1. Grades for your reaction
Percent Yield
Grades for your reaction 1 1 1 1 1 1 1

2. Life Is Rarely Perfect
The amount of product you calculate from the ratios is the theoretical yield—the amount you will get if everything works perfectly...
...few things in life work perfectly 2 2 2 2 2 2 2

3. Life Is Rarely Perfect
In reality, people spill things, reactions make other products besides the one you want, things don't get heated for long enough, etc.
Whatever the theoretical yield you calculate is, you will probably not get that much.
The amount you get when you actually try it
is the actual yield or experimental yield. 3 3 3 3 3 3 3

4. Percent Yield Percent Yield = 100 * actual yield / theoretical yield
It's basically just a grade for your reaction.
If you were expecting to get 10 grams, and you only got 7.5 g, then you have a 75% yield.
(You might notice this is basically just the opposite of % error—in the case above, you would have a 25% error) 4 4 4 4 4 4 4

5. Thing to Think About
What does it mean if you get more than a 100% yield? 5 5 5 5 5 5 5