Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Title: Alcohols Details Questions and Answers
Description: When one or more hydrogen atoms in an aliphatic hydrocarbon are replaced by one or more hydroxyl (OH) groups, the resulting compounds are known as alcohols. According to the number of the hydroxyl groups present in them, they are known as monohydric, dihydric, trihydric or polyhydric alcohols. In case of polyhydric alcohols (having more than one OH group), the hydroxyl groups are always present on different carbon atoms. It is because the alcohols having two or more OH groups attached to the same carbon are unstable.
Description: When one or more hydrogen atoms in an aliphatic hydrocarbon are replaced by one or more hydroxyl (OH) groups, the resulting compounds are known as alcohols. According to the number of the hydroxyl groups present in them, they are known as monohydric, dihydric, trihydric or polyhydric alcohols. In case of polyhydric alcohols (having more than one OH group), the hydroxyl groups are always present on different carbon atoms. It is because the alcohols having two or more OH groups attached to the same carbon are unstable.
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Chemistry
Alcohols
1
...
(i)
Ethanol is oxidised to ethanoic acid by an acidic solution of potassium dichromate
...
CH3 COOH + C2 H5 OH
2
...
Ethyl alcohol is used
3
...
As a solvent for fats and many other organic compounds
...
In the preparation of esters, used as perfumes
...
In the manufacture of chemical such as chloroform, chloral, iodoform, ether,
acetic acid, ethylene, etc
...
As a fuel in the form of power alcohol
...
As a beverage
...
As a preservative for biological specimens
...
As an antifreeze for automobile radiators
...
As an antiseptic in hospitals
9
...
10
...
g
...
in which alcohol
coloured with a dye is used
...
Fermentation is a slow anaerobic decomposition of big organic molecules into simpler ones
under the catalytic influence of non – living complex substance called ferments
...
Example:
C12H22O11
Sucrose
+ H2O
Invertase
C6H12O6
glucose or fructose
C6H12O6
glucose
Zymase
+ C6H12O6
fructose
2C5H5OH +
ethanol
2CO2
Note: The sugars formed are named as sucrose, maltose, fructose, glucose, etc
...
4
...
which on
hydrolysis with water form ethyl alcohol
...
Give any three uses of ethyl alcohol
...
1
...
2
...
3
...
What is esterification? Give example
...
When ethanol is warmed with ethanoic acid in presence of a few drops of concentrated
sulphuric acid, sweet smell of ethyl ethanoate (ethyl acetate) is produced
...
H2SO4
CH3 COO C2 H5 + H2 O
ethylacetate
7
...
Alcohols are classified according to the number of hydroxyl groups present
...
For example:
CH3CH2OH
ethyl alcohol
(monohydric)
CH2OH
|
CH2OH
ethylene glycol
(dihydric)
CH2OH
|
CHOH
|
CH2OH
glycerol (trihydric)
Monohydric Alcohols: Monohydric alcohols are classified as primary (1), secondary (2)
and Tertiary (3) alcohols depending upon whether the hydroxyl group is attached to a primary,
secondary or tertiary carbon atom
...
H
1
CH3 C OH
primary carbon
H
ethyl alcohol ( primary alcohol, 1)
(b) When the carbon atom having the – OH group is attached to two carbon atoms, the alcohol
is termed as secondary (2) alcohol
...
CH3
CH3
3
C OH
CH3
Tertiary carbon
t - Butyl alcohol (Tertiary alcohol, 3)
1
...
1
...
2C2H5OH
+ 2Na
Ethanol
2
...
C2H5OH
C2H5Cl + POCl3 + HCl
+ PCl5
Phosphorus
pentachloride
2
...
(a) When ethanol is treated with an acidic solution of potassium dichromate it is oxidised
to ethanoic acid
...
C2 H5 OH + 3 O2
Ethanol
2 CO2 + 3 H2O
3
...
Manufacture of Ethanol:
Fermentation process (From Molasses): Molasses is the mother liquor left over after the
crystallization of sugar from the sugarcane juice
...
The manufacturing process involves the following steps:
Step 1: Molasses is diluted with water to get 10% sugar solution
...
Step 3: Some amount of ammonium sulphate or ammonium phosphate is added as food for
yeasts
...
The enzyme invertase present in yeast hydrolysis sucrose into glucose and fructose the
enzyme zymase present in yeast converts glucose and fructose to ethyl alcohol and carbon
dioxide
...
Invertase
C12H22O11
sucrose
+
H2O
C6 H12 O6
Glucose or fructose
zymase
C6 H12 O6
glucose
2 C5 H5 OH
ethanol
+ C6 H12 O6
fructose
+ 2 CO2
Yeast is filtered off
...
It is also
called wash
...
5% alcohol and 4
...
This is called rectified spirit
...
13C
...
It is then distilled
...
Final traces of water are removed by distillation with calcium metal to get absolute
alcohol (100% alcohol)
...
4
...
Name and common name for the following compounds
Title: Alcohols Details Questions and Answers
Description: When one or more hydrogen atoms in an aliphatic hydrocarbon are replaced by one or more hydroxyl (OH) groups, the resulting compounds are known as alcohols. According to the number of the hydroxyl groups present in them, they are known as monohydric, dihydric, trihydric or polyhydric alcohols. In case of polyhydric alcohols (having more than one OH group), the hydroxyl groups are always present on different carbon atoms. It is because the alcohols having two or more OH groups attached to the same carbon are unstable.
Description: When one or more hydrogen atoms in an aliphatic hydrocarbon are replaced by one or more hydroxyl (OH) groups, the resulting compounds are known as alcohols. According to the number of the hydroxyl groups present in them, they are known as monohydric, dihydric, trihydric or polyhydric alcohols. In case of polyhydric alcohols (having more than one OH group), the hydroxyl groups are always present on different carbon atoms. It is because the alcohols having two or more OH groups attached to the same carbon are unstable.