12 Chemistry Unit-19 Carboxylic Acids
Prepared by: G. KUPPUSWAMY, P. G. Asst., Pachaiyapp's HSS, Kanchipuram.
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Questions and Answers
- 1.
P{margin-bottom:0.08in;} Which of the following is least acidic a) C2H5OH b) CH3COOH c) C6H5OH d) ClCH2COOH
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
A. Option 1Explanation
The correct answer is a) C2H5OH. C2H5OH is least acidic among the given options because it is an alcohol and does not contain any acidic functional groups. CH3COOH (option b) is acetic acid, which is a weak acid. C6H5OH (option c) is phenol, which is a weak acid. ClCH2COOH (option d) is chloroacetic acid, which is a stronger acid compared to the other options. Therefore, C2H5OH is the least acidic compound among the given options.Rate this question:
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- 2.
P { margin-bottom: 0.08in; } Weakest acid among the following is a) Acetic acid b) Phenol c) Water d) Acetylene
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
D. Option 4Explanation
Acetylene is the weakest acid among the given options because it is a nonpolar molecule and does not readily donate a proton (H+) in solution. Acetylene (C2H2) does not have any acidic functional groups like carboxylic acid (acetic acid) or hydroxyl group (phenol) that can easily release a proton. Water (H2O) can act as a weak acid in certain conditions, but it is still stronger than acetylene in terms of acidity. Therefore, acetylene is the weakest acid among the options provided.Rate this question:
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- 3.
P { margin-bottom: 0.08in; } Ester formation involves the reaction of a) an aldehyde and a ketone b) An alcohol with RMgX c) Two molecules of an acid with dehydrating agent d) An acylhalide with an alcohol
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
D. Option 4Explanation
Ester formation involves the reaction of an acylhalide with an alcohol.Rate this question:
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- 4.
P { margin-bottom: 0.08in; } Heating a mixture of sodium acetate and soda lime gives a) methane b) ethane c) acetic acid d) benzene
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
A. Option 1 -
- 5.
P { margin-bottom: 0.08in; } The acid which reduces Tollen's reagent is a) acetic acid b) benzoic acid c) formic acid d) oxalic acid
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
C. Option 3Explanation
Formic acid is the acid that reduces Tollen's reagent.Rate this question:
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- 6.
P { margin-bottom: 0.08in; } CH3 │ The IUPAC name of CH3-CH2-CH-COOH is a) α-methyl butric acid b) 3-methy butanoic acid c) 2-methyl butanoic acid d) Iso pentanoic acid
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
C. Option 3Explanation
The correct answer is option 3, 2-methyl butanoic acid. This is because the molecule CH3-CH2-CH-COOH has a methyl group attached to the second carbon atom in the chain, making it a 2-methyl compound. The butanoic acid part comes from the fact that the chain has four carbon atoms, so it is a butanoic acid.Rate this question:
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- 7.
P { margin-bottom: 0.08in; } P { margin-bottom: 0.08in; } The Isomerism exhibited by CH3-CH2-COOH and CH3-COOCH3 is a) metamerism b) position c) chain d) functional
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
D. Option 4Explanation
The isomerism exhibited by CH3-CH2-COOH and CH3-COOCH3 is functional isomerism. Functional isomerism occurs when two or more compounds have the same molecular formula but different functional groups. In this case, CH3-CH2-COOH is a carboxylic acid, while CH3-COOCH3 is an ester. They have the same molecular formula (C3H6O2), but different functional groups, resulting in different chemical properties and reactivity.Rate this question:
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- 8.
P { margin-bottom: 0.08in; } The acid that cannot be prepared by Grignard reagent a) acetic acid b) formic acid c) butyric acid d) benzoic acid
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
B. Option 2Explanation
Grignard reagents are organometallic compounds that react with carbonyl compounds to form alcohols. However, formic acid is not a carbonyl compound and therefore cannot be prepared using a Grignard reagent.Rate this question:
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- 9.
P{margin-bottom:0.08in;} Which order of arrangement is correct in terms of the strength of the acid P{margin-bottom:0.08in;} P { margin-bottom: 0.08in; } a) CH3-CH2-COOH > CH3COOH < HCOOH < ClCH2-COOH b) ClCH2-COOH > HCOOH < CH3COOH < CH3-CH2-COOH c) CH3-CH2-COOH < CH3COOH < HCOOH < ClCH2-COOH d) HCOOH > CH3-CH2-COOH < CH3COOH > ClCH2-COOH
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
C. Option 3Explanation
The correct order of arrangement in terms of the strength of the acid is CH3-CH2-COOH < CH3COOH < HCOOH < ClCH2-COOH. This is because the strength of an acid is determined by its ability to donate a proton (H+ ion). In this case, the acidity increases as the electron-withdrawing groups (such as Cl) are added to the carboxylic acid. Therefore, ClCH2-COOH is the strongest acid, followed by HCOOH, CH3COOH, and CH3-CH2-COOH.Rate this question:
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- 10.
P{margin-bottom:0.08in;} P { margin-bottom: 0.08in; } The compound which undergoes intramolecular dehydration with P2O5 is a) acetic acid b) formic acid c) propionic acid d) buryric acid
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
B. Option 2 -
- 11.
P{margin-bottom:0.08in;} H─C=O ? The product is ⁄ HO a) CO + H2O b) HCOOH c) H2 + CO2 d) HCHO + O2
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
C. Option 3Explanation
The correct answer is option 3, H2 + CO2. This is because the reactant H─C=O is a ketone, which can undergo a reaction called the Cannizzaro reaction. In this reaction, the ketone molecule is simultaneously oxidized and reduced. The carbon atom in the ketone is oxidized to form CO2, while the hydrogen atom is reduced to form H2. Therefore, the product of the reaction is H2 + CO2.Rate this question:
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- 12.
P { margin-bottom: 0.08in; } When chlorine is passed through acetic acid in presence of red P, it forms. a) acetyl chloride b) Trichloro acetaldehyde c) Trichloro acetic acid d) Methyl chloride
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
C. Option 3Explanation
When chlorine is passed through acetic acid in the presence of red P (red phosphorus), it forms trichloroacetic acid.Rate this question:
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- 13.
P { margin-bottom: 0.08in; } Which of the following compounds will react with NaHCO3 solution to give sodium salt and CO2 a) acetic acid b) n-hexanol c) phenol d) both (a) and (b)
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
A. Option 1Explanation
Acetic acid will react with NaHCO3 solution to give sodium acetate and CO2. Acetic acid is a carboxylic acid and reacts with NaHCO3 (sodium bicarbonate) to form the corresponding sodium salt (sodium acetate) and release carbon dioxide gas. This is a common reaction known as an acid-base reaction or neutralization reaction.Rate this question:
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- 14.
P { margin-bottom: 0.08in; } when propanoic acid is treated with aqueous sodium – bicarbonate ,CO2 is liberated. The “C” of CO2 comes from a) methyl group b) carboxylic acid group b) methylene group d) bicarbonate
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
D. Option 4 -
- 15.
P { margin-bottom: 0.08in; } Carboxylic acids are more acidic than phenol and alcohol because of a) inte molecular hydrogen bonding b) formation of dimers c) highly acidic hydrogen d) greater resonance stabilisation of their conjugate base
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
D. Option 4Explanation
Carboxylic acids are more acidic than phenol and alcohol because the conjugate base of carboxylic acids is more stabilized by resonance. The presence of the carbonyl group in carboxylic acids allows for delocalization of the negative charge on the oxygen atom, resulting in greater stability. This resonance stabilization makes it easier for carboxylic acids to donate a proton and therefore makes them more acidic compared to phenol and alcohol.Rate this question:
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- 16.
P { margin-bottom: 0.08in; } Among the following the strongest acid is a) ClCH2-COOH b) Cl3C-COOH c) CH3CHOHCOOH d) Cl2CH-COOH
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
B. Option 2Explanation
The strongest acid among the given options is Cl3C-COOH. This is because the presence of three chlorine atoms in the molecule increases the electron-withdrawing effect, making the molecule more acidic. The more electron-withdrawing groups a molecule has, the more stable the conjugate base will be, leading to a stronger acid.Rate this question:
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- 17.
P { margin-bottom: 0.08in; } Which of the following compound is optically active ? a) CH3CH2COOH b) HOOC-CH2-COOH c) CH3CH(OH)CHO d) Cl2CHCOOH
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
C. Option 3Explanation
CH3CH(OH)CHO is optically active because it contains a chiral carbon atom, which is a carbon atom bonded to four different groups. This chiral carbon allows the molecule to exist in two non-superimposable mirror image forms, known as enantiomers. Therefore, CH3CH(OH)CHO can rotate the plane of polarized light and is optically active.Rate this question:
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- 18.
P{margin-bottom:0.08in;} CH3CH(OH)COOH ? The product is a) CH3COCOOH b) CH3CH2COOH c) CH3CHOHCHO d) HOOC-CH2-COOH
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
A. Option 1Explanation
The correct answer is option 1, CH3COCOOH. This is because the compound CH3CH(OH)COOH is an alcohol with a carboxylic acid functional group. When an alcohol reacts with a strong oxidizing agent, such as potassium dichromate (K2Cr2O7) or potassium permanganate (KMnO4), the alcohol group is oxidized to a carbonyl group (C=O), resulting in the formation of a carboxylic acid. In this case, the alcohol group (-OH) in CH3CH(OH)COOH is oxidized to a carbonyl group (C=O), resulting in the formation of CH3COCOOH.Rate this question:
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- 19.
P { margin-bottom: 0.08in; } The compound found in some stony deposit in kidneys is a) potassium oxalate b) oxalic acid c) potassium succinate d) calcium oxalate
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
D. Option 4Explanation
The compound found in some stony deposits in kidneys is calcium oxalate.Rate this question:
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- 20.
P { margin-bottom: 0.08in; } Ethylene cyanide on hydrolysis using acid gives a) oxalic acid b) succinic acid c) adipic acid d) propionic acid
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
B. Option 2Explanation
Ethylene cyanide, also known as acetonitrile, undergoes hydrolysis using acid to produce succinic acid.Rate this question:
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Mar 21, 2023Quiz Edited by
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Dec 24, 2013Quiz Created by
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