WorksheetsElectrochemistry Form 4
Total questions: 20
Worksheet time: 40mins
Which of the following is true about an electrolyte?
I Electrolyte conducts electricity in molten state.
II Electrolyte conducts electricity in solid state.
III Electrolyte is soluble in water.
IV Electrolyte undergoes chemical decomposition when it conducts electricity.
I and II only
II and III only
II and IV only
I and IV only
Which of the following is not an electrolyte?
Molten glucose
Aqueous ammonia
Molten lead (II) bromide
Molten potassium iodide
Naphthalene does not conduct electricity because it
contains freely moving electrons.
has very low melting points.
consists of molecules which are uncharged particles.
contains ionic compounds which can dissolve in water.
Which of the following is most probably substance X?
Molten napthalene
Pure ethanol
Solid lead (II) bromide
Potassium iodide solution
What are the ions present in molten lead (II) bromide?
PbBr2
Pb and Br
Pb2+ and Br–
Pb2+ and Br2–
Which of the following happens during the electrolysis of molten sodium bromide?
I Sodium ions are attracted to the cathode.
II Bromide ions are attracted to the anode.
III Electrons are moving from anode to cathode.
IV At the cathode, bromine ions accept electron from anode.
I, II and III only
I, II and IV only
I, III and IV only
II, III and IV only
What is formed at carbon electrode Q?
Hydrogen gas
Oxygen gas
Iron metal
Nitrogen gas
The electrolysis of aqueous sodium nitrate using carbon electrode was carried out in a lab. Which of the following is true about this experiment?
The sodium ions are discharged at the cathode.
The nitrate ions are discharged at the anode.
Hydrogen gas is produced in the anode
Oxygen gas is produced in the anode.
What need to be changed in order to get different gas from this experiment?
Substitute carbon electrodes with copper electrodes.
Use a more concentrated copper (II) chloride solution.
Change the position of the battery.
Substitute carbon electrodes with platinum.
Which of the following are the factors that determine the type of ions to be discharged at the electrodes?
I Type of electrode used.
II Concentration of ions in the solution.
III The molecular mass of the atom used.
IV Position of ions in electrochemical series.
I, II and III only
I, II and IV only
I, III and IV only
II, III and IV only
Diagram 4 shows the set-up of the apparatus used to electroplate an iron key with silver. What is the observation after 30 minutes?
I At anode, silver foil become thinner.
II At anode, shinny grey deposits are formed.
III At cathode, gas bubbles are released.
IV At cathode, shinny grey deposits are formed.
I and II only
II and III only
II and IV only
I and IV only
Which of the following is true about electroplating an iron key with copper?
A
B
C
D
Which of the following is true about the voltaic cell?
I The copper plate dissolves gradually.
II The zinc plate acts as negative terminal.
III The zinc plate become thinner.
IV Electrons flow from zinc plate to copper plate.
I, II and III only
I, II and IV only
I, III and IV only
II, III and IV only
Which of the following changes can increase the reading on the voltmeter?
Use a more concentrated sodium chloride.
Change the zinc plate to magnesium plate.
Change the copper plate to lead plate.
Increase the volume of aqueous sodium chloride.
What is the correct chemical reaction that takes place in the positive terminal of the chemical cell?
Zn2+ + 2e → Zn
Zn → Zn2+ + 2e
Ag+ + e → Ag
Ag → Ag+ + e
Which of the following pairs can produce the highest reading on the voltmeter?
Zinc / Magnesium
Zinc / Copper
Magnesium / Copper
Magnesium / Silver
Jenny wants to make her ring more beautiful and prevent corrosion. What is the best way to achieve this?
Dip the ring in oil.
Wash the ring with soap.
Plate the ring with gold.
Polished the ring with water.
Table 1 shows the information about three simple cells.
What is the potential difference of the metal pair Q and S?
0.5 V
0.9 V
1.8 V
2.6 V
Table 2 shows the information of two simple cells.
Which of the following is the ascending order of electrode X, Y and Z in the electrochemical series?
Z, Y and X
Y, X and Z
X, Y and Z
X, Z and Y
Which of the following is not the example of electrochemical industries in our daily life?
Voltaic cells are used in different devices such as radio, hand phones, and others.
Electroplating of iron can prevent it from corrosion.
Chemical substance such as chlorine is used to produce toxic solution.
Extraction of useful metals such as aluminium using electrolysis.
