Question

Pls help means is 3 rd but what's the description ​

Answer 1

Answer:

N2 + 3 H2 -> 2 NH3

x is what reamains of H2 after this reaction has occured

and at the beginning we know there was one mole of H2 present

so for the reaction you need 3 units of H2 and 2 units of NH3

let's write this out n(NH3)/n(H2) = 3/2  

in our case some H2 was used for the reaction and some was left over afterwards so: n(H2)= n(H2 starting) - X that is how much it was used in the reaction. Lets move this to the reaction above

n(NH3)/n/H2)=3/2=n(NH3)/(n(H2 starting)- X) you do some scrambling of this eqation to get: n(NH3)= 2 (n(H2 starting)-X)/3  and n(H2 starting) we know is one mole so: n(NH3) = 2(1-x)/3