Chemistry: Dilutions


Let's say that I want to make as much of a 0.100 M NaCl solution as I can, but the only thing in my stockroom is 1.50 L of a 0.450 M NaCl solution. How would I turn the 0.450 M solution into a 0.100 M solution?

I would dilute it! Dilution is the process by which a solvent is added to a solution to make the solution less concentrated. The equation we'd use for dilutions is:

  • M1V1= M2V2
You've Got Problems

Problem 3: How much of a 0.500 M NaCl solution would be needed to make 750 mL of a 0.125 M solution?

M1 is the initial molarity of the solution, V1 is the initial volume of the solution, M2 is the molarity of the solution after it has been diluted, and V2 is the volume after dilution.

To determine how we'd make my 0.100 M NaCl solution, we'd use the equation above, inserting the values that I know:

M1V1 = M2V2

(0.450 M)(1.50 L) = (0.100 M)V2

V2= 6.75 L

I can make 6.75 L of a 0.100 M NaCl solution.

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Excerpted from The Complete Idiot's Guide to Chemistry © 2003 by Ian Guch. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.

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