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. the concentrations and volumes are related by the following equation: M1V1 = M2V2 initial diluted

Moles don’t change!

Dilution Calculations What volume of a 2.00 M HCl solution can be prepared by diluting 25.0 mL of 14.0 M (m/v) HCl solution? Prepare a table: M1= 14.0 M V1 = 25.0 mL M2= 2.00M V2 = ? Solve dilution equation for unknown and enter values: M1V1 = M2V2 V2 = V1M1 = (25.0 mL)(14.0M) = 175 mL M2 2.00M

Learning Check What is the molarity of a solution prepared by diluting 10.0 mL of 9.00M NaOH to 60.0 mL?

Solution What is the molarity of a solution prepared by diluting 10.0 mL of 9.00M NaOH to 60.0 mL? Prepare a table: M1= 9.00 M V1 = 10.0 mL M2= ? V2 = 60.0 mL Solve dilution equation for unknown and enter values: M1V1 = M2V2 M2 = M1 V1 = (10.0 mL)(9.00M) = 1.50 M V2 60.0 mL

Learning Check What is the final volume (mL) of 15.0 mL of a 1.80 M KOH diluted to give a 0.300 M solution?

Solution What is the final volume (mL) of 15.0 mL of a 1.80 M KOH diluted to give a 0.300 M solution? Prepare a table: M1= 1.80 M V1 = 15.0 mL M2= 0.300 M V2 = ? Solve dilution equation for V2 and enter values: M1V1 = M2V2 V2 = M1V1 = (1.80 M)(15.0 mL) = 90.0 mL M2 0.300 M

Whiteboarding! 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 mL of 5.0 M copper(II) sulfate solution is added to 160.0 mL 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 CuCl2 is boiled until the final volume of the solution is 1.4 L. What is the final molarity?

M= total mol/ total volume. Dilution Example #4 Calculate the final concentration if 2.00 L of 3.00 M of NaCl and 4.00 L of 1.50M of NaCl 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 NaCl and 4.00 L of 1.50M of NaCl are mixed.

Dilution Example #5 What concentration results from mixing 400. mL of 2.0 M HCl with 600. mL of 3.0 M HCl?

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