alcohols ether phenol Flashcards
- GR
The relative ease of dehydration of alcohol is tert>sec>pri
the +R effect of teh OH grp increases the electron density at O and P positions in phenol
10 1
Ethanol<H2O<Phenol
- (-I) Effect, electron density decreases on oxygen atom
- Phenoxide ion is more stable due to resonance
10 2
CO bond in phenol is stronger than the CH3OH
Phenol due to +R effect CO has partial double bond character.
- CO bond in CH3OH is a single bond
10 3
Alcohols and ethers have different boiling point
Ether has only dipole - dipole interaction which is weaker, alc has intermolecular H bonding.
10 4
C-OH bond angle is less than C-O-C bond
sp3 hybridized ROH has lp-lp repulsion which is greater. Therefore bond angle is lower than tetrahedral but ethers due to their large bulky alkyl grps have greater repulsion C-O-C bond angle is greater than tetrahedral angle.
10 5
p-nitrophenol is more acidic than o-nitrophenol
p-nitrophenol has NO2 gp in the p position. Therefore the -R effect is more dominant in the para position than o position.
10 6
Ditertbutyl ether cannot be prepared by williamson’s synthesis
Di tert butyl requires (CH3)3CONa and (CH3)3CBr
which is more sterically hindered and undergoes dehydrogenation (beta elemination) in the presence of a strong nucleophile. then substitution and then forms an alkene.
10 7
Sodium phenoxide is used in Kolbe’s rxn
In Sodium phenoxide ionization is easier.
Therefore, phenoxide acts as a strong nucleophile for weaker electrophile O=C=O.
10 8
Phenol is more easily nitrated than benzene
+R effect of OH grp increases electron density o and p position in phenol.
10 9
H2O>R-OH>CH≡CH
acidic strength
Strong acid displace weak acid from its salt.
H2O + RONa –> ROH + NaOH
H2O + HC≡CNa –> HC≡CH + NaOH
ROH + HC≡CNa–> HC≡CH + RONa
10 10
ocresol<Phenol<o-nitrophenol
acidic strength
