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Calculations of reactants based on equations? o_o;

OK, I think I may just be being exceedingly dumb at this moment in time, but I can't for the life of me answer this question:

When nitrogen reacts with hydrogen in the haber process only 17% of the nitrogen is converted to ammonia. What volume of nitrogen and what volume of hydrogen would be needed to produce one tonne of ammonia? (1 tonne - 10 x 10^6g)

OK, so the equation for the haber process is N2 + 3H2 ---> 2NH3

and Mr Ammonia = 34 if that's any help.

Anyway, please help me? Because I think I must have left my brain at college this weekend :C Thank you x
Reply 1
First, you need to calculate the number of moles that would be present in one tonne of ammonia. Then halve that value to find the number of moles of N2.

You know only 17% of nitrogen reacts, so scale up the number of moles you have by dividing it by 0.17.

One mole of gas occupies 24 dm3, so you can work out the volume of N2 from there.

That's a rough outline of what you have to do for nitrogen, hope it helps :smile:
Reply 2
Hmm, ok thank you very much, but why would you half it to find the number of moles of N2? I found the answers for this question on the internet, but I would really like to understand how to work it out x3 Sorry for being so useless XD

btw, if it's of any help, the answers are supposedly 4.15 x 10^6 dm3 nitrogen, and 12.5 x 10^6 dm3 hydrogen
moles of ammonia required = 1,000,000g/34 = 29,411 moles
so 29,411 moles of N2 are needed to form ammonia at 100% success - 172917 moles at 17% success
this means you need 518750 (3 x 172917) moles of H2
so the volume is 518750 x 24 = 1.245 x 106 dm3 of H2
and a third of that value for nitrogen :smile:

edit: don't half the number of moles of N2 because ammonia only has one nitrogen in it whilst molecular nitrogen has two - so the equation is balanced in terms of atoms of nitrogen
Reply 4
OK, thank you so much <3 that has helped a lot! It was just the whole 17% bit which confused me, but you explained it very well ^^ Thanks again!
Original post by Sockpirate
OK, I think I may just be being exceedingly dumb at this moment in time, but I can't for the life of me answer this question:

When nitrogen reacts with hydrogen in the haber process only 17% of the nitrogen is converted to ammonia. What volume of nitrogen and what volume of hydrogen would be needed to produce one tonne of ammonia? (1 tonne - 10 x 10^6g)

OK, so the equation for the haber process is N2 + 3H2 ---> 2NH3

and Mr Ammonia = 34 if that's any help.

Anyway, please help me? Because I think I must have left my brain at college this weekend :C Thank you x


Original post by Sockpirate
OK, thank you so much <3 that has helped a lot! It was just the whole 17% bit which confused me, but you explained it very well ^^ Thanks again!

The Mr of ammonia is not 34,its 17
Original post by Nusaiba Sayed
The Mr of ammonia is not 34,its 17

12-year-old thread, but yes, you are correct! :smile:
Reply 7
Original post by Nusaiba Sayed
The Mr of ammonia is not 34,its 17

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Reply 8
Original post by Nusaiba Sayed
The Mr of ammonia is not 34,its 17


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