Catalyst End

Which tastes the strongest? Give tables 3 cups of lemon water. 1 will contain dilute lemon juice, 1 will be a medium solution, and 1 will be the strongest. Have students analyze the reason for the difference between the cups.

Justify – TPS Why did the cup you picked taste the strongest? What was different about it from the other cups?

Lecture 3.4 – Solution Chemistry

Today’s Learning Targets LT 3.5 – I can identify the solute and solvent in a given solution. LT 3.6 – I can calculate the molarity and percent composition of a solution and discuss what the final concentration indicates. LT 3.10 – I can analyze a substances molarity and determine the number of grams of a compound that are contained within a solution.

How do we describe solutions?

I. Solute and Solvent The solvent is the substance in which the solute is dissolved and is primary ingredient in a solution. The solute is the substance that is dissolved in the solvent.

II. Solute and Solvent Water is the universal solvent. If ever there is a solution that is water and another compound, then the solvent is always water.

How do we calculate molarity?

I. Concentration The concentration of a solution is the amount of a particular substance in a given quantity of solution.

II. Molarity Molarity is a concentration unit of a solution expressed as moles of solute dissolved per liter of solution.

Class Example I have 72 g of HCl that I dissolved in 4 L of solution. What is the molarity of this final solution?

Table Talk In order to torture this gummy bear you need you make a solution of KClO3 you dissolve 1,220 g of KClO3 in 1 L of water. What is the molarity of your final solution?

SUMMARIZE

White Board Races

Question 1 You have a solution that is sugar dissolved in water. What is the solute in this solution?

Question 2 You have a solution of naphthalene dissolved in methanol. What is the solvent?

Question 3 You have 82 g of NaOH and you dissolve it in 4 L. What is the molarity of the solution?

Question 4 You have 52 g of H2SO4 dissolved in 0.5 L. What is the molarity of the solution?

Question 5 You have 52 g of CaCl2 dissolved in 0.1 L. What is the molarity of the solution?

How do we determine grams from molarity?

I. Hold Up! We Can Work in Reverse We can work backwards if we have a molarity and volume of solution. From this we can determine both the moles and mass of our solute Molarity of the solution Molar Mass of solute

Class Example If you have a 3 L of a 0.6 M solution of AgNO3, then what mass of AgNO3 is contained in this solution?

Table Talk If all the water in 430 mL of a 0.45 M NaCl solution evaporates, what mass of NaCl remains?

How do we calculate percent composition?

I. Percent Composition Percent composition conveys the concentration in terms of percent of solute in a solution.

Class Example A 4 g sugar cube (Sucrose: C12H22O11) is dissolved in a 350 g of water. What is the percent composition by mass of the sugar solution that is created?

Table Talk You have 5 moles of NaCl and you dissolve this in 500 g of water, what is the concentration of this solution in terms of percent composition?

SUMMARIZE

Connect 4 With a partner you will be using the connect 4 sheet to practice problems. Silently read through the directions on the sheet in front of you

Closing Time Homework 3.6 due Tuesday/Wednesday