Alcohol Flashcards
Why do alcohols (and phenols) have higher mp BP than organic compounds with comparable size of e cloud?
Stronger intermolecular hydrogen bonding, lp of o bonds to H of other alcohols.
Why solubility of OH decrease as number of C increases?
Non-polar R group makes the alcohol more hydrophobic and energy comes from idid instead of hydro bond between h2o and oh which is not enough go overcome hydro bond between h20 and oh respectively
Why alcohol so weak as acid
Electron donating r group make alkoxide -ve charge intense and conjugate base destable
How to electrophilc addition alkane to alcohol?
Steam, H3po4 high T and P
OR
Cold Conc H2SO4 +hot water
Oxidation of 1 alcohol?
K2cr2O7, dil H2So4, heat with immediate distillation
To continue oxidising OR strong Oxidation, k2cr2o7/Kmno4 dil H2so4 heat
Oxidation of 2 alcohol?
Acidified(only diluted) K2cr2o7/kmno4, heat
Why phenol more acidic than water but alcohol isn’t?
Lp of O- delocalise into benzene ring’ dispersal -ve charge of phenoxide ion, BUT a electron donating side chain could intensify the-ve charge but vice versa for electron withdrawing side chains.
Why phenols only does condensation/esterification with acyl chloride and not cooh like alcohols?
Esterification is nucleophilic attack of OH on electron deficient carbon of cooh( OH ->H), but phenol weaker nucleophile cause lp of O delocalise into benzene
Why neutralisation with naoh(aq) increase rate of condensation for phenol?
Phenoxide stronger nucleophile
Why phenols don’t need conc H2so4 catalyst for nitration like benzene?
Lp of e from O delocalise. Increasing electron density in ring making it more reactive towards electrophile
Test via halogen E sub phenol?
Cl2 in ccl4 would decolonisation pale yellow while Br2 orange red would decolourise
