Most Important Carboxylic Acid Quiz Test Online

Carboxylic Acid Quiz Test Online

Carboxylic Acid Test. 1

1 / 20

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

Pleasant and fruity

Odorless

Pungent

Sweet

They are colorless liquids with a characteristic pungent odor.

2 / 20

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

NaBH₄ in an acidic medium

H₂/Ni in an acidic medium

K₂Cr₂O₇ in an acidic medium

LiAlH₄ in an acidic medium

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

3 / 20

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

A mineral acid

An alkali

An organic base

An alcohol

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

4 / 20

4) What is the common name for CH₃CH₂CH₂COOH?

Propionic acid

Butyric acid

Valeric acid

Acetic acid

CH₃CH₂CH₂COOH is commonly known as Butyric acid.

5 / 20

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

Carboxylic acids

Ethers

Alcohols

Ketones

Alkaline KMnO₄ cleaves double bonds oxidatively to yield carboxylic acids.

6 / 20

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

-ol

-oic acid

-one

-al

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

7 / 20

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

-COOR

-COOH

-CHO

-OH

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

8 / 20

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

Formic acid

Acetic acid

Benzoic acid

Oxalic acid

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

9 / 20

9) Acetic acid was first isolated from which source?

Vinegar

Ants

Fats and oils

Butter

Acetic acid was first isolated from vinegar.

10 / 20

10) What type of carboxylic acid is benzoic acid?

Aromatic monocarboxylic acid

Aromatic dicarboxylic acid

Aliphatic monocarboxylic acid

Aliphatic dicarboxylic acid

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

11 / 20

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

Carbonyl and alkyl

Carbonyl and hydroxyl

Hydroxyl and aldehyde

Carbonyl and ether

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

12 / 20

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

The same number of carbon atoms

Two carbon atoms more

One carbon atom more

One less carbon atom

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

13 / 20

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

Organic solvents

Water only

Mineral acids or alkalis

Strong bases only

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

14 / 20

14) 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.

15 / 20

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

Strong dipole-dipole interactions

Covalent bonding

London dispersion forces

Intermolecular hydrogen bonding

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

16 / 20

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

R-OH

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

Ar-C-OH

R-CHO

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

17 / 20

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

Aqueous ethanol

Dilute HCl

Acetic acid

Conc. sodium hydroxide

This forms a salt which on acidification gives carboxylic acid.

18 / 20

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

Due to van der Waals forces

Due to ionic character

Due to hydrogen bonding

Due to their small size only

Hydrogen bonding with water molecules makes them highly soluble.

19 / 20

19) What is the IUPAC name for formic acid?

Ethanoic acid

Methanoic acid

Propanoic acid

Butanoic acid

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

20 / 20

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

Water

Aldehydes

Carbon dioxide

Alcohols

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

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The average score is 81%

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Carboxylic Acid Test. 2

1 / 20

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

Ketones

Ethers

Esters

Aldehydes

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

2 / 20

2) 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 displays the chemistry of both the carbonyl and the hydroxyl groups.

It only displays the chemistry of the hydroxyl group.

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

3 / 20

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

Aldehydes

Ethers

Salts

Esters

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

4 / 20

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

Its immiscibility with water.

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

Its very low boiling point.

Its strong pungent smell.

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

5 / 20

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

Monomers

Cyclic dimers

Polymers

Open-chain trimers

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

6 / 20

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

HCl

Cl₂

H₂O

SO₂

CH₃COOH + PCl₅ → CH₃COCl + POCl₃ + HCl

7 / 20

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

Acid amides

Acid anhydrides

Carboxylic acids

Esters

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

8 / 20

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

Carbon dioxide

Carbon monoxide

Hydrogen

Methane

2CH₃COOH + Na₂CO₃ → 2CH₃COONa + CO₂ + H₂O

9 / 20

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

Acetic anhydride

Acetaldehyde

Acetamide

Ethyl acetate

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

10 / 20

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

R⁻

H⁺

OH⁻

CO₃²⁻

They furnish H⁺ when dissolved in water.

11 / 20

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

Their melting points are similar.

There is no observable trend.

They have higher melting points.

They have lower melting points.

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

12 / 20

12) 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

H and CH₃

Only halogen atoms

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

13 / 20

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

Reduction of methyl cyanide

Fermentation of glucose directly

Oxidation of methane

Oxidation of ethyl alcohol

Ethyl alcohol is oxidized to acetic acid in laboratory synthesis.

14 / 20

14) Carboxylic acids are considered weaker acids compared to:

Phenols

Mineral acids

Alcohols

Water

Carboxylic acids are weaker acids than mineral acids.

15 / 20

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

Fruity

Sour

Unpleasant

Pungent

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

16 / 20

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

The carbonyl group

The alkyl group

The hydroxyl group

The carboxyl group

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

17 / 20

17) 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.

18 / 20

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

Carbon dioxide gas

Hydrogen gas

Nitrogen gas

Oxygen gas

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

19 / 20

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

Addition reaction

Nucleophilic addition followed by substitution

Oxidation reaction

Elimination 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.

20 / 20

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

Hydroxyl group

Alkyl group

Carbonyl group

Carboxyl group as a whole

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

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The average score is 59%

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Carboxylic Acid Test. 3

1 / 20

1) 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.

2 / 20

2) 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 remains unchanged.

It is reduced to a hydrogen atom.

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.

3 / 20

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

Acetamide

Ethyl alcohol

Ethyl acetate

Ethanoic anhydride

CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O.

4 / 20

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

Lithium aluminum hydride (LiAlH₄)

Concentrated H₂SO₄

Phosphorus pentoxide (P₂O₅)

Potassium permanganate (KMnO₄)

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

5 / 20

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

Ester

Acyl halide

Anhydride

Amide

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

6 / 20

6) 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.

7 / 20

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

Alcohols

Ethers

Alkanes

Aldehydes

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

8 / 20

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

It remains as H⁺

It combines with the solvent to form an insoluble precipitate

It breaks away as H₃O⁺ ion

It forms a covalent bond with the carboxylate ion

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

9 / 20

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

Deprotonation of the carboxylic acid

Elimination of an alkane

Formation of a ketone intermediate

Protonation of the carboxylic acid

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

10 / 20

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

PCl₅

SOCl₂

Cl₂

SCl₂

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

11 / 20

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

CH₃COCl + SO₂ + HCl

CH₃COOS + H₂O

CH₃COCl + SO₃ + HCl

CH₃COCl + H₂O

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

12 / 20

12) 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.

13 / 20

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

Amide

Aldehyde

Ester

Carboxylic acid

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

14 / 20

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

Acid anhydrides

Acid amides

Esters

Acyl halides

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

15 / 20

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

Ethyl acetate + Water

Acetic acid + Ammonia

Acetic anhydride + Water

Acetamide + Water

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

16 / 20

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

Ethyl acetate

Acetamide

Acetic anhydride

Acetyl chloride (CH₃COCl)

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

17 / 20

17) 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.

18 / 20

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

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

The carbonyl group decreases the reactivity.

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.

19 / 20

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

Saponification

Esterification

Dehydration

Hydrolysis

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

20 / 20

20) 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.

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The average score is 53%

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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?

Protonation of the alkyl group

Reduction of the carbonyl group

Addition of water

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.

2 / 20

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

Alkanes

Ethers

Aldehydes

Alcohols

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

3 / 20

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

Potassium permanganate (KMnO₄)

Concentrated H₂SO₄

Lithium aluminum hydride (LiAlH₄)

Phosphorus pentoxide (P₂O₅)

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

4 / 20

4) 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.

5 / 20

5) 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.

6 / 20

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

Acetic acid + Ammonia

Acetamide + Water

Acetic anhydride + Water

Ethyl acetate + Water

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

7 / 20

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

Alkanes

Aldehydes

Alkynes

Alkenes

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

8 / 20

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

Acyl halides

Amides

Esters

Ethers

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

9 / 20

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

Hydrolysis

Esterification

Saponification

Amidation

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

10 / 20

10) 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

Formation of a ketone intermediate

Deprotonation of the carboxylic acid

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

11 / 20

11) 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 replaced by another group.

It is reduced to a hydrogen atom.

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.

12 / 20

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

It remains as H⁺

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

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

13 / 20

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

Saponification

Hydrolysis

Dehydration

Esterification

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

14 / 20

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

Ammonium salt only

Acid amide

Alkyl nitrile

Acid anhydride

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

15 / 20

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

SOCl₂

SCl₂

PCl₅

Cl₂

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

16 / 20

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

CH₃COCl + SO₃ + HCl

CH₃COCl + SO₂ + HCl

CH₃COCl + H₂O

CH₃COOS + H₂O

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

17 / 20

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

Carboxylic acid

Ester

Amide

Aldehyde

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

18 / 20

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

Ethyl acetate

Acetyl chloride (CH₃COCl)

Acetamide

Acetic anhydride

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

19 / 20

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

Ethanoic anhydride

Ethyl alcohol

Ethyl acetate

Acetamide

CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O.

20 / 20

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

Esters

Acid amides

Acyl halides

Acid anhydrides

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

Your score is

The average score is 53%

Most Important Carboxylic Acid Quiz Test Online

Carboxylic Acid Quiz Test Online

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