{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# 3.3 – Phase equilibriums" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## 3.3.0 – Learning objectives\n", "\n", "By the end of this notebook, you should be able to:\n", "\n", "1. Conceptually understand Solid-Liquid, Solid-Vapour and Liquid-Liquid Equilibrium.\n", "2. Identify which equilibrium is present in different processes.\n", "3. Utilize densities and fractional compositions of liquid-liquid mixtures to determine masses before and after separation.\n", "4. Understand the difference between the physical and chemical equilibrium cases for the 3 equilibrium cases.\n", "\n", "\n", "---" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## 3.3.1 – Introduction\n", "\n", "In this section, we will be exploring **phase equilibriums**, **chemical and physical properties** and **temperatures and pressures** that allow the equilibrium to exist in chemical processes (e.g. boiling points, sublimation points). We will also be learning about chemical and physical properties of substances. We will also be factoring in the phase equilibriums in our balances for separation, such as in a distillation column.\n", "\n", "---" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## 3.3.2 – Solid-Liquid Equilibrium (melting and freezing)\n", "\n", "Solid-Liquid Equilibrium, as a **physical** property of a substance, is the temperature and pressure at which a solid and a liquid can co-exist. This is usually the **melting or freezing points** of a substance. \n", "\n", "At this stage, even when the heating is continued, the temperature does not change until the whole of solid is converted into liquid. The state when solid and liquid phases of a substance coexist is called **solid-liquid equilibrium**. \n", "\n", "Since a solid is very hard to transport over a process, we usually melt it into liquid form and collect it as a precipitant at the end of the process.\n", "\n", "---" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## 3.3.3 – Solid-Liquid Equilibrium (solubility)\n", "\n", "Solid-Liquid Equilibrium, as a **chemical** property of a solid substance, is the **solubility** of the solid substance. Solubility refers to the ability of a given solute to dissolve in a solvent.\n", "\n", "It is measured in terms of the maximum amount of solute dissolved in a solvent at equilibrium. The resulting solution is called a **saturated solution**. Under various conditions, the equilibrium solubility can be exceeded to give a so-called **supersaturated solution**.\n", "\n", "### Case of Two Substances\n", "\n", "![Figure 1](../figures/Module-3/Eutectic_phase_diagram_Tie_Line.png)\n", "
Figure 1.
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