Chapter 10 - An Introduction to Chemistry: Chemical Calculations ...

378 Chapter 10 Chemical Calculations and Chemical Equations
we will do for chemical reactions. Assume that you are making bicycles to earn money
for college. If your storeroom contains seven frames and twelve wheels, what is the
maximum number of bicycles you can make? To decide how many bicycles you can
make, you need to determine which of your components will run out first. You can
do this by first determining the maximum number of bicycles each component can
make. Whichever component makes the fewer bicycles must run out first and limit the
amount of product that can be made. From the formula for producing a bicycle, you
obtain the necessary conversion factors:
1 bicycle
1 frame
and
? bicycles = 7 frames
1 bicycle
2 wheels
1 bicycle
1 frame
= 7 bicycles
1 bicycle
? bicycles = 12 wheels = 6 bicycles
2 wheels
You have enough frames for seven bicycles but enough wheels for only six. The
wheels will run out first. Even if you had 7000 frames, you could only make six bicycles
with your twelve wheels. Therefore, the wheels are limiting, and the frames are in excess
(Figure 10.3).
Figure 10.3
Limiting
Component
+
The wheels run out first,
limiting the number of
bicycles to six.
The frames
are in excess.