The strength depends on how easy it is to break H-O, that is, whether the group connected to -OH is electron-attracting or electron-pushing (phenol>H2O>HO-R)

The benzene ring forms a conjugated system with O, absorbing O electrons and helping O absorb H electrons.

H does not absorb or give electrons

Hydrocarbon group donates electrons

The larger the hydrocarbon group, the stronger the electron pushing effect and the weaker the acidity of the alcohol: methanol > primary alcohol > secondary alcohol > tertiary alcohol

Sodium alkoxide: colorless solid, used as a base in organic synthesis, alkaline: RONa>NaOH (judgment by poor electronegativity)

Alcohol Strong Acid/Lewis Acid (Containing Empty Orbitals) -> Amethyst Salt (Dissolved in Acid)

O provides a lone pair of electrons to form a coordination bond with the acid

-OH2 in aluminium salt is easy to lose, making the C-O bond easy to break, so substitution and elimination reactions generally use acids as catalysts

Avoid the production of C and no rearrangement, and can be used to prepare high-purity halogenated hydrocarbons.

H-X activity order: HI>HBr>HCl>>HF

nucleophilic substitution

140℃-form into ether

170℃-forming alkene

Generally only dehydration to alkenes occurs

R-CH2-CH2-OH H ——>R-CH2-CH2-OH2 ——>R-CH2-CH2 ——>RCH=CH2

不能用醇和卤代烃制备，酸性:HO-H>RO-H，R-X只能水解（碱性条件），不能醇解

Tertiary halogenated hydrocarbons

C=C-X/ph-X

X is not lively

Primary alcohol-acid

Secondary alcohol-ketone

Tertiary alcohol - not oxidized (same as benzene ring a-H oxidation)

Cr: 6 (orange) 3 (dark green)

Does not oxidize double bonds

Only oxidizes the hydroxyl group to the ketone carbonyl group

HIO4 is extremely oxidizing, directly breaking the C-C connected to -OH, and each fracture will combine with one -OH and then lose water.