Given #N_2(g) +3H_2(g) rarr 2NH_3(g)+92*kJ#...what energy is associated with the formation of #A.# #"4 moles of ammonia"#; and #B.# #"4 g ammonia is produced"#?

1 Answer
Oct 11, 2016

Answer:

#N_2(g) + 3H_2(g) rarr 2NH_3(g) + Delta#

#A.# #=# #-368*kJ;# #B.# #=# #-10.8*kJ#

Explanation:

The given thermodynamic paramters are always quoted per mol of reaction as written. Thus if the one mole of dinitrogen reacts, #-92*kJ*mol^-1# (of given reaction) are evolved. If 4 moles, then #-368*kJ#

If #4*g# ammonia are produced, this is a molar quantity of #(4.00*g)/(17.03*g*mol^-1)# #=# #0.235*mol#.

Given that #-46*kJ# are produced per mole of ammonia, this gives a quantity of #-46*kJ*mol^-1xx0.235*mol# #=# #-10.8*kJ#.

Why is this an important reaction?