The weak electrolytes are ionised to lesser extent in aqueous solution and have lower values of . It is arbitrarily assigned an electrode potential of zero (0). A colourless gas is produced which extinguishes a burning splint with a pop sound. Instead copper electrode dissolves. When electricity is passed through an ionic compound in molten or solution form, it is decomposed to obtain products at the electrodes. However, if the ion that requires more energy to discharge is present in greater concentration than the other one lower in the electro chemical series, it will be discharged preferentially. The three basic components to learn electrochemistry for SPM Form 4 Chemistry students consist of electrolyte, non-electrolyte and also conductors. Potassium bromide solution is colourless solution. The following is the electrochemical cell. Electrolyte Non-electrolyte Meaning Example 2. Substances which allow the passage of electricity through their fused state or aqueous solution and undergo chemical decomposition are called electrolytic conductors, e.g., aqueous solutionof acids. [Newman] = Newman, John, and Karen E. Thomas-Alyea. Electrochemistry is the relationship between electricity and chemical reactions. General Advantages of Electrochemistry: a) selective for particular redox state of a species e.g. Cu2+ ions are lower in the electrochemical series and are therefore preferentially discharged by gaining electrons to form a brown solid deposit of copper. The following video clip shows the displacement reaction of iron and copper (II) Sulphate solution. Instead copper electrode dissolves. In this lesson we will discuss the electrochemical cell. The cells are of two types: (a) Electrolytic cells (b) Galvanic cells I=Q/t, Rearranging the equation, we obtain,Q=It where, Q is the charge in coulombsI is the current in
Over all equation 4OH-(aq)
The copper ion gains two electrons to form copper atom. Click the button below to download the full Chemistry Form 4 Notes pdf document, with all the topics. The equation for the reaction is Cu(s)
â Br2(g) + 2e-
Click to play the video to observe what happens, Click to play the video and observe what happens carefully, Click to play the following video to observe how electrolysis is used to extract a metal, Order this CD Today to Experience the Full Multimedia State of the Art Technology, Purchase Online and have the CD sent to your nearest Parcel Service. Electrochemistry is used for the following purposes. The concentration of copper ions in beaker B decreases because they gain electrons given up by zinc and are converted to solid copper which is deposited on the copper strip. Michael Faraday investigated the quantities of substances deposited during electrolysis. Choice of ions to be discharged based on position of ions in the electrochemical series. This is called preferential discharge. copper, none of the ions are discharged. 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