Solution Dilutions Dilution In a dilution water is

Solution Dilutions

Dilution In a dilution • water is added. • volume increases. • concentration decreases. Copyright © 2009 by Pearson Education, Inc.

Comparing Initial and Diluted Solutions In the initial and diluted solution: the moles of solute are the same. 2. the concentrations and volumes are related by the following equation: 1. M 1 V 1 initial = M 2 V 2 diluted

Moles don’t change!

Dilution Calculations What volume of a 2. 00 M HCl solution can be prepared by diluting 25. 0 m. L of 14. 0 M (m/v) HCl solution? Prepare a table: M 1= 14. 0 M V 1 = 25. 0 m. L M 2= 2. 00 M V 2 = ? Solve dilution equation for unknown and enter values: M 1 V 1 = M 2 V 2 = V 1 M 2 = (25. 0 m. L)(14. 0 M) = 175 m. L 2. 00 M

Learning Check What is the molarity of a solution prepared by diluting 10. 0 m. L of 9. 00 M Na. OH to 60. 0 m. L?

Solution What is the molarity of a solution prepared by diluting 10. 0 m. L of 9. 00 M Na. OH to 60. 0 m. L? Prepare a table: M 1= 9. 00 M V 1 = 10. 0 m. L M 2 = ? V 2 = 60. 0 m. L Solve dilution equation for unknown and enter values: M 1 V 1 = M 2 V 2 M 2 = M 1 V 1 = (10. 0 m. L)(9. 00 M) = 1. 50 M V 2 60. 0 m. L

Learning Check What is the final volume (m. L) of 15. 0 m. L of a 1. 80 M KOH diluted to give a 0. 300 M solution?

Solution What is the final volume (m. L) of 15. 0 m. L of a 1. 80 M KOH diluted to give a 0. 300 M solution? Prepare a table: M 1= 1. 80 M V 1 = 15. 0 m. L M 2= 0. 300 M V 2 = ? Solve dilution equation for V 2 and enter values: M 1 V 1 = M 2 V 2 = M 1 V 1 M 2 = (1. 80 M)(15. 0 m. L) = 90. 0 m. L 0. 300 M

Whiteboarding! l l In a moment I will assign you a number between 1 -6 Go to your station and using a whiteboard, solve the following 5 questions!

Dilution Example #1 100. 0 m. L of 5. 0 M copper(II) sulfate solution is added to 160. 0 m. L of water to achieve what concentration copper(II) sulfate solution?

Dilution Example #2 There are 3. 00 L of 0. 200 M HF. 1. 70 L of this is poured out, what is the concentration of the remaining HF? ANS: The concentration remains 0. 200 M, both volume and moles are removed when the solution is poured out. Just like the density of a copper penny does not change if it is cut in half, the concentration of a solution does not change if it is cut in half.

Dilution Example #3 4. 5 L of a 2. 00 M solution of Cu. Cl 2 is boiled until the final volume of the solution is 1. 4 L. What is the final molarity?

Dilution Example #4 Calculate the final concentration if 2. 00 L of 3. 00 M of Na. Cl and 4. 00 L of 1. 50 M of Na. Cl are mixed. Note: For this, you must use the equation: M= total mol/ total volume. So you must find the total number of moles to do this calculation.

Dilution Example #4 Calculate the final concentration if 2. 00 L of 3. 00 M of Na. Cl and 4. 00 L of 1. 50 M of Na. Cl are mixed.

Dilution Example #5 What concentration results from mixing 400. m. L of 2. 0 M HCl with 600. m. L of 3. 0 M HCl?

Dilutions Worksheet Complete the Dilution Worksheet AND Hebden p. 101 -103 Q’s 74 -94 EVEN Upcoming dates: l Next Class: Molarity/Dilution Quiz