Match List I with List II.
| Reagent (R) | Name of the product formed on addition to carbonyl compounds (P) |
| A. NH2NHCONH2 | I. Oxime |
| B. NH2–OH | II. Hydrazone |
| C. NH2NH2 | III. 2,4-Dinitrophenylhydrazone |
D.  | IV. Semicarbazone |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A-IV, B-I, C-II, D-III
Ammonia derivatives Z–NH2 add to the C=O group and lose water to give >C=N–Z:
A. NH2NHCONH2 — This matches IV. Semicarbazone. Semicarbazide reacts through its free –NH2.
\( \ce{R2C=O + H2N-NH-CO-NH2 -> R2C=N-NH-CO-NH2 + H2O} \)
B. NH2–OH — This matches I. Oxime. Hydroxylamine gives the C=N–OH group.
\( \ce{R2C=O + H2N-OH -> R2C=N-OH + H2O} \)
C. NH2NH2 — This matches II. Hydrazone. Hydrazine gives the C=N–NH2 group.
\( \ce{R2C=O + H2N-NH2 -> R2C=N-NH2 + H2O} \)
D. 2,4-Dinitrophenylhydrazine — This matches III. 2,4-Dinitrophenylhydrazone. The product is a yellow, orange or red solid.
\( \ce{R2C=O + H2N-NH-C6H3(NO2)2 -> R2C=N-NH-C6H3(NO2)2 + H2O} \)