InterviewSolution
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InterviewSolution
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(a) Out of the following pairs, predict with reason which pair will allow greater conduction of electricity: (i) Silver wire at 30^(@)C or silver at 60^(@)C. (ii) 0.1 M CH_(3)COOH solution or 1 M CH_(3)COOH solution. (iii) KCl solution at 20^(@)C or KClsolution at 50^(@)C . Give two points of differences between electrochemical and electrolytic cells. |
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Answer» Solution :(a) (i) SILVER wire at `30^(@)C` or silver wire at `60^(@)C`. Silver wire at `30^(@)C` shows greater conduction of electricity. Conductivity of metals decreases with rise of temperature. This is because vibration of kernels increases with temperature. (ii) 0.1 M `CH_(3)COOH` solution or 1 M `CH_(3)COOH` solution. 0.1 M `CH_(3)COOH` shows greater conductivity. For weak ELECTROLYTES, conductivity increases with dilution because of increased ionisation and increase in the VOLUME of solution containing 1 mole of the electrolyte. (iii) KCl solution at `20^(@)C` or KCl solution at `50^(@)C`. KCl solution at `50^(@)C` will show greater conductance because ionic mobility increases with temperature. (b) Electrochemical cell and Electrolytic cell (i) Chemical energy of a reaction is converted into electrical energy in an electrochemical cell. Electrical energy is used to bring about a chemical change in electrolytic cell. (ii) An electrochemical cell consists of two parts, an anode where the oxidation takes place and a cathode where reduction takes place. The two parts are joined by a salt bridge. In an electrolyticcell, the substance in solution or molten state is taken in a vessel. Two electrodes a cathode and an anode of suitable material are dipped into it. On passing electricity, cations are deposited at cathode and anions are deposited at anode. |
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