True or False?
Molten ionic compounds can conduct electricity.
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True or False?
Molten ionic compounds can conduct electricity.
True.
Molten ionic compounds can conduct electricity.
True or False?
The electrodes used in electrolysis must be inert.
True.
The electrodes used in electrolysis must be inert.
What is the electrolyte?
The electrolyte is the ionic compound in molten or dissolved solution that conducts the electricity.
What is the anode?
The anode is the positive electrode.
What is the cathode?
The cathode is the negative electrode.
Which way do electrons flow in the circuit during electrolysis? (Extended Tier Only)
Electrons flow from the anode to the cathode.
Why are cations attracted to the cathode? (Extended Tier Only)
Positive cations are attracted to the negatively charged cathode because opposite charges attract.
Why are anions attracted to the anode? (Extended Tier Only)
Negative anions are attracted to the positively charged anode because opposite charges attract.
True or False?
The electrolyte must be solid or molten to undergo electrolysis.
False.
The electrolyte must be molten or in solution to undergo electrolysis.
Define electrolysis
Electrolysis is the process of using an electric current to decompose or break down a molten or aqueous ionic compound.
What is produced at the cathode during electrolysis of molten lead(II) bromide?
Molten lead is produced at the cathode during electrolysis of molten lead(II) bromide.
What is produced at the anode during electrolysis of molten lead(II) bromide?
Brown fumes of bromine gas are produced at the anode during electrolysis of molten lead(II) bromide.
What would be the products of electrolysis of molten zinc chloride?
The products of electrolysis of molten zinc chloride would be zinc at the cathode and chlorine at the anode.
What type of electrodes are typically used in the electrolysis of molten compounds?
Graphite or platinum electrodes are typically used in the electrolysis of molten compounds.
Why do molten ionic compounds conduct electricity?
Molten ionic compounds conduct electricity because their ions can move freely and carry the current.
Explain how a molecule of chlorine forms during the electrolysis of lead(II) chloride.
Two chloride ions are attracted to the anode where they each lose one electron.
They bond to form a molecule of chlorine.
2Cl- ⟶ Cl2 + 2e-
True or False?
The positive ion will migrate towards the cathode and the negative ion will migrate towards the anode.
True.
The positive ion will migrate towards the cathode and the negative ion will migrate towards the anode.
True or False?
The cathode product will always be the non-metal and the product formed at the anode will always be the metal.
False.
The cathode product will always be the metal l and the product formed at the anode will always be the non-metal.
What is brine?
Brine is a concentrated solution of aqueous sodium chloride.
What are the products of the electrolysis of brine?
The products of the electrolysis of brine are chlorine gas, hydrogen gas, and sodium hydroxide solution.
True or False?
During the electrolysis of brine, sodium ions are discharged at the cathode.
False.
During the electrolysis of brine, hydrogen ions are discharged at the cathode, not sodium ions.
What gas is produced at the anode during the electrolysis of brine?
Chlorine gas is produced at the anode during the electrolysis of brine.
In the electrolysis of dilute sulfuric acid, what gas is produced at the cathode?
In the electrolysis of dilute sulfuric acid, hydrogen gas is produced at the cathode.
What is produced at the anode during the electrolysis of dilute sulfuric acid?
Oxygen gas is produced at the anode during the electrolysis of dilute sulfuric acid.
True or False?
The volume of hydrogen produced is twice that of oxygen in the electrolysis of dilute sulfuric acid.
True.
The volume of hydrogen produced is twice that of oxygen in the electrolysis of dilute sulfuric acid.
What is the test and result for oxygen gas?
The test for oxygen gas is that a glowing splint will relight when dipped into a sample of the gas.
What is the test and result for hydrogen gas?
Hydrogen gas is tested for by dipping a lit splint into a sample of the gas, which will produce a squeaky pop.
What is the test and result for chlorine gas?
The test for chlorine gas is that damp litmus paper will turn red and then bleach to a white colour when dipped into a sample of the gas.
What ions are always present in aqueous solutions? (Extended Tier Only)
Aqueous solutions always have H+ and OH- ions present from the splitting of water molecules.
True or False?
Concentrated and dilute solutions of the same compound always give the same products during electrolysis. (Extended Tier Only)
False.
Concentrated and dilute solutions of the same compound can give different products during electrolysis.
What determines which ions are discharged at the electrodes during electrolysis of aqueous solutions? (Extended Tier Only)
The relative reactivity of the elements involved determines which ions are discharged at the electrodes during electrolysis of aqueous solutions.
In the electrolysis of concentrated copper(II) chloride solution, what is produced at the anode? (Extended Tier Only)
In the electrolysis of concentrated copper(II) chloride solution, chlorine is produced at the anode.
What is produced at the anode during the electrolysis of dilute halide solutions? (Extended Tier Only)
Oxygen is produced at the anode during the electrolysis of dilute halide solutions.
True or False?
Metals above hydrogen in the reactivity series will be produced at the cathode during electrolysis of their aqueous solutions. (Extended Tier Only)
False.
For metals above hydrogen in the reactivity series, hydrogen gas will be produced at the cathode instead of the metal.
What is produced at the cathode during the electrolysis of aqueous copper sulfate? (Extended Tier Only)
Copper metal is produced at the cathode during the electrolysis of aqueous copper sulfate.
In the electrolysis of aqueous copper sulfate with copper electrodes, what happens to the anode? (Extended Tier Only)
In the electrolysis of aqueous copper sulfate with copper electrodes, the anode decreases in mass.
What is produced at the anode during the electrolysis of dilute sulfuric acid? (Extended Tier Only)
Oxygen gas is produced at the anode during the electrolysis of dilute sulfuric acid.
What ions are attracted to the positive electrode? (Extended Tier Only)
Negatively charged OH- ions and non-metal ions are attracted to the positive electrode.
What ions are attracted to the negative electrode? (Extended Tier Only)
H+ ions and metal ions are attracted to the negative electrode.
How is the product at the cathode determined? (Extended Tier Only)
The product at the cathode is determined by the position of the metal in the reactivity series relative to hydrogen.
What is produced at the cathode during electrolysis of dilute sodium chloride solution? (Extended Tier Only)
Hydrogen gas is produced at the cathode during electrolysis of sodium chloride solution.
What is oxidation in terms of electron transfer? (Extended Tier Only)
Oxidation is the loss of electrons.
What is reduction in terms of electron transfer? (Extended Tier Only)
Reduction is the gain of electrons.
True or False?
Oxidation occurs at the cathode during electrolysis. (Extended Tier Only)
False.
Oxidation occurs at the anode during electrolysis.
Write the ionic half-equation for the reduction of copper(II) ions. (Extended Tier Only)
The ionic half-equation for the reduction of copper(II) ions is:
Cu2+ + 2e- → Cu
Write the ionic half-equation for the oxidation of chloride ions. (Extended Tier Only)
The ionic half-equation for the oxidation of chloride ions is:
2Cl- → Cl2 + 2e-
What is the ionic half-equation for the reduction of hydrogen ions? (Extended Tier Only)
The ionic half-equation for the reduction of hydrogen ions is:
2H+ + 2e- → H2
Write the ionic half- equation for the reduction of Sn2+ ions at the cathode? (Extended Tier Only)
The ionic half- equation for the reduction of Sn2+ ions is:
Sn2+ + 2e- → Sn
State the ionic half- equation for the reduction of Pb2+ ions at the cathode. (Extended Tier Only)
The ionic half-equation for the reduction of Pb2+ ions at the cathode is:
Pb2+ + 2e- → Pb
True or False?
In ionic half- equations, the charges on each side of the equation should always balance. (Extended Tier Only)
True.
In ionic half-equations, the charges on each side of the equation should always balance.
Balance the ionic half- equation for the oxidation of water molecules at the anode in acidic solutions:
.... H2O → O2 + .... H+ + .... e-
(Extended Tier Only)
The balanced ionic half-equation for the oxidation of water molecules at the anode in acidic solutions is:
2H2O → O2 + 4H+ + 4e-