Difficulty: Easy
Correct Answer: none of these
Explanation:
Introduction / Context:
The Othmer chart is a classic graphical correlation used in chemical engineering to estimate latent heats of vaporization from readily available boiling or temperature data when detailed thermophysical tables are unavailable. Recognizing what a named chart estimates helps avoid misapplication in design problems.
Given Data / Assumptions:
Concept / Approach:
Heats of mixing, wetting, and adsorption are interfacial or solution enthalpies requiring different measurements or correlations. The Othmer approach targets vaporization enthalpy (lambda), a bulk phase-change property. Since “latent heat of vaporization” is not among options a–c, the correct choice is “none of these.”
Step-by-Step Solution:
Identify the property tied to Othmer charts: latent heat of vaporization.Compare with listed options: none matches vaporization heat.Therefore, select “none of these.”
Verification / Alternative check:
Handbooks show Othmer-type correlations linking lambda with normal boiling point or reduced temperature, confirming the intended use.
Why Other Options Are Wrong:
Mixing, wetting, and adsorption heats arise from molecular interactions at interfaces or in solutions and are not what Othmer charts predict.
Common Pitfalls:
Confusing any “heat” correlation with solution phenomena; keep phase-change enthalpies distinct from interfacial enthalpies.
Final Answer:
none of these
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