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Alkenes undergo hydration (addition of water across C=C bond) in presence of dilute H 2 SO 4 to produce alcohols. In the case of unsymmetrical alkenes, addition of water to the double bond is in accordance with Markownikoff’s rule. Industrially, the alkene obtained by cracking of hydrocarbons, is absorbed by passing it into sulphuric acid at k and atmospheric pressure. The acid is diluted and treated with steam to release the alcohol.

Alkyl halides are hydrolysed to the corresponding alcohols on boiling with aqueous alkali (NaOH or KOH) or moist silver oxide (Ag 2 O). RX + NaOH --------> R-OH + NaX CH 3 Br + NaOH -----------> CH 3 OH + NaBr Primary alkyl halides give a high yield of alcohols. But tertiary alkyl halides get dehydrogenated into alkenes. More Helpful article For YOU Preparation of alcohols from alkene by hydration Preparation of Alcohols from alkyl halides Preparation of Ethanol (Drinking Alcohol) Preparation of alcohols from Aldehydes and ketones Preparation of Methanol

Aldehydes and ketones are converted into alcohols by different methods, they are 1. Reduction 2. Using Grignard reagent Reduction Aldehydes and Ketones are reduced to the corresponding alcohols by 1. Addition of hydrogen in the presence of catalysts (catalytic hydrogenation), such as finely divided platinum, palladium, nickel and ruthenium 2. Treating aldehydes and ketones with chemical reagents such as sodium borohydride (NaBH4) or lithium aluminum hydride (LiAlH4). Aldehydes yield primary alcohols while ketones give secondary alcohols. R – CHO (Aldehyde) + H2 ----pd------> R CH2OH (primary alcohol) CH3CHO (Acetaldehyde) + H2 ----Ni------> CH3CH2OH (Ethanol) R CO R’ (Ketone) ----- 1.NaBH4 , 2.H2O ---> R – CH –R’–OH (secondary alcohol) UsIng Grignard reagent When Grignard reagent are treated with aldehydes or ketones, addition products (magnesium salt) are formed. These products on hydrolysis give alcohols. The overall result is to blind the alkyl group of Grignard reagent to ...