Redox, Electrolysis Flashcards
(25 cards)
What is oxidation?
The loss of electrons or gain of oxygen.
What is reduction?
The gain of electrons or loss of oxygen.
What is a redox reaction?
A reaction where both oxidation and reduction occur.
In terms of electrons, what happens during oxidation?
Electrons are lost.
In terms of electrons, what happens during reduction?
Electrons are gained.
What is the mnemonic for redox?
OIL RIG: Oxidation Is Loss, Reduction Is Gain (of electrons).
What happens in a displacement reaction?
A more reactive metal displaces a less reactive one, involving electron transfer.
What is electrolysis?
The breaking down of a substance using electricity.
What is an electrolyte?
A liquid or solution that conducts electricity and contains ions.
What is an electrode?
A conductor through which electricity enters or leaves the electrolyte.
What are the names of the two electrodes?
Anode (positive) and cathode (negative).
What happens at the cathode during electrolysis?
Reduction – positive ions gain electrons.
What happens at the anode during electrolysis?
Oxidation – negative ions lose electrons.
What is the product at the cathode in molten electrolysis?
The metal.
What is the product at the anode in molten electrolysis?
The non-metal element.
What is an example of electrolysis of a molten compound?
Electrolysis of molten lead bromide (PbBr₂).
What is extracted by electrolysis of aluminium oxide?
Aluminium.
Why is cryolite used in aluminium extraction?
To lower the melting point of aluminium oxide and reduce energy costs.
Which ions are attracted to the cathode?
Positive ions (cations).
Which ions are attracted to the anode?
Negative ions (anions).
In aqueous electrolysis, what other ions are present?
H⁺ and OH⁻ from water.
What forms at the cathode in aqueous solutions?
The least reactive positive ion or hydrogen (H₂).
What forms at the anode in aqueous solutions?
Oxygen unless halide ions are present, then the halogen is released.
What is the half-equation for hydrogen at the cathode?
2H⁺ + 2e⁻ → H₂
