WBBSE Solutions For Class 8 School Science Chapter 2 Element Compound And Chemical Reaction Chemical Effects Of Electricity Review Questions

Chapter 2 Element Compound and Chemical Reaction Chemical Effects Of Electricity MCQs

Question 1. An Example Of An Electrolyte Is

  1. Mercury
  2. Potassium Chloride
  3. Copper
  4. Distilled Water

Answer: 2. Potassium Chloride

Question 2. During the Electrolysis Of Water, The Substance Which Is Mixed In Small Amount With Water To Increase Its Electrical Conductivity Is

  1. Dilute H2S04
  2. Potassium Permanganate
  3. Manganese Dioxide
  4. Benzene

Answer: 1. Dilute H2S04

Question 3. Electroplating Of Zinc Is Done On the Surface Of Iron

  1. To Prevent Rusting
  2. To Increase Its Weight
  3. To Reduce The Consumption Of Electricity During Electrolysis
  4. To Increase The Price

Answer: 1. To Prevent Rusting

Question 4. During the Electroplating Of Copper On Another Material, The Weight Of the Anode

  1. Remains Unchanged
  2. Gradually Decreases
  3. Gradually Increases
  4. None Of These

Answer: 2. Gradually Decreases

Read And Learn More WBBSE Solutions For Class 8 School Science Review Questions

Question 5. Electrolysis Of Fused Calcium Chloride Yields The Following At the Anode :

  1. Calcium
  2. Hydrogen
  3. Oxygen
  4. Chlorine

Answer: 3. Oxygen

Question 6. During the Electroplating Of Gold On Silver Ornaments, The Anode Is Made Of

  1. Silver
  2. Gold
  3. Graphite
  4. Platinum

Answer: 2. Gold

Question 7. Which One Of The Following Is A Weak Electrolyte?

  1. Aqueous Solution Of Ammonia
  2. Aqueous Solution Of H2S04
  3. Aqueous Solution Of Sodium Hydroxide
  4. Molten Naci

Answer: 1. Aqueous Solution Of Ammonia

Question 8. Which One Of The Following Is A Strong Electrolyte?

  1. Aqueous Solution Of Ammonia
  2. Aqueous Solution Of Urea
  3. Aqueous Solution Of Kci
  4. Dilute Solution Of Carbonic Acid

Answer: 3. Aqueous Solution Of Kci

Question 9. When Molten Sodium Chloride Is Electrolyzed, Sodium Metal Is Obtained At

  1. Cathode
  2. Anode
  3. Molten Salt
  4. Base Of The Electrolytic Cell

Answer: 1. Cathode

Question 10. When A Particular Substance Is Electrolyzed, The Nature Of the Substance Formed At The Two Electrodes

  1. Depends On The Nature Of The Electrodes Used
  2. Does Not Depend On The Nature Of The Electrodes Used
  3. Depends On Temperature
  4. Depends On the Concentration Gradient

Answer: 1. Depends On The Nature Of The Electrodes Used

Question 11. For the Electroplating Of Nickel Over An Iron Article, the Following Are Used As Anode, Cathode And Electrolyte:

  1. Nickel, Copper, Aqueous Solution Of Copper Sulphate
  2. Iron, Nickel, Acidulated Water,
  3. Iron, Nickel, Aqueous, Solution Of Nickel Sulphate With Boric Acid
  4. Nickel, Iron, Aqueous Solution Of Nickel Sulphate With Boric Acid

Answer: 4. Nickel, Iron, Aqueous Solution Of Nickel Sulphate With Boric Acid

Question 12. Anode Attracts

  1. Cation
  2. Anion
  3. Both
  4. None Of These

Answer: 2. Anion

Question 13. Electrolytes Conduct Electricity Due To The Movement Of

  1. Electrodes
  2. Atoms
  3. Electrons
  4. Ions

Answer: 4. Ions

Question 14. Which One Of The Following Is Not Used For Electroplating?

  1. Nickel
  2. Chromium
  3. Silver
  4. Sodium

Answer: 4. Sodium

Question 15. The Aqueous Solution Of Non-Electrolytes Contains

  1. Atoms
  2. Molecules
  3. Electrons
  4. Ions

Answer: 2. Molecules

Chapter 2 Element Compound And Chemical Reaction Chemical Effects Of Electricity Fill In The Blanks

Question 1. The vessel in which the electrolysis is carried out is called___________.
Answer: Voltameter

Question 2. Mercury is a good conductor of electricity but it is not ___________.
Answer: Electrolyte

Question 3. During electrolysis, oxidation occurs at and ___________ occurs at the cathode.
Answer: Anode, reaction

Question 4. When some amount of dilute sulphuric acid is added to pure water number of ___________ increases in the solution.
Answer: Ions

Question 5. Galvanization is the process of coating a thin film of ___________ on another metal surface.
Answer: Zinc

Question 6. An aqueous solution of sugar is a ___________ conductor of electricity
Answer: Bad

Question 7. Electrolysis is basically a ___________reaction.
Answer: Redox (oxidation-reduction)

Question 8. During electrolysis of acidified water, hydrogen gas is liberated at ___________.
Answer: Cathode

Question 9. Anions are ___________ charged ions.
Answer: Negatively

Question 10. ___________ are positively charged ions.
Answer: Cations

Question 11. The human body is a ___________ conductor of electricity.
Answer: Good

Question 12. Coconut oil is a___________ conductor of electricity.
Answer: Bad

Question 13. During the electroplating of any metal on any article, the articles to be electroplated are used as ___________
Answer: Cathode

Chapter 2 Element Compound And Chemical Reaction Chemical Effects Of Electricity Identify As True Or False

Question 1. The human body is a good conductor of electricity.
Answer: True

Question 2. Electrolysis of acidified water is an example of chemical change.
Answer: True

Question 3. Acidified water is a good conductor of electricity.
Answer: True

Question 4. Pure water is a good conductor of electricity.
Answer: False

Question 5. An aqueous solution of sugar is a good conductor of electricity.
Answer: False

Question 6. Anions are positively charged ions.
Answer: False

Question 7. Cations are positively charged ions.
Answer: False

Question 8. During the electrolysis of acidified water, a reduction reaction occurs cathode.
Answer: True

Question 9. During the electrolysis of acidified water, a reduction reaction occurs at the anode.
Answer: True

Question 10. An aqueous solution of H2S04 is a strong electrolyte.
Answer: False

Question 11. An aqueous solution of acetic acid is a strong electrolyte.
Answer: False

Question 12. An aqueous solution of ammonia is a strong electrolyte.
Answer: False

Question 13. An aqueous solution of NaOH is a strong electrolyte.
Answer: True

Question 14. During the electrolysis of an aqueous solution of an electrolyte, the ions conduct electricity within the solution.
Answer: True

Question 15. Number of ions in pure water is very small, so pure water is a bad conductor of electricity.
Answer: True

Question 16. Impure copper is purified by electrolysis.
Answer: True

Question 17. Graphite can be used as an electrode during electrolysis.
Answer: True

 

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