\documentclass[10pt,a4paper]{article} % Packages \usepackage{fancyhdr} % For header and footer \usepackage{multicol} % Allows multicols in tables \usepackage{tabularx} % Intelligent column widths \usepackage{tabulary} % Used in header and footer \usepackage{hhline} % Border under tables \usepackage{graphicx} % For images \usepackage{xcolor} % For hex colours %\usepackage[utf8x]{inputenc} % For unicode character support \usepackage[T1]{fontenc} % Without this we get weird character replacements \usepackage{colortbl} % For coloured tables \usepackage{setspace} % For line height \usepackage{lastpage} % Needed for total page number \usepackage{seqsplit} % Splits long words. %\usepackage{opensans} % Can't make this work so far. Shame. Would be lovely. \usepackage[normalem]{ulem} % For underlining links % Most of the following are not required for the majority % of cheat sheets but are needed for some symbol support. \usepackage{amsmath} % Symbols \usepackage{MnSymbol} % Symbols \usepackage{wasysym} % Symbols %\usepackage[english,german,french,spanish,italian]{babel} % Languages % Document Info \author{michaelysy3} \pdfinfo{ /Title (chemistry-electrolysis.pdf) /Creator (Cheatography) /Author (michaelysy3) /Subject (Chemistry electrolysis Cheat Sheet) } % Lengths and widths \addtolength{\textwidth}{6cm} \addtolength{\textheight}{-1cm} \addtolength{\hoffset}{-3cm} \addtolength{\voffset}{-2cm} \setlength{\tabcolsep}{0.2cm} % Space between columns \setlength{\headsep}{-12pt} % Reduce space between header and content \setlength{\headheight}{85pt} % If less, LaTeX automatically increases it \renewcommand{\footrulewidth}{0pt} % Remove footer line \renewcommand{\headrulewidth}{0pt} % Remove header line \renewcommand{\seqinsert}{\ifmmode\allowbreak\else\-\fi} % Hyphens in seqsplit % This two commands together give roughly % the right line height in the tables \renewcommand{\arraystretch}{1.3} \onehalfspacing % Commands \newcommand{\SetRowColor}[1]{\noalign{\gdef\RowColorName{#1}}\rowcolor{\RowColorName}} % Shortcut for row colour \newcommand{\mymulticolumn}[3]{\multicolumn{#1}{>{\columncolor{\RowColorName}}#2}{#3}} % For coloured multi-cols \newcolumntype{x}[1]{>{\raggedright}p{#1}} % New column types for ragged-right paragraph columns \newcommand{\tn}{\tabularnewline} % Required as custom column type in use % Font and Colours \definecolor{HeadBackground}{HTML}{333333} \definecolor{FootBackground}{HTML}{666666} \definecolor{TextColor}{HTML}{333333} \definecolor{DarkBackground}{HTML}{4110A3} \definecolor{LightBackground}{HTML}{F3F0F9} \renewcommand{\familydefault}{\sfdefault} \color{TextColor} % Header and Footer \pagestyle{fancy} \fancyhead{} % Set header to blank \fancyfoot{} % Set footer to blank \fancyhead[L]{ \noindent \begin{multicols}{3} \begin{tabulary}{5.8cm}{C} \SetRowColor{DarkBackground} \vspace{-7pt} {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}} } \end{tabulary} \columnbreak \begin{tabulary}{11cm}{L} \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{Chemistry electrolysis Cheat Sheet}}}} \\ \normalsize{by \textcolor{DarkBackground}{michaelysy3} via \textcolor{DarkBackground}{\uline{cheatography.com/82864/cs/19677/}}} \end{tabulary} \end{multicols}} \fancyfoot[L]{ \footnotesize \noindent \begin{multicols}{3} \begin{tabulary}{5.8cm}{LL} \SetRowColor{FootBackground} \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}} \\ \vspace{-2pt}michaelysy3 \\ \uline{cheatography.com/michaelysy3} \\ \end{tabulary} \vfill \columnbreak \begin{tabulary}{5.8cm}{L} \SetRowColor{FootBackground} \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}} \\ \vspace{-2pt}Published 22nd May, 2019.\\ Updated 22nd May, 2019.\\ Page {\thepage} of \pageref{LastPage}. \end{tabulary} \vfill \columnbreak \begin{tabulary}{5.8cm}{L} \SetRowColor{FootBackground} \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}} \\ \SetRowColor{white} \vspace{-5pt} %\includegraphics[width=48px,height=48px]{dave.jpeg} Measure your website readability!\\ www.readability-score.com \end{tabulary} \end{multicols}} \begin{document} \raggedright \raggedcolumns % Set font size to small. Switch to any value % from this page to resize cheat sheet text: % www.emerson.emory.edu/services/latex/latex_169.html \footnotesize % Small font. \begin{multicols*}{3} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{What is electrolysis}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Electrolysis is the process of using electricity to break down or decompose a compound (usually an ionic compound in the molten state or aqueous solution). It takes place in an electrolytic cell.} \tn % Row Count 4 (+ 4) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{How does electrolysis work?}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{In the external circuit: Electrons flow from the positive terminal to the negative terminal} \tn % Row Count 2 (+ 2) % Row 1 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{within the electrolyte: The flow of Ions flow towards the electrodes constitutes the flow of electric current through the electrolyte} \tn % Row Count 5 (+ 3) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{Anode: During electrolysis, Anions move to the Anode and are discharged at the anode by losing electrons; oxidation occurs} \tn % Row Count 8 (+ 3) % Row 3 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{cathode: During electrolysis, cations move to the cathode and are discharged at the cathode by gaining electrons; reduction occurs} \tn % Row Count 11 (+ 3) \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Aqueous solutions of ionic compounds}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{In aqueous solutions of ionic compounds, the ionic compounds ionised to form cations \& anions together with hydrogen ions (H+) and hydroxide ions (OH-) from water. Thus, there are more than one type of cation or anion are present in the electrolyte.} \tn % Row Count 5 (+ 5) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Aqueous solutions of ionic compounds}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{In aqueous solutions of ionic compounds, the ionic compounds ionised to form cations \& anions together with hydrogen ions (H+) and hydroxide ions (OH-) from water. Thus, there are more than one type of cation or anion are present in the electrolyte.} \tn % Row Count 5 (+ 5) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Electrolysis of concentrated solutions}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Example: Concentrated NaCl solution} \tn % Row Count 1 (+ 1) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{At the anode, (1) OH– and Cl– ions are attracted to the anode. (2) Being concentrated, Cl– ions are preferentially discharged as chlorine gas. (3) OH– ions remain in solution.} \tn % Row Count 5 (+ 4) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{At the cathode, (1) H+ and Na+ ions are attracted to the cathode. (2) H+ ions are preferentially discharged as hydrogen gas. (3) Na+ ions remain in solution.} \tn % Row Count 12 (+ 7) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{Observations: Effervescence of chlorine gas is seen at the anode. Chlorine gas can be collected. Effervescence of hydrogen gas is seen at the cathode. Hydrogen gas can be collected. The ratio of volumes of chlorine to hydrogen is 1:1. The electrolyte becomes alkaline as NaOH is left behind, pH increases.} \tn % Row Count 19 (+ 7) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Equal volumes of hydrogen gas and chlorine gas are produced. The resulting solution becomes alkaline because the remaining Na+ and OH– ions recombine to form sodium hydroxide.} \tn % Row Count 23 (+ 4) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Types of simple cells}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Galvanic or voltaic cells} \tn % Row Count 1 (+ 1) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{A galvanic cell, or voltaic cell, named after Luigi Galvani, or Alessandro Volta respectively, is an electrochemical cell that derives electrical energy from spontaneous redox reactions taking place within the cell. It generally consists of two different metals connected by a salt bridge, or individual half-cells separated by a porous membrane.} \tn % Row Count 8 (+ 7) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{It is made up of two separate half-cells. A half-cell is composed of an electrode (a strip of metal, M) within a solution containing Mn+ ions in which M is any arbitrary metal. The two half cells are linked together by a wire running from one electrode to the other. A salt bridge also connects to the half cells.} \tn % Row Count 15 (+ 7) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Salt bridge}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{The role of the salt bridge which contains a salt solution (e.g. NaCl / KCl) is to maintain electrical neutrality in the cell and allow the free flow of ions from one cell to another. The solution at the anode side will turn more positively charged when more Zn dissolves to form Zn2+ ions and the solution at the cathode side will turn more negatively charged when more Cu2+ ions form Cu atoms. The ions from the salt bridge will move to the respective solutions at the anode and cathode to balance the charges. Without the salt bridge, positive and negative charges will build up around the electrodes causing the reaction to stop.} \tn % Row Count 13 (+ 13) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Parts of a electrolytic cell}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{(1) Battery Acts as an electron pump and draws electrons away from the anode. Anode becomes positively charged. Electrons enter the positive terminal of the battery and are 'pumped out' at the negative terminal thus the cathode becomes negatively charged.} \tn % Row Count 6 (+ 6) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{(2) Electrodes Conduct electricity. They are usually carbon (i.e. graphite) rods or metal plates. Anode - Electrode connected to positive terminal and is positively charged. Cathode - Electrode connected to negative terminal and is negatively charged.} \tn % Row Count 12 (+ 6) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{(3) Electrolyte Conducts electricity. It contains free-moving ions which allow electricity to flow through. It is a molten ionic compound or an aqueous solution. The electrolyte will be decomposed to form cations and anions. Examples: dilute H2SO4, molten NaCl, CuSO4 solution.} \tn % Row Count 18 (+ 6) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Electrolysis using inert electrodes}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Inert electrodes such as carbon (graphite) or platinum electrodes are used to prevent reactions from occurring between the products of electrolysis and the electrode.} \tn % Row Count 4 (+ 4) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Example of electrolysis of aqueous solution}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Example: NaCl} \tn % Row Count 1 (+ 1) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{At the anode, (1) OH– and Cl– ions are attracted to the anode. (2) OH– ions are preferentially discharged as water and oxygen gas. (3) Cl– ions remain in solution.} \tn % Row Count 5 (+ 4) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{At the cathode, (1) H+ and Na+ ions are attracted to the cathode. (2) H+ ions are preferentially discharged as hydrogen gas. (3) Na+ ions remain in solution.} \tn % Row Count 9 (+ 4) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{Observations: Effervescence of oxygen gas is seen at the anode. Oxygen gas can be collected. Effervescence of hydrogen gas is seen at the cathode. Hydrogen gas can be collected. The ratio of volumes of oxygen to hydrogen is 1:2. The electrolyte becomes more concentrated sodium chloride solution.} \tn % Row Count 15 (+ 6) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Simple cells}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{A simple cell is a device that converts chemical energy into electrical energy. It is also known as an electric cell. It is made by placing two different metals in contact with an electrolyte. The metals act as electrodes for the simple cell.} \tn % Row Count 5 (+ 5) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{The more reactive metal (higher in electrochemical series) will become the negative terminal. The atom of the reactive metal will lose electron(s) to form positive ions and dissolves into the solution. Oxidation takes place.} \tn % Row Count 10 (+ 5) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{The electrons lost by the more reactive metal are then moved to the other metal plate through the wire. As a result, current is produced (there is a potential difference) and the ammeter /voltmeter deflects.} \tn % Row Count 15 (+ 5) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{The less reactive metal (lower in electrochemical series) will become the positive terminal. At the positive terminal, the positive ions in the solution (electrolyte) will gain electrons (from the negative terminal) and be discharged.} \tn % Row Count 20 (+ 5) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{If the positive ions are less reactive than hydrogen, a metal coating will be formed at the positive terminal.} \tn % Row Count 23 (+ 3) % Row 5 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{If the positive ions are more reactive than hydrogen, effervescence (hydrogen gas) is formed at the positive terminal.} \tn % Row Count 26 (+ 3) % Row 6 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{In a voltaic cell, the negative terminal is the anode while the positive terminal is the cathode.} \tn % Row Count 28 (+ 2) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Simple cell- voltage}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{The further apart the two metals are in the reactivity series, the greater the voltage produced.} \tn % Row Count 2 (+ 2) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Electrolyte- molten or aqueous solution?}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{In the solid state, ions are held in the lattice structure. Thus, they cannot conduct electricity. In the molten state, or in aqueous solution, ions are free to move and can conduct electricity.} \tn % Row Count 4 (+ 4) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Electrolysis of molten compounds}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Example: NaCl} \tn % Row Count 1 (+ 1) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{At the anode: Negatively charged Cl– ions are attracted to the anode. Cl– ions lose electrons to form chlorine gas. Cl– ions are said to be discharged. They are oxidized.} \tn % Row Count 5 (+ 4) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{At the cathode: Positively charged Na+ ions are attracted to the cathode. Each Na+ ion gains one electron to form a sodium atom. Na+ ions are said to be discharged. It is reduced. Observation: Silvery beads of liquid sodium found on the cathode or found at the bottom of the container.} \tn % Row Count 12 (+ 7) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Electrolysis using reactive electrodes}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Electrodes which react with the electrolyte or products of electrolysis are called reactive electrodes. E.g. Copper} \tn % Row Count 3 (+ 3) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{example: Copper (II) sulfate using reactive copper electrodes} \tn % Row Count 5 (+ 2) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{At the anode, (1) OH– and SO42– ions are attracted to the anode. (2) Since copper is a reactive electrode, OH– and SO42– ions, copper electrode dissolves to form Cu2+ ions in the solution. (3) The anode decreases in mass.} \tn % Row Count 11 (+ 6) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{At the cathode, (1) H+ and Cu2+ ions are attracted to the cathode. (2) Cu2+ ions are preferentially discharged as copper metal (atoms). (3) The cathode increases in mass.} \tn % Row Count 16 (+ 5) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Observations: The anode decreases in mass. The cathode increases in mass. The colour and concentration of copper(II) sulfate remain unchanged. This is because the Cu2+ ions that are discharged at the cathode come mainly from the anode.There is no net loss of Cu2+ ions from the solution.} \tn % Row Count 22 (+ 6) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Simple cell example}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Example: Zinc- copper cell} \tn % Row Count 1 (+ 1) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{Zinc electrode: zinc atoms being more reactive give up electrons and go into the solution as zinc ions} \tn % Row Count 4 (+ 3) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{The electrode from which electrons flow out is the negative electrode, thus zinc is the negative electrode} \tn % Row Count 7 (+ 3) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{Zinc electrode becomes smaller} \tn % Row Count 8 (+ 1) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Copper electrode: Cu2+ ions from the electrolyte (CuSo4) take up electrons to form copper metal} \tn % Row Count 10 (+ 2) % Row 5 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{Copper is the positive electrode} \tn % Row Count 11 (+ 1) % Row 6 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Reddish brown copper is formed} \tn % Row Count 12 (+ 1) % Row 7 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{In a simple cell, the flow of electrons is always from the more reactive metal to the less reactive metal. The more reactive metal becomes the negative electrode and the less reactive metal the positive electrode.} \tn % Row Count 17 (+ 5) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} % That's all folks \end{multicols*} \end{document}