Sample Study Sheet: Dilution Problems

Tip-off  There are several tip-offs for this type of problem. Perhaps the most general is the mention of two concentrations of the same substance. Other tip-offs include a reference to dilution, especially to making a more dilute solution from a more concentrated solution.

General Steps  There are two possible approaches.

Using Dimensional Analysis - You can use the general dimensional analysis thought process, taking care to identify clearly the units of concentrated solution, dilute solution, and pure solute. The molarities given in the problem are used as conversion factors. The following is one general example:

 

Using the Dilution Equation (a shorter alternative) Assign the variables MC, VC, MD, and VD to the values you are given and the value that you want.

  • Write the dilution equation.

MCVC = MDVD

  • Solve the equation for the unknown variable.
  • Plug in the values for the other variables.
  • Cancel your units.
  • If your units do not cancel to yield the desired unit, make the necessary unit conversions so the units do cancel correctly.
  • Complete the calculation, round your answer to the correct significant figures, and report the correct unit.

Click here to see Example 2 with the dimensional analysis technique.

Click here to see Example 2 with the dilution equation.

Click here to see an exercise.

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