 Objective: › Today I will be able to:  Calculate the molarity, molality, mole fraction and dilution for a solution  Analyze the effect of changing the temperature on the solubility of a compound  Evaluation/Assessment: › Informal Assessment – monitoring student interactions and questions as they complete the worksheets › Formal Assessment – analyzing student responses to the worksheet and exit ticket  Common Core Connection › Make sense of problem and persevere in solving them › Look for and make use of structure › Use appropriate tools strategically

 Evaluate: Warm-Up (5 minutes)  Elaborate: Solutions Calculations Review ◦ 25 minutes  Explain: Solubility Curves (5 minutes)  Elaborate: Solubility Curve practice ◦ 15 minutes  Evaluate: Exit Ticket

 Describe how to prepare 150 ml of a 1.2 M HCl solution from a 4.0 M HCl stock solution.

 Today I will be able to: ◦ Calculate the molarity, molality, mole fraction and dilution for a solution ◦ Analyze the effect of changing the temperature on the solubility of a compound

 Study for the Molarity, Molality, Mole Fraction and Dilution Quiz Tomorrow

 Warm – Up  Concentration Practice  Solubility Curve Notes  Solubility Curve Practice  Exit Ticket

 Molarity (M) – moles of solute/liters of solution

 Use Molarity calculations  Use a 1 L volumetric flask - calculate the formula weight of the compound - Dilute compound with water to the 1 L mark on the flask - Invert solution to mix - Creates a 1 M concentration solution

 Dilution of a more concentrated solution to a less concentrated one  V old x M old = V new x M new

 Molality = moles of solute/kg of solvent  Practice: What is the molality of a solution in which 3.0 moles of NaCl is dissolved in 1.5 kg of water?

Χ i = moles of i total moles

 mole of NaCl is dissolved into grams of pure H 2 O. What is the mole fraction of NaCl? ◦ Steps to solve the problem  Convert mass of H 2 O  moles of H 2 0  Add the moles of H 2 O and NaCl together to get the total number of moles in the solution  Divide the moles of NaCl by the total number of moles  Answer:  No units because it is a ratio!

Lets review some of the answers from the worksheets you all completed on Friday.

Think about: How does temperature affect solubility

 What effect does increasing the temperature have on the solubility of a liquid? ◦ In general it increases  Why? ◦ Molecules move around more rapidly to dissolve quicker

 Gas solubility decreases with temperature increase  Why does this happen? ◦ Molecules move faster, the gas particles escape the solution

Complete the questions relating to the solubility curve. Ask Mr. Klotz for help if you have questions

 What is the molality of a saturated KCl solution At 80 o C?