00:01
Okay, so let's say you have a reaction where you have 2a plus 1 mole of b forms 3 moles of c.
00:10
So let's go ahead and draw the rate expression that looks at the concentration of each of these reactants and products over time.
00:22
So the rate is going to be equal to negative 1ā2 times the change in concentration of a over the change in time.
00:34
Equal or yes, which is going to be equal to the negative change in the concentration of b over a change in time, which is going to be equal to one -third times the change in concentration of c over the change in time.
00:53
Because remember, rate expressions are written in terms of a change in some quantity, which in this case is concentration, per unit of time.
01:10
And the reactants are always going to have a negative charge because if you think about it during the course of reaction, the reactions are being consumed and products are being formed.
01:21
So products are going to have a positive charge, and then you just need to add in a fraction to account for the coefficients.
01:34
So let's say in part b, if a decreases at a rate of 0 .10...