Basic Science Solutions for Class 8 Science Chapter 11 Chemical Effects Of Electric Current are provided here with simple step-by-step explanations. These solutions for Chemical Effects Of Electric Current are extremely popular among Class 8 students for Science Chemical Effects Of Electric Current Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Basic Science Book of Class 8 Science Chapter 11 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Basic Science Solutions. All Basic Science Solutions for class Class 8 Science are prepared by experts and are 100% accurate.

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An electrode is a conductor that is kept in contact with a non-metallic substance like a solution or agar in a circuit.

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An ion is an atom or a radicle that is formed when a neutral atom acquires a positive or a negative charge due to the donation or acceptance of electron(s), respectively.

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The current through mercury is constituted by the flow of electrons.

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Metal will be deposited at the cathode.

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An acid or an ionic salt is added to water during electrolysis as it will increase the conductivity of water.

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Metals are good conductors of electricity because electrons in the metals are not tightly bound to the atoms. They can move in different directions in the metal. On applying a voltage across a piece of metal, electrons orient towards one direction and start flowing from a low to a high potential. Therefore, metals can conduct electric current.

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Electrolytes are liquids or moist paste that have ions. These ions are responsible for conducting the current in an electrolyte.
Example: a solution of NaCl, a solution of potassium iodide (KI) etc.

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When a voltage is applied across electrodes that are placed in an electrolyte, it causes a chemical change called electrolysis. On passing the current, the positive ions of the electrolyte move towards the cathode to become neutral by gaining electrons whereas the negative ions move towards the anode to become neutral by losing electrons.

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Electrolysis is a process in which an electrolyte is decomposed by passing electricity through it.
During electrolysis, water is decomposed into hydrogen and oxygen. It first splits into hydrogen (H+) and hydroxide (OH) ions. These ions form hydrogen and oxygen at the electrodes by gaining and losing the electrons, respectively.
The following reactions take place:
H2O → H+ + OH
2H+ + 2e → H2                               (at the cathode)
4OH − 2e → O2 + 2H2O               (at the anode)

The overall reaction is as follows:
2H2O Current2H2+O

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The following are the uses of electrolysis:

(a) It is used to extract the metals from their ores.
(b) It is used in the manufacture of chlorine.
(c) Oxygen is produced by the electrolysis of water in submarines. This oxygen is used for breathing.
(d) It is used for electroplating different objects.
(e) It is used in metal refining of some metals like copper.

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Electroplating is the process of coating an inexpensive metal (conductor) with another metal, using electrolysis. It is done for protection or decoration of different objects.

Steel spoons are electroplated with silver for decoration. A solution of silver salt is taken as the electrolyte. The spoon is connected to the negative terminal and the silver bar is connected to the positive terminal of the battery. Both the objects are dipped in the electrolyte. On passing voltage, the positively charged silver ions move towards the spoon that is the negative electrode. This forms a coating of silver on the spoon.

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1. An electrode connected to the negative terminal of a battery is called the cathode.
2. In the electrolysis of water, hydrogen is formed at the cathode.
3. In the electrolysis of potassium iodide, iodine is formed at the anode.
4. A compound formed by ions is called an ionic compound.
5. The electrolyte and the electrodes used in electrolysis form an electrolytic cell.



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