Modeling Redox Reactions

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Redox Reaction Noun

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[ree-doks ree-ak-shun]

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Redox Reaction

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A chemical reaction characterized by the transfer of electrons between species, resulting in a change in their oxidation numbers.

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Example: This diagram models the combustion of methane, a type of redox reaction where atoms from methane and oxygen rearrange to form new molecules.

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Oxidation Number Noun

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[ok-si-day-shun num-ber]

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Oxidation Number

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A number assigned to an element in a compound representing the number of electrons lost or gained by its atoms.

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Example: This image shows that the same element, Nitrogen (N), can have different oxidation numbers (-3, -1, +2, +3, +5) in different molecules.

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Oxidation Noun

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[ok-si-day-shun]

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Oxidation

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The chemical process of losing one or more electrons during a reaction, which results in an increase in oxidation number.

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Example: This diagram shows a carbon atom (orange) being oxidized. It starts bonded to hydrogen atoms and ends up bonded to oxygen atoms, forming carbon dioxide.

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Reduction Noun

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[ri-duk-shun]

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Reduction

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The chemical process of gaining one or more electrons during a reaction, which results in a decrease in oxidation number.

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Example: In a redox reaction, atom B undergoes reduction by gaining an electron from atom A, causing its charge to become more negative.

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Oxidized Adjective

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[ok-si-dized]

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Oxidized

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Describes a substance that has lost electrons during a redox reaction, thereby increasing its oxidation state.

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Example: This diagram shows a sodium atom losing an electron to a chlorine atom. The process of losing an electron is called oxidation, so the sodium becomes oxidized.

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Reduced Adjective

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[ri-doost]

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Reduced

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Describes a substance that has gained electrons during a redox reaction, thereby decreasing its oxidation state.

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Example: This diagram shows that atom B is 'reduced' because it gains an electron from atom A during a chemical reaction, causing its charge to become negative.

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Oxidizing Agent Noun

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[ok-si-dize-ing ay-jent]

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Oxidizing Agent

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A substance that causes another substance to be oxidized by accepting its electrons, and is itself reduced in the process.

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Example: This Bohr model of an oxygen atom shows it has six valence electrons, making it unstable and likely to accept electrons from other atoms.

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Reducing Agent Noun

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[ri-doos-ing ay-jent]

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Reducing Agent

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A substance that causes another substance to be reduced by donating its electrons, and is itself oxidized in the process.

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Example: The diagram shows that the Reducing Agent (A) is the substance that loses electrons. This loss of electrons is called oxidation, and it causes another substance (B) to be reduced.

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Single-Replacement Reaction Noun

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[sing-gul ri-plays-ment ree-ak-shun]

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Single-Replacement Reaction

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A type of redox reaction where an element reacts with a compound and displaces another element in that compound.

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Example: This diagram shows an element (A) taking the place of another element (B) in a compound (BC), resulting in a new compound (AC) and a free element (B).

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Activity Series of Metals Noun

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[ak-tiv-i-tee seer-eez ov met-uls]

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Activity Series of Metals

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A list that ranks metals according to their reactivity, specifically their tendency to be oxidized and lose electrons.

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Example: This chart ranks metals from most reactive (top) to least reactive (bottom). A higher metal on the list can displace a lower metal in a reaction.