Question 1
Question
Which electrode are connected at anode?
Answer
-
copper
-
carbon
-
oxygen
-
sulphur
Question 2
Question
What is the use of the sand paper?
Answer
-
to clean the beaker
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to clean up spilled electrolyte
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to remove oxide layer on the electrode
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to remove dust on the electrode
Question 3
Question
Arrange the most applicable steps when weighing the copper.
A) Close the door of analytical balance
B) Record the weight to four decimal places
C) Use TARE button
D) Clean the copper before weighing
Answer
-
D, C, A, B
-
C, A, B, D
-
C, A, D, B
-
D, B, C, A
Question 4
Question
Arrange the following steps in conducting the experiment (Faraday's Law)
A) Set up the electrolytic cell
B) Remove oxide layer on electrode
C) Dry the copper after electrolysis and record the final mass.
D) Start the stopwatch and disconnect the circuit immediately
Answer
-
D, C, B, A
-
D, C, A, B
-
B, A, C, D
-
B, A, D, C
Question 5
Question
If the electrolyte used is CuSO4, carbon is the anode and copper is the electrode, which of the following would be the expected observation?
Answer
-
bubble gas evolved at the cathode
-
bubble gas evolved at the anode
-
carbon electrode becomes thicker
-
brown solid deposited at anode
Question 6
Question
If an ammeter in an electrolytic cell does not shows any reading, what could be wrong?
Answer
-
The wires is not connected properly
-
The power button is switched on
-
The analytical balance is not functioning properly
-
The stopwatch stop ticking
Question 7
Question
In the experiment to determine Faraday's Law, electrolytic cell is used. Which of the following is not a relevant precaution steps in this experiment?
Answer
-
The cathode electrode need to dry properly before the final mass is weighed
-
When running the electrolysis, both electrodes should not be in contact with each other.
-
The electrodes used should be cleaned with sand paper properly.
-
The electrodes need to immerse in the electrolyte fully.
Question 8
Question
The theoretical value of Faraday's Law is 96500 C. Choose the correct source of errors at which the experimental value is far from the theoretical value.
I. Inaccuracy in weighing
II. Size of the electrodes
III. Fluctuations in electric current
IV. Colour of the electrolyte
Answer
-
II & IV
-
I, II, & III
-
I & III
-
All of the above
Question 9
Question
The following statement is true about the experiment to determine Faraday's Law except:
Answer
-
The electrolytic cell is set up using ammeter and power supply.
-
The electrolyte must be filled to 3/4 volume of the beaker
-
The time taken for the electrolysis should be recorded using a stopwatch
-
The electrode used at the cathode should be weighed immediately after the electrolysis is stopped
Question 10
Question
All experiment should be conducted with a noble manner. Which of the following is not a good noble value while conducting an experiment to determine Faraday's Law?
Answer
-
Clean up workplace after the experiment is done
-
If a hair dryer is used, make sure it was used at appropriate distance to the electrode
-
Put all used sand papers left in the dustbin
-
Pour back the electrolyte used in their original flask to avoid wasting
Question 11
Question
Why does the ammeter reading fluctuate during electrolysis?
Answer
-
The wires are not connected properly
-
Both electrodes touch each other
-
Both electrodes are not immerse in the electrolyte
-
The negative terminal is connected to anode and the positive terminal is connected to cathode
Question 12
Question
What is the function of TARE button on the analytical balance?
Answer
-
To stabilize the reading
-
To reset the reading to zero display
-
To hold the mass of the substances displayed
-
To remove the weight of the door of the analytical balance.
Question 13
Question
The following cause could affect the mass of electrode after electrolysis except?
Answer
-
The solid deposited at the bottom of the beaker is not collected
-
The analytical balance are closed while weighing.
-
The TARE button is not used.
-
The electrodes are weighed immediately after electrolysis stopped.
Question 14
Question
The following statement is correct for electrolysis involving copper electrode at cathode and carbon electrode at anode in CuSO4 solution
Answer
-
carbon electrode is connected to the positive terminal of the power supply
-
carbon electrode is connected to the negative terminal of the power supply
-
carbon electrode is connected to the ammeter
-
copper electrode is connected to the positive terminal of the power supply
Question 15
Question
What should we do if a small amount of copper deposited fell to the bottom of the beaker?
Answer
-
If it is a small amount, we can ignore as the small amount will not affect the final mass.
-
Try to collect the solid using filter paper, dry and add the mass with the mass of the electrode.
-
Try to collect the solid using filter paper, if the mass does not exceed 0.5 g, we should ignore the mass.
-
Try to collect the solid using filter paper, dry and add the mass with mass of the electrode only if it weighs more than 0.5 g.
Question 16
Question
Which of the following is the source of errors that could happen in the experiment of electrolytic cell
i. The volume of the electrolyte are not at appropriate meniscus level.
ii. The volume of the electrolytes is not the same as instructed in the procedure.
iii. The electrodes are not cleaned properly
iv. The electrodes are left in contact with each other
Answer
-
ii. iii and iv
-
i, iii and iv
-
iii and iv
-
All of the above
Question 17
Question
During the experiment using CuSO4 solution, copper cathode and carbon anode, how many electrons are gained to deposit 1 mol of solid copper?
Question 18
Question
If 0.0316 g of copper is deposited, the no of moles of copper is [blank_start]0.000497[blank_end] moles. (6 d.p)
Question 19
Question
If 0.00048 moles produced by 90 C of current, calculate the Faradays constant.
Faradays's constant is [blank_start]93 750[blank_end] C.
Question 20
Question
What is the value of Q if the current is 0.15 A and the time used for the electrolysis is 10 minutes.
Q = [blank_start]90[blank_end] C