(i) Distinction based on physical properties:
(a) Smell Ethanoic acid has a pungent smell.
Ethanol has a pleasant smell.
(b) Melting point Ethanol has lower melting point (156 K) than ethanoic acid (290 K).
(c) Physical state Ethanoic acid is solid (glacial acetic acid) in winters but ethanol is always a liquid.
(ii) Distinctions based on chemical properties:
(a) Reaction with sodium hydrogen carbonate On adding a small amount of sodium hydrogen carbonate to ethanoic acid, carbon dioxide gas is evolved with brisk effervescence. However, no such reaction noticed in case of ethanol.
CH₃COOH + NaHCO₃ \(\rightarrow\) CH₃CO\(\bar{O}\)\(\overset{+}{N}\)a + CO₂\(\uparrow\) H₂O
Ethanoic acid
C₂H₅OH + NaHCO₃ \(\rightarrow\) No reaction
Ethanol
(b) Reaction with caustic alkalies Ethanoic acid reacts with both sodium hydroxide (NaOH) and potassium hydroxide (KOH) to form corresponding salt and water. Ethanol fails to react with either of these.
CH₃COOH + NaOH \(\rightarrow\) CH₃CO\(\bar{O}\)\(\overset{+}{N}\)a + H₂O
CH₃COOH + KOH \(\rightarrow\) CH₃CO\(\bar{O}\)\(\overset{+}{K}\) + H₂O

(i) Aldehyde : \(\underset{\\\\ \ -\mathrm{C}-\mathrm{H}}{\overset{\mathrm{O}}{||}}\)
(ii) Alcohol: -OH

Hydrogenation.

Carbon, due to Strong C-C bond.

Propyne C₃H₄

Those compounds, which have same molecular formula but different structural formulae are called isomers.

In first three members of alkane series, branching is not possible. Therefore, we cannot have isomers.

A is ethanol (C₂H₅OH) which is essential constituent of wine and beer and 'B' is acetic acid (CH₃COOH) which is present in vinegar.
\(\underset{(Present\ in\ wine\ and\ beer)\\ 'A'}{CH_3CH_2OH}+2[O]\xrightarrow[Oxidation]{Alkaline\ KMnO_4}\underset{Acid\\ (Present\ in\ vinegar)\\ 'B'}{CH_3COOH}+H_2O\)
When 'A' and 'B' react in the presence of an acid catalyst, ethyl ethanoate is formed.
 \(\underset{'A'}{CH_3COOH(l)}+\underset{'A'}{C_2H_5OH(l)}\xrightarrow{Conc. H_2SO_4} CH_3COOC_2H_5(l)+H_2O(l)\)

a) The electronic configuration of chlorine with atomic number 17 is
K L M
2 8 7
b) Electron dot structure of chlorine molecule Cl2 is

Carbon atoms have 4 electrons in their outcomes shell. So need to gain or lose electrons to attain noble gas configuration.
(i) It could gain four electrons forming c^4- anion. But it would be difficult for the nucleus with six protons to hold on to ten electrons.
(ii) It could lose four electrons forming C⁴⁺ cations. But it would require a large amount energy to remove four electrons from its outermost shell.
Because of these reasons, carbon shares its valence electrons to complete its octet with other atoms to form covalent bonds.
(a) Covalent compounds are bad conductors of electricity because they do not contain ions.
(b) Covalent compounds have usually low melting and boiling because they are made up of electronically neutral molecule. So the force of attraction between the molecules of a covalent compound is very weak. Only a small amount of heat energy is required to break these weak molecular forces, due to which covalent compounds have low melting and boiling points.

i) Since compound C on combustion forms two moles of CO₂ and 3 moles of H₂ O, therefore compound C must contain two carbon atoms and six hydrogen atmos. Thus compound C must be C₂H₆ (ethane)
\(\underset{Ethene(C)}{2C_2H_6}+\underset{Oxygen}{7O_2}\xrightarrow{Heat}\underset{Carbon\ dioxide}{4CO_2}+\underset{Water}{6H_2O}\)
ii) Since compound (C) is obtained by addition of 1 mole of H₂ in presence of Ni to compound (B), therefore (B) must be ethane.
\(\underset{Ethene(B)}{CH2}=CH_2+H_2\xrightarrow{Ni/Heat}\underset{Ethene(C)}{CH_3-CH_3}\)
iii) Since compound (B) is formed by heating compound (A) with cone. H₂SO₄ therefore compound (A) must be ethanol.
\(\underset{Ethanol(A)}{CH_3CH_2OH}\xrightarrow{Conc. H_2SO_4,443K}CH_2=CH_2+\underset{Ethene(B)}{H_2O}\)