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Q8.18(ii):
Give plausible explanation for the following:
(ii) There are two (–NH_{2}) groups in semicarbazide. However, only one is involved in the formation of semicarbazones.
Solution :
1. Structural Analysis of Semicarbazide
Semicarbazide is represented by the chemical formula $H_{2}N-NH-CO-NH_{2}$. Structurally, it consists of two distinct types of nitrogen-containing functional groups:
- The hydrazinic-like amino group ($-NH_{2}$) attached to the nitrogen atom ($-NH-$).
- The amide-like amino group ($-NH_{2}$) attached directly to the carbonyl group ($C=O$).
2. Resonance and Electronic Distribution
The reactivity of the $-NH_{2}$ groups is governed by the availability of the lone pair of electrons on the nitrogen atom for nucleophilic attack. In semicarbazide, these electrons are subject to different electronic effects:
In the $-CO-NH_{2}$ moiety, the lone pair on the nitrogen atom participates in delocalization (resonance) with the adjacent carbonyl group. This can be illustrated by the resonance hybrid:
$H_{2}N-NH-C(=O)-NH_{2} \leftrightarrow H_{2}N-NH-C(-O^{-})=N^{+}H_{2}$
[Per the principle of resonance-induced electron withdrawal, the electron density on the nitrogen of the amide group is significantly reduced.]
3. Comparative Nucleophilicity
For the formation of a semicarbazone (a derivative formed via nucleophilic addition to a carbonyl compound), the nitrogen must act as a nucleophile. The nitrogen atom of the terminal $-NH_{2}$ group (the one adjacent to the $-NH-$ group) is not involved in resonance with the carbonyl group. Consequently, its lone pair is highly available for donation [By the Lewis Base theory].
4. Visual Representation of Molecular Structure
5. Conclusion on Selectivity
The amino group adjacent to the $-NH-$ linkage is inherently more nucleophilic because it lacks the electron-withdrawing effect of the $C=O$ group. The amide nitrogen, conversely, is deactivated toward nucleophilic attack due to the delocalization of its lone pair into the $C=O$ bond [Per the Conjugation Effect].
| Feature | $-NH_{2}$ (terminal) | $-NH_{2}$ (amide) |
|---|---|---|
| Electronic Effect | Available lone pair | Resonance delocalized |
| Nucleophilicity | High | Very Low |
Final Solution: The $-NH_{2}$ group directly attached to the carbonyl group (amide nitrogen) has its lone pair involved in resonance with the $C=O$ group, making it less nucleophilic. The other $-NH_{2}$ group is significantly more nucleophilic and thus selectively reacts with carbonyl compounds to form semicarbazones.
More Questions from Class 12 Chemistry Aldehydes Exercises
- Q8.1(i): What is meant by the following terms ? Give an example of the reaction in each case. (i) Cyanohydrin
- Q8.1(i): What is meant by the following term? Give an example of the reaction. (i) Cyanohydrin
- Q8.1(ii): What is meant by the following terms ? Give an example of the reaction in each case. (ii) Acetal
- Q8.1(ii): What is meant by the following term? Give an example of the reaction. (ii) Acetal
- Q8.1(iii): What is meant by the following terms ? Give an example of the reaction in each case. (iii) Semicarbazone
- Q8.1(iii): What is meant by the following term? Give an example of the reaction. (iii) Semicarbazone
- Q8.1(iv): What is meant by the following terms ? Give an example of the reaction in each case. (iv) Aldol
- Q8.1(iv): What is meant by the following term? Give an example of the reaction. (iv) Aldol
- Q8.1(ix): What is meant by the following terms ? Give an example of the reaction in each case. (ix) 2,4-DNP-derivative
- Q8.1(ix): What is meant by the following term? Give an example of the reaction. (ix) 2,4-DNP-derivative
- Q8.1(v): What is meant by the following terms ? Give an example of the reaction in each case. (v) Hemiacetal
- Q8.1(v): What is meant by the following term? Give an example of the reaction. (v) Hemiacetal
- Q8.1(vi): What is meant by the following terms ? Give an example of the reaction in each case. (vi) Oxime
- Q8.1(vi): What is meant by the following term? Give an example of the reaction. (vi) Oxime
- Q8.1(vii): What is meant by the following terms ? Give an example of the reaction in each case. (vii) Ketal
- Q8.1(vii): What is meant by the following term? Give an example of the reaction. (vii) Ketal
- Q8.1(viii): What is meant by the following terms ? Give an example of the reaction in each case. (viii) Imine
- Q8.1(viii): What is meant by the following term? Give an example of the reaction. (viii) Imine
- Q8.1(x): What is meant by the following terms ? Give an example of the reaction in each case. (x) Schiff’s base
- Q8.1(x): What is meant by the following term? Give an example of the reaction. (x) Schiff’s base
- Q8.10: An organic compound with the molecular formula \(C_{9}H_{10}O\) forms 2,4-DNP derivative, reduces Tollens’ reagent and undergoes Cannizzaro reaction. On vigorous oxidation, it gives 1,2-benzenedicarboxylic acid. Identify the compound.
- Q8.10: An organic compound with the molecular formula (C_{9}H_{10}O) forms 2,4-DNP derivative, reduces Tollens’ reagent and undergoes Cannizzaro reaction. On vigorous oxidation, it gives 1,2-benzenedicarboxylic acid. Identify the compound.
- Q8.11: An organic compound (A) (molecular formula \(C_{8}H_{16}O_{2}\)) was hydrolysed with dilute sulphuric acid to give a carboxylic acid (B) and an alcohol (C). Oxidation of (C) with chromic acid produced (B). (C) on dehydration gives but-1-ene. Write equations for the reactions involved.
- Q8.11: An organic compound (A) (molecular formula (C_{8}H_{16}O_{2})) was hydrolysed with dilute sulphuric acid to give a carboxylic acid (B) and an alcohol (C). Oxidation of (C) with chromic acid produced (B). (C) on dehydration gives but-1-ene. Write equations for the reactions involved.
- Q8.12(i): Arrange the following compounds in increasing order of their property as indicated: (i) Acetaldehyde, Acetone, Di-tert-butyl ketone, Methyl tert-butyl ketone (reactivity towards HCN)
- Q8.12(i): Arrange the following compounds in increasing order of their property as indicated: (i) Acetaldehyde, Acetone, Di-tert-butyl ketone, Methyl tert-butyl ketone (reactivity towards HCN)
- Q8.12(ii): Arrange the following compounds in increasing order of their property as indicated: (ii) \(CH_{3}CH_{2}CH(Br)COOH\), \(CH_{3}CH(Br)CH_{2}COOH\), \((CH_{3})_{2}CHCOOH\), \(CH_{3}CH_{2}CH_{2}COOH\) (acid strength)
- Q8.12(ii): Arrange the following compounds in increasing order of their property as indicated: (ii) (CH_{3}CH_{2}CH(Br)COOH), (CH_{3}CH(Br)CH_{2}COOH), ((CH_{3})_{2}CHCOOH), (CH_{3}CH_{2}CH_{2}COOH) (acid strength)
- Q8.12(iii): Arrange the following compounds in increasing order of their property as indicated: (iii) Benzoic acid, 4-Nitrobenzoic acid, 3,4-Dinitrobenzoic acid, 4-Methoxybenzoic acid (acid strength)
- Q8.12(iii): Arrange the following compounds in increasing order of their property as indicated: (iii) Benzoic acid, 4-Nitrobenzoic acid, 3,4-Dinitrobenzoic acid, 4-Methoxybenzoic acid (acid strength)
- Q8.13(i): Give simple chemical tests to distinguish between the following pairs of compounds. (i) Propanal and Propanone
- Q8.13(i): Give simple chemical tests to distinguish between the following pair of compounds. (i) Propanal and Propanone
- Q8.13(ii): Give simple chemical tests to distinguish between the following pairs of compounds. (ii) Acetophenone and Benzophenone
- Q8.13(ii): Give simple chemical tests to distinguish between the following pair of compounds. (ii) Acetophenone and Benzophenone
- Q8.13(iii): Give simple chemical tests to distinguish between the following pairs of compounds. (iii) Phenol and Benzoic acid
- Q8.13(iii): Give simple chemical tests to distinguish between the following pair of compounds. (iii) Phenol and Benzoic acid
- Q8.13(iv): Give simple chemical tests to distinguish between the following pairs of compounds. (iv) Benzoic acid and Ethyl benzoate
- Q8.13(iv): Give simple chemical tests to distinguish between the following pair of compounds. (iv) Benzoic acid and Ethyl benzoate
- Q8.13(v): Give simple chemical tests to distinguish between the following pairs of compounds. (v) Pentan-2-one and Pentan-3-one
- Q8.13(v): Give simple chemical tests to distinguish between the following pair of compounds. (v) Pentan-2-one and Pentan-3-one
- Q8.13(vi): Give simple chemical tests to distinguish between the following pairs of compounds. (vi) Benzaldehyde and Acetophenone
- Q8.13(vi): Give simple chemical tests to distinguish between the following pair of compounds. (vi) Benzaldehyde and Acetophenone
- Q8.13(vii): Give simple chemical tests to distinguish between the following pairs of compounds. (vii) Ethanal and Propanal
- Q8.13(vii): Give simple chemical tests to distinguish between the following pair of compounds. (vii) Ethanal and Propanal
- Q8.14(i): How will you prepare the following compounds from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom (i) Methyl benzoate
- Q8.14(i): How will you prepare the following compound from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom (i) Methyl benzoate
- Q8.14(ii): How will you prepare the following compounds from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom (ii) m-Nitrobenzoic acid
- Q8.14(ii): How will you prepare the following compound from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom (ii) m-Nitrobenzoic acid
- Q8.14(iii): How will you prepare the following compounds from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom (iii) p-Nitrobenzoic acid
- Q8.14(iii): How will you prepare the following compound from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom (iii) p-Nitrobenzoic acid
- Q8.14(iv): How will you prepare the following compounds from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom (iv) Phenylacetic acid
- Q8.14(iv): How will you prepare the following compound from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom (iv) Phenylacetic acid
- Q8.14(v): How will you prepare the following compounds from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom (v) p-Nitrobenzaldehyde.
- Q8.14(v): How will you prepare the following compound from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom (v) p-Nitrobenzaldehyde.
- Q8.15(i): How will you bring about the following conversions in not more than two steps? (i) Propanone to Propene
- Q8.15(i): How will you bring about the following conversion in not more than two steps? (i) Propanone to Propene
- Q8.15(ii): How will you bring about the following conversions in not more than two steps? (ii) Benzoic acid to Benzaldehyde
- Q8.15(ii): How will you bring about the following conversion in not more than two steps? (ii) Benzoic acid to Benzaldehyde
- Q8.15(iii): How will you bring about the following conversions in not more than two steps? (iii) Ethanol to 3-Hydroxybutanal
- Q8.15(iii): How will you bring about the following conversion in not more than two steps? (iii) Ethanol to 3-Hydroxybutanal
- Q8.15(iv): How will you bring about the following conversions in not more than two steps? (iv) Benzene to m-Nitroacetophenone
- Q8.15(iv): How will you bring about the following conversion in not more than two steps? (iv) Benzene to m-Nitroacetophenone
- Q8.15(ix): How will you bring about the following conversions in not more than two steps? (ix) Benzoic acid to \(m\)- Nitrobenzyl alcohol
- Q8.15(ix): How will you bring about the following conversion in not more than two steps? (ix) Benzoic acid to m-Nitrobenzyl alcohol
- Q8.15(v): How will you bring about the following conversions in not more than two steps? (v) Benzaldehyde to Benzophenone
- Q8.15(v): How will you bring about the following conversion in not more than two steps? (v) Benzaldehyde to Benzophenone
- Q8.15(vi): How will you bring about the following conversions in not more than two steps? (vi) Bromobenzene to 1-Phenylethanol
- Q8.15(vi): How will you bring about the following conversion in not more than two steps? (vi) Bromobenzene to 1-Phenylethanol
- Q8.15(vii): How will you bring about the following conversions in not more than two steps? (vii) Benzaldehyde to 3-Phenylpropan-1-ol
- Q8.15(vii): How will you bring about the following conversion in not more than two steps? (vii) Benzaldehyde to 3-Phenylpropan-1-ol
- Q8.15(viii): How will you bring about the following conversions in not more than two steps? (viii) Benzaldehyde to \(\alpha\)-Hydroxyphenylacetic acid
- Q8.15(viii): How will you bring about the following conversion in not more than two steps? (viii) Benzaldehyde to (\alpha)-Hydroxyphenylacetic acid
- Q8.16(i): Describe the following: (i) Acetylation
- Q8.16(i): Describe the following: (i) Acetylation
- Q8.16(ii): Describe the following: (ii) Cannizzaro reaction
- Q8.16(ii): Describe the following: (ii) Cannizzaro reaction
- Q8.16(iii): Describe the following: (iii) Cross aldol condensation
- Q8.16(iii): Describe the following: (iii) Cross aldol condensation
- Q8.16(iv): Describe the following: (iv) Decarboxylation
- Q8.16(iv): Describe the following: (iv) Decarboxylation
- Q8.17: Complete each synthesis by giving missing starting material, reagent or products
- Q8.17(i): Complete each synthesis by giving missing starting material, reagent or products.
- Q8.17(ii): Complete each synthesis by giving missing starting material, reagent or products.
- Q8.17(iii): Complete each synthesis by giving missing starting material, reagent or products.
- Q8.17(iv): Complete each synthesis by giving missing starting material, reagent or products.
- Q8.17(ix): Complete each synthesis by giving missing starting material, reagent or products.
- Q8.17(v): Complete each synthesis by giving missing starting material, reagent or products.
- Q8.17(vi): Complete each synthesis by giving missing starting material, reagent or products.
- Q8.17(vii): Complete each synthesis by giving missing starting material, reagent or products.
- Q8.17(viii): Complete each synthesis by giving missing starting material, reagent or products.
- Q8.17(x): Complete each synthesis by giving missing starting material, reagent or products.
- Q8.17(xi): Complete each synthesis by giving missing starting material, reagent or products.
- Q8.18(i): Give plausible explanation for each of the following: (i) Cyclohexanone forms cyanohydrin in good yield but 2,2,6-trimethylcyclo-hexanone does not.
- Q8.18(i): Give plausible explanation for the following: (i) Cyclohexanone forms cyanohydrin in good yield but 2,2,6-trimethylcyclo-hexanone does not.
- Q8.18(ii): Give plausible explanation for each of the following: (ii) There are two \(-NH_{2}\) groups in semicarbazide. However, only one is involved in the formation of semicarbazones.
- Q8.18(iii): Give plausible explanation for each of the following: (iii) During the preparation of esters from a carboxylic acid and an alcohol in the presence of an acid catalyst, the water or the ester should be removed as soon as it is formed.
- Q8.18(iii): Give plausible explanation for the following: (iii) During the preparation of esters from a carboxylic acid and an alcohol in the presence of an acid catalyst, the water or the ester should be removed as soon as it is formed.
- Q8.19: An organic compound contains 69.77% carbon, 11.63% hydrogen and rest oxygen. The molecular mass of the compound is 86. It does not reduce Tollens’ reagent but forms an addition compound with sodium hydrogensulphite and give positive iodoform test. On vigorous oxidation it gives ethanoic and propanoic acid. Write the possible structure of the compound.
- Q8.19: An organic compound contains 69.77% carbon, 11.63% hydrogen and rest oxygen. The molecular mass of the compound is 86. It does not reduce Tollens’ reagent but forms an addition compound with sodium hydrogensulphite and give positive iodoform test. On vigorous oxidation it gives ethanoic and propanoic acid. Write the possible structure of the compound.
- Q8.2(i): Name the following compounds according to IUPAC system of nomenclature: (i) \(CH_{3}CH(CH_{3})CH_{2}CH_{2}CHO\)
- Q8.2(i): Name the following compound according to IUPAC system of nomenclature: (i) (CH_{3}CH(CH_{3})CH_{2}CH_{2}CHO)
- Q8.2(ii): Name the following compounds according to IUPAC system of nomenclature: (ii) \(CH_{3}CH_{2}COCH(C_{2}H_{5})CH_{2}CH_{2}Cl\)
- Q8.2(ii): Name the following compound according to IUPAC system of nomenclature: (ii) (CH_{3}CH_{2}COCH(C_{2}H_{5})CH_{2}CH_{2}Cl)
- Q8.2(iii): Name the following compounds according to IUPAC system of nomenclature: (iii) \(CH_{3}CH=CHCHO\)
- Q8.2(iii): Name the following compound according to IUPAC system of nomenclature: (iii) (CH_{3}CH=CHCHO)
- Q8.2(iv): Name the following compounds according to IUPAC system of nomenclature: (iv) \(CH_{3}COCH_{2}COCH_{3}\)
- Q8.2(iv): Name the following compound according to IUPAC system of nomenclature: (iv) (CH_{3}COCH_{2}COCH_{3})
- Q8.2(v): Name the following compounds according to IUPAC system of nomenclature: (v) \(CH_{3}CH(CH_{3})CH_{2}C(CH_{3})_{2}COCH_{3}\)
- Q8.2(v): Name the following compound according to IUPAC system of nomenclature: (v) (CH_{3}CH(CH_{3})CH_{2}C(CH_{3})_{2}COCH_{3})
- Q8.2(vi): Name the following compounds according to IUPAC system of nomenclature: (vi) \((CH_{3})_{3}CCH_{2}COOH\)
- Q8.2(vi): Name the following compound according to IUPAC system of nomenclature: (vi) ((CH_{3})_{3}CCH_{2}COOH)
- Q8.2(vii): Name the following compounds according to IUPAC system of nomenclature: (vii) \(OHCC_{6}H_{4}CHO-p\)
- Q8.2(vii): Name the following compound according to IUPAC system of nomenclature: (vii) (OHCC_{6}H_{4}CHO-p)
- Q8.20: Although phenoxide ion has more number of resonating structures than carboxylate ion, carboxylic acid is a stronger acid than phenol. Why?
- Q8.20: Although phenoxide ion has more number of resonating structures than carboxylate ion, carboxylic acid is a stronger acid than phenol. Why?
- Q8.3(i): Draw the structures of the following compounds. (i) 3-Methylbutanal
- Q8.3(i): Draw the structure of the following compound. (i) 3-Methylbutanal
- Q8.3(ii): Draw the structures of the following compounds. (ii) p-Nitropropiophenone
- Q8.3(ii): Draw the structure of the following compound. (ii) p-Nitropropiophenone
- Q8.3(iii): Draw the structures of the following compounds. (iii) p-Methylbenzaldehyde
- Q8.3(iii): Draw the structure of the following compound. (iii) p-Methylbenzaldehyde
- Q8.3(iv): Draw the structures of the following compounds. (iv) 4-Methylpent-3-en-2-one
- Q8.3(iv): Draw the structure of the following compound. (iv) 4-Methylpent-3-en-2-one
- Q8.3(v): Draw the structures of the following compounds. (v) 4-Chloropentan-2-one
- Q8.3(v): Draw the structure of the following compound. (v) 4-Chloropentan-2-one
- Q8.3(vi): Draw the structures of the following compounds. (vi) 3-Bromo-4-phenylpentanoic acid
- Q8.3(vi): Draw the structure of the following compound. (vi) 3-Bromo-4-phenylpentanoic acid
- Q8.3(vii): Draw the structures of the following compounds. (vii) p,p’-Dihydroxybenzophenone
- Q8.3(vii): Draw the structure of the following compound. (vii) p,p’-Dihydroxybenzophenone
- Q8.3(viii): Draw the structures of the following compounds. (viii) Hex-2-en-4-ynoic acid
- Q8.3(viii): Draw the structure of the following compound. (viii) Hex-2-en-4-ynoic acid
- Q8.4(i): Write the IUPAC names of the following ketones and aldehydes. Wherever possible, give also common names. (i) \(CH_{3}CO(CH_{2})_{4}CH_{3}\)
- Q8.4(i): Write the IUPAC name of the following ketone or aldehyde. Wherever possible, give also common name. (i) (CH_{3}CO(CH_{2})_{4}CH_{3})
- Q8.4(ii): Write the IUPAC names of the following ketones and aldehydes. Wherever possible, give also common names. (ii) \(CH_{3}CH_{2}CHBrCH_{2}CH(CH_{3})CHO\)
- Q8.4(ii): Write the IUPAC name of the following ketone or aldehyde. Wherever possible, give also common name. (ii) (CH_{3}CH_{2}CHBrCH_{2}CH(CH_{3})CHO)
- Q8.4(iii): Write the IUPAC names of the following ketones and aldehydes. Wherever possible, give also common names. (iii) \(CH_{3}(CH_{2})_{5}CHO\)
- Q8.4(iii): Write the IUPAC name of the following ketone or aldehyde. Wherever possible, give also common name. (iii) (CH_{3}(CH_{2})_{5}CHO)
- Q8.4(iv): Write the IUPAC names of the following ketones and aldehydes. Wherever possible, give also common names. (iv) \(Ph-CH=CH-CHO\)
- Q8.4(iv): Write the IUPAC name of the following ketone or aldehyde. Wherever possible, give also common name. (iv) (Ph-CH=CH-CHO)
- Q8.4(v): Write the IUPAC names of the following ketones and aldehydes. Wherever possible, give also common names. (v)
- Q8.4(v): Write the IUPAC name of the following ketone or aldehyde. Wherever possible, give also common name. (v)
- Q8.4(vi): Write the IUPAC names of the following ketones and aldehydes. Wherever possible, give also common names. (vi) \(PhCOPh\)
- Q8.4(vi): Write the IUPAC name of the following ketone or aldehyde. Wherever possible, give also common name. (vi) (PhCOPh)
- Q8.5(i): Draw structures of the following derivatives. (i) The 2,4-dinitrophenylhydrazone of benzaldehyde
- Q8.5(i): Draw structures of the following derivative. (i) The 2,4-dinitrophenylhydrazone of benzaldehyde
- Q8.5(ii): Draw structures of the following derivatives. (ii) Cyclopropanone oxime
- Q8.5(ii): Draw structures of the following derivative. (ii) Cyclopropanone oxime
- Q8.5(iii): Draw structures of the following derivatives. (iii) Acetaldehydedimethylacetal
- Q8.5(iii): Draw structures of the following derivative. (iii) Acetaldehydedimethylacetal
- Q8.5(iv): Draw structures of the following derivatives. (iv) The semicarbazone of cyclobutanone
- Q8.5(iv): Draw structures of the following derivative. (iv) The semicarbazone of cyclobutanone
- Q8.5(v): Draw structures of the following derivatives. (v) The ethylene ketal of hexan-3-one
- Q8.5(v): Draw structures of the following derivative. (v) The ethylene ketal of hexan-3-one
- Q8.5(vi): Draw structures of the following derivatives. (vi) The methyl hemiacetal of formaldehyde
- Q8.5(vi): Draw structures of the following derivative. (vi) The methyl hemiacetal of formaldehyde
- Q8.6(i): Predict the products formed when cyclohexanecarbaldehyde reacts with following reagents. (i) \(PhMgBr\) and then \(H_{3}O^{+}\)
- Q8.6(i): Predict the products formed when cyclohexanecarbaldehyde reacts with following reagent. (i) (PhMgBr) and then (H_{3}O^{+})
- Q8.6(ii): Predict the products formed when cyclohexanecarbaldehyde reacts with following reagents. (ii) Tollens’ reagent
- Q8.6(ii): Predict the products formed when cyclohexanecarbaldehyde reacts with following reagent. (ii) Tollens’ reagent
- Q8.6(iii): Predict the products formed when cyclohexanecarbaldehyde reacts with following reagents. (iii) Semicarbazide and weak acid
- Q8.6(iii): Predict the products formed when cyclohexanecarbaldehyde reacts with following reagent. (iii) Semicarbazide and weak acid
- Q8.6(iv): Predict the products formed when cyclohexanecarbaldehyde reacts with following reagents. (iv) Excess ethanol and acid
- Q8.6(iv): Predict the products formed when cyclohexanecarbaldehyde reacts with following reagent. (iv) Excess ethanol and acid
- Q8.6(v): Predict the products formed when cyclohexanecarbaldehyde reacts with following reagents. (v) Zinc amalgam and dilute hydrochloric acid
- Q8.6(v): Predict the products formed when cyclohexanecarbaldehyde reacts with following reagent. (v) Zinc amalgam and dilute hydrochloric acid
- Q8.7(i): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (i) Methanal
- Q8.7(i): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (i) Methanal
- Q8.7(ii): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (ii) 2-Methylpentanal
- Q8.7(ii): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (ii) 2-Methylpentanal
- Q8.7(iii): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (iii) Benzaldehyde
- Q8.7(iii): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (iii) Benzaldehyde
- Q8.7(iv): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (iv) Benzophenone
- Q8.7(iv): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (iv) Benzophenone
- Q8.7(ix): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (ix) 2,2-Dimethylbutanal
- Q8.7(ix): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (ix) 2,2-Dimethylbutanal
- Q8.7(v): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (v) Cyclohexanone
- Q8.7(v): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (v) Cyclohexanone
- Q8.7(vi): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (vi) 1-Phenylpropanone
- Q8.7(vi): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (vi) 1-Phenylpropanone
- Q8.7(vii): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (vii) Phenylacetaldehyde
- Q8.7(vii): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (vii) Phenylacetaldehyde
- Q8.7(viii): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (viii) Butan-1-ol
- Q8.7(viii): Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction. (viii) Butan-1-ol
- Q8.8(i): How will you convert ethanal into the following compounds? (i) Butane-1,3-diol
- Q8.8(i): How will you convert ethanal into the following compound? (i) Butane-1,3-diol
- Q8.8(ii): How will you convert ethanal into the following compounds? (ii) But-2-enal
- Q8.8(ii): How will you convert ethanal into the following compound? (ii) But-2-enal
- Q8.8(iii): How will you convert ethanal into the following compounds? (iii) But-2-enoic acid
- Q8.8(iii): How will you convert ethanal into the following compound? (iii) But-2-enoic acid
- Q8.9: Write structural formulas and names of four possible aldol condensation products from propanal and butanal. In each case, indicate which aldehyde acts as nucleophile and which as electrophile.
- Q8.9: Write structural formulas and names of four possible aldol condensation products from propanal and butanal. In each case, indicate which aldehyde acts as nucleophile and which as electrophile.
CBSE Solutions for Class 12 Chemistry Aldehydes
Chapters in CBSE - Class 12 Chemistry
Top Tutors who teach Aldehydes
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BRS Nagar, Ludhiana
1 yrs of
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I was a student in one of the top colleges of Ludhiana. I have proficiency in English . I can teach all subjects to primary wing .
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Ashok Nagar D' Souza Layout, Bangalore
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Total Years of Experience: Over [X years] of experience in teaching across various academic levels, focusing on delivering engaging, student-centered education. 2. Educational Levels Taught: Primary, Secondary, and Senior Secondary levels Undergraduate-level classes (if applicable) Coaching for competitive exams (NEET, JEE, UPSC, etc.) 3. Key Responsibilities: Planning and delivering lessons based on prescribed curriculum. Assessing students’ understanding through regular tests, quizzes, and assignments. Using various teaching methodologies including lectures, group activities, demonstrations, and ICT tools. Providing remedial classes for weak students and enrichment activities for high performers. Maintaining discipline, fostering motivation, and ensuring an inclusive classroom environment. 4. Classroom Management: Successfully managed classrooms of 30–60 students. Promoted active participation and collaborative learning. Ensured timely syllabus completion while maintaining quality of instruction. 5. Communication and Interaction: Maintained regular communication with parents regarding student progress. Participated in parent-teacher meetings, academic planning sessions, and faculty training programs. 6. Technology Integration: Used smart boards, PowerPoint presentations, online quizzes, and digital simulations to enhance learning outcomes. Conducted online classes using platforms like Google Meet, Zoom, and Microsoft Teams during the COVID-19 pandemic. 7. Co-curricular and Administrative Roles: Organized and participated in educational tours, science exhibitions, and debate competitions. Assisted in exam invigilation, results compilation, and record keeping. 8. Achievements and Impact: Improved student performance and pass percentage year-on-year. Received positive feedback from students and parents for teaching effectiveness and approachability. Mentored students who went on to excel in competitive exams and higher education
had a great learning experience under the guidance of my History teacher. Their teaching style is clear, engaging, and well-structured. Complex topics like the Nationalism in India, Partition, and World War themes were explained with such depth and simplicity that it made understanding and remembering easy. They don’t just teach dates and events—they bring history to life with stories, critical thinking, and real-world connections. Regular assessments, personalized feedback, and doubt-clearing sessions really helped me improve my writing and analytical skills. Highly recommended for any Class 12th student aiming for high marks in board exams!
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Zafarpur Mahawan, Karari
10 yrs of
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6 students
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I am an experienced, qualified teacher and tutor with over 20 years of experience in teaching accountancy, business studies and English literature in CBSE school. Passionate about communication in English, over the years I have helped thousands of students overcome their stage fright and nervousness in expressing themselves in public. So far, I have worked with Dr. Rizvi Springfield School (Prayagraj) and Global Classroom, Lucknow (branch of CMS) and currently freelancing with Planet Spark as an Expert in Public Speaking & Creating Writing. I specialize in teaching Accountancy and Business Studies to classes 11 and 12, along with Spoken English. With a strong academic background, including a B. Com., M. Com., and an M.Ed., as well as completing a Management Development Program, I bring a wealth of knowledge and expertise to my teaching. With over 22 years of administrative experience and 10 years of teaching, I have had the privilege of holding key roles such as PGT English, Commerce teacher, Headmistress, and Principal. These experiences have helped me develop a profound understanding of education, enabling me to cater to the unique needs of my students effectively. Teaching has been the most enjoyable and fulfilling part of my professional journey. Over the years, I have built strong connections with my students, fostering an environment of trust and growth. My passion for education has been recognized through several accolades, including a prestigious Principal Award in Delhi. I conduct online classes where I follow a structured lesson plan to ensure my sessions are engaging and interactive. I use PPTs and videos to make concepts clear and relatable, catering to the diverse learning styles of my students. I also provide comprehensive notes and content to support my students' learning and revision. These resources are meticulously prepared to align with the curriculum and focus on enhancing students’ understanding and performance. My approach to teaching is rooted in creating a supportive and motivating environment. I am committed to helping my students achieve their academic and personal goals while instilling confidence and a love for learning in them. Teaching is not just my profession; it is my passion and purpose.
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Vakil Garden City, Bangalore
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Have teaching experience for both subjective and competitive exams. Have experience in doing crash course for CET NEET and IIT mains and advanced.
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Arrah Chowk, Arrah
11 yrs of
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23 students
815 hrs of classes completed
400
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A Highly talented Chemistry teacher with excellent communication skills demonstrated by 11 years of teaching experience. Strong theoretical and good knowledge of Chemistry. A good Communication skills to maintain great relationship with students and ability to work well with others. You Can also watch me on my YouTube channel L.k.Soni Chemistry Classes. During live classes developed an approach where students can focus on the classes without any Distraction.
I had the opportunity to attend one-on-one Classes for class 12 CBSE Chemistry with him, and the experience was excellent. His way of explaining concepts is very clear, simple, and easy to understand. He makes sure that every doubt is addressed patiently and focuses not just on memorising reactions and formulas, but on developing a proper understanding of the concepts. I especially appreciated his exam-oriented approach, which makes difficult topics feel much more manageable and helps build confidence for the CBSE Board exams. He is very knowledgeable, supportive, and genuinely dedicated to his students. I would highly recommend his classes to any Class 12 CBSE Chemistry student looking for strong conceptual clarity and effective preparation.
