{ "cells": [ { "cell_type": "markdown", "metadata": { "deletable": false, "editable": false, "nbgrader": { "checksum": "d5862fa652218ed20e203b3e49616312", "grade": false, "grade_id": "cell-eb91677c04f5685a", "locked": true, "schema_version": 1, "solution": false } }, "source": [ "# Overview\n", "This exercise uses the Jupyter and Python you have learned in the tutorials, to manipulate, plot, and then analyse some experimental data. You will be given data for the **vapour pressure** of CO2. This is the pressure of a gas when it is in equilibrium with a condensed phase (solid or liquid). The vapour pressure approximately varies with temperature according to the Clausius-Clapeyron equation. \n", "\n", "If you have not yet seen the derivation of this equation, it is not essential for this exercise, but is included [below](#clausius_clapeyron_derivation) if you are interested. \n", "\n", "Integrating the Clausius-Clapeyron equation gives a **linear** relationship between $\\ln p$ and $1/T$, which means for a given phase equilibrium (i.e. solid—gas or liquid—gas) a plot of $\\ln p$ against $1/T$ gives (approximately) a straight line. Furthermore, as explained below, the **slope** of this line is proportional to the **phase transition enthalpy** for these two phases.\n", "\n", "This means that experimental **vapour pressure** data can used to fit a straight line (linear regression) according to the Clausius-Clapeyron equation. This fitting allows you to describe the range of temperatures and pressures where either solid and gas, or solid and liquid, or all three phases, are in equilibrium, and to calculate various enthalpy changes for phase transitions." ] }, { "cell_type": "markdown", "metadata": { "deletable": false, "editable": false, "nbgrader": { "checksum": "f39912a7f5f6ca5c9e4d4f9d56924350", "grade": false, "grade_id": "cell-52b04944a15bdf71", "locked": true, "schema_version": 1, "solution": false } }, "source": [ "