Video Transcript
The boxes below each contain an
equal number of reactant molecules. The boxes are heated to different
temperatures. Which box will have the greatest
frequency of collisions between molecules?
In order for two reactant molecules
to react with one another, they have to collide. There are several factors that can
affect the number of collisions between reactant molecules. Two of these factors are
concentration and temperature. Concentration is a measure of the
amount of substance in a given volume. We are told, and can see, that each
box contains the same number of red and blue reactant molecules. So the concentration of reactant
molecules is the same in each box. But the temperature of each box is
not the same.
Let’s consider this picture of
orange and pink particles. At this temperature, each particle
moves at a particular speed and collisions between particles are occurring. As we increase the temperature, the
particles gain energy and move faster. The faster they move, the more
likely they are to collide. So the frequency of collisions will
increase. This means that the box which will
have the greatest frequency of collisions between molecules is the box which has the
highest temperature. Box (D), at 80 degrees, has the
highest temperature and will therefore have the greatest frequency of
collisions. So the correct answer is (D).
