电化学专业英语原电池.ppt

primary battery,庄宗霖,background,The fact that chemical action can produce a direct current of electricity was discovered in 1785.The simplest chemical cell consists of a strip of copper and a strip of zinc immersed in a solution of sulfuric acid.,The chemical action of the acid on the zinc causes the flow of electrical charges.The current produced is the result of chemical energy being changed to electrical energy.When the copper and the zinc plate are connected with a wire,the electrons flow to the copper.,The zinc is the negative plate.The copper is positive with respect to the zinc.This is because the copper has a lower electric potential than zinc.,In the change from zinc two electrons are given off.The zinc ions surround the zinc plate,and the electrons collect on the copper plate or flow through the external circuit.ZnZn2+2e-,Hydrogen ions are also present in the solution.These excess zinc ions repel the hydrogen ions.The hydrogen ions are driven to the copper strip where they collect electrons and become hydrogen atoms.2H+2e-H2,A primary battery where chemical energy is converted into electrical energy is made up of two electrodes immersed in a electrolyte.In the simplest primary battery electrolyte is a solution of sulfuric acid in the water.,summary,The flow of electrons from the zinc plate to the copper plate represents electrical energy.This energy comes from the zinc that has been dissolved in the electrolyte.When electrons move through a wire,electrical energy is available.Moving electrons can do work.They can produce heat and light and can make motors run.,thank you 庄宗霖,