Given below are the four isomeric compounds (P, Q, R, S) [figure] Identify correct statements from below. Choose the correct option.
- C and E only
- A and E only
- A, B, D and E only
- A, C and E only
Answer
(4) A, C and E only
Solution
P: 1-phenylprop-2-en-1-ol (C6H5CH(OH)CH=CH2) – an alcohol with a C=C bond
Q: 3-phenylpropanal (C6H5CH2CH2CHO) – an aldehyde
R: 1-phenylpropan-2-one (C6H5CH2COCH3) – a methyl ketone
S: 1-phenylpropan-1-one (C6H5COCH2CH3) – an ethyl ketone
A. Q, R and S contain a carbonyl group and give orange-yellow 2,4-DNP derivatives. Correct.
B. Baeyer's test (cold, dilute alkaline KMnO4) is the test for unsaturation (C=C); P has a C=C bond but Q has none. Incorrect.
C. Q and R are aromatic compounds with a high carbon content and burn with a sooty flame. Correct.
D. R (CH3CO- group) gives the iodoform test, but S (C6H5COCH2CH3) has no CH3CO- group and does not. Incorrect.
E. Only Q is an aldehyde, so only Q gives the silver mirror with Tollens' reagent. Correct.
A, C and E are correct.
Answer: (4)