Which statement is correct in regard to the thermodynamics of ammonia synthesis...? #N_2(g) + 3H_2(g ) rarr 2NH_3(g)+91.8*kJ#

#"A. one equiv dinitrogen reacts with three of dihydrogen."#
#"B. ammonia synthesis is exothermic."#
#"C. ammonia synthesis is endothermic."#
#"D. forward and reverse reactions have different reaction profiles."#

1 Answer
May 1, 2017

Answer:

#"Option B............."#

Explanation:

#"B"# is the only viable option. The quoted thermodynamic data show that the formation of ammonia is thermodynamically downhill, so #C# and #D# are contraindicated. Option #D# is simply wrong; forward and reverse reactions necessarily have the same energy profile. #A# merely relates to stoichiometry, and clearly the reaction could proceed in the presence of higher concentrations of dinitrogen. That the reaction is sluggish must be attributed to an exceptionally high activation energy.