Most Important Carboxylic Acid Quiz Test Online

Carboxylic Acid Quiz Test Online

Carboxylic Acid Test. 1

1 / 20

1) Which of the following is an example of an aliphatic dicarboxylic acid?

Formic acid

Oxalic acid

Benzoic acid

Acetic acid

Oxalic acid (Ethanedioic acid) is an example of an aliphatic dicarboxylic acid.

2 / 20

2) The IUPAC names of saturated monocarboxylic acids are derived from alkanes by changing the ending 'e' to:

-al

-oic acid

-ol

-one

The IUPAC names of saturated monocarboxylic acids are alkanoic acids, ending with -oic acid.

3 / 20

3) What is the IUPAC name for formic acid?

Propanoic acid

Butanoic acid

Ethanoic acid

Methanoic acid

Formic acid is also known as Methanoic acid in IUPAC nomenclature.

4 / 20

4) What type of carboxylic acid is benzoic acid?

Aromatic monocarboxylic acid

Aliphatic monocarboxylic acid

Aliphatic dicarboxylic acid

Aromatic dicarboxylic acid

Benzoic acid is an aromatic monocarboxylic acid due to the benzene ring.

5 / 20

5) Acetic acid was first isolated from which source?

Ants

Fats and oils

Vinegar

Butter

Acetic acid was first isolated from vinegar.

6 / 20

6) How many carboxyl groups are present in a tricarboxylic acid?

Four

Three

Two

One

Carboxylic acids are classified based on the number of carboxyl groups; 'tri' indicates three.

7 / 20

7) The carboxyl group is a combination of which two groups?

Hydroxyl and aldehyde

Carbonyl and alkyl

Carbonyl and hydroxyl

Carbonyl and ether

The carboxyl group is made up of a carbonyl group (>C=O) and a hydroxyl group (-OH).

8 / 20

8) What is the smell characteristic of the first three aliphatic acids (formic, acetic, propionic acid)?

Pungent

Sweet

Odorless

Pleasant and fruity

They are colorless liquids with a characteristic pungent odor.

9 / 20

9) Which of the following functional groups defines a carboxylic acid?

-OH

-COOH

-COOR

-CHO

The functional group for carboxylic acids is the carboxyl group, which is written as -COOH.

10 / 20

10) Symmetrical alkenes when heated with alkaline KMnO₄ are cleaved at the double bond to form:

Ethers

Alcohols

Carboxylic acids

Ketones

Alkaline KMnO₄ cleaves double bonds oxidatively to yield carboxylic acids.

11 / 20

11) Carboxylic acids have relatively high boiling points due to:

London dispersion forces

Intermolecular hydrogen bonding

Covalent bonding

Strong dipole-dipole interactions

Hydrogen bonding between carboxylic acid molecules leads to higher boiling points.

12 / 20

12) What is the common name for CH₃CH₂CH₂COOH?

Butyric acid

Propionic acid

Acetic acid

Valeric acid

CH₃CH₂CH₂COOH is commonly known as Butyric acid.

13 / 20

13) The hydrolysis of alkanenitriles to carboxylic acids requires boiling with:

Mineral acids or alkalis

Water only

Strong bases only

Organic solvents

Boiling with mineral acids or alkalis hydrolyzes nitriles to carboxylic acids.

14 / 20

14) Why are the first four members of aliphatic acids very soluble in water?

Due to their small size only

Due to ionic character

Due to van der Waals forces

Due to hydrogen bonding

Hydrogen bonding with water molecules makes them highly soluble.

15 / 20

15) The hydrolysis of esters to form carboxylic acids is typically done by boiling with:

Conc. sodium hydroxide

Dilute HCl

Aqueous ethanol

Acetic acid

This forms a salt which on acidification gives carboxylic acid.

16 / 20

16) In the preparation of carboxylic acids from Grignard reagents, the addition product is reacted with:

A mineral acid

An alcohol

An alkali

An organic base

The addition product is acidified with a mineral acid to yield the acid.

17 / 20

17) Which of the following is the general formula for an aliphatic carboxylic acid?

Ar-C-OH

R-C-OH (where R = H or an alkyl group)

R-OH

R-CHO

The general formula is R-COOH or R-C(=O)OH, where R is H or an alkyl group.

18 / 20

18) Primary alcohols and aldehydes can be oxidized to carboxylic acids using which of the following reagents?

H₂/Ni in an acidic medium

LiAlH₄ in an acidic medium

K₂Cr₂O₇ in an acidic medium

NaBH₄ in an acidic medium

Potassium dichromate in acidic medium is a strong oxidizing agent for this purpose.

19 / 20

19) Carboxylic acids can be prepared from Grignard reagents by reacting them with:

Aldehydes

Water

Alcohols

Carbon dioxide

Grignard reagents react with CO₂ followed by acidification to form carboxylic acids.

20 / 20

20) How many carbon atoms does the carboxylic acid produced from an alkyl halide via alkanenitrile hydrolysis have, compared to the original alkyl halide?

One carbon atom more

Two carbon atoms more

One less carbon atom

The same number of carbon atoms

Cyanide adds one carbon atom during the reaction, increasing the chain length.

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The average score is 71%

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Carboxylic Acid Test. 2

1 / 20

1) The reaction of CH₃COOH with PCl₅ produces CH₃COCl, POCl₃, and:

SO₂

HCl

Cl₂

H₂O

CH₃COOH + PCl₅ → CH₃COCl + POCl₃ + HCl

2 / 20

2) In most reactions of carboxylic acids, which part of the molecule is typically retained?

The carboxyl group

The alkyl group

The carbonyl group

The hydroxyl group

In most reactions of carboxylic acids, the carboxyl group is retained.

3 / 20

3) Which of the following is a laboratory method for preparing acetic acid?

Oxidation of methane

Oxidation of ethyl alcohol

Fermentation of glucose directly

Reduction of methyl cyanide

Ethyl alcohol is oxidized to acetic acid in laboratory synthesis.

4 / 20

4) What is 'glacial acetic acid' characterized by?

Its very low boiling point.

Its immiscibility with water.

Its strong pungent smell.

Its ability to freeze into an ice-like solid at 17 °C.

Pure acetic acid solidifies at 17 °C, resembling ice — hence the term 'glacial'.

5 / 20

5) What is formed when carboxylic acids react with bases like NaOH or KOH?

Ethers

Aldehydes

Esters

Salts

Carboxylic acids react with bases (NaOH, KOH) to form salts.

6 / 20

6) Carboxylic acids are considered weaker acids compared to:

Water

Mineral acids

Alcohols

Phenols

Carboxylic acids are weaker acids than mineral acids.

7 / 20

7) What type of reaction occurs when a nucleophile attacks the carboxyl group, followed by the displacement of the -OH group?

Elimination reaction

Addition reaction

Nucleophilic addition followed by substitution

Oxidation reaction

The addition of a nucleophile to the carboxyl group is always followed by the displacement of the -OH group by some other group, producing a carboxylic acid derivative.

8 / 20

8) The -OH group of carboxylic acids can be replaced by which of the following to form acid derivatives?

O and N

X, OR and NH₂

Only halogen atoms

H and CH₃

The -OH group can thus be replaced by X, OR and NH₂ to form halides, esters and amides, respectively.

9 / 20

9) When dissolved in water, carboxylic acids furnish which ion?

H⁺

CO₃²⁻

R⁻

OH⁻

They furnish H⁺ when dissolved in water.

10 / 20

10) Heating carboxylic acids with alcohols in the presence of concentrated H₂SO₄ leads to the formation of:

Ethers

Aldehydes

Esters

Ketones

When carboxylic acids are heated with alcohols in the presence of concentrated H₂SO₄, esters are formed.

11 / 20

11) What is the characteristic smell of esters, often leading to their use as artificial flavors?

Unpleasant

Sour

Pungent

Fruity

Esters have a fruity smell and are used as artificial flavors.

12 / 20

12) The hydrolysis of ethanenitrile to acetic acid proceeds through which intermediate?

Ethyl acetate

Acetic anhydride

Acetaldehyde

Acetamide

The intermediate formed is acetamide, which hydrolyzes to acetic acid.

13 / 20

13) When carboxylic acids react with active metals (Na, K, Ca, Mg), what is evolved along with the formation of their salts?

Oxygen gas

Hydrogen gas

Carbon dioxide gas

Nitrogen gas

Carboxylic acids react with active metals (Na, K, Ca, Mg etc.) to form their salts with the evolution of hydrogen gas.

14 / 20

14) What is the melting point trend observed for carboxylic acids with an even number of carbon atoms compared to their odd-numbered counterparts?

There is no observable trend.

They have lower melting points.

Their melting points are similar.

They have higher melting points.

Even-numbered acids pack more efficiently in solids, leading to higher melting points.

15 / 20

15) What are ammonium salts formed when carboxylic acids react with ammonia?

Acid amides

Carboxylic acids

Acid anhydrides

Esters

Carboxylic acids react with ammonia to form ammonium salts which on heating produce acid amides.

16 / 20

16) Which gas is evolved when carboxylic acids decompose carbonates and bicarbonates?

Carbon dioxide gas

Hydrogen gas

Oxygen gas

Methane gas

Carboxylic acids decompose carbonates and bicarbonates evolving carbon dioxide gas with effervescence.

17 / 20

17) Which of the following statements about the carboxyl group's reactivity is true?

It only displays the chemistry of the carbonyl group.

It has no specific reactivity due to its stable nature.

It only displays the chemistry of the hydroxyl group.

It displays the chemistry of both the carbonyl and the hydroxyl groups.

The carboxyl group displays the chemistry of both the carbonyl and the hydroxyl groups.

18 / 20

18) The reaction of acetic acid with sodium carbonate produces sodium acetate, water, and:

Methane

Carbon monoxide

Carbon dioxide

Hydrogen

2CH₃COOH + Na₂CO₃ → 2CH₃COONa + CO₂ + H₂O

19 / 20

19) The reactivity of carboxylic acid molecules is primarily a consequence of the presence of which group?

Hydroxyl group

Carboxyl group as a whole

Alkyl group

Carbonyl group

The reactivity of these molecules is a consequence of the presence of the carbonyl group.

20 / 20

20) In non-polar solvents like benzene, carboxylic acids exist as:

Cyclic dimers

Polymers

Monomers

Open-chain trimers

In non-polar solvents, two acid molecules dimerize through hydrogen bonding.

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The average score is 57%

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Carboxylic Acid Test. 3

1 / 20

1) The dehydration of carboxylic acids using phosphorus pentoxide (P₂O₅) on strong heating leads to the formation of:

Acyl halides

Acid amides

Acid anhydrides

Esters

Carboxylic acids are dehydrated on heating strongly in the presence of phosphorus pentoxide to form acid anhydrides.

2 / 20

2) What is the product formed when carboxylic acids react with NH₃ and are subsequently heated?

Alkyl nitrile

Acid anhydride

Acid amide

Ammonium salt only

Carboxylic acids react with ammonia to form ammonium salts which on heating produce acid amides.

3 / 20

3) Which of the following compounds has a fruity smell and is used as an artificial flavor?

Ester

Aldehyde

Amide

Carboxylic acid

Esters have a fruity smell and are used as artificial flavours.

4 / 20

4) Which of the following is a key step in the mechanism of ester formation from carboxylic acids and alcohols?

Protonation of the carboxylic acid

Deprotonation of the carboxylic acid

Elimination of an alkane

Formation of a ketone intermediate

The first step in the mechanism of ester formation (esterification) is the protonation of the carboxylic acid.

5 / 20

5) What is the product when acetic acid (CH₃COOH) reacts with PCl₅?

Acetamide

Acetyl chloride (CH₃COCl)

Ethyl acetate

Acetic anhydride

The reaction of CH₃COOH with PCl₅ yields CH₃COCl (Acetyl chloride), POCl₃, and HCl.

6 / 20

6) When CH₃COOH reacts with SOCl₂, what are the products?

CH₃COOS + H₂O

CH₃COCl + SO₃ + HCl

CH₃COCl + H₂O

CH₃COCl + SO₂ + HCl

The reaction of CH₃COOH with SOCl₂ produces acetyl chloride (CH₃COCl), sulfur dioxide (SO₂), and hydrochloric acid (HCl).

7 / 20

7) The formation of an ester from a carboxylic acid and an alcohol in the presence of concentrated H₂SO₄ is known as:

Esterification

Hydrolysis

Amidation

Saponification

When carboxylic acids are heated with alcohols in the presence of concentrated H₂SO₄, esters are formed.

8 / 20

8) The overall process by which carboxylic acids react with alcohols to form esters and water is known as:

Saponification

Hydrolysis

Esterification

Dehydration

The formation of an ester when carboxylic acids are heated with alcohols in the presence of concentrated H₂SO₄ is known as esterification.

9 / 20

9) Which reagent is used to dehydrate carboxylic acids on strong heating to form acid anhydrides?

Phosphorus pentoxide (P₂O₅)

Lithium aluminum hydride (LiAlH₄)

Concentrated H₂SO₄

Potassium permanganate (KMnO₄)

Carboxylic acids are dehydrated on heating strongly in the presence of phosphorus pentoxide.

10 / 20

10) Which reagent is used to convert carboxylic acids into acyl chlorides, along with SO₂ and HCl as by-products?

Cl₂

PCl₅

SOCl₂

SCl₂

Carboxylic acids react with SOCl₂ to form acyl chlorides, SO₂, and HCl.

11 / 20

11) What happens to the proton (H⁺) in the presence of water (H₂O) when a carboxylic acid dissociates?

It breaks away as H₃O⁺ ion

It forms a covalent bond with the carboxylate ion

It combines with the solvent to form an insoluble precipitate

It remains as H⁺

In the presence of water (H₂O), the proton breaks away as H₃O⁺ ion.

12 / 20

12) What is the product of the partial reduction of carboxylic acids with lithium aluminum hydride (LiAlH₄)?

Aldehydes

Alkanes

Ethers

Alcohols

Carboxylic acids on reaction with lithium aluminum hydride (LiAlH₄) are reduced to alcohols.

13 / 20

13) Which of the following is a common step in the mechanism of forming acyl chlorides from carboxylic acids using SOCl₂?

Protonation of the alkyl group

Addition of water

Reduction of the carbonyl group

Formation of a sulfinyl chloride intermediate

The mechanism for the reaction of CH₃COOH with SOCl₂ shows the formation of an intermediate where sulfur is bonded to the carboxyl oxygen and a chlorine atom.

14 / 20

14) Which of the following is NOT a common carboxylic acid derivative discussed in the text?

Amides

Acyl halides

Ethers

Esters

The -OH group can be replaced by X, OR and NH₂ to form halides, esters and amides, respectively.

15 / 20

15) What type of functional group is formed when the -OH group of a carboxylic acid is replaced by −NH₂?

Acyl halide

Amide

Ester

Anhydride

The -OH group can be replaced by X, OR, and NH₂ to form halides, esters, and amides, respectively.

16 / 20

16) What is the product when ammonium acetate (CH₃COONH₄) is heated?

Acetamide + Water

Acetic anhydride + Water

Acetic acid + Ammonia

Ethyl acetate + Water

Ammonium salts formed by the reaction of carboxylic acids with ammonia produce acid amides upon heating (CH₃COONH₄ → CH₃CONH₂ + H₂O).

17 / 20

17) What is the product of the reaction between ethanoic acid (CH₃COOH) and ethanol (C₂H₅OH) in the presence of H₂SO₄?

Ethyl acetate

Ethanoic anhydride

Acetamide

Ethyl alcohol

CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O.

18 / 20

18) What are carboxylic acids completely reduced to when reacted with HI and red phosphorus?

Aldehydes

Alkanes

Alkenes

Alkynes

Carboxylic acids on reduction with HI and red phosphorus give alkanes.

19 / 20

19) Which of the following is true regarding the reactivity of carboxylic acids based on the carbonyl group?

The carbonyl group decreases the reactivity.

The reactivity is a consequence of the presence of the carbonyl group.

The carbonyl group has no influence on reactivity.

The carbonyl group only affects physical properties, not reactivity.

The reactivity of these molecules is a consequence of the presence of the carbonyl group.

20 / 20

20) What happens to the -OH group of a carboxylic acid when it forms a derivative like an acyl halide, ester, or amide?

It is oxidized to a carbonyl group.

It is reduced to a hydrogen atom.

It is replaced by another group.

It remains unchanged.

The addition of a nucleophile to the carboxyl group is always followed by the displacement of the -OH group by some other group, producing a carboxylic acid derivative.

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The average score is 45%

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Carboxylic Acid Test. 3

1 / 20

1) Which of the following is a common step in the mechanism of forming acyl chlorides from carboxylic acids using SOCl₂?

Addition of water

Reduction of the carbonyl group

Formation of a sulfinyl chloride intermediate

Protonation of the alkyl group

The mechanism for the reaction of CH₃COOH with SOCl₂ shows the formation of an intermediate where sulfur is bonded to the carboxyl oxygen and a chlorine atom.

2 / 20

2) Which reagent is used to convert carboxylic acids into acyl chlorides, along with SO₂ and HCl as by-products?

SCl₂

Cl₂

PCl₅

SOCl₂

Carboxylic acids react with SOCl₂ to form acyl chlorides, SO₂, and HCl.

3 / 20

3) Which of the following compounds has a fruity smell and is used as an artificial flavor?

Amide

Aldehyde

Carboxylic acid

Ester

Esters have a fruity smell and are used as artificial flavours.

4 / 20

4) What happens to the -OH group of a carboxylic acid when it forms a derivative like an acyl halide, ester, or amide?

It is reduced to a hydrogen atom.

It remains unchanged.

It is oxidized to a carbonyl group.

It is replaced by another group.

The addition of a nucleophile to the carboxyl group is always followed by the displacement of the -OH group by some other group, producing a carboxylic acid derivative.

5 / 20

5) The overall process by which carboxylic acids react with alcohols to form esters and water is known as:

Dehydration

Saponification

Esterification

Hydrolysis

The formation of an ester when carboxylic acids are heated with alcohols in the presence of concentrated H₂SO₄ is known as esterification.

6 / 20

6) When CH₃COOH reacts with SOCl₂, what are the products?

CH₃COOS + H₂O

CH₃COCl + SO₂ + HCl

CH₃COCl + SO₃ + HCl

CH₃COCl + H₂O

The reaction of CH₃COOH with SOCl₂ produces acetyl chloride (CH₃COCl), sulfur dioxide (SO₂), and hydrochloric acid (HCl).

7 / 20

7) What is the product when acetic acid (CH₃COOH) reacts with PCl₅?

Acetyl chloride (CH₃COCl)

Acetamide

Acetic anhydride

Ethyl acetate

The reaction of CH₃COOH with PCl₅ yields CH₃COCl (Acetyl chloride), POCl₃, and HCl.

8 / 20

8) What is the product of the reaction between ethanoic acid (CH₃COOH) and ethanol (C₂H₅OH) in the presence of H₂SO₄?

Ethyl alcohol

Ethyl acetate

Acetamide

Ethanoic anhydride

CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O.

9 / 20

9) Which of the following is NOT a common carboxylic acid derivative discussed in the text?

Ethers

Esters

Amides

Acyl halides

The -OH group can be replaced by X, OR and NH₂ to form halides, esters and amides, respectively.

10 / 20

10) Which reagent is used to dehydrate carboxylic acids on strong heating to form acid anhydrides?

Potassium permanganate (KMnO₄)

Lithium aluminum hydride (LiAlH₄)

Phosphorus pentoxide (P₂O₅)

Concentrated H₂SO₄

Carboxylic acids are dehydrated on heating strongly in the presence of phosphorus pentoxide.

11 / 20

11) Which of the following is a key step in the mechanism of ester formation from carboxylic acids and alcohols?

Protonation of the carboxylic acid

Elimination of an alkane

Deprotonation of the carboxylic acid

Formation of a ketone intermediate

The first step in the mechanism of ester formation (esterification) is the protonation of the carboxylic acid.

12 / 20

12) What is the product formed when carboxylic acids react with NH₃ and are subsequently heated?

Acid anhydride

Ammonium salt only

Acid amide

Alkyl nitrile

Carboxylic acids react with ammonia to form ammonium salts which on heating produce acid amides.

13 / 20

13) The formation of an ester from a carboxylic acid and an alcohol in the presence of concentrated H₂SO₄ is known as:

Esterification

Amidation

Hydrolysis

Saponification

When carboxylic acids are heated with alcohols in the presence of concentrated H₂SO₄, esters are formed.

14 / 20

14) The dehydration of carboxylic acids using phosphorus pentoxide (P₂O₅) on strong heating leads to the formation of:

Esters

Acid amides

Acid anhydrides

Acyl halides

Carboxylic acids are dehydrated on heating strongly in the presence of phosphorus pentoxide to form acid anhydrides.

15 / 20

15) What are carboxylic acids completely reduced to when reacted with HI and red phosphorus?

Alkanes

Alkenes

Alkynes

Aldehydes

Carboxylic acids on reduction with HI and red phosphorus give alkanes.

16 / 20

16) What happens to the proton (H⁺) in the presence of water (H₂O) when a carboxylic acid dissociates?

It breaks away as H₃O⁺ ion

It remains as H⁺

It forms a covalent bond with the carboxylate ion

It combines with the solvent to form an insoluble precipitate

In the presence of water (H₂O), the proton breaks away as H₃O⁺ ion.

17 / 20

17) Which of the following is true regarding the reactivity of carboxylic acids based on the carbonyl group?

The carbonyl group decreases the reactivity.

The carbonyl group only affects physical properties, not reactivity.

The carbonyl group has no influence on reactivity.

The reactivity is a consequence of the presence of the carbonyl group.

The reactivity of these molecules is a consequence of the presence of the carbonyl group.

18 / 20

18) What is the product when ammonium acetate (CH₃COONH₄) is heated?

Acetic anhydride + Water

Acetic acid + Ammonia

Ethyl acetate + Water

Acetamide + Water

Ammonium salts formed by the reaction of carboxylic acids with ammonia produce acid amides upon heating (CH₃COONH₄ → CH₃CONH₂ + H₂O).

19 / 20

19) What type of functional group is formed when the -OH group of a carboxylic acid is replaced by −NH₂?

Ester

Anhydride

Amide

Acyl halide

The -OH group can be replaced by X, OR, and NH₂ to form halides, esters, and amides, respectively.

20 / 20

20) What is the product of the partial reduction of carboxylic acids with lithium aluminum hydride (LiAlH₄)?

Ethers

Aldehydes

Alcohols

Alkanes

Carboxylic acids on reaction with lithium aluminum hydride (LiAlH₄) are reduced to alcohols.

Your score is

The average score is 45%

Most Important Carboxylic Acid Quiz Test Online

Carboxylic Acid Quiz Test Online

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