Alevel有機化學一定要掌握的11個定義！

Hydrocarbon:

A compound consisting of hydrogen and carbon only

這個概念很好理解，只有H和O組成的化合物，比如CH4.

Saturated:

Carbon chains that contain the maximum number of hydrogens per carbon; only single C-C bonds

飽和鍵，化合物中C-C之間都是單鍵

Unsaturated:

Carbon chains that don’t have the maximum number of hydrogens per carbon; contain C=C double bonds不飽和鍵，C和C之間是雙鍵（Double bond）或者三鍵（Triple bond）

Empirical formula:

The simplest whole number ratio of atoms of each element in the compound

最簡式；比如C2H6的Emprical fomula是CH3

Molecular formula:

The actual number of each type of atom in the compound

分子式；明確的給出每一種原子的個數，比如C2H6O

General formula:

Algebraic formula for a homologous series

通式；表示同一類化合物分子組成的公式，比如alkane，烷烴類的通式為CnH2n+2

Structural formula:

Shows the minimal detail of the arrangement of atoms in a molecule結構式

Displayed formula:

Shows all the covalent bonds present in a molecule

展示所有的原子和鍵

Skeletal formula:

Shows the simplest organic formula of the carbon skeleton and associated functional groups

Homologous Series:

Families of organic compounds with the same functional group and general formula

同系物；是指結構相似、通式相同、分子組成相差若干個“CH2”原子團的有機化合物；是同一類物質（含有相同且數量相等的官能團。比如：CH4；C2H6；C3H8

Functional group:

The atom/group of atoms which provide the chemical properties of a substance

官能團，是決定有機化合物的化學性質的原子或原子團。常見官能團碳碳雙鍵、碳碳三鍵、羥基、羧基、醚鍵、醛基、羰基等。有機化學反應主要發生在官能團上，官能團對有機物的性質起決定作用，如—X、OH、-CHO、-COOH、-NO2、-SO3H、-NH2、RCO-。