redox reaction terms

Oxidising agent

A substance that oxidises another atom or ion by causing it to lose electrons, while itself getting reduced.

Reducing agent

A substance that reduces another atom or ion by causing it to gain electrons, while itself getting oxidised.

Redox reaction

A chemical reaction involving the transfer of electrons between two species, consisting of both oxidation and reduction processes.

Half equation

An equation that shows either the oxidation or reduction process in a redox reaction.

Electrochemical cell

A device that generates electrical energy from chemical reactions or causes chemical changes through the introduction of electricity.

Primary alcohol

An alcohol whose -OH group is attached to a carbon atom bonded to only one other carbon atom.

Secondary alcohol

An alcohol whose -OH group is attached to a carbon atom bonded to two other carbon atoms.

Tertiary alcohol

An alcohol whose -OH group is attached to a carbon atom bonded to three other carbon atoms.

Lithium aluminium hydride (LiAlH4)

A strong reducing agent used to reduce carboxylic acids and aldehydes to primary alcohols.

Sodium borohydride (NaBH4)

A less reactive reducing agent used to reduce aldehydes and ketones, but not carboxylic acids.

Hydrogenation

The process of adding hydrogen to unsaturated compounds to convert them into saturated compounds.

Electrolysis

A process in which electrical energy is used to drive a non-spontaneous chemical reaction, breaking down compounds into their components.

Voltaic cell

An electrochemical cell that generates electricity from spontaneous redox reactions.

Electrolytic cell

An electrochemical cell that consumes electricity to drive chemical reactions.

Manganate(VII) titration

A type of redox titration where manganate(VII) ions are used to determine the concentration of reducing agents.

Iodine-thiosulfate titration

A redox titration that involves the reaction of iodine with thiosulfate ions, commonly used to analyze oxidizing agents.

Oxidation

A process that involves the loss of electrons, an increase in oxidation state, the gain of oxygen, or the loss of hydrogen.

Reduction

A process that involves the gain of electrons, a decrease in oxidation state, the loss of oxygen, or the gain of hydrogen.

Oxidizing agent

The species that gets reduced in a chemical reaction, meaning it gains electrons and causes another species to be oxidized.

Reducing agent

The species that gets oxidized in a chemical reaction, meaning it loses electrons and causes another species to be reduced.

Oxidized species

The species that loses electrons and undergoes an increase in oxidation state during a redox reaction.

Reduced species

The species that gains electrons and undergoes a decrease in oxidation state during a redox reaction.

Half-equation

An equation that shows either the oxidation or reduction process separately, indicating the gain or loss of electrons.

How are oxidation states deduced?

Oxidation states are deduced by following a set of rules, typically involving assigning known oxidation states to common elements (like oxygen as -2 and hydrogen as +1) and then calculating the unknown oxidation state for the remaining atom, ensuring the sum of oxidation states equals the charge of the compound or ion.

Advantages of using oxidation states

Advantages include providing a systematic way to track electron transfer in redox reactions, helping to balance redox equations, and understanding the reactivity of elements across various compounds.

Limitations of using oxidation states

Limitations include that oxidation states are theoretical assignments, not always reflective of actual charges, and can sometimes be ambiguous, especially in covalent compounds where electron sharing is more complex than a simple transfer.

Oxidation numbers in naming compounds

Oxidation numbers are used in naming compounds, particularly for transition metals and other elements that exhibit variable oxidation states, to clearly indicate the specific oxidation state of the metal (e.g., Iron(II) chloride where Fe has an oxidation state of +2).

Corrosion

The surface oxidation of metals which can lead to degradation and structural damage.

Consequences of corrosion

Consequences include material degradation, structural failure, safety hazards, economic losses due to repair and replacement, and environmental impact from corroded materials or corrosion products.

Reactive metal + dilute acid reaction

Reactive metals react with dilute acids to produce a salt and hydrogen gas. For example, Mg(s) + 2HCl(aq) \rightarrow MgCl2(aq) + H2(g)