Page 1 of 1

Midterm Q3

Posted: Wed Jun 13, 2018 4:50 pm
by Natalie_Martinez_1I
For this question how are we supposed to know that oxygen isn't in the empirical formula of nicotine?

Re: Midterm Q3

Posted: Wed Jun 13, 2018 10:47 pm
by Jared Pagal 1J
This problem is a combustion problem so we know that one of the reactants is O2, and given the products of CO2, H2O, and N, we know that the oxygen in the products comes from O2. This would mean that C,H, and N make up nicotine. Also I believe during that midterm he told us it was CHN

Re: Midterm Q3

Posted: Thu Jun 14, 2018 1:53 am
by Natalie_Martinez_1I
But in other problems there have been compounds that included oxygen in the empirical formula so how can we assume that O2 is the only thing that contributes to all the oxygen?

Re: Midterm Q3

Posted: Thu Jun 14, 2018 4:23 pm
by Chem_Mod
You can add up the mass of C, H, N which you can determine to see if this adds up to the mass of the sample that was combusted. You will find that it is approximately equal to (within experimental uncertainty) to the mass of burnt sample. So, there is no mass contribution by the oxygen.