1. Concentration of Solutions What is Concentration? What is Concentration? The amount of solute dissolved in a specified amount of solution The amount of solute dissolved in a specified amount of solution It is like a ratio It is like a ratio Mass of solute divided by Volume solution Mass of solute divided by Volume solution Grams solute/Liters solution Grams solute/Liters solution g/L g/L

2. Concentration of Solutions There are three ways to express a concentration: There are three ways to express a concentration: % by Volume % by Volume % by Mass % by Mass Molarity Molarity

3. Concentration of Solutions Percent by volume Percent by volume used to measure the concentration of one liquid dissolved in another. used to measure the concentration of one liquid dissolved in another.

4. Concentration of Solutions Percent by mass Percent by mass is the percent of a solution’s total mass that is accounted for by a solute. is the percent of a solution’s total mass that is accounted for by a solute.

5. Concentration of Solutions Molarity Molarity Used to compare the number of solute particles in solutions Used to compare the number of solute particles in solutions number of moles of a solute dissolved per liter of solution. number of moles of a solute dissolved per liter of solution. Molecular weight of compound

6. Molarity example How many grams of NaCl are going to have to be added to 1 liter of water to make a 1M solution? How many grams of NaCl are going to have to be added to 1 liter of water to make a 1M solution? How to find out? How to find out? 1. Calculate the molar mass of the solute 2. Divide by Amount of Solution NaCl = 58 grams (look at table)

7. 1. Compound X has a solubility of 20 g in 100 g of water at 20°C. What is the minimum amount of water needed to dissolve 50 g of compound X? a. 250 g b. 100 g c. 500 g d. 200 g ANS:A