Question

10 moles of N2 and 15 moles of H2 were allowed to react over a suitable catalyst. 10 moles of NH3 were formed. The remaining moles of N2 and H2 respectively are:
(a) 5 moles, 0 mole
(b) 0 mole,5 moles
(c)9 moles, 12 moles
(d)0 mole, 0 mole

(a) is the correct answer but how??

Answer 1

N2 +3H2 gives 2NH3
divide by stoichiometry coefficient
then
10/1=10 mol of N2
15/3=5 mol of H2
therefore (a) is correct option

Answer 2

10 MOL (N2) +15 MOL(H2)

15 MOL OF H2=5 MOL OF H3

10 MOLE OF N

5MOL H3+ 10 MOL N

5 MOL OF N IS REQUIRED TO COMPLETE TOTAL HYDROGEN (10-5 =5 MOL OF N2 IS LEFT)

SO,5MOL OF N2,0 MOLE OF H2 ARE LEFT