Fundamentals M. 19

Moderators: Chem_Mod, Chem_Admin

Jeffrey Doeve 2I
Posts: 96
Joined: Wed Sep 30, 2020 9:51 pm

Fundamentals M. 19

Postby Jeffrey Doeve 2I » Mon Oct 05, 2020 5:14 pm

A stimulant in coffee and tea is caffeine, a substance of molar mass 194 g? When 0.376 g of caffeine was burned, 0.682 g of carbon dioxide, 0.174 g of water, and 0.110 g of nitrogen
were formed. Determine the empirical and molecular formulas of caffeine, and write the equation for its combustion.

So for this problem, I ended up solving it correctly. But I was wondering where the question mentions nitrogen, does it mean N or N2? I know nitrogen naturally exists as N2(nitrogen gas), but I wanted to make sure as it did not specify nitrogen gas. So if you solve by treating nitrogen as N or N2, you get the same number of mol N. Im starting to lean toward treating it as N2 as I finish writing out this question(0.110g * (1 mol/28.02g) * (2 mol N/1 mol N2))

KatarinaReid_3H
Posts: 176
Joined: Wed Sep 30, 2020 9:41 pm
Been upvoted: 4 times

Re: Fundamentals M. 19

Postby KatarinaReid_3H » Mon Oct 05, 2020 5:20 pm

Yes, I assumed Nitrogen to be N2 gas as a product because Nitrogen is a diatomic element, meaning in nature it will always exist as N2.

Melody Haratian 2J
Posts: 108
Joined: Wed Sep 30, 2020 9:48 pm
Been upvoted: 1 time

Re: Fundamentals M. 19

Postby Melody Haratian 2J » Mon Oct 05, 2020 5:24 pm

^^ I also used N2 gas while doing my calculations. N2 is likely the product since it is diatomic and the form typically found in nature.

Natallie K 3B
Posts: 61
Joined: Wed Sep 30, 2020 9:51 pm

Re: Fundamentals M. 19

Postby Natallie K 3B » Mon Oct 05, 2020 5:29 pm

I used nitrogen as N2 because nitrogen gas is found in nature in its diatomic form.

Crystal Pan 2G
Posts: 107
Joined: Wed Sep 30, 2020 10:04 pm
Been upvoted: 2 times

Re: Fundamentals M. 19

Postby Crystal Pan 2G » Mon Oct 05, 2020 5:31 pm

Nitrogen gas is a diatomic element, along with 6 other elements that are classified as Halogens.

Brian Bui 3H
Posts: 91
Joined: Wed Sep 30, 2020 9:42 pm

Re: Fundamentals M. 19

Postby Brian Bui 3H » Tue Oct 06, 2020 11:04 am

Not completely relevant to this problem, but a way I learned in the past to remember the 7 diatomic elements is the phrase "high on ficklebur", which corresponds to the elements H, I, O, N, F, Cl, Br (if you read it out in that order, it kind of sounds like it)!

Sofia Lombardo 2C
Posts: 85
Joined: Wed Sep 30, 2020 9:31 pm

Re: Fundamentals M. 19

Postby Sofia Lombardo 2C » Thu Oct 08, 2020 9:57 pm

Brian Bui 2A wrote:Not completely relevant to this problem, but a way I learned in the past to remember the 7 diatomic elements is the phrase "high on ficklebur", which corresponds to the elements H, I, O, N, F, Cl, Br (if you read it out in that order, it kind of sounds like it)!



I have also heard of BrINClHOF (sounds like "brinklehoff") - Br, I, N, Cl, H, O, F


Return to “Empirical & Molecular Formulas”

Who is online

Users browsing this forum: No registered users and 1 guest