Mix Examples - Carbon and its Compounds Questions in English

(C) In $IUPAC$ nomenclature,functional groups are identified by specific suffixes.
$1$. The suffix $-ol$ is used for the alcohol functional group,which is represented by the hydroxyl group $-OH$.
$2$. The suffix $-al$ is used for aldehydes $(-CHO)$.
$3$. The suffix $-one$ is used for ketones $(>C=O)$.
$4$. Halogens $(-X)$ are indicated by prefixes like chloro-,bromo-,etc.
Therefore,the correct option is $C$.

(D) Methyl ethanoate is an organic compound with the chemical formula $CH_3COOCH_3$.
It belongs to the class of organic compounds known as esters.
The general formula for an ester is $R-COO-R'$,where $R$ and $R'$ are alkyl groups.
In methyl ethanoate,the functional group present is the ester group $(-COO-)$.
Therefore,the correct option is $D$.

(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.

(C) Formalin is an aqueous solution of formaldehyde.
Formaldehyde is the simplest aldehyde with the chemical formula $HCHO$.
It is commonly used as a disinfectant and a preservative for biological specimens.

(C) The reduction of an aldehyde results in the formation of a primary alcohol.
Methanal $(HCHO)$ is the simplest aldehyde with one carbon atom.
When methanal undergoes reduction (addition of hydrogen),it is converted into methanol $(CH_{3}OH)$.
The chemical reaction is: $HCHO + 2[H] \rightarrow CH_{3}OH$.

(D) The Fischer-Tropsch process is a collection of chemical reactions that converts a mixture of carbon monoxide $(CO)$ and hydrogen $(H_2)$ into liquid hydrocarbons.
This process is primarily used to produce synthetic fuels,such as synthetic gasoline or diesel,and various alcohols like ethanol $(C_2H_5OH)$.
Among the given options,ethanol is the product that can be synthesized using this industrial method.

(A) Propanone,commonly known as acetone,is a widely used organic solvent.
It is primarily used as a nail polish remover because it can dissolve various organic substances,including the polymers found in nail polish.
It is not used as an antiseptic,antibiotic,or preservative in common applications.

(D) The reaction between a carboxylic acid and an alcohol in the presence of an acid catalyst,such as concentrated $H_{2}SO_{4}$,is known as esterification.
In this reaction,the carboxylic acid and alcohol combine to form an ester and water.
The general chemical equation is: $RCOOH + R'OH \xrightarrow{conc. H_{2}SO_{4}} RCOOR' + H_{2}O$.
Concentrated $H_{2}SO_{4}$ acts as a dehydrating agent and a catalyst in this process.

(C) The functional group $>C=O$ represents a ketone.
For a ketone to exist,the carbonyl carbon $(C=O)$ must be bonded to two other carbon atoms (one on each side).
Therefore,the simplest ketone is propanone $(CH_3-CO-CH_3)$,which contains $3$ carbon atoms.
In contrast,$-COOH$ (carboxylic acid) and $-CHO$ (aldehyde) can exist with only $1$ carbon atom (e.g.,methanoic acid $HCOOH$ and methanal $HCHO$).
$-C-O-$ (ether) can exist with $2$ carbon atoms (e.g.,dimethyl ether $CH_3-O-CH_3$).

(C) Polythene is a polymer formed by the addition polymerization of ethene monomers.
In this process,many molecules of ethene $(CH_{2}=CH_{2})$ undergo a chemical reaction under high pressure and temperature in the presence of a catalyst to form a long-chain polymer known as polythene (polyethylene).
The chemical equation is: $n(CH_{2}=CH_{2}) \rightarrow -[CH_{2}-CH_{2}]_{n}-$.
Therefore,the correct monomer is ethene $(CH_{2}=CH_{2})$.

(D) Acetic acid $(CH_3COOH)$ has several industrial and domestic applications:
$1$. It is primarily used in the preparation of vinegar,which typically contains $5-8\%$ acetic acid in water.
$2$. It is used in the manufacturing of white lead,a pigment used in paints.
$3$. It serves as an important chemical reagent in laboratories and industries for the synthesis of various organic compounds like esters and polymers.

(D) Neoprene is a synthetic rubber produced by the polymerization of chloroprene.
It possesses excellent chemical stability and maintains flexibility over a wide temperature range.
Due to its high resistance to oil,heat,and weathering,it is widely used in the manufacturing of conveyor belts,gaskets,and hoses.

(B) The functional group present in alcohols is the hydroxyl group,which is represented as $-OH$.
- Option $A$ $(-CHO)$ represents the aldehyde group.
- Option $B$ $(-OH)$ represents the hydroxyl group,characteristic of alcohols.
- Option $C$ $(-COOH)$ represents the carboxylic acid group.
- Option $D$ $(>C=O)$ represents the carbonyl group found in ketones.

(C) When one hydrogen atom of an alkane is replaced by a hydroxyl group $[-OH]$,the resulting compound belongs to the class of organic compounds known as alcohols.
The general formula for an alkane is $C_nH_{2n+2}$.
Replacing one hydrogen atom with an $-OH$ group gives the general formula $C_nH_{2n+1}OH$,which represents an alcohol.
For example,replacing one hydrogen in methane $(CH_4)$ with an $-OH$ group results in methanol $(CH_3OH)$.

(A) The general formula for an alkane is $C_{n}H_{2n+2}$.
When one hydrogen atom is replaced by a hydroxyl group $(-OH)$ in an alkane,it forms an alcohol.
Replacing one $H$ atom from $C_{n}H_{2n+2}$ gives the alkyl group $C_{n}H_{2n+1}$.
Attaching the $-OH$ group to this alkyl group results in the general formula for alcohol,which is $C_{n}H_{2n+1}OH$.

(B) Methanol is the simplest alcohol,belonging to the homologous series of alcohols with the general formula $C_{n}H_{2n+1}OH$.
For methanol,the number of carbon atoms $n = 1$.
Substituting $n = 1$ into the general formula: $C_{1}H_{2(1)+1}OH = CH_{3}OH$.
Therefore,the molecular formula of methanol is $CH_{3}OH$.

(A) Ethyl alcohol,also known as ethanol,is a primary alcohol with the chemical formula $C_{2}H_{5}OH$.
It consists of an ethyl group $(C_{2}H_{5})$ attached to a hydroxyl group $(-OH)$.
Option $A$ represents ethanol,while option $B$ represents methanol,option $C$ represents propanoic acid,and option $D$ represents acetaldehyde.

(B) Biochemical catalysts are substances that increase the rate of chemical reactions occurring within living organisms without being consumed in the process.
These biological catalysts are known as $Enzymes$.
Most $Enzymes$ are proteinaceous in nature and are essential for metabolic processes such as digestion,respiration,and $DNA$ replication.

(A) The conversion of milk into curd is a biological process carried out by lactic acid bacteria,commonly known as $Lactobacillus$.
These bacteria produce lactic acid,which coagulates the milk protein called casein,resulting in the formation of curd.
$Lactase$ is an enzyme that breaks down lactose (milk sugar),$Sucrase$ breaks down sucrose,and $Zymase$ is involved in fermentation.
Since the question asks for the agent responsible for this conversion,$Lactobacillus$ is the correct biological agent.

(C) The formation of curd from milk is a fermentation process carried out by Lactic Acid Bacteria $(LAB)$,such as Lactobacillus.
During this process,the bacteria convert the milk sugar,known as lactose,into lactic acid.
This increase in acidity causes the milk proteins (casein) to coagulate,resulting in the thickening of milk into curd.

(D) Fermentation is an anaerobic metabolic process that converts sugar into acids,gases,or alcohol.
In the process of alcoholic fermentation,yeast breaks down glucose into ethanol and carbon dioxide $(CO_{2})$.
The release of $CO_{2}$ gas during this process creates bubbles or effervescence in the mixture.

(C) The hydrolysis of sucrose (sugar or molasses) into glucose and fructose is catalyzed by the enzyme $Invertase$.
The chemical reaction is as follows:
$C_{12}H_{22}O_{11} (sucrose) + H_2O \xrightarrow{Invertase} C_6H_{12}O_6 (glucose) + C_6H_{12}O_6 (fructose)$.
$Zymase$ is the enzyme responsible for the further conversion of glucose and fructose into ethanol and carbon dioxide.

(A) The fermentation of glucose or fructose is a biochemical process carried out by yeast.
In this process, the enzyme $Zymase$ acts as a catalyst.
The chemical reaction is: $C_6H_{12}O_6 \xrightarrow{Zymase} 2C_2H_5OH + 2CO_2$.
$Invertase$ is used to convert sucrose into glucose and fructose, whereas $Zymase$ is responsible for the conversion of these sugars into ethanol and carbon dioxide.

(D) When $CH_3OH$ (Methanol) is added to ethanol $(C_2H_5OH)$ as an adulterant,it becomes toxic. Methanol is oxidized to methanal in the liver. Methanal reacts rapidly with the components of cells,causing the protoplasm to coagulate. Furthermore,methanol affects the optic nerve,leading to blindness and potentially death.

(C) The modern industrial production of ethanol involves the direct hydration of ethene $(C_2H_4)$.
This reaction is carried out by passing a mixture of ethene and steam over a catalyst.
The catalyst used is typically phosphoric acid $(H_3PO_4)$ supported on silica, but in many textbook contexts, concentrated sulfuric acid $(H_2SO_4)$ is cited as the dehydrating/hydrating agent used in the industrial process to facilitate the addition of water to the double bond of ethene.
The reaction is: $C_2H_4 + H_2O \xrightarrow{H_2SO_4} C_2H_5OH$.

(B) When ethanol $(C_{2}H_{5}OH)$ reacts with sodium $(Na)$ metal,it forms sodium ethoxide $(C_{2}H_{5}ONa)$ and releases hydrogen gas $(H_{2})$.
The chemical equation for this reaction is:
$2C_{2}H_{5}OH + 2Na \rightarrow 2C_{2}H_{5}ONa + H_{2} \uparrow$
Therefore,the gas produced is hydrogen $(H_{2})$.

(D) The reaction between a carboxylic acid (acetic acid) and an alcohol (ethanol) in the presence of an acid catalyst (concentrated $H_{2}SO_{4}$) is known as esterification.
In this reaction, the hydroxyl group $(-OH)$ of the acid and the hydrogen atom $(-H)$ of the alcohol combine to form a water molecule $(H_{2}O)$, while the remaining parts join to form an ester called ethyl acetate $(CH_{3}COOCH_{2}CH_{3})$.
The chemical equation is: $CH_{3}COOH + C_{2}H_{5}OH \xrightarrow{conc. H_{2}SO_{4}} CH_{3}COOC_{2}H_{5} + H_{2}O$.

(B) Ethyl acetate is an ester formed by the reaction between acetic acid $(CH_{3}COOH)$ and ethanol $(C_{2}H_{5}OH)$.
In the esterification reaction,the hydroxyl group $(-OH)$ of the acid and the hydrogen atom of the alcohol's hydroxyl group are removed as water $(H_{2}O)$.
The remaining parts combine to form the ester: $CH_{3}COOH + C_{2}H_{5}OH \rightarrow CH_{3}COOC_{2}H_{5} + H_{2}O$.
Therefore,the molecular formula of ethyl acetate is $CH_{3}COOC_{2}H_{5}$.

(C) The given molecular formula is $CH_{3}COOCH_{3}$.
This compound belongs to the ester functional group,which has the general formula $R-COO-R'$.
In $CH_{3}COOCH_{3}$,the acyl group is derived from acetic acid (ethanoic acid),which contains two carbon atoms $(CH_{3}CO-)$.
The alkyl group attached to the oxygen is a methyl group $(-CH_{3})$.
Therefore,the $IUPAC$ name is methyl ethanoate.

(C) Esters are chemical compounds formed by the reaction of a carboxylic acid with an alcohol.
Ethyl acetate $(CH_3COOC_2H_5)$ is an ester formed by the reaction between acetic acid and ethanol.
Esters are generally known for their characteristic sweet,fruity smell and are widely used in perfumes and flavoring agents.
Therefore,the correct option is $C$.

(D) The medicine given to individuals habituated to alcohol consumption is $Disulfiram$.
It works by inhibiting the enzyme aldehyde dehydrogenase,which is responsible for breaking down acetaldehyde in the body.
When a person taking $Disulfiram$ consumes alcohol,acetaldehyde accumulates in the bloodstream,causing unpleasant symptoms like nausea,vomiting,flushing,and headache.
This creates a conditioned aversion to alcohol,helping the individual to stop drinking.

(B) The functional group present in aldehyde compounds is the formyl group,which is represented as $-CHO$.
- Option $A$ $(-Cl)$ represents a chloro group (haloalkane).
- Option $B$ $(-CHO)$ represents an aldehyde group.
- Option $C$ $(-COOH)$ represents a carboxylic acid group.
- Option $D$ $(-OH)$ represents a hydroxyl group (alcohol).

(D) ketone is an organic compound characterized by the presence of a carbonyl group $(>C=O)$ bonded to two carbon atoms.
In a ketone,the carbonyl carbon is attached to two alkyl or aryl groups.
Option $A$ $(-CHO)$ represents an aldehyde group.
Option $B$ $(-COOH)$ represents a carboxylic acid group.
Option $C$ $(-OH)$ represents a hydroxyl group (alcohol).
Option $D$ $(>C=O)$ represents the carbonyl group found in ketones.

(C) The general formula for an alkane is $C_nH_{2n+2}$. For methane $(n=1)$,the formula is $CH_4$.
An aldehyde is a functional group characterized by a carbonyl group $(C=O)$ bonded to at least one hydrogen atom. The general formula for an aldehyde is $R-CHO$.
For the simplest aldehyde,where $R=H$,the compound is $HCHO$,which is known as methanal (formaldehyde).
Since methane has one carbon atom,its corresponding aldehyde must also contain one carbon atom,which is methanal.

(B) An aldehyde is represented by the general formula $R-CHO$,where $R$ is an alkyl group or a hydrogen atom.
In $Methanal$ $(HCHO)$,the $R$ group is replaced by a hydrogen atom $(H)$.
Therefore,$Methanal$ is the only aldehyde that does not contain an alkyl group attached to the carbonyl carbon.
$Methanol$ is an alcohol,not an aldehyde.
$Ethanal$ $(CH_3CHO)$ contains a methyl group $(CH_3)$,and $Propanal$ $(CH_3CH_2CHO)$ contains an ethyl group $(CH_3CH_2)$.

(A) The functional groups are analyzed as follows:
$1$. The hydroxyl group $(-OH)$ consists of an oxygen atom bonded to a hydrogen atom via a single covalent bond. It does not contain any double bonds.
$2$. The carbonyl group $(>C=O)$ contains a carbon atom double-bonded to an oxygen atom.
$3$. The carboxyl group $(-COOH)$ contains a carbonyl group $(C=O)$ and a hydroxyl group $(-OH)$,thus it possesses a double bond.
$4$. The aldehyde group $(-CHO)$ contains a carbon atom double-bonded to an oxygen atom $(C=O)$.
Therefore,the hydroxyl group $(-OH)$ is the only one among the options that does not possess a double bond.

(B) $Methanal$ is the $IUPAC$ name for the simplest aldehyde,which has the chemical formula $HCHO$.
Its common name is $Formaldehyde$.
$Acetaldehyde$ is the common name for $Ethanal$ $(CH_3CHO)$.
$Methyl$ alcohol is $Methanol$ $(CH_3OH)$.
$Formic$ acid is $Methanoic$ acid $(HCOOH)$.

(C) Methanal is the simplest aldehyde,containing one carbon atom.
Its $IUPAC$ name is methanal,and its common name is formaldehyde.
The general formula for an aldehyde is $R-CHO$.
For methanal,the $R$ group is a hydrogen atom $(H)$,resulting in the formula $HCHO$.

(D) The chemical formula of ethanal is $CH_3CHO$.
It belongs to the aldehyde functional group with two carbon atoms.
The $IUPAC$ name is ethanal,and its common name is acetaldehyde.

(C) Ethanol is an alcohol with a two-carbon chain.
Its chemical structure consists of an ethyl group $(C_{2}H_{5})$ attached to a hydroxyl functional group $(-OH)$.
Therefore,the molecular formula of ethanol is $C_{2}H_{5}OH$.

(D) The molecular formula $CH_{3}CHO$ represents an aldehyde with two carbon atoms.
In the $IUPAC$ nomenclature, an aldehyde with two carbon atoms is named as $Ethanal$.
Its common name is $Acetaldehyde$.
Therefore, the correct option is $D$.

(D) Formalin is a saturated aqueous solution of formaldehyde gas. It typically contains $37 \%$ to $40 \%$ formaldehyde by mass or volume,but in many educational contexts,it is often referred to as a $40 \%$ solution. Among the given options,the most accurate representation of a standard commercial formalin solution is often cited in the range of $37-40 \%$. However,if we look at the provided options,there seems to be a discrepancy with standard textbook values. Given the context of common biology laboratory reagents,formalin is defined as a $40 \%$ aqueous solution of formaldehyde. Since $40 \%$ is not explicitly listed as a single choice,and considering the options provided,the question might be referring to a specific dilution or a typo in the source. Re-evaluating the standard definition,formalin is $37-40 \%$ formaldehyde. If this is a multiple-choice question where one must be selected,please note that none of the options perfectly match the standard $40 \%$ definition. Assuming a potential typo in the question options,$40 \%$ is the correct scientific answer.

(B) Formalin is a $40\%$ aqueous solution of formaldehyde $(HCHO)$.
It is widely used in laboratories and museums to preserve biological specimens, including the dead bodies of animals, because it prevents decomposition by inhibiting the growth of bacteria and fungi.

(C) The oxidation of primary alcohols like methanol $(CH_{3}OH)$ in the presence of a mild oxidizing agent like $Ag_{2}O$ (silver oxide) at an appropriate temperature leads to the formation of an aldehyde.
Specifically, methanol is oxidized to form methanal $(HCHO)$, which is also known as formaldehyde.
The reaction can be represented as: $CH_{3}OH + [O] \xrightarrow{Ag_{2}O} HCHO + H_{2}O$.

(C) The oxidation of an aldehyde in the presence of an oxidising agent (like alkaline $KMnO_4$ or acidified $K_2Cr_2O_7$) results in the formation of a carboxylic acid with the same number of carbon atoms.
Methanal $(HCHO)$ is an aldehyde with one carbon atom.
Upon oxidation,it gets converted into methanoic acid $(HCOOH)$,which also contains one carbon atom.
The reaction is: $HCHO + [O] \xrightarrow{\text{oxidising agent}} HCOOH$.

(D) The Tollen's test,also known as the silver mirror test,is a chemical test used to distinguish between aldehydes and ketones.
Aldehydes contain the $-CHO$ functional group,which acts as a reducing agent.
When an aldehyde is treated with Tollen's reagent (ammoniacal silver nitrate),it reduces the silver ions $(Ag^+)$ to metallic silver $(Ag)$,which deposits on the inner walls of the test tube,forming a 'silver mirror'.
Ketones do not have the $-CHO$ group and therefore do not give a positive Tollen's test.

(D) Glucose is a reducing sugar because it contains a free aldehyde group $(-CHO)$ or a hemiacetal group that can open to form an aldehyde.
Both Fehling's test and Benedict's test are used to detect the presence of reducing sugars like glucose.
However,in the context of standard chemistry curricula,Benedict's test is the most commonly cited qualitative test for the detection of glucose in biological samples.
Therefore,the correct option is $D$.

(A) The reduction of an aldehyde in the presence of a catalyst like palladium $(Pd)$ or nickel $(Ni)$ leads to the formation of a primary alcohol.
Methanal $(HCHO)$ is the simplest aldehyde.
When methanal undergoes catalytic hydrogenation (reduction),it reacts with hydrogen $(H_2)$ to form methanol $(CH_3OH)$.
The chemical equation is: $HCHO + H_2 \xrightarrow{Pd} CH_3OH$.

(C) The general formula for a ketone group is $R-CO-R'$,where $R$ and $R'$ are alkyl groups.
For the simplest ketone,the smallest possible alkyl groups are methyl groups $(-CH_3)$.
Therefore,the simplest ketone is $CH_3-CO-CH_3$,which is known as Propanone (also called Acetone).
Methanal and Ethanal are aldehydes,and Propenal is an unsaturated aldehyde.