Property estimation tools: The Othmer chart is primarily used for estimating which thermal property from boiling/temperature data?

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:

• Othmer charts relate temperature/boiling data to approximate latent heats.
• The options listed focus on surface/solution phenomena (mixing, wetting, adsorption), which are different categories of enthalpy change.

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