CBSE · Class 11 · Chemistry · Chemical ThermodynamicsBy convention, the standard enthalpy of formation ($\Deltaf H^\circ$) of an element in its reference (standard) state is taken as:
Step-by-Step Solution
By standard thermodynamic conventions, the standard enthalpy of formation of an element in its most stable physical state (reference state) at 298.15 K and 1 bar pressure is defined as zero.
Detailed Options Breakdown
Option : Zero (Correct Answer)
Correct choice. Refer to the step-by-step verified solution guidelines above for details.
Option 1: 1 kJ mol⁻¹
Incorrect choice. This distractor represents a common misunderstanding of the core principles of Chemical Thermodynamics.
Option 2: Positive value
Incorrect choice. This distractor represents a common misunderstanding of the core principles of Chemical Thermodynamics.
Option 3: Negative value
Incorrect choice. This distractor represents a common misunderstanding of the core principles of Chemical Thermodynamics.
💡 Study Guide: This question tests core syllabus concepts from Chemical Thermodynamics. For formulas, key summaries, and mock exam reference guides, read the full Chemical Thermodynamics Revision Notes.