For a reaction 2 NH3 ➞ N2,+ 3H2, which of the following statements is correct.
Correct answer: C. ∆H = ∆E
- A. ∆H = 0
- B. ∆H > ∆E
- C. ∆H = ∆E
- D. ∆H < ∆E
Explanation
For the reaction 2 NH3 ➞ N2 + 3 H2, the correct statement is that ∆H = ∆E. This is because, in many reactions at constant pressure, the change in enthalpy (∆H) and the change in internal energy (∆E) can be equal, particularly when there is no significant pressure-volume work involved. In this decomposition reaction, the work done on or by the system is minimal, leading to ∆H equaling ∆E. Other options are incorrect because they either misrepresent the relationship between ∆H and ∆E or wrongly assume ∆H as zero, which is not characteristic of an exothermic reaction.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Thermochemistry and Energetics of Chemical Reactions
Thermochemistry measures energy changes in chemical reactions and distinguishes exothermic from endothermic processes. Work covers systems, surroundings and state functions, internal energy, the first law of thermodynamics, enthalpy and Hess's law, including the sign conventions used when heat enters or leaves a system.
Practise Thermochemistry and Energetics of Chemical Reactions
728 free Thermochemistry and Energetics of Chemical Reactions MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Chemistry questions like this
Chemistry is on 14 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Thermochemistry and Energetics of Chemical Reactions questions
Internal energy does not include:
Combustion of graphite to form CO2 can be done in two ways. Reactions are given as follows:
'∆H' Will be given a negative sign in:
∆H,-572kJ/mol-1 for water It means that:
For which of the following reactions the change in enthalpies is equal to the change in internal energy:
Change in enthalpy is defined as: