Which one of the following statements is not true concerning the equation below? N2(g) + 3 H2(g) → 2 NH3(g) AH°rxn= -459.0 kJ > A) The production of 1.00 mole of ammonia is accompanied by the production of 229.5 kJ of heat. B) The complete reaction of 1.00 moles of nitrogen requires 459 kJ of heat. C) The complete reaction of 1.00 moles of hydrogen produces 153 kJ of heat. D) The complete reaction of 0.8278 moles of hydrogen requires 0.2759 moles of nitrogen. E) The reaction is exothermic.
Thermochemistry
Thermochemistry can be considered as a branch of thermodynamics that deals with the connections between warmth, work, and various types of energy, formed because of different synthetic and actual cycles. Thermochemistry describes the energy changes that occur as a result of reactions or chemical changes in a substance.
Exergonic Reaction
The term exergonic is derived from the Greek word in which ‘ergon’ means work and exergonic means ‘work outside’. Exergonic reactions releases work energy. Exergonic reactions are different from exothermic reactions, the one that releases only heat energy during the course of the reaction. So, exothermic reaction is one type of exergonic reaction. Exergonic reaction releases work energy in different forms like heat, light or sound. For example, a glow stick releases light making that an exergonic reaction and not an exothermic reaction since no heat is released. Even endothermic reactions at very high temperature are exergonic.
In this problem 1 mol H2 produces 153kJ of heat, which is 1/3 of the total 459kJ of the reaction. Why does 1 mol N2 not produce 459kJ? Since 3 mol H2 adds up to 459, why doesn't 1 mol N2 as well?
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
