00:01
To determine the rate constant in its units, we first need to determine the rate law.
00:05
If we look at experiments 1 and 2, we see that the concentration of b is doubled.
00:14
The concentration of b goes from 0 .240 to 0 .480, and the rate stays constant.
00:29
So the rate stays at 0 .0239.
00:35
So if you double the concentration and nothing happens to the rate, that's zero order.
00:42
So it's zero order in b.
00:46
But then if we look at experiments 1 and 3, we see that we are only changing a, the b concentration stays constant, but the a concentration goes from 0 .230 to 0 .460, and then the rate goes from 0 .2, no, 0 .0 .39 to 0 .0956.
01:31
So what is that increase? 956 divided by 0 .0239 is equal to 4.
01:47
So if we double the concentration and it results in a quadrupling of the rate, then that's second order...