Page 1 of 1

### Pseudo 1st order reaction

Posted: Thu Mar 14, 2019 9:55 pm
What is a pseudo first order reaction and what homework problem is it used in?

### Re: Pseudo 1st order reaction

Posted: Thu Mar 14, 2019 11:23 pm
We use pseudo first order reactions when we are studying a reaction with multiple reactants with concentrations that could affect the rate law. For example if the reaction in question is A+B-->P we would design an experiment to find out how the rate changes with the concentrations of each reactant. The rate law=k' * [A]^n * [B]^m. To find [A], the [B] is made very high so that it remains relatively constant and the [A] is varied. We can then analyze the data like we did earlier in the section in order to calculate n. If n is 1 then the reaction is pseudo first order. Since we do not know the order for B, it is only pseudo first order not first order. We can then repeat the process for the other reactants.

### Re: Pseudo 1st order reaction

Posted: Fri Mar 15, 2019 12:09 am
okay, thank you! is there a homework problem like this?