Chemical Effects of Electric Current - Chapter Wise CBSE Solved Question and Answer Based On NCERT
Long Q&A:
Q1: Explain the process of electroplating, along with its advantages and uses.
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Ans:
One of the most common applications of the chemical effect of electric current is electroplating. In this process, there exists a liquid, usually called the electrolyte, through which current passes. Two electrodes, connected to the terminals of a battery with a switch in between, are inserted in the liquid. The electrode that is connected to the positive terminal of the battery is called the “anode,” and the other connected to the negative terminal is called the “cathode”. Electroplating is done in industries to have an anti-reactive coating on the parts of machines so that they do not react with the raw material, to have an anti-corrosive coating for the machines so that they do not get corroded, and a heat-resistivecoating for parts like boilers to resist the heat produced by the machinery.The process of electroplating is used for plating parts of vehicles with nickel and chromium, which protects them from corrosion.
Q2:
A tester is used to check the conduction of electricity through two liquids, labelled A and B. It is found that the bulb of the tester glows brightly for liquid A while it glows very dimly for liquid B. You would conclude that
liquid A is a better conductor than liquid B.
liquid B is a better conductor than liquid A.
both liquids are equal conducting.
Conducting properties of liquid cannot be compared in this manner.
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Ans:
Liquid A is a better conductor than liquid B.
Q3: Most liquids that conduct electricity are solutions of acid, bases and salt . Justify the statement.
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Ans:
Good conductor, becauseWhen we add kitchen salt (NaCl) to the distilled water the salt dissolves in water by splitting its molecules in ions:
H2O + NaCl --> H2O + (Na+) + (Cl-)
The NaCl molecules react to give ions. This happens because the NaClis a strong electrolyte. Solutions of strong electrolytes are good conductors of electricity because they contain a relatively high concentration of ions.
Poor conductor, because Sugar, as a non-electrolyte substance, does not produce ions when dissolved in water. A solution of sugar contains molecules of sucrose,but no ions. The absence of ions in a sugar aqueous solution makes it a non-electricity conductor fluid.
