Ethanol and Ethanoic Acid Questions in English

(N/A) $(i)$ Ethanoic acid $(CH_{3}COOH)$:
$H-C(H)(H)-C(=O)-OH$
$(ii)$ Yes,structural isomers are possible for bromopentane $(C_{5}H_{11}Br)$. Three common isomers are:
$1$. $1$-Bromopentane: $CH_{3}-CH_{2}-CH_{2}-CH_{2}-CH_{2}-Br$
$2$. $2$-Bromopentane: $CH_{3}-CH_{2}-CH_{2}-CH(Br)-CH_{3}$
$3$. $3$-Bromopentane: $CH_{3}-CH_{2}-CH(Br)-CH_{2}-CH_{3}$

(N/A) The chemical reaction is represented as: $\text{CH}_3\text{CH}_2\text{OH} \xrightarrow{[O]} \text{CH}_3\text{COOH}$.
An oxidation reaction is defined as the addition of oxygen or the removal of hydrogen from a substance.
In the conversion of ethanol $(\text{CH}_3\text{CH}_2\text{OH})$ to ethanoic acid $(\text{CH}_3\text{COOH})$, an oxygen atom is added to the molecule.
Since oxygen is added to ethanol to form ethanoic acid, this process is classified as an oxidation reaction.

(N/A) The chemical reaction for the combustion of ethyne is: $2HC \equiv CH + 5O_2 \to 4CO_2 + 2H_2O + \text{Heat}$.
When ethyne is burnt in air,it produces a sooty flame due to incomplete combustion caused by the limited supply of oxygen in the air.
However,when ethyne is burnt with pure oxygen,it undergoes complete combustion,producing a clean,high-temperature flame reaching approximately $3000 \, ^\circ C$.
This oxy-acetylene flame provides the necessary heat for welding metals.
It is not possible to attain such a high temperature using only air,which is why a mixture of ethyne and air is not used for welding.

(A) We can distinguish between an alcohol and a carboxylic acid based on their reaction with carbonates and hydrogen carbonates.
Carboxylic acids react with metal carbonates and metal hydrogen carbonates to evolve $CO_2$ gas,which turns lime water milky.
Reaction: $\text{Metal Carbonate} / \text{Metal Hydrogen carbonate} + \text{Carboxylic acid} \rightarrow \text{Salt} + \text{Water} + \text{Carbon dioxide}$.
Alcohols,on the other hand,do not react with carbonates or hydrogen carbonates,so no gas is evolved.

(N/A) Physical Properties:
$1$. Odour: Ethanol has a pleasant,characteristic alcoholic odour,whereas ethanoic acid has a pungent,vinegar-like smell.
$2$. Melting Point: The melting point of ethanoic acid is $17\,^{\circ}C$,which is below room temperature,causing it to freeze in winter. Ethanol has a much lower melting point $(-114\,^{\circ}C)$ and remains liquid at room temperature.
Chemical Properties:
$1$. Reaction with Carbonates/Hydrogencarbonates: Ethanoic acid reacts with metal carbonates and metal hydrogencarbonates to evolve $CO_{2}$ gas,which turns lime water milky. Ethanol does not react with these compounds.
Reaction:
$2CH_{3}COOH + Na_{2}CO_{3} \longrightarrow 2CH_{3}COONa + H_{2}O + CO_{2} \uparrow$
$CH_{3}CH_{2}OH + Na_{2}CO_{3} \longrightarrow \text{No reaction}$

(A) When ethanol $(C_2H_5OH)$ reacts with sodium metal $(Na)$,it undergoes a substitution reaction where the hydrogen atom of the hydroxyl group is replaced by sodium.
The chemical equation for this reaction is:
$2C_2H_5OH + 2Na \rightarrow 2C_2H_5ONa + H_2 \uparrow$
In this reaction,$C_2H_5ONa$ (sodium ethoxide) and $H_2$ (hydrogen gas) are formed.
Therefore,the correct products are sodium ethoxide and hydrogen.

(B) Butanoic acid is a carboxylic acid with a four-carbon chain. The general formula for a carboxylic acid is $R-COOH$. For butanoic acid,the chain length is $n=4$. The structure is $CH_3-CH_2-CH_2-COOH$. Option $B$ correctly represents this structure,where the carbon atoms are bonded in a linear chain and the terminal carbon is part of the carboxyl group $(-COOH)$.

(C) Vinegar is a common household substance used for cooking and preservation.
It is chemically defined as a dilute solution of acetic acid $(CH_3COOH)$.
The standard concentration of acetic acid in vinegar typically ranges from $5 \%$ to $8 \%$ by volume.
The solvent used in this solution is water.
Therefore,vinegar is a $5 \%-8 \%$ solution of acetic acid in water.

(N/A) The chemical formula of ethyne is $C_2H_2$.
In ethyne, there is a triple bond between the two carbon atoms and a single bond between each carbon atom and a hydrogen atom.
Electron dot structure: $H : C \vdots \vdots C : H$
Structural formula: $H - C \equiv C - H$

(A) The carboxylic acid is ethanoic acid $(CH_{3}COOH)$.
$(b)$ The alcohol is ethanol $(C_{2}H_{5}OH)$.
$(c)$ The compound $X$ is ethyl ethanoate $(CH_{3}COOC_{2}H_{5})$.
The reaction is an esterification reaction:
$CH_{3}COOH + C_{2}H_{5}OH \xrightarrow{H_{2}SO_{4}} CH_{3}COOC_{2}H_{5} + H_{2}O$

(N/A) Ethanol,when heated with excess concentrated sulphuric acid $(H_{2}SO_{4})$ at $443\, K$,undergoes dehydration to produce ethene.
The chemical reaction is as follows:
$CH_{3}CH_{2}OH \xrightarrow[443\, K]{\text{Hot conc. } H_{2}SO_{4}} CH_{2}=CH_{2} + H_{2}O$

(N/A) Methanol is oxidized to methanal in the liver.
Methanal reacts rapidly with the components of cells.
It causes the protoplasm to coagulate.
It also affects the optic nerve,causing blindness.

(N/A) When ethanol $(CH_{3}CH_{2}OH)$ reacts with sodium metal $(Na)$,it forms sodium ethoxide $(CH_{3}CH_{2}ONa)$ and releases hydrogen gas $(H_{2})$.
The balanced chemical equation for this reaction is:
$2CH_{3}CH_{2}OH + 2Na \rightarrow 2CH_{3}CH_{2}ONa + H_{2}$

(N/A) In this reaction,concentrated sulphuric acid acts as a dehydrating agent,which removes a water molecule from the ethanol molecule.
The balanced chemical equation is:
$CH_3CH_2OH \xrightarrow[443\, K]{\text{Hot conc. } H_2SO_4} CH_2=CH_2 + H_2O$

(N/A) The chemical equation for the reaction is:
$CH_{3}COOH + NaHCO_{3} \rightarrow CH_{3}COONa + H_{2}O + CO_{2}$
$X$ is sodium ethanoate $(CH_{3}COONa)$.
The gas evolved is carbon dioxide $(CO_{2})$.
Activity:
$1$. Take a test tube and add a small amount of sodium hydrogencarbonate $(NaHCO_{3})$ to it.
$2$. Add a few drops of ethanoic acid $(CH_{3}COOH)$ to the test tube.
$3$. You will observe effervescence due to the evolution of a gas.
$4$. Pass this gas through a delivery tube into another test tube containing lime water $(Ca(OH)_{2})$.
$5$. The lime water will turn milky,which confirms that the evolved gas is carbon dioxide $(CO_{2})$.
Chemical reaction with lime water:
$Ca(OH)_{2} + CO_{2} \rightarrow CaCO_{3} + H_{2}O$

(N/A) Activity:
$1$. Take $1 \, mL$ of ethanol (absolute alcohol) and $1 \, mL$ of glacial acetic acid in a test tube.
$2$. Add a few drops of concentrated sulphuric acid to the mixture.
$3$. Warm the mixture in a water-bath at about $60 \, ^\circ C$ for at least $15 \, \text{min}$ as shown in the diagram. (Note: It should not be heated directly on a flame because ethanol is highly flammable).
$4$. Pour the contents into a beaker containing $20-50 \, mL$ of water and smell the resulting mixture. $A$ sweet,fruity smell indicates the formation of an ester.
Reaction:
$CH_3COOH + CH_3CH_2OH \xrightarrow{Conc. H_2SO_4} CH_3COOCH_2CH_3 + H_2O$
(Ethanoic acid + Ethanol $\rightarrow$ Ethyl ethanoate + Water)

(A) is Ethanoic acid $(CH_3COOH)$.
$R$ is Sodium acetate $(CH_3COONa)$ and the gas evolved is Hydrogen $(H_2)$.
$A$ is Methanol $(CH_3OH)$.
$S$ is Methyl acetate $(CH_3COOCH_3)$.
$(a)$ Reaction with $Na$ metal:
$2CH_3COOH + 2Na \to 2CH_3COONa + H_2 \uparrow$
$(b)$ Esterification reaction:
$CH_3COOH + CH_3OH \xrightarrow{Conc. H_2SO_4} CH_3COOCH_3 + H_2O$
$(c)$ Reaction with $NaOH$ (Neutralization):
$CH_3COOH + NaOH \to CH_3COONa + H_2O$
$(d)$ Saponification reaction:
$CH_3COOCH_3 + NaOH \to CH_3COONa + CH_3OH$

(N/A) The calcium hydroxide solution will turn milky due to the formation of calcium carbonate.
$(b)$ The chemical reactions are as follows:
In test tube $A$: Ethanoic acid reacts with sodium carbonate to produce carbon dioxide gas.
$2CH_{3}COOH + Na_{2}CO_{3} \rightarrow 2CH_{3}COONa + H_{2}O + CO_{2}$
In test tube $B$: Carbon dioxide gas reacts with calcium hydroxide (lime water) to form calcium carbonate,which makes the solution milky.
$Ca(OH)_{2} + CO_{2} \rightarrow CaCO_{3} + H_{2}O$
Note: If excess $CO_{2}$ is passed through the solution,the milkiness disappears due to the formation of soluble calcium bicarbonate.
$CaCO_{3} + H_{2}O + CO_{2} \rightarrow Ca(HCO_{3})_{2}$

(A) Since one mole of compound $C$ gives $2$ moles of $CO_2$ and $3$ moles of $H_2O$, its molecular formula is $C_2H_6$ (Ethane).
Compound $C$ is obtained by the hydrogenation of compound $B$, so $B$ must be $C_2H_4$ (Ethene).
Compound $B$ is formed by the dehydration of compound $A$ using concentrated $H_2SO_4$, which indicates $A$ is an alcohol, specifically $C_2H_5OH$ (Ethanol).
Reaction $1$: $C_2H_5OH \xrightarrow{\text{Hot conc. } H_2SO_4} C_2H_4 + H_2O$
Reaction $2$: $C_2H_4 + H_2 \xrightarrow{Ni} C_2H_6$
Reaction $3$: $2C_2H_6 + 7O_2 \to 4CO_2 + 6H_2O + \text{Heat and light}$

(N/A) Butane has the chemical formula $C_{4}H_{10}$.
When one hydrogen atom is replaced by a hydroxyl group $(-OH)$,it forms an alcohol.
The molecular formula for butanol is $C_{4}H_{9}OH$ or $CH_{3}CH_{2}CH_{2}CH_{2}OH$.

(A) When a small piece of sodium metal is added to ethanol,it reacts to produce sodium ethoxide and hydrogen gas. The hydrogen gas is released as bubbles.
$2Na + 2C_{2}H_{5}OH \to 2C_{2}H_{5}ONa + H_{2} \uparrow$

(N/A) When $5\%$ alkaline $KMnO_4$ solution is added drop by drop to warm ethanol,the initial pink colour of the potassium permanganate solution disappears. This happens because the alkaline $KMnO_4$ acts as an oxidising agent and oxidises ethanol to ethanoic acid. The chemical reaction is: $CH_3CH_2OH + [O] \xrightarrow{\text{alkaline } KMnO_4} CH_3COOH + H_2O$. The name of the compound formed is Ethanoic acid.

(B) The melting point of pure ethanoic acid is $290 \,K$ $(17 \,^{\circ}C)$.
Because this temperature is close to room temperature in cold climates,it often freezes during winter.
When it freezes,it forms solid,ice-like flakes or crystals,which is why it is commonly referred to as glacial acetic acid.

(N/A) $(i)$ When ethanol is burnt in air,it undergoes combustion to produce carbon dioxide,water,and energy.
$CH_{3}CH_{2}OH + 3O_{2} \longrightarrow 2CO_{2} + 3H_{2}O + \text{Energy}$
$(ii)$ When ethanol is oxidized using oxidizing agents like alkaline $KMnO_{4}$ or acidified $K_{2}Cr_{2}O_{7}$,it is converted into ethanoic acid.
$CH_{3}CH_{2}OH \xrightarrow[\text{Acidified } K_{2}Cr_{2}O_{7}]{\text{Alkaline } KMnO_{4}} CH_{3}COOH$

(B) When $C_{2}H_{5}OH$ reacts with $CH_{3}COOH$,i.e.,ethanol with ethanoic acid,in the presence of concentrated $H_{2}SO_{4}$,a sweet-smelling ester is formed. This reaction is known as esterification.
The chemical equation is:
$CH_{3}COOH + C_{2}H_{5}OH \xrightarrow{Conc. H_{2}SO_{4}} CH_{3}COOC_{2}H_{5} + H_{2}O$
In this reaction,$CH_{3}COOC_{2}H_{5}$ is ethyl ethanoate,which is an ester.

(N/A) The three chemical reactions for the conversion of ethanoic acid $(CH_{3}COOH)$ to sodium ethanoate $(CH_{3}COONa)$ are as follows:
$1$. Reaction with Sodium Hydroxide (Neutralization):
$CH_{3}COOH + NaOH \rightarrow CH_{3}COONa + H_{2}O$
Reactant: Sodium hydroxide $(NaOH)$; Product: Water $(H_{2}O)$.
$2$. Reaction with Sodium Carbonate:
$2CH_{3}COOH + Na_{2}CO_{3} \rightarrow 2CH_{3}COONa + H_{2}O + CO_{2}$
Reactant: Sodium carbonate $(Na_{2}CO_{3})$; Products: Water $(H_{2}O)$ and Carbon dioxide $(CO_{2})$.
$3$. Reaction with Sodium Bicarbonate:
$CH_{3}COOH + NaHCO_{3} \rightarrow CH_{3}COONa + H_{2}O + CO_{2}$
Reactant: Sodium bicarbonate $(NaHCO_{3})$; Products: Water $(H_{2}O)$ and Carbon dioxide $(CO_{2})$.

(N/A) Three physical properties of ethanol:
$(i)$ Ethanol is a liquid at room temperature.
$(ii)$ It is a good solvent.
$(iii)$ It is a colourless liquid with a pleasant smell.
Three uses of ethanol:
$(i)$ It is used as an active ingredient in all alcoholic drinks.
$(ii)$ It is used in medicines such as tincture of iodine,cough syrups,and tonics.
$(iii)$ It is used as a solvent in the manufacturing of perfumes and paints.

(A) $X$ is Ethanol $(C_{2}H_{5}OH)$ and $Y$ is Hydrogen gas $(H_{2})$.
The chemical equation for the reaction is:
$2C_{2}H_{5}OH + 2Na \longrightarrow 2C_{2}H_{5}ONa + H_{2} \uparrow$
When $X$ (ethanol) is heated with excess concentrated sulphuric acid $(H_{2}SO_{4})$ at $443 \ K$,it undergoes dehydration to form Ethene $(C_{2}H_{4})$.
The name of the product is Ethene.
The structure of Ethene is $CH_{2}=CH_{2}$.

(N/A) The reaction is known as $Esterification$.
The chemical reaction is:
$CH_3COOH + C_2H_5OH \xrightarrow{Conc. H_2SO_4} CH_3COOC_2H_5 + H_2O$
The product obtained is $Ethyl \ ethanoate$ (an ester).

(N/A) $(i)$ Carboxylic acid: Ethanoic acid $(CH_{3}COOH)$. Structure: $CH_{3}-C(=O)OH$.
$(ii)$ Alcohol: Ethanol $(CH_{3}CH_{2}OH)$. Structure: $CH_{3}-CH_{2}-OH$.
$(iii)$ Compound $'X'$: Ethyl ethanoate $(CH_{3}COOC_{2}H_{5})$. Structure: $CH_{3}-C(=O)-O-CH_{2}-CH_{3}$.
Explanation: The reaction between ethanoic acid and ethanol in the presence of an acid catalyst is an esterification reaction,producing the ester ethyl ethanoate $('X')$.

(N/A) An atom or a group of atoms that determines the chemical properties of organic compounds is called a functional group. They confer specific properties to the compound,regardless of the length and nature of the carbon chain.

Organic compound	Functional group and Structure
$(i)$ Ethanol	Alcohol group $(-OH)$: $CH_{3}-CH_{2}-OH$
$(ii)$ Ethanoic acid	Carboxylic acid group $(-COOH)$: $CH_{3}-C(=O)OH$

(N/A) $(i)$ Substances that are capable of adding oxygen to other substances are known as oxidising agents.
$(ii)$ Alkaline potassium permanganate $(KMnO_4)$ or acidified potassium dichromate $(K_2Cr_2O_7)$ act as oxidising agents because they provide oxygen to oxidise alcohols into carboxylic acids.
$(iii)$ The oxidation reaction of ethanol is:
$CH_3CH_2OH \xrightarrow[\text{Acidified } K_2Cr_2O_7]{\text{Alkaline } KMnO_4} CH_3COOH$

(N/A) $(i)$ $A$ $5-8 \%$ solution of acetic acid in water is known as vinegar. Its use: It is commonly used as a preservative in pickles and various food items.
$(ii)$ When dilute ethanoic acid is added to sodium bicarbonate,carbon dioxide $(CO_2)$ gas is produced. Test: This gas turns lime water milky and extinguishes a burning splinter.

(N/A) $(a) (i)$ $2CH_{3}COOH + 2Na \rightarrow 2CH_{3}COONa + H_{2} \uparrow$
$(ii)$ $2CH_{3}COOH + Na_{2}CO_{3} \rightarrow 2CH_{3}COONa + H_{2}O + CO_{2} \uparrow$
$(iii)$ $CH_{3}COOH + C_{2}H_{5}OH \xrightarrow{\text{conc. } H_{2}SO_{4}} CH_{3}COOC_{2}H_{5} + H_{2}O$
$(b)$ Concentrated sulphuric acid acts as a dehydrating agent. It removes the water molecule formed during the reaction,which shifts the equilibrium forward,thereby increasing the yield of the ester.
$(c)$ Ethanoic acid is used as a preservative in pickles and for making vinegar.

(D) Vinegar is made by the fermentation of ethanol using bacteria like $Acetobacter$ $aceti$,which produces a $5-8\%$ aqueous solution of acetic acid.
$(b)$ Pure ethanoic acid (acetic acid) is known as glacial acetic acid because it freezes into an ice-like solid at temperatures below $290 \ K$.
$(c)$ Carboxylic acids are called weak acids because they do not ionize completely in an aqueous solution; they only partially dissociate into ions.
$(d)$ When the ester $CH_{3}COOC_{2}H_{5}$ (ethyl ethanoate) undergoes saponification,it reacts with a base (like $NaOH$) to form:
$1.$ Sodium ethanoate $(CH_{3}COONa)$
$2.$ Ethanol $(C_{2}H_{5}OH)$

(N/A) To distinguish between ethanol and ethanoic acid,the Sodium Hydrogen Carbonate $(NaHCO_3)$ test is used.
Procedure: Take a small amount of both substances in separate test tubes and add a pinch of solid $NaHCO_3$ to each.
Observation: Ethanoic acid reacts with $NaHCO_3$ to produce brisk effervescence due to the evolution of $CO_2$ gas.
Conclusion: Ethanol does not react with $NaHCO_3$ and shows no effervescence,thus allowing us to distinguish between the two.

(N/A) Ethanol undergoes dehydration in the presence of hot concentrated sulfuric acid $(H_2SO_4)$ at $443 \ K$ to form ethene:
$CH_3CH_2OH \xrightarrow[Conc. H_2SO_4]{443 \ K} CH_2=CH_2 + H_2O$
$(b)$ Ethanol undergoes oxidation in the presence of alkaline potassium permanganate $(KMnO_4)$ or acidified potassium dichromate $(K_2Cr_2O_7)$ to form ethanoic acid:
$CH_3CH_2OH \xrightarrow[alk. KMnO_4]{Oxidation} CH_3COOH$

(N/A) The alcohol with three carbon atoms is $Propanol$ (specifically $Propan-1-ol$).
The chemical formula is $C_{3}H_{7}OH$.
The structural formula is:
$CH_{3}-CH_{2}-CH_{2}-OH$

(N/A) $(i)$ Reaction with Sodium:
$2CH_{3}COOH + 2Na \longrightarrow 2CH_{3}COONa + H_{2}$
Main product: Sodium ethanoate.
$(ii)$ Reaction with Sodium hydroxide:
$CH_{3}COOH + NaOH \longrightarrow CH_{3}COONa + H_{2}O$
Main product: Sodium ethanoate.
$(iii)$ Reaction with Ethanol:
$CH_{3}COOH + C_{2}H_{5}OH \xrightarrow{acid} CH_{3}COOC_{2}H_{5} + H_{2}O$
Main product: Ethyl ethanoate (ester).

(A) $(i)$ $'A'$ is Ethanol $(CH_{3}CH_{2}OH)$ and $'B'$ is Ethanoic acid $(CH_{3}COOH)$.
$(ii)$ The reaction of Ethanoic acid with baking soda $(NaHCO_{3})$ is:
$CH_{3}COOH + NaHCO_{3} \longrightarrow CH_{3}COONa + CO_{2} \uparrow + H_{2}O$
This reaction releases carbon dioxide gas,which causes the observed effervescence.

(N/A) $(i)$ Ethanol test (Reaction with Sodium metal):
Ethanol reacts with sodium metal to evolve hydrogen gas,which can be tested by bringing a burning splinter near the gas,producing a 'pop' sound.
$2 CH_3CH_2OH + 2 Na \rightarrow 2 CH_3CH_2ONa + H_2 \uparrow$
$(ii)$ Ethanoic acid test (Esterification reaction):
Ethanoic acid reacts with ethanol in the presence of an acid catalyst to form an ester,which has a sweet,fruity smell.
$CH_3COOH + CH_3CH_2OH \xrightarrow{H^+} CH_3COOCH_2CH_3 + H_2O$
$(b)$ Pure ethanoic acid has a melting point of $290 \, K$. In cold climates,it often freezes into an ice-like solid during winter,which is why it is known as glacial acetic acid.

(D) The conversion of ethanol $(CH_3CH_2OH)$ to ethanoic acid $(CH_3COOH)$ involves the addition of oxygen or the removal of hydrogen.
This chemical process is known as oxidation.
In the presence of oxidizing agents like alkaline potassium permanganate $(KMnO_4)$ or acidified potassium dichromate $(K_2Cr_2O_7)$, ethanol is oxidized to ethanoic acid.
The reaction is: $CH_3CH_2OH + 2[O] \xrightarrow{alkaline KMnO_4/heat} CH_3COOH + H_2O$.

(C) Ethanol $(CH_{3}CH_{2}OH)$ can be oxidised to ethanoic acid $(CH_{3}COOH)$ using strong oxidising agents.
Alkaline potassium permanganate $(KMnO_{4})$ is a common oxidising agent used in laboratory settings to convert alcohols into carboxylic acids.
While acidic potassium dichromate $(K_{2}Cr_{2}O_{7})$ is also a strong oxidising agent,the question specifically asks for an alkaline agent,making alkaline $KMnO_{4}$ the correct choice.

(A) When ethanol $(C_2H_5OH)$ reacts with sodium metal $(Na)$,it undergoes a substitution reaction where the hydrogen atom of the hydroxyl group is replaced by sodium.
This reaction produces sodium ethoxide $(C_2H_5ONa)$ and releases hydrogen gas $(H_2)$.
The balanced chemical equation is: $2C_2H_5OH + 2Na \rightarrow 2C_2H_5ONa + H_2 \uparrow$.

(B) Vinegar is a common household substance used as a preservative and flavoring agent.
It is chemically defined as a dilute solution of acetic acid $(CH_3COOH)$.
Specifically,vinegar typically contains $5 \%-8 \%$ acetic acid dissolved in water.
Therefore,the correct option is $B$.

(FALSE) The statement is False.
When alcohols (such as ethanol) react with sodium metal,they produce sodium alkoxide and hydrogen gas $(H_2)$,not carbon dioxide $(CO_2)$.
The chemical equation for the reaction is:
$2CH_3CH_2OH + 2Na \rightarrow 2CH_3CH_2ONa + H_2 \uparrow$

(A) The statement is True.
When ethanol $(CH_3CH_2OH)$ is heated with excess concentrated sulphuric acid $(H_2SO_4)$ at $443 \,K$,it undergoes dehydration.
The concentrated sulphuric acid acts as a dehydrating agent,removing a water molecule from the ethanol.
The chemical reaction is: $CH_3CH_2OH \xrightarrow[443 \,K]{Conc. H_2SO_4} CH_2=CH_2 + H_2O$ (ethene).

(TRUE) True. Ethanoic acid $(CH_3COOH)$ is a weak organic acid. When it reacts with a strong base like sodium hydroxide $(NaOH)$,it undergoes a neutralization reaction to form sodium ethanoate $(CH_3COONa)$ and water $(H_2O)$. The chemical equation is: $CH_3COOH + NaOH \rightarrow CH_3COONa + H_2O$.

(B) Molasses is a dark,viscous byproduct of the sugar refining process,which is rich in sucrose $(C_{12}H_{22}O_{11})$.
In the process of fermentation,enzymes like invertase and zymase (produced by yeast) act on the sugars present in molasses.
First,invertase converts sucrose into glucose and fructose $(C_6H_{12}O_6)$.
Then,zymase converts these simple sugars into ethanol $(C_2H_5OH)$ and carbon dioxide $(CO_2)$.
Therefore,ethanol is the primary compound obtained through the fermentation of molasses.

(C) The solution of ethanol containing approximately $5\%$ water is known as Rectified spirit.
It is produced by the fractional distillation of fermented molasses or other sugar-containing substances.
Rectified spirit typically contains about $95\%$ ethanol and $5\%$ water by volume.
It is widely used as a solvent in industries and as a starting material for the preparation of absolute alcohol.