Difficulty: Easy
Correct Answer: Cox
Explanation:
Introduction / Context:
Engineers often linearize empirical correlations to ease data plotting and interpolation. The Antoine equation expresses vapor pressure as a function of temperature, typically in the logarithmic form. A specific chart, widely used in older design practice and hand-calculations, presents vapor pressure–temperature data on axes that render the relation near-linear, simplifying estimation and extrapolation.
Given Data / Assumptions:
Concept / Approach:
The Cox chart is a semi-empirical plot that linearizes vapor-pressure data for many substances by choosing appropriate temperature and pressure scales. When Antoine (or similar) relations hold, substances appear approximately as straight lines on Cox charts, enabling quick interpolation between tabulated points without solving equations.
Step-by-Step Solution:
Recognize that Antoine-type correlations are customarily plotted on Cox charts.Match the chart name to the equation usage: “Cox” is the correct association.
Verification / Alternative check:
Process handbooks and classic design texts provide Cox charts for families of compounds along with Antoine constants; these charts were historically used before ubiquitous digital tools.
Why Other Options Are Wrong:
Ostwald: commonly associated with viscosity or dilution laws, not vapor pressure charts.Mollier’s (h–s) chart is for steam/thermodynamics, unrelated to Antoine equation plotting.Enthalpy–concentration: used in humidification or solutions, not specific to Antoine vapor-pressure plotting.
Common Pitfalls:
Confusing different thermodynamic charts; assuming any enthalpy-related chart is tied to vapor-pressure data; overlooking that Antoine is logarithmic in pressure.
Final Answer:
Cox
Discussion & Comments