Solution Concentration Molarity Dilute vs Concentrated Qualitative descriptions

Dilute vs. Concentrated Qualitative descriptions of a solution • Weak solution • Strong Solution

Which is more concentrated? 1) 5 mol in 1 L of solution or 1

(M)olarity is the • Quantitative measure of solution concentration • number of moles of

• What is the Molarity (M) of a solution if 37. 0 g

• If you add water or evaporate it you will change the molarity

• If a 5. 0 L solution is 2. 0 M and 1500.

• STEP 2 SUBSTITUE and solve M 1 V 1 = M 2

• IF you want to make 500 m. L of a 1. 5

• This represents the volume of the concentrated solution (12 M) you need.

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Solution Concentration Molarity

Dilute vs. Concentrated Qualitative descriptions of a solution • Weak solution • Strong Solution • few particles of • LOTS of solute particles solute in a dissolved in a solvent

Which is more concentrated? 1) 5 mol in 1 L of solution or 1 mol in 5 L of solution 2) 2. 5 mol in 2 L solution or 3. 0 mol in 1. 5 L solution 3) Which picture?

(M)olarity is the • Quantitative measure of solution concentration • number of moles of solute dissolved per liter of solution

• What is the Molarity (M) of a solution if 37. 0 g of KCl is dissolved to make 250. 0 m. L of solution? • Step 1 CONVERT 250. 0 m. L . 250 L 37. 0 g of KCl to moles

• Step 2 SUBSTITUTE into Formula 2. 0 M

• If you add water or evaporate it you will change the molarity of the solution • Use this formula to determine the new molarity… M 1 V 1 = M 2 V 2

• If a 5. 0 L solution is 2. 0 M and 1500. 0 m. L of water is added, what is the new (M)olarity? Step 1 MAKE a list and do any conversions M 1 = 2. 0 V 1 = 5. 0 L M 2=? V 2= 1500 m. L 1. 5 L+ 5. 0 L = 6. 5 L In this problem…. You have to add for the total solution volume

• STEP 2 SUBSTITUE and solve M 1 V 1 = M 2 V 2 (2. 0 M) (5. 0 L) = M 2 (6. 5 L) 1. 54 M = new molarity

• IF you want to make 500 m. L of a 1. 5 M solution from a 12. 0 M solution, How much of the concentrated solution do you need and how much water do you need? M 1 = 1. 5 M V 1 = 500 m. L M 2=12 M V 2= ? M 1 V 1 = M 2 V 2 (1. 5)(500) = (12)V 2 = 62. 5 m. L Ask yourself…. . what does this volume represent? ?

• This represents the volume of the concentrated solution (12 M) you need. • But I need 1. 5 M and 500 m. L of it…. how do I get there? • To go from 12 M to 1. 5 M you have to add water. • But how much water? ? • Let’s draw a diagram to find out.

62. 5 m. L of 12 M 500 m. L of 1. 5 M TOTAL Vol you WANT Vol you have 500 m. L – 62. 5 m. L = 437. 5 m. L Vol you need to ADD

Molarity Practice M 1 V 1 = M 2 V 2

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