Preparation and Chemical Properties of Alcohols

Flashcards covering the industrial and laboratory preparation methods of alcohols, specific enzymatic processes, and chemical reactions like esterification and Grignard reagent interactions.

Preparation from Haloalkanes

A method where a haloalkane reacts with a dilute solution of alkali (e.g., $CH_3Cl + KOH \rightarrow CH_3OH + KCl$) to produce an alcohol.

Reduction of Aldehydes

The process of reducing an aldehyde using $Ni/Pt$ or $LiAlH_4$ to produce a primary alcohol.

Reduction of Ketones

The process of reducing a ketone using $Pt/LiAlH_4$ to produce a secondary alcohol.

Reduction of Carboxylic Acids

The process of reducing a carboxylic acid using $LiAlH_4$ to yield an alcohol (e.g., $CH_3COOH + 2H_2 \rightarrow CH_3CH_2OH + H_2O$).

Reaction of Primary Amines

Aliphatic primary amines react with $HNO_2$ to give alcohol.

Hydrolysis of Esters

The process where an ester, on hydrolysis in the presence of acids, gives an alcohol and a carboxylic acid.

Molasis

A dark brown sugar liquid containing $60\%$ sugar that is a waste material of the sugar industry, used for industrial alcohol preparation.

Conc. $H_2SO_4$ (in Molasis preparation)

A few drops added to the molasis solution to prevent unwanted bacterial growth.

Nutrients for yeast in Molasis

$(NH_4)_2 Soy$ and $(NH_4)_3 Poy$ are added to increase the working efficiency of the fermentation process.

Invertase

The enzyme in yeast that converts sucrose ($C_{12}H_{22}O_{11} + H_2O$) into glucose and fructose.

Zymase

The enzyme that converts glucose ($C_6H_{12}O_6$) into ethanol ($2C_2H_5OH$) and carbon dioxide ($2CO_2$).

Wash

The mixture obtained after fermentation that contains $6\text{--}10\%$ (or $10\text{--}12\%$) alcohol.

Mash

A starch solution obtained by steaming starchy substances like potatoes, rice, maize, or barley at $140$ to $150^\circ C$ under pressure.

Dia-stase

An enzyme that converts starch present in mash into maltose ($C_{12}H_{22}O_{11}$).

Malt

Dried germinated barley prepared by steeping in water at $203\text{--}206K$ for approximately 2 days, kept in the dark to stop germination, and then heated to $335K$.

Esterification

The reaction of alcohols (e.g., $H-O-R'$) with carboxylic acid ($R-COOH$) in the presence of conc. $H_2SO_4$ to produce an ester ($R-COO-R'$), known by the IUPAC name Alkyle Alkania.

Reaction with Grignard Reagent

The reaction of alcohols with $R-Mg-X$ (alkyle magnesium halide) to produce an alkane (e.g., $CH_3CH_2OH + CH_3MgBr \rightarrow CH_4 + Mg(OC_2H_5)Br$).