Q.1
What gas forms at the positive electrode during the extraction of aluminium?
  • Hydrogen
  • Chlorine
  • Nitrogen
  • Oxygen
Q.2
Which of the following is NOT a use for chlorine?
  • Kill bacteria
  • Make bleach
  • Make PVC
  • Control pH
Q.3
The hydrogen produced by the electrolysis of brine is NOT used to...
  • make margarine
  • make bleach
  • make hydrochloric acid
  • make hydrogen chloride gas
Q.4
If graphite electrodes are used instead of copper in the electrolysis of copper sulfate, the equation that shows what happens at the anode is...
  • H2O → H+ + O2 + e-
  • Cu2+ + 2e- → Cu
  • 2H2O → 4H+ + O2+ 4e-
  • Cu → Cu 2+ +2e-
Q.5
When an electrical current is passed through brine (sodium chloride solution), three products are formed. They are...
  • chlorine gas, hydrogen gas, sodium chloride solution
  • chloride ions, hydrogen gas, sodium hydroxide solution
  • chlorine gas, hydrogen gas, sodium hydroxide solution
  • chlorine gas, hydrogen ions, sodium hydroxide solution
Q.6
Pick the correct half equations for the electrolysis of copper sulfate using copper electrodes.
  • Cathode: Cu(s) → Cu2+(aq) + 2e- Anode: Cu2+(aq) + 2e- → Cu(s)
  • Cathode: Cu2+(aq) + 2e- → Cu(s) Anode: Cu(s)→ Cu2+(aq) + 2e-
  • Cathode: Cu(s) → Cu+(aq) + e- Anode: Cu2+(aq) + 2e- → Cu(s)
  • Cathode: Cu(s) → Cu2+(aq) + 2e- Anode: Cu+(aq) + e- → Cu(s)
Q.7
Aluminium ore (bauxite) must be dissolved in molten cryolite before it can be electrolysed. Why?
  • Raise the melting point
  • Lower the melting point
  • Increase its viscosity
  • Reduce its viscosity
Q.8
Choose the correct half equations for the electrolysis of brine.
  • Anode 2Cl- → Cl2 + 2e- Cathode 2H+ + 2e- → H2
  • Anode Cl- → Cl2 + e- Cathode 2H+ + e- → H2
  • Anode 2Cl- → Cl2 + 2e- Cathode Na+ + e- → Na
  • Anode Cl- → Cl + 2e- Cathode H+ + e- → H2
Q.9
Copper can be purified using electrolysis. Pick the correct combination of components for the electrolytic cell.
  • Cathode: Impure copper Anode: Pure copper Electrolyte: Copper sulfate
  • Cathode: Pure copper Anode: Impure copper Electrolyte: Copper sulfate
  • Cathode: Pure copper Anode: Pure copper Electrolyte: Copper sulfate
  • Cathode: Impure copper Anode: Pure copper Electrolyte: Water
Q.10
The third product from the electrolysis of brine is sodium hydroxide. This is NOT used to...
  • make bleach
  • make paper
  • make soap
  • make margarine
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