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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
Acetone upon condensation can give :A. mesityl oxideB. phoroneC. CrotonaldehydeD. mesitylene |
| Answer» Correct Answer - A::B::D | |
| 102. |
Which one of the following has the maximum acid strength ?A. o-Nitrobenzoic acidB. m-Nitrobenzoic acidC. p-Nitrobenzoic acidD. p-Nitrophenol |
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Answer» Correct Answer - C Carboxylic acids are stronger acids than phenolic compounds. |
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| 103. |
Identify `Z` in the following series `CH_(2)=CH_(2) overset(HBr)rarr X overset(Hydrolysis)rarr Y overset(Na_(2) CO_(3))underset(I_(2)excess)rarrZ`A. `C_2 H_5 I`B. `C_2 H_5 OH`C. `CHI_3`D. `CH_3 CHO` |
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Answer» Correct Answer - B `(X) = CH_3 CH_2 Br` `(Y) = CH_3 CH_2 OH underset ("Iodoform") rarr CHI_3 + HCOO^(Ө)`. |
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| 104. |
In which of the following the number of carbon atoms are not the same when carboxylic acid is obtained by oxiadation ?A. `CH_(3)COCH_(3)`B. `C"C"l_(3)CH_(2)CHO`C. `CH_(3)CH_(2)CH_(2)OH`D. `CH_(3)CH_(2)CHO` |
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Answer» Correct Answer - A (a) `CH_(3)COCH_(3)overset(HNO_(3))underset("Oxidation")rarrCH_(3)COOH+CO_(2)` |
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| 105. |
Explain the following about acetic acid (i) Its boiling point is higher than that of n-propyl alcohol (ii) It is weaker acid than formic acid and `alpha`-chloroacetic acid |
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Answer» Correct Answer - A (i) Due to greater magntude of intermolecular hydrogen bonding (ii) `CH_(3) group has greater +I effect than H atom and less -I effect than Cl atom. |
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| 106. |
Give the names of the reagents which bring about the following conversions : (i) Ethanoic acid to ethanol (ii) Sodium benzoate to benzene. |
| Answer» (i) `LiAIH_(4)//H_(3)O^(+)` , (ii) Soda lime `(NaOH//CaO)` | |
| 107. |
The correct increasing order of the acid strength fo acids, butyric acid (I), 2-chlorobutyric acid (II), 3-chlorobutyaric acid (III), 2,2-dichlorobutyric acid (IV) is :A. `IltIIltIIIltIV`B. `IIIltIIltIVltI`C. `IIIltIltIIltIV`D. `IVltIIIltIIltI` |
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Answer» Correct Answer - C (c) It is linked with the relative positions of the electron withdrawing Cl atoms with-I effect and also their number. |
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| 108. |
Which of the following is the best method for the synthesis of ester `(I) (Me_3 C-COOMe)` ?A. `Me_3 C-COCl + MeOH rarr`B. `Me_3 C-COOH + MeOH rarr`C. `Me_3 C-COOH + CH_2 N_2 rarr`D. `Me_3 C-COCl + MeONa rarr` |
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Answer» Correct Answer - C The esterification of an alcohol with `RCOCl` ro with `RCOOH` is affected by steric hindrance. Bulky group on either alcohol or acid derivatives slow down the reaction. So, the esterification with diazomethane `(CH_2N_2)` is the best method. |
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| 109. |
The molecular weight of benzoic acid in benzene as determined by depression in the freezing point method corresponds toA. Ionization of benzoic acidB. Dimerisation of benzoic acidC. Trimerisation of benzoic acidD. Solution of benzoic acid. |
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Answer» Correct Answer - B (b) Benzoic acid exists as a dimer in benzene |
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| 110. |
The boiling point of propionic acid is less than that of n-butyl alcohol, an alcohol of comparable molecular weight. |
| Answer» Boiling point of an acid is higher than that of an alcohol of comparable molecular weight due to stronger intramolecular `H-`bonding. | |
| 111. |
How will your prepare teriary butyl alcohol from acetic acid ? |
| Answer» Correct Answer - A | |
| 112. |
Assertion : Carbxoylic acids donot give characteristic reactions of carbonyl group. Reason : The carbonyl group is sterically hindered in carboxylic acid.A. If both assertion and reason are correct and reason is correct explanation for assertion.B. If both assertion and reason are correct but reason is not correct explanation for assertion.C. If assertion is correct but reason is incorrect.D. If assertion and reason are both incorrect. |
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Answer» Correct Answer - C (c) Correct reason. The carbonyl group in carboxyl group has both single and double bond characters due to resonance. |
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| 113. |
Assertion (A) The `alpha`-hydrogen atom in carbonyl compounds is less acidic. Reason (R) The anion formed after the loss of `alpha`-hydrogen atom is resonance stabilised.A. Assertion and reason both are correct and reason is correct explanation of assertion.B. Assertion and reason both are wrong statements.C. Assertion is correct statement but reason is wrong statement.D. Assertion is wrong statement but reason is correct statement. |
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Answer» Correct Answer - D (d) Correct assertion : `alpha`-hydrogen atoms in carbonyl compounds are more acidic. |
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| 114. |
In the following reaction , product P is `R-undersetunderset(O)(||)C-Clunderset(Pd- BaSO_4)overset(H_2)to P`A. `RCH_2OH`B. `RCOOH`C. `RCHO`D. `RCH_3` |
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Answer» Correct Answer - C The given reaction is Rosenmund reaction `R-undersetunderset(O)(||)C-Clunderset(Pd-BaSO_4)overset(H_2)to R-undersetunderset((P))(O)underset(||)C-H+HCl` |
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| 115. |
Assertion : `(CH_(3))_(3)C"C"OOH` does not give HVZ reaction. Reason : `(CH_(3))_(3)C"C"OOH` does not have any `alpha`-hydrogen atom.A. If both assertion and reason are correct and reason is correct explanation for assertion.B. If both assertion and reason are correct but reason is not correct explanation for assertion.C. If assertion is correct but reason is incorrect.D. If assertion and reason are both incorrect. |
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Answer» Correct Answer - A (a) Reason is the correct explanation for assertion. |
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| 116. |
Identify the correct order of boiling points of the following compounds. `underset((A)) (CH_(3) CH_(2) CH_(2) CH_(2) OH),underset((B)) (CH_(3) CH_(2) CH_(2) CHO), underset((C)) (CH_(3) CH_(2) CH_(2) COOH`.A. `(A) gt (B) gt ( C)`B. `( C) gt (A) gt (B)`C. `(A) gt ( C) gt (B)`D. `( C) gt (B) gt (A)` |
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Answer» Correct Answer - B Acid `( C)` forms dimer due to intramolecular `H-`bonding. Alcohol `(A)` forms intermolecular `H-`bonding `H-`bonding in `(C )` is stronger than in `(A)`. Aldehyde `(B)` has dipole-dipole interaction. So the order of boiling points is : `(C) gt (A) gt (B)`. |
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| 117. |
(a) How will you prepare benzoic acid (i) from ethyl benzene (ii) by using Grignard reagent? (b) How is benzoic acid converted to (i) Benzyl alcohol (ii) Benzyl ethanoate ? |
| Answer» Correct Answer - A | |
| 118. |
The acidity of carboxylic acid is determined by the nature of the alkyl group attached and the substiuent present on it. It is affected mainly by the inductive effect of the substituent and its position with respect to the -COOH group. Electron-donating substituent tends to decrease the acidic strength whereas electron-withdrawing substituent tends to increase acidic strength. The acidic strength of aromatic carboxylic acid on the other hand depends upon both the inductive and resonance effects of the substituents. Which of the following acids has the smallest dissocation constant ?A. `CH_(3)CHFCOOH`B. `FCH_(2)CH_(2)COOH`C. `BrCH_(2)CH_(2)COOH`D. `CH_(3)CHBCOOH.` |
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Answer» Correct Answer - C (c) It has the smallest `K_(a)` value (weakest acid). |
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| 119. |
The acidity of carboxylic acid is determined by the nature of the alkyl group attached and the substiuent present on it. It is affected mainly by the inductive effect of the substituent and its position with respect to the -COOH group. Electron-donating substituent tends to decrease the acidic strength whereas electron-withdrawing substituent tends to increase acidic strength. The acidic strength of aromatic carboxylic acid on the other hand depends upon both the inductive and resonance effects of the substituents. Which of the following would be expected to be most highly ionized in water ?A. `ClCH_(2)CH_(2)CH_(2)COOH`B. `CH_(3)CHClCH_(2)COOH`C. `CH_(3)CH_(2)C"C"l_(2)COOH`D. `CH_(3)CH_(2)CHClCOOH` |
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Answer» Correct Answer - C (c) It is the strongest acid since it has two Cl atoms with -I effect. |
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| 120. |
The correct order of increasing acidic strength isA. `"Phenol" lt "Ethanol" lt "Chloroacetic acid" lt "Acetic acid"`B. `"Ethanol" lt "Phenol" lt "Chloroacetic acid" lt "Acetic acid"`C. `"Ethanol" lt "Phenol" lt "Acetic acid" lt "Chloroacetic acid"`D. `"Chloroacetic acid" lt "Acetic acid" lt "Phenol" lt Ethanol".` |
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Answer» Correct Answer - C (c) It is the correct order of increasing acidic strength. |
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| 121. |
Which order is improper for acidic strength ?A. `Cl_(3)C"C"OOHgtCl_(2)CHCOOHgtClCH_(2)COOH`B. `CH_(3)-CH-underset(Cl)underset(|)CH-COOHgtCH_(3)-underset(Cl)underset(|)CH-CH_(2)-COOHgtunderset(Cl)underset(|)CH_(2)-CH_(2)-CH_(2)-CH_(2)-COOH`C. D. `HCOOHgtCH_(3)COOHgtC_(6)H_(5)COOH` |
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Answer» Correct Answer - D (d) The correct order is : `{:(HCOOHgtC_(6)H_(5)COOHgtCH_(3)COOH),((Ka)17.7xx10^(-5)" "6.3xx10^(-5)" "1.75xx10^(-5)):}` |
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| 122. |
Which of the following represents the correct decreasing order of acidic strength of following ? (i)Methanoic acid (ii)Ethanoic acid (iii)Propanoic acid (iv)Butanoic acidA. (i) gt (ii) gt (iii) gt (iv)B. (ii) gt (iii) gt (iv) gt (i)C. (i) gt (iv) gt (iii) gt (ii)D. (iv) gt (i) gt (iii) gt (ii) |
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Answer» Correct Answer - A The correct order of acidic strength is methanoic acid gt ethanoic acid gt propanoic acid gt butanoic acid because the +I - effect of alkyl group increases in the order. `CH_3 lt C_2H_5 lt C_3H_7 lt C_4H_9` Acidic Nature `prop ("-I - effect (EWG)")/(+I - effect (ERG))` -I - effect increases hence, acidic nature increases. |
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| 123. |
The correct order of increasing acidic strength of the compounds: A. `BltDltAltC`B. `DltAltCltB`C. `DltBltAltC`D. `AltDltCltB` |
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Answer» Correct Answer - C (c) `CH_(3)` group with +I effect decreases acidity while F with -I effect increases acidity. |
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| 124. |
Which of the following represents the correct order of the acidic strength in the given compounds ?A. `FCH_(2)COOHgtCH_(3)COOHgtBrCH_(2)COOHgtClCH_(2)COOH`B. `BrCH_(2)COOHgtClCH_(2)COOHgtFCH_(2)COOHgtCH_(3)COOH`C. `FCH_(2)COOHgtClCH_(2)COOHgtBrCH_(2)COOHgtCH_(3)COOH`D. `CH_(3)COOHgtBrCH_(2)COOHgtClCH_(2)COOHgtFCH_(2)COOH` |
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Answer» Correct Answer - C (c) is the correct order. |
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| 125. |
Arrange the following compounds in increasing order of acidic strength 2, 4-dinitrobenzoic acid, 4-methoxybenzoic acid, 4-nitrobenzoic acid. |
| Answer» The increasing order of acidic strength : 4-methoxybenzoic acid lt 4-nitrobenzoic acid lt 2, 4-dinitrobenzoic acid. | |
| 126. |
Which of the following represents the correct order of the acidic strength in the given compounds ?A. `FCH_2COOH gt CH_3COOH gt BrCH_3COOH gt ClCH_2COOH`B. `BrCH_2COOH gt ClCH_2COOH gt FCH_2COOH gt CH_3COOH`C. `FCH_2COOH gt ClCH_2COOH gt BrCH_2COOH gt CH_3COOH`D. `CH_3COOH gt BrCH_2COOH gt ClCH_2COOH lt FCH_2COOH` |
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Answer» Correct Answer - C The acidity of halogenated acid increases with increase in electronegativity of the halogen present. The electronegativity of the halogen decreases in order as F gt Ce gt Br. Therefore correct order of given compound is `FCH_2COOH gt ClCH_2COOH gt BrCH_2COOH gt CH_3COOH` |
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| 127. |
Propionic acid with `Br_(2)`/`P` yields a dibromo product. Its structure would beA. `CH_2Br-CHBr-COOH`B. `H-undersetunderset(Br)(|)oversetoverset(Br)(|)C-CH_2COOH`C. `CH_2Br-CH_2-COBr`D. `CH_3-undersetunderset(Br)(|)oversetoverset(Br)(|)C-COOH` |
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Answer» Correct Answer - D `underset("Propionic aicd")(CH_3-undersetunderset(H)(|)oversetoverset(H)(|)C-COOH)underset(-2HBr)overset(Br_2//P)to CH_3-undersetunderset(Br)(|)oversetoverset(Br)(|)C-COOH` Carbonylic acids reacts with `Cl_2` or `Br_2` in presence of red P to give exclusively `alpha`-chloro or `alpha` -bromo acids. This reaction is called Hell-Volhard-Zelinsky (HVZ) reduction . This reaction is example of `alpha` H-substitution. |
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| 128. |
Describe a test to distinguish between phenol and benzoic acid. |
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Answer» Correct Answer - A Distinction can be made by `NaHCO_(3)` test as well as by `Fecl_(3)` test. |
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| 129. |
Phenol and benzoic acid may be distinguished by their reaction with :A. Aqueous `NaOH`B. Aqueous `NaHCO_(3)`C. Neutral `FeCl_(3)`D. Aqueous `NH_(3)` |
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Answer» Correct Answer - B::C (b,c) Aqueous `NaHCO_(3)` evolves `CO_(2)` from benzoic acid and not from phenol. Similarly, neutral `FeCl_(3)` gives violet colouration with phenol and not with benzoic acid. |
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| 130. |
(b) Give reasons : (i) p-Nitrobenzoic acid has higher `K_(a)` value than benozic acid (ii) Acetone is soluble in water but benzophenone is not. |
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Answer» (i) In p-Nitrobenzoic acid, the-`NO_(2)` group present at para position in the ring is an electron withdrawing group. Under its influence, the release of `H^(+)` ion from the acid becomes easier as compared to benzoic acid in which no such group is present. Therefore, `K_(a)` value of p-nitrobenzoic acid is more `(3.6xx10^(-4))` as compared to benzoic acid `(6.3xx10^(-5))`. (ii) Acetone `(CH_(3)COCH_(3))` is solube in water to small extent due to the presence of polar carbonyl group which is involved in hydrogen bonding with `H_(2)O` molecules of water. Benzophenone `(C_(6)H_(5)COC_(6)H_(5))` has two phenyl groups which are quite big in size. They try to mask the polar cabonyl group to large extent. As a result. As a result, hydrogen bonding is negligible and therefore, it does not dissolve in water. |
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| 131. |
Out of but-3-enoic acid and but-3-yonic acid, which is a stronger acid ? |
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Answer» `underset((I))underset("But-3-enoic acid")underset()(CH_(2)=CH-CH_(2))-overset(O)overset(||)C-OH " " underset((II))underset("But-3-yonic acid")underset()(CHequivC-CH_(2)-overset(O)overset(||)C-OH)` In acid (II), the triple bonded carbon atoms are sp hybridised and more electronegative (more electron withdrawing) than the double bonded carbon atoms in acid (I) which are `sp^(2)`hybridised. Therefore, the release of `H^(+)` ion from acid (II) is easier and it is a stronger acid than acid (I). |
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| 132. |
An Organic compound (A) `C_(4)H_(7)Cl_(3)` yields (B) with KOH(aq.) (B) on treating with `NH_(3)` gives (C) which on heating gives (D). On heating (D) with `P_(2)O_(5)`, 2-methyl propane nitrile is formed. What are (A), (B), (C) and (D)? |
| Answer» (A) `(CH_(3))_(2)CH"CC"l_(3)`, (B) `(CH_(3))_(2)CHCOOH`, (C) `(CH_(3))_(2)CHCOONH_(4)`, (D) `(CH_(3))_(2) CHCONH_(2)` | |
| 133. |
Which `H` atom in the following ester is most acidic ? `overset(1)(CH_(3))-overset(2)(CH_(2))-overset(O)overset(||)(C)-overset(3)(CH_(2))-overset(O)overset(||)(C)-O-overset(4)(CH_(2))overset(5)(CH_(3))`A. 1B. 2C. 3D. 4 |
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Answer» Correct Answer - C `(overset(3) C H_2)` is most acidic due to two electron-withdrawing `(C=O)` groups. |
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| 134. |
Give the star mark to the hydrogen which is most acidic in the following compounds: (a) `CH_(3)-CH_(2)-overset(O)overset(||)C-CH_(2)-CH_(3)` (b) `H_(2)C=CH-CH_(2)-overset(O)overset(||)C-H` (c ) `CH_(3)-overset(O)overset(||)C-O-CH_(2)-CH_(3)` (d) `CH_(3)-overset(OH)overset(|)"CH"-overset(O)overset(||)C-OH` |
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Answer» (a) Hydrogen of methylene group will be most acidic. `CH_(3)-underset(**)CH_(2)-overset(O)overset(||)C-underset(**)CH_(2)-CH_(3)` (b) In this compound, allylic hydrogen will be most acidic. `H_(2)C=CH-underset(**)CH_(2)-overset(O)overset(||)C-H` (c ) Hydrogen of methylene group will be most acidic. `CH_(3)-overset(O)overset(||)C-O-underset(**)CH_(2)-CH_(3)` (d) Hydrogen of carboxylic group will be most acidic. `CH_(3)-overset(OH)overset(|)"CH"-overset(O)overset(||)C-Ounderset(**)H` |
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| 135. |
Why is pKa of `F-CH_(2)COOH` lower than that of `Cl-CH_(2)COOH`? |
| Answer» Fluorine (-F) has a stronger -I effect as compared to chlorine (-Cl). Therefore, release of `H^(+)` ion from `prop`-fluoroacetic acid is easier than from `beta`-chloroacetic acid. | |
| 136. |
Which of the following on oxidation followed by hydrolysis gives acetic acid ?A. Acetaldehyde cyanolydrinB. Acetone cyanohydrinC. Formaldehyde cyanohydrinD. None of these. |
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Answer» Correct Answer - A (a) `CH_(3)-overset(OH)overset(|)CH-CNoverset("Oxidation")rarrCH_(3)-overset(O)overset(||)C-CNoverset(H_(2)O"/"H^(+))rarrCH_(3)-overset(O)overset(||)C-OH` |
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| 137. |
Carbonation of methyl magnesium bromide gives an organic compound which can also be obtained by :A. Hydrolysis of acetonitrile with mineral acidB. Oxidation of methyl alcoholC. Hydrolysis of methyl isocyanide with mineral acidD. Hydrolysis of methyl formate with mineral acid. |
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Answer» Correct Answer - A (a) `CH_(3)COOH` is the acid formed in both the cases |
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| 138. |
What reagents are required for making the following changes in functional groups? (a) ` -CHOto -CH_(2)`OH (b) `-CN to-COOH` (c) `-COOHto H` (d) `-CONH_(2) to -NH_(2)` |
| Answer» (a) `LiAIH_(4)`, (b) dil. HCI, (c) Soda lime, (d) `Br_(2)` and KOH | |
| 139. |
`3-Phenol` propanic acid `(B)` can be prepared by both nitrile and carbonation method as shown. Path `I` gives a good yield of `(B)`. `overset (Ө) C N` initiates elimination reaction.A. If both `(A)` are `( R)` are true and `( R)` is the correct explanation of `(A)`.B. If both `(A)` and `( R)` are true but `( R)` is not the correct explanation of `(A)`.C. If `(A)` is true but `( R)` is false.D. If `(A)` is false but `( R)` is true. |
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Answer» Correct Answer - A Since `3-phenol` propanoic acid is `1^@ RX`, preparation by both methods can occur. |
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| 140. |
How will you convert acetic acid into acetaldehyde ? |
| Answer» Correct Answer - A | |
| 141. |
(a) Describe the preparation of acetic acid from acetylene. How can the following be obtained from acetic acd ? (i) Acetone (ii) Acetaldehyde (b) In what way can acetic acid be distinguished from acetone ? (c) Why does carboxylic acid not give the characteristic reactions of a carbonyl group ? |
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Answer» Correct Answer - A (b) by `NaHCO_(3)` test (c) because the carbonyl group is involved in conjugation. |
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