// Numbas version: finer_feedback_settings {"name": "Chemical Thermodynamics: Non-Standard Chemical Potential 1", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Chemical Thermodynamics: Non-Standard Chemical Potential 1", "tags": [], "metadata": {"description": "
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", "licence": "Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International"}, "statement": "", "advice": "The chemical potential of a substance in a mixture, $\\mathrm{\\mu_x}$, is given by the following equation:
\n$\\mathrm{\\mu_x={\\mu_x}^\\circ + RTln(a_x)}$ ,
\nwhere $\\mathrm{{\\mu_x}^\\circ}$ is the standard chemical potential of the substance, in $\\mathrm{J \\space mol^{-1}}$; $\\mathrm{R=8.314\\space J \\space K^{-1}\\space mol^{-1}}$ is the universal gas constant; $\\mathrm{T}$ is the temperature of the system, in $\\mathrm{K}$; and $\\mathrm{a_x}$ is the activity (effective concentration) of the substance, which is unitless.
\n\n\nWe are asked to calculate $\\mathrm{\\mu_{_{SO_3}}}$ when the activity of sulfur trioxide is $\\mathrm{a_{_{SO_3}}=\\var{a}}$.
\nWe are given the standard chemical potential of sulfur trioxide, $\\mathrm{{\\mu_{_{SO_3}}}^\\circ =\\var{gso3} \\space kJ \\space mol^{-1}}$, which we convert by multiplying by one thousand, to $\\mathrm{{\\mu_{_{SO_3}}}^\\circ =\\var{realg} \\space J \\space mol^{-1}}$ .
\n\nNow, we can simply substitute our values into the original equation to calculate $\\mathrm{\\mu_{_{SO_3}}}$:
\n$\\mathrm{\\mu_{_{SO_3}}={\\mu_{_{SO_3}}}^\\circ + RTln(a_{_{SO_3}})}$
\n\n$\\mathrm{\\Rightarrow\\space\\space\\space \\mu_{_{SO_3}}=\\var{realg} + [8.341\\times 298\\times ln(\\var{a})]=\\var{sigformat(pot,5)}\\space J\\space mol^{-1}}$ .
\n\nTo quote our answer in the units asked for, we divide by one thousand to obtain:
\n$\\mathrm{\\mu_{_{SO_3}}=\\var{sigformat(p,5)}\\space kJ\\space mol^{-1}}$ .
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\nWhat is the chemical potential of the sulfur trioxide when its activity is $\\mathrm{\\var{a}}$?
\n[[0]] $\\mathrm{kJ\\space mol^{-1}}$
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