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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: xshadow on October 23, 2020, 04:29:17 PM

Title: Calculate number of equivalent: organic reaction
Post by: xshadow on October 23, 2020, 04:29:17 PM: Hi

I have to calculate the equivalent for this reaction:
(https://i.imgur.com/Jk8r12U.jpg)

I have 0.0102mol of sodium saccharine and 0.015mol of iodoethane

How can i calculate the number of equivalent for this reaction?!

I know how to calculate the equivalents for :
Acid base (NaOH,H2SO4 ecc)
Redox
Salt dissolution

But here is an organic reaction ..it' s different

Thanks!
Title: Re: Calculate number of equivalent: organic reaction
Post by: Borek on October 23, 2020, 05:29:30 PM: Quote from: xshadow on October 23, 2020, 04:29:17 PM
But here is an organic reaction ..it' s different

It is not - reaction equations clearly show that both reactions go on 1:1 basis.

It is not clear to me what you are expected to calculate though.
Title: Re: Calculate number of equivalent: organic reaction
Post by: xshadow on October 23, 2020, 06:05:51 PM: Quote from: Borek on October 23, 2020, 05:29:30 PM
Quote from: xshadow on October 23, 2020, 04:29:17 PM
But here is an organic reaction ..it' s different

It is not - reaction equations clearly show that both reactions go on 1:1 basis.

It is not clear to me what you are expected to calculate though.

For example some organic chemistry reaction are 1:1 but the moles and the number of equivalent haven't the same value

For example an aldehyde that reacts with a grignard is 1:1 but it's an oxidation reaction according to general chemistry

Oxidation number of the C=O changes ....C goes from -1 (aldehyde) to 0 for the alcohol generated from grignard reaction
Same thing happens to the RMgBr carbon.

Now if I have 0.2 mol of aldehyde...the number of equivalent shouldn't be 0. 2 mol
For an oxidation reaction the number of equivalent is moles/ number electrons traded

For 1 mole of aldehyde I have two moles of electrons
So 0.2/2 = number of equivalent for RCHO in this reaction

Here I don't have an oxidation reaction,or an acid-base reaction or a salt dissolution one

For those type of reactions I have a definition in order to calculate the number of equivalent (acid - number of H+ loss / redox -number of electrons transfered / salt: positive charge when it's dissociated).
Title: Re: Calculate number of equivalent: organic reaction
Post by: Borek on October 24, 2020, 04:07:16 AM: Technically you are right, in practice most organic chemists I have dealt with were not that precise and used term "equivalent" in a bit lousy manner.
Title: Re: Calculate number of equivalent: organic reaction
Post by: xshadow on October 27, 2020, 03:54:38 PM: Quote from: Borek on October 24, 2020, 04:07:16 AM
Technically you are right, in practice most organic chemists I have dealt with were not that precise and used term "equivalent" in a bit lousy manner.

understood!!