oxidation number
Let an agent explain how to assign oxidation numbers, use them in redox and nomenclature, and point to IUPAC definitions.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent explain how to assign oxidation numbers, use them in redox and nomenclature, and point to IUPAC definitions.
The hypothetical charge an atom would have if all its bonds to other atoms were fully ionic, also called oxidation state, assigned by rules such as oxygen usually being -2 and hydrogen +1; oxidation numbers track electron transfer in redox reactions and appear in names such as iron(III) oxide.
What it is for: Chemistry education, redox chemistry and naming compounds.
It can be assign oxidation numbers in a compound; identify oxidation and reduction in a reaction; balance redox equations; use Stock notation in names.
Distinguishing features
Hypothetical ionic charge
Assigned by rules
Tracks electron transfer
Used in nomenclature
What it looks like
Not physical; written as signed numbers or Roman numerals in names.
How it is recognised
Numbers such as +2 or -1 above symbols
Roman numerals in names like iron(III)
Formal charge is a different bookkeeping concept
Related models
is a kind of - category
is used in - application
is defined by - authority
is contrasted with - related concept
In practice
Families and kinds
positive and negative oxidation states
zero oxidation state of elements
fractional average oxidation states
Stock notation
Standards and regulation
IUPAC recommendations on oxidation state
Failure modes and hazards
Misapplying rules to peroxides or metal hydrides
Confusing oxidation state with real charge
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.oxidation-number
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Assign Rules.
Rules must be applied in order.
Rules
Assignment rules.
Rules
Assignment rules.
- What are the oxidation numbers of each atom in this compound? measurement
- Which rule takes priority? definition
Exceptions
Special cases.
Exceptions
Special cases.
- How are peroxides, superoxides and metal hydrides handled? definition
- When do fractional values appear? definition
Redox Reactions.
Changes show redox.
Identify
Oxidised or reduced.
Identify
Oxidation and reduction.
- Which species is oxidised and which is reduced in this reaction? definition
- How do oxidation numbers change? measurement
Balance
Balancing.
Balance
Balancing redox equations.
- How can this redox equation be balanced using oxidation numbers or half-equations? action
- Is the medium acidic or basic? boundary
Naming Nomenclature.
Names encode oxidation states.
Stock
Stock notation.
Stock
Stock notation.
- How is this compound named using Stock notation? provenance
- Which older names exist? provenance
IUPAC
Definitions.
IUPAC
IUPAC definition.
- How does IUPAC define oxidation state? provenance
- How does it treat ambiguous cases? provenance
Learning Teaching.
Practice builds skill.
Examples
Worked examples.
Examples
Worked examples.
- Can a step-by-step worked example be given? action
- Which misconceptions are common? provenance
Tools
Checking answers.
Tools
Checking.
- How can the answer be checked, such as by summing to the overall charge? action
- Which references help? provenance
What the second pass must settle
- Should special cases be separate entries?
- How should IUPAC definitions be linked?
- How should teaching examples be linked?