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?
Electrons flow from the anode to the cathode.
Why are cations attracted to the cathode?
Positive cations are attracted to the negatively charged cathode because opposite charges attract.
Why are anions attracted to the anode?
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 ions are always present in aqueous solutions?
Aqueous solutions always have H+ and OH- ions present from the splitting of water molecules.
What ions are attracted to the positive electrode?
Negatively charged OH- ions and non-metal ions are attracted to the positive electrode.
True or False?
If halide ions are present in the aqueous electrolyte, they are discharged at the anode.
True.
If halide ions are present in the aqueous electrolyte, they are discharged at the anode.
What gas is produced at the anode if no halide ions are present in the electrolyte?
If no halide ions are present, OH- is discharged at the anode, forming oxygen gas.
What ions are attracted to the negative electrode?
H+ ions and metal ions are attracted to the negative electrode.
How is the product at the cathode determined?
The product at the cathode is determined by the position of the metal in the reactivity series relative to hydrogen.
True or False?
Copper is produced at the cathode during electrolysis of copper chloride solution.
True.
Copper is produced at the cathode during electrolysis of copper chloride solution.
What is produced at the cathode during electrolysis of sodium chloride solution?
Hydrogen gas is produced at the cathode during electrolysis of sodium chloride solution.
What are the products of electrolysis of sodium sulfate solution?
The products of electrolysis of sodium sulfate solution are hydrogen at the cathode and oxygen at the anode.
What are the products of electrolysis of acidified water?
The products of electrolysis of acidified water are hydrogen at the cathode and oxygen at the anode.
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.
Define oxidation in terms of electron transfer.
Oxidation is when a substance loses electrons.
Define reduction in terms of electron transfer.
Reduction is when a substance gains electrons.
What happens at the anode during electrolysis?
At the anode, negatively charged ions lose electrons and are therefore oxidised.
What happens at the cathode during electrolysis?
At the cathode, positively charged ions gain electrons and are thus reduced.
What is a half equation?
A half equation is an equation that describes the movement of electrons at each electrode during electrolysis.
State the half equation for the reduction of Pb2+ ions at the cathode.
The half equation for the reduction of Pb2+ ions at the cathode is:
Pb2+ + 2e- → Pb
State the half equation for the oxidation of Br- ions at the anode.
The half equation for the oxidation of Br- ions at the anode is:
2Br- → Br2 + 2e-
True or False?
In half equations, the charges on each side of the equation should always balance.
True.
In half equations, the charges on each side of the equation should always balance.
State the half equation for the reduction of hydrogen ions at the cathode in aqueous solutions.
The half equation for the reduction of hydrogen ions at the cathode in aqueous solutions is:
2H+ + 2e- → H2
Balance the half equation for the oxidation of water molecules at the anode in acidic solutions:
.... H2O → O2 + .... H+ + .... e-
The balanced half equation for the oxidation of water molecules at the anode in acidic solutions is:
2H2O → O2 + 4H+ + 4e-