Why do most covalent compounds not conduct electricity? (Extended Tier Only)
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Why do most covalent compounds not conduct electricity? (Extended Tier Only)
Most covalent compounds do not conduct electricity because they have no freely moving charged particles (ions or electrons) to carry the current.
Why can't solid ionic compounds conduct electricity? (Extended Tier Only)
Solid ionic compounds cannot conduct electricity because the ions are in fixed positions and are unable to move.
What are the positive and negative electrodes called? (Extended Tier Only)
The positive and negative electrodes are called:
Positive = anode
Negative = cathode
True or False?
Molten ionic compounds can conduct electricity. (Extended Tier Only)
True.
Molten ionic compounds can conduct electricity.
During electrolysis, which electrode do cations move towards? (Extended Tier Only)
During electrolysis, cations (positive ions) move towards the negative electrode / cathode.
What is an insulator?
An insulator is a material that does not conduct electricity well.
What allows ionic compounds to conduct electricity in the molten state or in solution? (Extended Tier Only)
Ionic compounds can conduct electricity in the molten state or in solution because the ions can move and carry charge.
True or False?
Cations are positive and anions are negative. (Extended Tier Only)
True.
Cations are positive and anions are negative.
State the meaning of anion. (Extended Tier Only)
An anion is a negatively charged ion.
During electrolysis, which electrode do anions move towards? (Extended Tier Only)
During electrolysis, anions (negative ions) move towards the positive electrode / anode.
True or False?
In electrochemistry, electrons move from the cathode to the anode. (Extended Tier Only)
False.
In electrochemistry, electrons move from the anode to the cathode.
What type of electrodes are used in electrolysis experiments to avoid side reactions? (Extended Tier Only)
Inert electrodes,such as graphite or platinum, are used in electrolysis experiments to avoid side reactions with the electrolyte.
In terms of ions, how are electrolysis of molten and aqueous ionic compounds different? (Extended Tier Only)
In terms of ions, the electrolysis of molten ionic compounds has two ions, while electrolysis of aqueous ionic compounds has four ions.
During the electrolysis of a molten ionic compound, what is always produced at the anode (positive electrode)? (Extended Tier Only)
During the electrolysis of a molten ionic compound, the non-metal is always produced at the anode (positive electrode).
True or False?
The metal is always produced at the anode during the electrolysis of a molten ionic compound. (Extended Tier Only)
False.
The metal is always produced at the cathode during the electrolysis of a molten ionic compound.
What ions are present during electrolysis of a molten ionic compound? (Extended Tier Only)
The ions present during electrolysis of a molten ionic compound are:
The metal ion
The non-metal ion
What happens to the ions in an ionic compound when it is heated beyond its melting point? (Extended Tier Only)
When an ionic compound is heated beyond its melting point, the ions can move freely and conduct electricity.
What ions are present during electrolysis of an aqueous ionic compound? (Extended Tier Only)
The ions present during electrolysis of an aqueous ionic compound are:
The metal ion
The non-metal ion
The hydrogen ion
The hydroxide ion
What ions are attracted to the negative electrode (cathode) during the electrolysis of aqueous solutions? (Extended Tier Only)
During the electrolysis of aqueous solutions, hydrogen ions (H⁺) and metal ions are attracted to the negative electrode (cathode).
True or False?
Inverted test tubes can be used to collect gaseous products during the electrolysis of aqueous solutions. (Extended Tier Only)
True.
Inverted test tubes can be used to collect gaseous products during the electrolysis of aqueous solutions.
What ions are attracted to the positive electrode (anode) during the electrolysis of aqueous solutions? (Extended Tier Only)
During the electrolysis of aqueous solutions, hydroxide ions (OH⁻) and non-metal ions are attracted to the positive electrode (anode).
True or False?
If the metal is below hydrogen in the reactivity series, hydrogen will be produced at the cathode during the electrolysis of aqueous solutions. (Extended Tier Only)
False.
If the metal is above hydrogen in the reactivity series, hydrogen will be produced at the cathode during the electrolysis of aqueous solutions.
In terms of electron transfer, define oxidation. (Extended Tier Only)
In terms of electron transfer, oxidation is the process where a substance loses electrons.
Define reduction in terms of electrons. (Extended Tier Only)
Reduction is the process where a substance gains electrons.
What happens at the anode during electrolysis? (Extended Tier Only)
At the anode, negatively charged ions lose electrons and are oxidised.
What happens at the cathode during electrolysis? (Extended Tier Only)
At the cathode, positively charged ions gain electrons and are reduced.
What is the half equation for the reduction of Pb2+ ions? (Extended Tier Only)
Tthe half equation for the reduction of Pb2+ ions is:
Pb2+ + 2e- → Pb
Write the ionic equation for the oxidation of Br– during electrolysis of molten lead(II) bromide. (Extended Tier Only)
Tthe ionic equation for the oxidation of Br– is:
2Br- → Br2 + 2e-
What is the half-equation for the reduction of H+ during electrolysis of dilute sulfuric acid? (Extended Tier Only)
The half-equation for the reduction of H+ is:
2H+ + 2e- → H2
What is produced at the positive electrode during the electrolysis of aqueous sodium chloride? (Extended Tier Only)
Chlorine gas is produced at the positive electrode during the electrolysis of aqueous sodium chloride.
What is the product at the positive electrode during the electrolysis of aqueous copper(II) sulfate? (Extended Tier Only)
Oxygen gas is produced at the positive electrode during the electrolysis of aqueous copper(II) sulfate.
State the half-equation for the oxidation of Cl- during the electrolysis of aqueous sodium chloride. (Extended Tier Only)
The half-equation for the oxidation of Cl- during the electrolysis of aqueous sodium chloride is:
2Cl- → Cl2 + 2e-
State the half-equation for the reduction of Cu2+ during the electrolysis of aqueous copper(II) sulfate. (Extended Tier Only)
The half-equation for the reduction of Cu2+ during the electrolysis of aqueous copper(II) sulfate is:
Cu2+ + 2e- → Cu
What is produced at the positive electrode during electrolysis of dilute sulfuric acid? (Extended Tier Only)
During the electrolysis of dilute sulfuric acid, oxygen gas is produced at the positive electrode.
True or False?
In electrochemistry, oxidation and reduction refer to the loss or gain of electrons rather than the addition or removal of oxygen. (Extended Tier Only)
True. In electrochemistry, oxidation and reduction refer to the loss or gain of electrons rather than the addition or removal of oxygen