--%>
Assignment Help - homework help

Explain methods for industrial preparation of alcohol.

The important methods for the preparation of alcohol on large-scale are given below:
    
By hydration of Alkenes

Alkenes are obtained by cracking of petroleum. They are easily converted to alcohols by the addition of water in presence of sulphuric acid.
                                 
1907_alcohol preparation.png 

In case of unsymmetrical alkenes, the addition takes place according to Markowniko's rule.
                          
681_alcohol preparation1.png 
    
By fermentation of carbohydrates

Formation of ethyl alcohol by the fermentation of sugar (obtained from molasses, grapes or beet) is one of the oldest methods. Sucrose is first of all changed to glucose and fructose with an enzyme invertase.
                                
1330_alcohol preparation2.png 

Enzyme zymase after that converts glucose and fructose into ethanol.

The enzyme zymase is present in yeast.
                              
65_alcohol preparation3.png 

The fermentation procedure is taken out under anaerobic conditions i.e. in the nonexistence of air. Carbon dioxide released during fermentation keeps the fermentation mixture out of contact of air. If the fermentation mixture gets exposed to air, the oxygen of air oxidizes ethanol to ethanoic acid which makes the mixture sour.

Ethanol is obtained from starchy materials such as barley, rice, maize and potatoes with enzymes diastase and maltase.
                        
1057_alcohol preparation4.png 

Enzyme diastase is obtained from germinated barley while enzyme maltase and zymase are obtained from yeast.
    
Oxo process

Alkenes react with carbon monoxide and hydrogen in the presence of Octacarbonyl dicobalt Co[CO]
                       
1121_alcohol preparation5.png

   Related Questions in Chemistry

  • Q : Question based on normality Provide

    Provide solution of this question. A 5 molar solution of H2SO4 is diluted from 1 litre to 10 litres. What is the normality of the solution : (a) 0.25 N (b) 1 N (c) 2 N (d) 7 N

    		•
  • Q : Molecular Properties Symmetry Molecular

    Molecular orbitals and molecular motions belong to certain symmetry species of the point group of the molecule.Examples of the special ways in which vectors or functions can be affected by symmetry operations are illustrated here. All wave functions soluti

    		•
  • Q : Normality of acetic acid Give me answer

    Give me answer of this question. The normality of 10% (weight/volume) acetic acid is: (a)1 N (b)10 N (c)1.7 N (d) 0.83 N

    		•
  • Q : Functions of centrioles Describe

    Describe briefly the functions of centrioles?

    		•
  • Q : Dipole attractions-London dispersion

    Describe how dipole attractions, London dispersion forces and the hydrogen bonding identical?

    		•
  • Q : Haloalkene with the help of polarity of

    with the help of polarity of c-x bond show that aryl halides are less reactive than alkyl halides

    		•
  • Q : Moles of chloride ion Select the right

    Select the right answer of the question. A solution of CaCl2 is 0.5 mol litre , then the moles of chloride ion in 500ml will be : (a) 0.25 (b) 0.50 (c) 0.75 (d)1.00

    		•
  • Q : Volumes of solution after concentration

    Hydrochloric acid solution A and B encompass concentration of 0.5N and 0.1N  corresspondingly. The volumes of solutions A and B needed to make 2liters of 0.2N of HCL are: (i) 0.5l of A + 1.5l of B (ii) 1.5l of A + 0.5 l of B  (iii) 1.0 l of A + 1.0l of B&nbs

    		•
  • Q : Molarity of solution Help me to go

    Help me to go through this problem. When 7.1gm Na2SO4 (molecular mass 142) dissolves in 100ml H2O , the molarity of the solution is: (a) 2.0 M (b) 1.0 M (c) 0.5 M (d) 0.05 M

    		•
  • Q : Utilization of glacial acetic acid What

    What is the utilization of glacial acetic acid? Briefly describe the uses.

    		•