CHEMISTRY COMMUNITY

Why can there never be an intermediate in a rate law?

the general rate law should only have reactants for the reaction as a whole. intermediates aren't found in the general reaction equation because they are created and then used up, so they wouldn't be in the rate law

The rate law is only composed of the reactants that are in the total reaction. Intermediates cannot be in the rate law as they are not found in the total reaction which is why we get rid of them when doing the general rate law. Hope this helps.

today in lecture it was said that you can never have an intermediate in a rate law

Adding on to this, this is why we can deduce the rate law directly from the coefficients of the reactants in an elementary reaction. We assume there are no intermediates in elementary reactions and so can derive the rate law just by looking at the reaction.

What else was discussed today? I unfortunately couldn't make it because I was feeling ill.

LorenzoDuvergne3I wrote:What else was discussed today? I unfortunately couldn't make it because I was feeling ill.

The pre-equilibrium approach and the relationship between temperature and reaction rate and activation energy and reaction rate

LorenzoDuvergne3I wrote:What else was discussed today? I unfortunately couldn't make it because I was feeling ill.

Expanding on the previous comment, as temperature increases, then K increases as well. This is because a higher temperature will increase the amount of collisions between reactants (as well as the energy in each collision). Furthermore, as the Activation Energy increases, then K decreases.

There are never intermediates in a rate law.