Thermodynamic Properties – Definition Check for Extensive Properties An extensive property of a system is one whose value for the whole system equals the sum of its values for all non-overlapping parts (e.g., mass, volume, total internal energy). Is this definition correct?

Introduction / Context:
Classifying properties as intensive or extensive is fundamental to formulating balances and scaling processes. The question asks whether the additivity definition correctly captures the essence of extensive properties.

Given Data / Assumptions:

• System can be subdivided into non-overlapping parts.
• Properties considered include mass, volume, total energy, and entropy (with care for interactions at interfaces).
• No chemical reaction across the imagined partitions changing totals.

Concept / Approach:

An extensive property scales with system size and is additive over disjoint subsystems: X_total = Σ X_i. Examples: mass, volume, total internal energy, total enthalpy. In contrast, intensive properties (pressure, temperature, density) are not additive; they do not scale simply with size and are defined locally or as ratios of extensive properties (e.g., specific volume v = V/m).

Step-by-Step Solution:

Verification / Alternative check:

Dimensional analysis: properties proportional to amount of substance (moles, mass) are typically extensive. Taking specific or molar forms (dividing by an extensive amount) yields intensive counterparts.

Why Other Options Are Wrong:

Homogeneity is not required; additivity holds as long as subsystems are disjoint. Saying properties “never add” contradicts conservation laws. Temperature constraints are irrelevant to extensivity.

Common Pitfalls:

Confusing entropy’s subtlety; despite path dependence, total entropy is extensive for non-interacting aggregates. Also, mixing up “sum” vs. “average” when combining subsystems.

Final Answer:

Yes