Electrochemical series

Main article: The data values of E°) are given in the table below, in • A temperature of 298.15K (25.00°C; 77.00°F). • An • A • An • Although many of the half cells are written for multiple-electron transfers, the tabulated potentials are for a single-electron transfer. All of the reactions should be divided by the stoichiometric coefficient for the electron to get the corresponding corrected reaction equation. For example, the equation Fe 2+ + 2 e − ⇌ Fe( s) (–0.44 V) means that it requires 2 × 0.44 eV = 0.88 s) from one Fe 2+ ion and two electrons, or 0.44 eV per electron, which is 0.44 J/C of electrons, which is 0.44 V. • After dividing by the number of electrons, the standard potential E° is related to the ΔG f° by: E = ∑ Δ G left − ∑ Δ G right F where F is the 2+ + 2 e − ⇌ Fe( s) (–0.44 V), the Gibbs energy required to create one neutral atom of Fe( s) from one Fe 2+ ion and two electrons is 2 × 0.44 eV = 0.88 eV, or 84 895 J/mol of electrons, which is just the Gibbs energy of formation of an Fe 2+ ion, since the energies of formation of e − and Fe( s) are both zero. The • Note that the table may lack consistency due to data from different sources. For example: Cu + + e − ⇌ Cu( s) ( E 1 = +0.520 V) Cu 2+ + 2 e − ⇌ Cu( s) ( E 2 = +0.337 V) Cu 2+ + e − ⇌ Cu + ( E 3 = +0.159 V) Calculating the potential using E 3 = 2 E 2 – E 1) gives the potential for E 3 as 0.154 V, not the experimental value of 0.159 V. Table of standard electrode potentials [ ] Legend: ( s) – solid; ...

Index • • • • • • • • • • • What is Electrochemical Series? The electrochemical series is also called the “ activity series”. It is a method of arranging elements in order of increasing reactivity. The ordering uses a value called “ electrode potential value”. What is Standard Electrode Potential Value? Electrode potential value is calculated as follows. An electrode consisting of metal (or non-metal) and its ion is connected to the Standard Hydrogen Electrode (SHE). SHE consists of H 2 and H + ions. Depending on what metal and ions are used, a characteristic value of voltage is observed across the electrodes, in standard conditions. This is called the “ standard electrode potential value” for the given metal/ion combination. What Does the Electrochemical Series Tell Us? The electrochemical series tells us how electropositive or electronegative the element/ion combination is, compared to Standard Hydrogen Electrode. This combination is also called a half-cell. A more electropositive metal loses electrons more easily than hydrogen does in the SHE. On the other hand, a more electronegative element gains electrons more easily. In general, a more electronegative element takes electrons from a more electropositive one. The electrochemical series thus can be said to be a measure of electronegative nature. Features of Electrochemical Series ( Above is a sample of common elements in the Electrochemical Series. Here are some important features of it: • Hydrogen (the Standard Hydrog...

\( \newcommand\) No headers • P1: Standard Reduction Potentials by Element • P2: Standard Reduction Potentials by Value • P3: Activity Series of Metals The reactivity series is a series of metals, in order of reactivity from highest to lowest. It is used to determine the products of single displacement reactions, whereby metal A will replace another metal B in a solution if A is higher in the series. Activity series of some of the more common metals, listed in descending order of reactivity. • P4: Polarographic Half-Wave Potentials

The electrochemical series When metals form ions, they give away one or more electrons. Some metals, such as lithium or sodium, lose their electrons very easily. Other metals, for example silver or gold do not give away electrons easily. The electrochemical series is a list of metals arranged in order of how easily the metal atoms lose electrons. Electricity from pairs of metals When metals give away their electrons, they do so with a certain force. This force is measured in volts. When two different metals are connected together in a cell, the metal with the higher force pushes its electrons on to the other metal. The image below shows a cell that is made from magnesium and copper in a beaker of ammonium chloride solution. • The two metals produce an electric current. • Magnesium is higher up the electrochemical series than copper • The magnesium can push away its electrons more strongly than copper. • Electrons flow along the wires and through the voltmeter from the magnesium to the copper. • The voltmeter measures the force that pushes the electrons through the wires. If you replaced the magnesium in this cell with other metals you would obtain different voltage readings. By arranging the metals in order of their voltage readings, you can build up the electrochemical series. Investigating zinc copper and iron copper electrical cells The further apart the metals are in the electrochemical series, the higher the voltage. Electrons flow along the wire from the metal higher...

Table of Contents • • • • • • • • Electrochemical series | What do you need to know? Created by comparing different electrode potentials to conventional hydrogen electrodes, the electrochemical series helps in the arrangement of components. It defines the sequence of rising potential values of the electrodes for the organize according to their reduction potentials’ magnitude. Electrochemical series applications There are many applications of electrochemical series, such as – Reduction and oxidation strengths • The electrochemical series helps identify different materials that are good reducing and oxidation agents. • All substances that appear on top of the electrochemical series act as good reduction agents. • All such substances that appear at the bottom of the electrochemical series act as good oxidation agents. Displacement reaction • A substance or metal higher in the electrochemical series will evict a material from its lower-in-the-series solution. • As a matter of fact, a higher metal in the series tends to supply electrons to the metal’s cations. • The substance with a lower Prediction of metals’ ability to liberate hydrogen gas from acid • All metals with negative electrode potential (-E) have an increased tendency to lose electrodes compared to Hydrogen. • Hence, when such a substance is placed in an acid solution, it gets oxidized, and an effective reduction of H+ ions occurs to form hydrogen gas. • Therefore, substances having -E values have the potential to f...

The electrochemical series, also known as the activity series, is a list of metals listed in order of decreasing reactivity or in order of decreasing ease of oxidation. The metals at the top of the series, such as the alkali metals and the alkaline earth metals, are more reactive or are most easily oxidized than the metals found at the bottom of the series. This basically means that they can react more easily to form compounds. These metals at the top of the activity series are called active metals. Only metals above hydrogen in the electrochemical series are able to react with acids to form hydrogen. For example, elements like magnesium, zinc, and nickel react with hydrochloric acid to form hydrogen according to the following reactions: Zn (s) + 2 HCl (aq) → ZnCl 2 (aq) + H 2 (g) Mg (s) + 2 HCl (aq) → MgCl 2 (aq) + H 2 (g) Ni (s) + 2 HCl (aq) → NiCl 2 (aq) + H 2 (g) Some questions on electrolysis, or the splitting of a substance by passing electricity through an aqueous solution of it, can also be explained from the electrochemical series. What happens when an aqueous solutions of certain metal salts are electrolyzed? Before going into electrolysis, let's first define and get to know what it means. Ionic substances in solution break down into elements during electrolysis. Different elements are released depending on the particular ionic substance. At the negative electrode (cathode), positively charged ions gain electrons. This is known as reduction, and you say tha...