Chemical Effects of Electric Current Worksheet

Objective Type Questions

1. Match items in column I (Term) with the item in column II (Function):
   
   
   State whether the statement is true or false: 
2. Electroplating is done on a metal surface to prevent the user from getting shocked.
   
   
3. Fill in the blanks:
   i. The passage of an electric current through a conducting solution cause ______________.
   ii. Most liquids that conduct electricity are solutions of acids, ________ and __________.
   iii. The path through which an electric current flow is called___________.
   
   
4. Unscramble the following words:
   i. OELERTCDE
   ii. LATCELERTINOGP
   
   
5. Pick the odd one out:
   Copper, Vegetable oil, Lemon juice, salt water.
   
   Multiple Choice Questions
   
   
6. What effect does an electric current produce when passed through a wire?
   (a) Heating effect
   (b) Chemical effect
   (c) Magnetic effect
   (d) All of the above
   
   
7. An electroplating factory has waste that needs to be disposed of, where should this waste be disposed of?
   (a) in the nearby river
   (b) in the nearby pond
   (c) in the nearby cornfield
   (d) according to the disposal guidelines of the local authority
    
8. While exploring his uncle’s car repair shop, Arjun noticed that certain parts had shiny and corrosion-resistant surfaces. Which metal is commonly used in electroplating to achieve this effect?
   (a) Iron
   (b) Copper
   (c) Chromium
   (d) Aluminum
   
   
9. Which chemical effects are observed when an electric current passes through a copper sulphate solution?
   (a) Formation of bubbles.
   (b) Change in colour.
   (c) Deposition of copper on the electrode.
   (d) Realise of oxygen gas.
   
   
10. Priya wants to electroplate a jewellery piece with a layer of silver. Which metal should she use as the base material for electroplating?
    (a) Gold
    (b) Copper
    (c) Brass
    (d) Silver
    
    SAQs
    
    
11. Shradha adds a couple of sugar cubes in distilled water. Will the solution conduct electricity? 
    
    
12. A child in a coastal region tests the drinking water and sea water with his tester setup, as shown below. 
    
    He finds that the compass needle deflects more in the case of seawater. Can you explain the reason?
     
13. While experimenting, Seema noticed that the bulb did not illuminate in the setup below. What may be the cause of this failure? 
    
    
    
14. According to our testers, can a solution, which is a poor conductor of electricity, ever allow the electric current to pass through it? Give a common example.
    
    
15. How will you modify an electroplating circuit to indicate that the electroplating process is over clearly?
    
    
16. Mention three common solutions that are good conductors of electric current. What is common in these solutions?
    
    Assertion-Reasoning Questions
    
    Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
     
17. Assertion: The salt solution is a good conductor of electricity.
    Reason: Some liquids are good conductors of electricity, and some are poor conductors
    
    
18. Assertion: Tin cans, used for storing food, are made by electroplating tin onto the iron.
    Reason:  Tin is less reactive than iron.
    
    
19. Assertion: Water we get by hand pump can conduct electricity.
    Reason: Most liquids are good conductors of electricity, including water.
    
    Case-Based Questions
    
    
20. During a science experiment, Aryan used a circuit given below to check the conductivity of a solution. 
    
    He joined the free ends of the tester together, and the bulb started glowing. Now he poured different liquids, such as vegetable oil, honey, and vinegar, into three different beakers and noted the reading in the below table.
    
    Answer the following questions based on the given information.
    (a) What was Aryan's objective in using the circuit to check the conductivity of a solution?
    (b) What did Aryan test when he joined the free ends of the tester together?
    (c) Did the bulb in the circuit glow when Aryan tested vegetable oil? What does this indicate about the conductivity of vegetable oil?
    (d) Did Aryan observe any conducting liquids among the solutions he tested? Complete the given table.

Objective Type Questions

1. Match items in column I (Term) with the item in column II (Function):
   
   Correct answer: (a)-(iii); (b)-(iv); (c)-(ii); (d)-(i)
   
   
   State whether the statement is true or false: 
2. Electroplating is done on a metal surface to prevent the user from getting shocked.
   Correct answer: False
   Electroplating is the process of coating metal objects with a thin layer of another metal through electrolysis, aiming to enhance appearance and corrosion resistance rather than to prevent the user from getting an electric shock. Other measures, such as insulation or grounding, prevent electric shocks.
   
   
3. Fill in the blanks:
   i. The passage of an electric current through a conducting solution cause ______________.
   Correct answer: chemical reaction.
   The passage of an electric current through a conducting solution causes chemical reactions.
   
   ii. Most liquids that conduct electricity are solutions of acids, ________ and __________.
   Correct answer:  bases, salt
   Most liquids that conduct electricity are acids, bases, and salt solutions.
   
   iii. The path through which an electric current flow is called___________.
   Correct answer: an electric circuit
   The path through which an electric current flow is called an electric circuit.
   
   
4. Unscramble the following words:
   i. OELERTCDE
   ii. LATCELERTINOGP
   Solution:
   i. ELECTRODE
   ii. ELECTROPLATING
   
   
5. Pick the odd one out:
   Copper, Vegetable oil, Lemon juice, salt water.
   Correct answer: Vegetable oil
   Solution:
   Vegetable oil is the odd one out. Copper, lemon juice, and Salt water are all conductors of electricity, while vegetable oil is an insulator and does not conduct electricity.
   Here are a few more examples of conducting and non-conducting liquids.
   
   
   Multiple Choice Questions
   
   
6. What effect does an electric current produce when passed through a wire?
   (a) Heating effect
   (b) Chemical effect
   (c) Magnetic effect
   (d) All of the above
   Correct option: (a) Heating effect
   Solution:  When an electric current is passed through a wire, it produces a heating effect. The flow of electrons through the wire encounters resistance, leading to heat generation.
   
   
7. An electroplating factory has waste that needs to be disposed of, where should this waste be disposed of?
   (a) in the nearby river
   (b) in the nearby pond
   (c) in the nearby cornfield
   (d) according to the disposal guidelines of the local authority
   Correct option: (d) according to the disposal guidelines of the local authority
   Solution:  Electroplating factory waste must adhere to local authority guidelines for safe, responsible disposal. Disposing off in rivers, ponds, or corn fields is irresponsible and can cause environmental pollution and harm living organisms.
    
8. While exploring his uncle’s car repair shop, Arjun noticed that certain parts had shiny and corrosion-resistant surfaces. Which metal is commonly used in electroplating to achieve this effect?
   (a) Iron
   (b) Copper
   (c) Chromium
   (d) Aluminum
   Correct option: (c) Chromium
   Solution:  Chromium is commonly used in electroplating to achieve a shiny and corrosion-resistant surface on car parts. This is because chromium has a shiny appearance, does not corrode easily, and resists scratches.
   
   
9. Which chemical effects are observed when an electric current passes through a copper sulphate solution?
   (a) Formation of bubbles.
   (b) Change in colour.
   (c) Deposition of copper on the electrode.
   (d) Realise of oxygen gas.
   Correct option: (c) Deposition of copper on the electrode.
   Solution: By passing an electric current through a copper sulphate solution, copper dissociates into copper and sulphate. The free copper ion gets drawn to the electrode connected to the battery's negative terminal.
   
   
10. Priya wants to electroplate a jewellery piece with a layer of silver. Which metal should she use as the base material for electroplating?
    (a) Gold
    (b) Copper
    (c) Brass
    (d) Silver
    Correct option: (d) Silver
    Solution: Priya should use a base material of copper for electroplating the jewellery piece with a layer of silver.
    
    SAQs
    
    
11. Shradha adds a couple of sugar cubes in distilled water. Will the solution conduct electricity?
    Solution: No, the sugar solution will not conduct electricity since it is a poor conductor of electricity. 
    
    
12. A child in a coastal region tests the drinking water and sea water with his tester setup, as shown below. 
    
    He finds that the compass needle deflects more in the case of seawater. Can you explain the reason?
    Solution: Sea water contains more dissolved salts than drinking water, which makes it more conducting. Because of this reason, the compass needle deflects more in seawater than in drinking water.
     
13. While experimenting, Seema noticed that the bulb did not illuminate in the setup below. What may be the cause of this failure? 
    
    Solution: The bulb may not glow because of the following reasons:
    (i) The liquid in the beaker may be non-conducting. In such a case, the electric current would not be able to pass through the liquid. Hence, the circuit will not be complete.
    (ii) The conductivity of the liquid may be very low, so the current flowing through the circuit may be too weak to produce enough heat in the filament of the bulb so as to make it glow.
    (iii) The battery may be exhausted and does not have sufficient energy to generate electricity.
    (iv) The bulb may be fuse, or the circuit connections may be loose.
    
    
14. According to our testers, can a solution, which is a poor conductor of electricity, ever allow the electric current to pass through it? Give a common example.
    Solution: Yes, even if a solution seems to be a poor conductor of electric current, it might become a good conductor if a high voltage is applied.
    A common example is air, which is a poor conductor according to all the testers we might devise, but still allows lightning, an electric current, to pass through it.
    
    
15. How will you modify an electroplating circuit to indicate that the electroplating process is over clearly?
    Solution: An LED can be added to the circuit in the same way it is connected to a tester. While electroplating occurs, electric current will flow, and the LED will be lit up. The moment electroplating stops so does the current flow; thus, the LED will also turn off.
    
    
16. Mention three common solutions that are good conductors of electric current. What is common in these solutions?
    Solution: Sea water contains more dissolved salts than drinking water, which makes it more conducting. Because of this reason, the compass needle deflects more in seawater than in drinking water.
    
    Assertion-Reasoning Questions
    
    Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
     
17. Assertion: The salt solution is a good conductor of electricity.
    Reason: Some liquids are good conductors of electricity, and some are poor conductors
    Correct option: (b) Both A and R are true, but R is not the correct explanation of the assertion.
    When salt dissolves in water, it dissociates into ions that can carry an electric charge, making the salt solution a good conductor of electricity. The reason given is also correct in that some liquids conduct electricity well while others do not. However, the reason does not explain why the salt solution is a good electrical conductor.
    
    
18. Assertion: Tin cans, used for storing food, are made by electroplating tin onto the iron.
    Reason:  Tin is less reactive than iron.
    Correct option: (a) Both A and R are true, and R is the correct explanation of the assertion.
    Tin cans, which are used to store food, are created by electroplating tin onto the iron. Tin is less reactive compared to iron. As a result, food does not come into contact with iron due to electroplating.
    
    
19. Assertion: Water we get by hand pump can conduct electricity.
    Reason: Most liquids are good conductors of electricity, including water.
    Correct option: (c) A is true, but R is false.
    The assertion that water from a hand pump can conduct electricity is true due to impurities and dissolved substances, but the reason provided, claiming that most liquids are good conductors, including water, is false as pure water is a poor conductor of electricity.
    
    Case-Based Questions
    
    
20. During a science experiment, Aryan used a circuit given below to check the conductivity of a solution. 
    
    He joined the free ends of the tester together, and the bulb started glowing. Now he poured different liquids, such as vegetable oil, honey, and vinegar, into three different beakers and noted the reading in the below table.
    
    Answer the following questions based on the given information.
    (a) What was Aryan's objective in using the circuit to check the conductivity of a solution?
    Solution: Aryan's objective was to determine whether the solutions he tested were good conductors of electricity or not.
    
    (b) What did Aryan test when he joined the free ends of the tester together?
    Solution: When Aryan joined the free ends of the tester together, he completed the circuit of the tester to check whether the bulb in the circuit glows or not.
    
    (c) Did the bulb in the circuit glow when Aryan tested vegetable oil? What does this indicate about the conductivity of vegetable oil?
    Solution: No, the bulb did not glow when Aryan tested vegetable oil. This indicates that vegetable oil is a non-conductor of electricity.
    
    (d) Did Aryan observe any conducting liquids among the solutions he tested? Complete the given table.
    Solution: Since the bulb glow, we can conclude that vinegar was a conducting liquid.