Spec

On the OCR A level chemistry specification it doesnt mention anything about limiting reagents or working out which reactant is in excess, identifying the limiting reagent. So do i have to learn it.

Reply 1

bl0bf1sh

Original post by waveyyx

On the OCR A level chemistry specification it doesnt mention anything about limiting reagents or working out which reactant is in excess, identifying the limiting reagent. So do i have to learn it.

Did you do it at GCSE? It's generally a useful thing to learn how to do, and it comes in handy when dealing with some acids & bases calculations (for example).

Spoiler

Reply 2

waveyyx

No I don’t remember being taught it during GCSEs. We have been taught how to do it in college and i been wanting to do revision for it as well but nothing is mentioned in the spec about it. I don’t know whether there’d be questions in the exam directly asking us to work out the limiting reagent or which reactant is in excess.

Reply 3

bl0bf1sh

Original post by waveyyx

I don't think it would hurt to have a look over it, like I said a lot of questions involving calculating pH may require you to know which reagents are in excess :smile:

Here's a decent video explaining how to do it: https://youtu.be/iamXnr_UGlA?si=LSOnRMfF_kc6KPKJ&t=283 (starts off with percentage yield then at 4:43 goes on to limiting reagent).

Reply 4

waveyyx

Original post by bl0bf1sh

I don't think it would hurt to have a look over it, like I said a lot of questions involving calculating pH may require you to know which reagents are in excess :smile:

Here's a decent video explaining how to do it: https://youtu.be/iamXnr_UGlA?si=LSOnRMfF_kc6KPKJ&t=283 (starts off with percentage yield then at 4:43 goes on to limiting reagent).