00:01
Okay, so for this problem, let's use an example.
00:05
Let's say, i'm going to draw a graph here, where we have the concentration of a versus time.
00:16
And this is going to be a reaction of, let's say, a to b.
00:24
And so we'll say at 1 mole, 0 mole, 0 seconds, and let's say 10 second.
00:38
I'll just separate that out.
00:41
So our graph here, let's say look something like this.
00:46
So as we go from a concentration of 1 to a concentration of 0, you can see that there's going to be a decrease in a over a time period from 0 seconds to 10 seconds.
00:59
So if we're going to be talking about average rate, what we're really talking about is the change in concentration between t2 and t1.
01:13
So in this case, i guess if we're looking at our overall rate expression, right, so rate is going to be equal to negative 1 over a times a change in concentration of a over the change in time.
01:28
So if we're talking about the average rate, what we're going to be talking about is the overall change in a given time.
01:37
So let's say we're going from zero seconds to 10 seconds.
01:43
So this will be the changing concentration of a at time two minus the changing concentration of a at time one over t2 minus t1, which in this example we can say at t2, which is 10 seconds, it has a concentration, i'm sorry, of zero...