)

Molarity EquationMolarity Equation

moles of solute

Molarity =

Liters of solution

Example: Calculate the molarity of 0.4 mol NaCl dissolved in 1.6 L solution.

Answer: 0.25 M NaCl

moles of solute

Molarity =

Liters of solution

Example: Calculate the molarity of 0.4 mol NaCl dissolved in 1.6 L solution.

Answer: 0.25 M NaCl

5 minute Independent Practice5 minute Independent Practice You will have a 5 minute Partner time next. 8-)Practice Problems: 1. 20.2 grams of potassium nitrate is dissolved in

enough water to make 250.0 mL of solution. What is the molarity?

2. Calculate the number of grams of solute needed to prepare 2.0 L of 2.0M nitric acid.

3. Challenge: Give the concentrations of all the ions in each of the following solutions:

1. 0.50M Co(NO3)2

2. 1 M FeCl3

You will have a 5 minute Partner time next. 8-)Practice Problems: 1. 20.2 grams of potassium nitrate is dissolved in

enough water to make 250.0 mL of solution. What is the molarity?

2. Calculate the number of grams of solute needed to prepare 2.0 L of 2.0M nitric acid.

3. Challenge: Give the concentrations of all the ions in each of the following solutions:

1. 0.50M Co(NO3)2

2. 1 M FeCl3

5 Minute Partner Review5 Minute Partner Review

Check your Practice Problem answers with your partner. Are your chemical formulas written

correctly? Did you make the appropriate conversions

before plugging into the molarity equation? What are your questions? (Write them

down, and prepare to ask with our large group.)

Check your Practice Problem answers with your partner. Are your chemical formulas written

correctly? Did you make the appropriate conversions

before plugging into the molarity equation? What are your questions? (Write them

down, and prepare to ask with our large group.)

Molarity - Correct AnswersMolarity - Correct Answers

1. Potassium nitrate = KNO3

20.2 g KNO3 is converted to 0.20 mol KNO3.

The volume of 250.0mL is converted to .250L.

The Molarity = 0.8 M KNO3

2. Nitric Acid = HNO3

4mol of HNO3 is calculated by plugging into the Molarity equation.

The mass of four moles of HNO3 is 252 grams.

1. Potassium nitrate = KNO3

20.2 g KNO3 is converted to 0.20 mol KNO3.

The volume of 250.0mL is converted to .250L.

The Molarity = 0.8 M KNO3

2. Nitric Acid = HNO3

4mol of HNO3 is calculated by plugging into the Molarity equation.

The mass of four moles of HNO3 is 252 grams.

MolalityMolality

The number of moles of solute per kilogram of solvent.

Write a mathematical equation to represent the definition of molality. Explain your equation. (B) Agree or disagree. (A)

The number of moles of solute per kilogram of solvent.

Write a mathematical equation to represent the definition of molality. Explain your equation. (B) Agree or disagree. (A)

Molality EquationMolality Equation

moles of soluteMolality =

kilograms of solvent

Example: What is the molality of a solution that contains 2.3 moles of glucose dissolved in 500.0 g of water?

Answer: 4.6 m

moles of soluteMolality =

kilograms of solvent

Example: What is the molality of a solution that contains 2.3 moles of glucose dissolved in 500.0 g of water?

Answer: 4.6 m

5 Minute Independent Practice5 Minute Independent Practice Practice Problems:

1. Find the molality of 131 g Ba(NO3)2 dissolved in 750.0 g H2O.

2. How many grams of sodium chloride must dissolve in 750.0 grams of water to make a 0.50 molal solution?

Practice Problems:1. Find the molality of 131 g Ba(NO3)2

dissolved in 750.0 g H2O.

2. How many grams of sodium chloride must dissolve in 750.0 grams of water to make a 0.50 molal solution?

Molality - Correct AnswersMolality - Correct Answers

1. 131 g Ba(NO3)2 is converted to 0.50 moles, and 750.0 g of H2O is converted to 0.750 kg H2O. The molality is 0.67 m Ba(NO3)2.

2. 750.0 grams of H2O is converted to 0.750 kg of H2O. The equation is solved to give 0.375 moles NaCl, which converts to 21.9 grams.

1. 131 g Ba(NO3)2 is converted to 0.50 moles, and 750.0 g of H2O is converted to 0.750 kg H2O. The molality is 0.67 m Ba(NO3)2.

2. 750.0 grams of H2O is converted to 0.750 kg of H2O. The equation is solved to give 0.375 moles NaCl, which converts to 21.9 grams.

Preparing a Solution LabPreparing a Solution Lab

Today, you will be writing a lab procedure to prepare a solution of a specific Molarity. Purpose Materials Procedure Calculations

Each group will be preparing a different solution.

Today, you will be writing a lab procedure to prepare a solution of a specific Molarity. Purpose Materials Procedure Calculations

Each group will be preparing a different solution.

Group Molarity (500 mL)

Solute

1 0.05 NaCl2 0.005 C12H22O11

3 0.0075 Na2SO4

4 0.015 Na2SO4

5 0.05 NH4Cl6 0.025 NH4Cl7 0.009 C12H22O11