Catalyst and Theme

• Catalyst:

1. If you have 15 moles of H2O, how many grams of H2O do you have?

2. You discover 150 g of arsenic and decide to put it in your least favorite teachers water. How many moles of As did you just put in their water?

3. Theme of this unit: How much does it take to kill you?

Which tastes the strongest?

Justify – TPS

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

Today’s Objectives

• I can identify the solute and solvent in a solution• I can calculate the concentration of a solution in

terms of grams per liter• I can calculate the concentration of a solution in

terms of molarity• I can calculate the concentration of solution in

terms of percent composition• I can calculate the concentration of solution in

terms of parts per million

Lab Next Week

• You must get above 70% on the exit slip next class if you want to do the lab next Monday/Tuesday

• The exit slip will only be on the content we cover today.

Solute and Solvent

• The solvent is the substance in which the solute is dissolved. This is the primary ingredient in a solution.

• The solute is the substance that is dissolved in the solvent.

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.

• When water is the solvent, it is an aqueous solution.

Concentration

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

• It expresses the ratio of solute to solvent

Four Ways to Express Concentration

• The four main ways of expressing concentration are:1. Grams per liter

2. Molarity

3. Percent composition

4. Parts per million

Grams per Liter

• Grams per Liter looks like• Make sure to convert everything to grams and

liters:

Class Example

• You have 15 g of KCl and you dissolve it in 3 L of water. You then inject it in your partners arm and their heart stops beating. What is the concentration in g/L?

My Turn!

• Bleach is a common household cleaner, but if you drink it you can do major damage to your respiratory solution. If you dissolve 50 g of sodium hypochlorite (the chemical in bleach) in 15 L of water and make your mortal enemy drink it, then what is the concentration of this solution in g/L?

Stoichiometry Review

• To convert from grams to moles:

• To convert from moles to grams:

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 concentration of this final solution?

Gummy Bear Torture Chamber

https://www.youtube.com/watch?v=uj9D3mc7tVg

My Turn!

• 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

We WILL FINISH THIS UP ON MONDAY/Tuesday. Do your Homework.

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?

Stop and Jot

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

Two More Ways to Calculate Concentration

• We can calculate the concentration of a solution two other ways:1. Percent composition

2. Parts per million

Percent Composition

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

Steps to Calculate Percent Composition

1. Determine the mass of the solute2. Determine the mass of the solvent. 3. Determine the total mass of the solute

by adding the mass of the solute and the mass of the solvent (msolute+msolvent=msolution)

4. Calculate the percent composition of the solution by dividing the mass of the solute by the mass of the 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?

Parts per Million

• The final concentration expression is parts per million

• Parts per million (ppm) is the number of grams of solute in 1 million grams of solution.

• It is a common unit used in environmental studies and pollutant concentration.

Calculating ppm

• Need to find mass of solute and mass of solvent and convert to grams.

Class Example

• Mercury poisoning is a very dangerous disease and humans often contract it by consuming fish that have been contaminated with mercury. The accepted safe level is 0.5 ppm of Hg in fish. What is the concentration of mercury in a fish if it has 0.0006 g of Hg in 500 g of H2O?

Stop and Jot

• Carbon Monoxide (CO) is a common toxin that cannot be smelt and will kill you at concentrations above 400 ppm. If there are 1,500 g of CO in a 3 g sample of air, then is this a toxic ppm concentration of CO?

SUMMARIZE

Work Time

Closing Time

• Doing the homework will help you score above a 70% on the exit slip tomorrow so that you can do the lab next Monday/Tuesday!

Homework Problem Sheet