Bread Question (2 Viewers)

[kaz1]

Since the conversion from Nitrogen to Ammonia is an equilibrium reaction are you supposed to assume the reaction went to completion?

I did and got something like 1.7%. Are you allowed to do this?

 

[mirror-match]

I think i got 3.6% or something.

I cant remember how though.

 

[Michaelmoo]

Yep. If you look closely at the question it said the nitrogen is converted ammonia.

Unless they gave a yield. In which case I didn't pick up on it.

 

[walesluke]

answer was 1.78% to 2dp 3 sig fig

 

[jhanz12]

answer was 1.78% to 2dp 3 sig fig

yeah.. i reckon i got the same.. but cant remember how ive done it..

 

[Timothy.Siu]

damnit, yeah my friends got 1.78 i got 1.79

 

[shaon0]

damnit, yeah my friends got 1.78 i got 1.79

Oh crap. I got 1.77% or something.

 

[kieranjackson91]

Oh crap. I got 1.77% or something.

yeah i think i got 1.77 too. probably got different answers cuz some people rounded their numbers before the final step. i did all the calculations from the start and used the calculator memory and ended up with 1.77. but i dont think being .01 off will lose you a mark, you showed your knowledge of chemistry to get 1.77-1.79 so i think they will be lenient.

 

[cdiddy7]

Does anyone remember what equations they got

 

[amrit92]

man i had no freaking idea on this question! I left it, returned to it at the end but ran outta time anyway! Did u have to use Haber Process or something?? This question and the molar heat screwed me over :mad1:

 

[mitchwong650]

man i had no freaking idea on this question! I left it, returned to it at the end but ran outta time anyway! Did u have to use Haber Process or something?? This question and the molar heat screwed me over :mad1:

haha no haber process,

its just like finding the % of sulfate in BaSO4 but instead of sulfate its nitrogen and instead of BaSO4 its ammonium

 

[mR sinister]

i had 0.8% .. hmm
Well i used the haber process.. since it said nitrogen is converted into ammonia, and the only sufficient way to do that is by the haber proces..

the ratio was 1:2

hmm i could be wrong either way, 1/2 marks atleast

 

[Gibbatron]

You had to work backwards to find the moles of ammonia present and thus the moles of Nitrogen and use that to determine the mass of N and hence the %w/m. I think i got 1. 78% or something similar

 

[Wyes]

This question completely threw me; we'd never done anything like it in class, and I didn't have any clue how to answer it. I just wrote some smartass answer and left it.

 

[neemaz]

i think i had 1.79 or 1.8 :S

 

[chuboy]

i had 0.8% .. hmm
Well i used the haber process.. since it said nitrogen is converted into ammonia, and the only sufficient way to do that is by the haber proces..

the ratio was 1:2

hmm i could be wrong either way, 1/2 marks atleast

Haber process had nothing to do with it, they said the nitrogen was converted to ammonia. That was for your information. It doesn't matter HOW they did it, what matters is that you assume 100% of the nitrogen was in ammonia because that's what they told you.

Don't try and be smart about how they did it because Year 12 chemistry is nothing compared to how it really works =(

 

[kblager]

i tried this question and failed... i ended up with 13% or something. ah well, the rest of the test seemed alright

 

[mR sinister]

Lol, i proceeded based on our syllabus.
because our syllabus taught us the most suitable way to convert nitrogen into ammonia is by adding hydrogen... which is the haber process
And because there was no quesiton on the haber process, i thought u had t use it...

ohh well.... guess im wrong compared to all your answer.
Did you guys use 1:1 RATIO?

 

[Gibbatron]

You didn't have to convert anything to ammonia though. You just had to find the moles of ammonia and because there is only one nitrogen atom in a molecule of hydrogen then there will be the same number of moles of nitrogen present as ammonia.