Question
Download Solution PDFC(s) + 2H₂(g) → CH₄(g); ΔH = −74.8 kJ mol⁻¹
Which of the following diagrams gives an accurate representation of the above reaction?
[R → reactants; P → products]
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFCONCEPT:
Enthalpy Change (ΔH) and Energy Diagram
- The enthalpy change (ΔH) of a reaction represents the difference in energy between the products and reactants.
- When ΔH is negative, the reaction is exothermic, meaning energy is released and the products have lower energy than the reactants.
- Energy diagrams for exothermic reactions show the reactants starting at a higher energy level and the products at a lower energy level, with an energy "drop" between them.
EXPLANATION:
- In the given reaction:
C(s) + 2H2(g) → CH4(g); ΔH = -74.8 kJ mol-1
- ΔH is negative, indicating that the reaction is exothermic.
- In an energy diagram for this reaction:
- The reactants (C and H2) start at a higher energy level.
- The products (CH4) are at a lower energy level, showing that energy is released during the reaction.
- The difference in energy between the reactants and products corresponds to the magnitude of ΔH (74.8 kJ mol-1).
Therefore, the correct energy diagram will show the reactants at a higher energy level than the products, with an energy drop of 74.8 kJ mol-1.
Last updated on Jun 16, 2025
-> NTA has released the NEET Scorecard 2025 on the official website.
-> NEET Toppers List 2025 is now available. Candidates can check the names, scores, and all India ranks of the highest scorers.
-> NEET final answer key 2025 has been made available on June 14, 2025 on the official website for the students to check.
->NEET 2025 exam is over on May 4, 2025.
-> The NEET 2025 Question Papers PDF are now available.
-> NTA has changed the NEET UG Exam Pattern of the NEET UG 2025. Now, there will be no Section B in the examination.
-> Candidates preparing for the NEET Exam, can opt for the latest NEET Mock Test 2025.
-> NEET aspirants can check the NEET Previous Year Papers for their efficient preparation. and Check NEET Cut Off here.