1.11 Electrode potentials and electrochemical cells

• A half cell is one half of an electrochemical cell, constructed of a metal dipped into its ions or a platinum electrode with two aqueous ions in.
• The reaction between a metal and its ions is in equilibrium.
• The reaction between Fe2+ and Fe3+ can occur in a half cell, as there is no solid version of Fe3+.
• A full cell is the complete electrochemical cell.
• In the context of electrochemistry, oxidation is represented by a minus sign and reduction is represented by a plus sign.
• The electrode potential of a half cell can be measured against a standard hydrogen electrode, which has an Enoch value of zero.
• Reduction is the gain of electrons, represented by the acronym 'oil-rig'.
• Oxidation is the loss of electrons, represented by the acronym 'oil-rig'.
• Zinc forms Zn2+ and copper forms Cu2+ in the reaction Zn + Cu2+ → Zn2+ + Cu.
• In the electrochemical series, all reactions are shown in the reduced form, meaning there are always plus electrons.
• A positive value in the electrochemical series means the reaction is very likely to go negative, while a negative value means it really isn't going to work.
• In the electrochemical series, agents on the left-hand side of the equation are more easily reduced.
• Oxidation is the loss of electrons, while an oxidizing agent gains electrons.
• The standard hydrogen electrode for copper is represented as Cu2+ + 1/2 O2 → Cu.
• Chlorine, for example, has an increasing tendency to gain electrons and is therefore a more powerful oxidizing agent.
• Chlorine has a positive value in this example, indicating it is a more powerful oxidizing agent.
• The electrochemical series is a table of half cell reactions and their standard electrical potential, calculated by measuring them against the standard hydrogen electrode under standard conditions.
• Reduction is the loss of electrons, while a reducing agent gains electrons.
• Zinc is more likely to give up electrons than copper in an electrochemical cell.
• An electrochemical cell is created by joining two different half cells together with a wire, a voltmeter, and a salt bridge.
• Copper accepts the electrons produced by zinc on the other side, causing reduction to occur.
• Electrochemical cells are used in batteries.
• The electrode on the copper side of the electrochemical cell gets thicker as copper two-plus ions accept the electrons to form copper metal.
• Zinc forms zinc two-plus ions and two electrons as it loses electrons in an electrochemical cell.
• Electrons flow from a more reactive metal to a less reactive one in an electrochemical cell.
• There is always a reduction side and an oxidation site in an electrochemical cell, and the type of reactions produced depend on what the cell is connected with.
• The electrochemical cell consists of two half-cells, one undergoing a reduction process and the other undergoing an oxidation process, creating a redox reaction.
• The electrode on the zinc side of the electrochemical cell gets thinner as zinc converts into ions in solution.
• Copper forms copper metal as it reacts with the electrons produced by zinc.
• The potential difference, measured in volts, is the voltage between two half-cells and is called the EMF or e cell.
• The overall equation for the discharge in a lithium-ion battery is determined by using the equation: produced minus oxidized.
• The most negative half equation in a lithium-ion battery is flipped around to show that electrons are being produced, indicating the negative electrode.
• Lithium-ion batteries are a type of rechargeable battery commonly used in wireless power tools, tablets, mobile phones, and electric cars.
• The electrolyte in a lithium-ion battery is the solution that contains lithium salt dissolved in an organic solvent, acting as the conductor pathway for ions to move from one electrode to the other.
• To identify the negative electrode in a lithium-ion battery, the electrode producing the electrons, or oxidation, is established.
• The positive electrode in a lithium-ion battery is kept the same, and the electrons are balanced and canceled out.
• Batteries are electrochemical cells joined together and come in two main forms: rechargeable and non-rechargeable.
• Rechargeable batteries are reversible and can last longer, making them cheaper in the long run.
• The overall reaction in a lithium-ion battery is determined by the half equations at each electrode.
• Rechargeable batteries work by simply plugging them in to supply a current, a flow of electrons.