Most Important Carboxylic Acid Quiz Test Online

Carboxylic Acid Quiz Test Online

Carboxylic Acid Test. 1

1 / 20

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

K₂Cr₂O₇ in an acidic medium

LiAlH₄ in an acidic medium

NaBH₄ in an acidic medium

H₂/Ni in an acidic medium

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

2 / 20

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

Water only

Mineral acids or alkalis

Organic solvents

Strong bases only

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

3 / 20

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

Carboxylic acids

Ketones

Ethers

Alcohols

Alkaline KMnO₄ cleaves double bonds oxidatively to yield carboxylic acids.

4 / 20

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

-OH

-COOR

-CHO

-COOH

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

5 / 20

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

Strong dipole-dipole interactions

Intermolecular hydrogen bonding

Covalent bonding

London dispersion forces

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

6 / 20

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

Dilute HCl

Conc. sodium hydroxide

Aqueous ethanol

Acetic acid

This forms a salt which on acidification gives carboxylic acid.

7 / 20

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

Two

One

Three

Four

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

8 / 20

8) 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.

9 / 20

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

-al

-ol

-one

-oic acid

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

10 / 20

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

Oxalic acid

Formic acid

Acetic acid

Benzoic acid

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

11 / 20

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

Pungent

Odorless

Pleasant and fruity

Sweet

They are colorless liquids with a characteristic pungent odor.

12 / 20

12) What is the common name for CH₃CH₂CH₂COOH?

Butyric acid

Acetic acid

Propionic acid

Valeric acid

CH₃CH₂CH₂COOH is commonly known as Butyric acid.

13 / 20

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

An alkali

A mineral acid

An alcohol

An organic base

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

14 / 20

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

Hydroxyl and aldehyde

Carbonyl and hydroxyl

Carbonyl and ether

Carbonyl and alkyl

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

15 / 20

15) Acetic acid was first isolated from which source?

Fats and oils

Butter

Ants

Vinegar

Acetic acid was first isolated from vinegar.

16 / 20

16) What type of carboxylic acid is benzoic acid?

Aromatic dicarboxylic acid

Aromatic monocarboxylic acid

Aliphatic dicarboxylic acid

Aliphatic monocarboxylic acid

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

17 / 20

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

Due to ionic character

Due to hydrogen bonding

Due to van der Waals forces

Due to their small size only

Hydrogen bonding with water molecules makes them highly soluble.

18 / 20

18) 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

The same number of carbon atoms

One less carbon atom

Two carbon atoms more

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

19 / 20

19) What is the IUPAC name for formic acid?

Methanoic acid

Ethanoic acid

Butanoic acid

Propanoic 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:

Alcohols

Water

Carbon dioxide

Aldehydes

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

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The average score is 71%

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Carboxylic Acid Test. 2

1 / 20

1) Carboxylic acids are considered weaker acids compared to:

Phenols

Water

Alcohols

Mineral acids

Carboxylic acids are weaker acids than mineral acids.

2 / 20

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

The hydroxyl group

The carboxyl group

The alkyl group

The carbonyl group

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

3 / 20

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

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.

It only displays the chemistry of the carbonyl group.

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

4 / 20

4) 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.

5 / 20

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

Nucleophilic addition followed by substitution

Addition reaction

Elimination reaction

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.

6 / 20

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

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

Its immiscibility with water.

Its strong pungent smell.

Its very low boiling point.

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

7 / 20

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

Unpleasant

Pungent

Sour

Fruity

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

8 / 20

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

Acid amides

Acid anhydrides

Esters

Carboxylic acids

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

9 / 20

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

R⁻

CO₃²⁻

H⁺

OH⁻

They furnish H⁺ when dissolved in water.

10 / 20

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

Oxidation of methane

Reduction of methyl cyanide

Fermentation of glucose directly

Oxidation of ethyl alcohol

Ethyl alcohol is oxidized to acetic acid in laboratory synthesis.

11 / 20

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

Only halogen atoms

X, OR and NH₂

O and N

H and CH₃

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

12 / 20

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

H₂O

Cl₂

SO₂

HCl

CH₃COOH + PCl₅ → CH₃COCl + POCl₃ + HCl

13 / 20

13) 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.

14 / 20

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

Hydroxyl group

Alkyl group

Carboxyl group as a whole

Carbonyl group

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

15 / 20

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

Hydrogen gas

Carbon dioxide gas

Oxygen gas

Methane gas

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

16 / 20

16) 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.

17 / 20

17) 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.

18 / 20

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

Ketones

Ethers

Aldehydes

Esters

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

19 / 20

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

Monomers

Cyclic dimers

Open-chain trimers

Polymers

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

20 / 20

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

Methane

Hydrogen

Carbon dioxide

Carbon monoxide

2CH₃COOH + Na₂CO₃ → 2CH₃COONa + CO₂ + H₂O

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The average score is 57%

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Carboxylic Acid Test. 3

1 / 20

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

Esters

Amides

Acyl halides

Ethers

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

2 / 20

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

Reduction of the carbonyl group

Formation of a sulfinyl chloride intermediate

Addition of water

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.

3 / 20

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

It is replaced by another group.

It remains unchanged.

It is oxidized to a carbonyl group.

It is reduced to a hydrogen atom.

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.

4 / 20

4) 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.

5 / 20

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

Amide

Acyl halide

Anhydride

Ester

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

6 / 20

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

Acid amide

Alkyl nitrile

Ammonium salt only

Acid anhydride

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

7 / 20

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

Ethyl alcohol

Acetamide

Ethanoic anhydride

Ethyl acetate

CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O.

8 / 20

8) 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.

9 / 20

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

Ethyl acetate

Acetamide

Acetyl chloride (CH₃COCl)

Acetic anhydride

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

10 / 20

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

Acid amides

Acyl halides

Acid anhydrides

Esters

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

11 / 20

11) 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.

12 / 20

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

CH₃COOS + H₂O

CH₃COCl + SO₃ + HCl

CH₃COCl + SO₂ + HCl

CH₃COCl + H₂O

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

13 / 20

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

Acetic acid + Ammonia

Ethyl acetate + Water

Acetic anhydride + Water

Acetamide + Water

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

14 / 20

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

PCl₅

Cl₂

SOCl₂

SCl₂

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

15 / 20

15) 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 reactivity is a consequence of the presence of the carbonyl group.

The carbonyl group has no influence on reactivity.

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

16 / 20

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

Alkanes

Alkynes

Aldehydes

Alkenes

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

17 / 20

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

Saponification

Amidation

Hydrolysis

Esterification

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

18 / 20

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

It breaks away as H₃O⁺ ion

It combines with the solvent to form an insoluble precipitate

It forms a covalent bond with the carboxylate ion

It remains as H⁺

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

19 / 20

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

Potassium permanganate (KMnO₄)

Phosphorus pentoxide (P₂O₅)

Lithium aluminum hydride (LiAlH₄)

Concentrated H₂SO₄

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

20 / 20

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

Aldehyde

Ester

Amide

Carboxylic acid

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

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The average score is 45%

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Carboxylic Acid Test. 3

1 / 20

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

SOCl₂

PCl₅

Cl₂

SCl₂

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

2 / 20

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

Elimination of an alkane

Deprotonation of the carboxylic acid

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.

3 / 20

3) 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 has no influence on reactivity.

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

The carbonyl group only affects physical properties, not reactivity.

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

4 / 20

4) 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.

5 / 20

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

Alkanes

Alkenes

Aldehydes

Alkynes

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

6 / 20

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

It breaks away as H₃O⁺ ion

It combines with the solvent to form an insoluble precipitate

It remains as H⁺

It forms a covalent bond with the carboxylate ion

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

7 / 20

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

Amidation

Esterification

Saponification

Hydrolysis

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:

Hydrolysis

Saponification

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

Acetic acid + Ammonia

Acetic anhydride + Water

Acetamide + Water

Ethyl acetate + Water

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

10 / 20

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

Acyl halides

Esters

Ethers

Amides

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

11 / 20

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

Acid anhydride

Acid amide

Alkyl nitrile

Ammonium salt only

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

12 / 20

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

Formation of a sulfinyl chloride intermediate

Addition of water

Protonation of the alkyl group

Reduction of the carbonyl 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) 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.

14 / 20

14) 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.

15 / 20

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

Acetic anhydride

Ethyl acetate

Acetyl chloride (CH₃COCl)

Acetamide

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

16 / 20

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

Ethyl acetate

Ethyl alcohol

Ethanoic anhydride

Acetamide

CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O.

17 / 20

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

Phosphorus pentoxide (P₂O₅)

Concentrated H₂SO₄

Lithium aluminum hydride (LiAlH₄)

Potassium permanganate (KMnO₄)

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

18 / 20

18) 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).

19 / 20

19) 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 is replaced by another group.

It is oxidized to a carbonyl 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.

20 / 20

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

Anhydride

Ester

Acyl halide

Amide

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

Your score is

The average score is 45%

Most Important Carboxylic Acid Quiz Test Online

Carboxylic Acid Quiz Test Online

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