Science Education Tutorials and Practice Exercises

General Chemistry :: Dimensional Analysis :: Example 2

Here is the instructions to use the practice exercise above in case you need it while you are doing the practice exercise.

Know your metric conversions! This tutorial does not use anything other than metric, but you must supply the conversions.

Using Scientific Notation: Use an "e" to replace the "x10". Don't skip any spaces.
For example: use 3.25e-6 to represent 3.25 x 10-6

To add a conversion factor to your equation:

  1. Click the button "Add a conv. factor".
  2. Type in the coefficients for both the numerator and denominator of the conversion factor. To change the coefficient, highlight it and type in a new coefficient.
  3. Click to select the units for both the numerator and denominator of the conversion factor. You can change the units you selected on a conversion factor by repeating this step.
  4. Enter an exponent for the conversion factor if it is anything other than 1.

To check your answer:
Click the button "Check Answer" to check your answer.

Tools to help you doing this practice exercise:

  1. Validation of conversion factors in your equation
    You do not have to validate a conversion factor in the equation. Validating the conversion factors in your equation will allow you to check your work as you construct the equation.
    Note: The program will only validate conversion factors that use units of the same category (length, volumne...) in the numerator & denominator. While density can be used correctly as a conversion factor, it has units of mixed categories (mass and volume) so it will not validate. But you can use it to get the right answer.

    To validate a conversion factor:
    Drag the "Balance" icon onto any of the conversion factor in your equation.
    It will tell you if the conversion factor is a valid one or not.
  2. Pencil and Eraser tools
    You can click and drag almost anywhere on the exercise page to draw lines to mark the canceling of units, like you would normally do on paper. The lines you drawn will not be graded here.
  3. To draw lines:
    Click and drag anywhere to draw a blue line.
    If you try to draw lines by clicking inside the parenthesis of the conversion factor, it may not appear. Try to start drawing from a little outside of the parenthesis area.
  4. To erase the lines you draw:
    Drag the Eraser icon over the lines that you want to erase.