Explore topic-wise MCQs in Organic Chemistry.

This section includes 13 Mcqs, each offering curated multiple-choice questions to sharpen your Organic Chemistry knowledge and support exam preparation. Choose a topic below to get started.

1.

In the absence of specific data, it can only be said that (R)–2–bromopentane is which of the following?

A. dextrorotatory (+)
B. levorotatory (–)
C. optically inactive
D. analogous in absolute configuration to (R)–2–chloropentane
Answer» E.
2.

Which of the following is not true of enantiomers?

A. boiling point
B. melting point
C. specific rotation
D. density
Answer» D. density
3.

How many enantiomers are there of the molecule shown below?

A. 6
B. 2
C. 0
D. 1
Answer» D. 1
4.

Which of the following is the definition for enatiomerism?

A. A pair of stereoisomers each of which has two chirality centres
B. A pair of stereoisomers that are not mirror images of one another
C. A pair of stereoisomers that are non-superimposable mirror images of one another
D. Any pair of stereoisomers
Answer» D. Any pair of stereoisomers
5.

WHICH_OF_THE_FOLLOWING_IS_NOT_TRUE_OF_ENANTIOMERS?_THEY_HAVE_THE_SAME:?$

A. boiling point
B. melting point
C. specific rotation
D. density
Answer» D. density
6.

In_the_absence_of_specific_data,_it_can_only_be_said_that_(R)–2–bromopentane_is_which_of_the_following?$#

A. dextrorotatory (+)
B. levorotatory (–)
C. optically inactive
D. analogous in absolute configuration to (R)–2–chloropentane
Answer» E.
7.

Which of the following is true of any (S)-enantiomerism?

A. It rotates plane-polarized light to the right
B. It rotates plane-polarized light to the left
C. It is a racemic form
D. It is the mirror image of the corresponding (R)-enantiomer
Answer» E.
8.

Which of the following molecules does not possess enantiomers?

A. CH<sub>3</sub>CH<sub>2</sub>CH<sub>2</sub>CHBrCH<sub>3</sub>
B. CH<sub>3</sub>CH<sub>2</sub>CBr<sub>2</sub>CH<sub>3</sub>
C. CH<sub>3</sub>CHBrCH<sub>2</sub>CH<sub>3</sub>
D. CHBr<sub>2</sub>CH<sub>2</sub>CHBrCH<sub>3</sub>
Answer» C. CH<sub>3</sub>CHBrCH<sub>2</sub>CH<sub>3</sub>
9.

Which among the following is true about enantiomerism?

A. Assignments of R and S labels and (+) and (–) labels are not connected
B. The labels R and S refer to different conformers
C. The labels (+) and (–) are used to distinguish enantiomers
D. The specific rotation of enantiomers is equal and opposite
Answer» C. The labels (+) and (‚Äö√Ñ√∂‚àö√ë‚àö¬®) are used to distinguish enantiomers
10.

Which of the following notations is not used to distinguish between pairs of enantiomers?

A. R and S
B. E and Z
C. + and –
D. D and L
Answer» C. + and ‚Äö√Ñ√∂‚àö√ë‚àö¬®
11.

Which of the following statements regarding optical rotation is not true?

A. All R enantiomers are dextrorotatory
B. All (+) enantiomers are laevorotatory
C. All (-) enantiomers rotate plane polarized light in a counter clockwise direction
D. (+) and (-) enantiomers rotate plane polarized light in opposite directions
Answer» D. (+) and (-) enantiomers rotate plane polarized light in opposite directions
12.

Which of the following statements is not true regarding pairs of enantiomers?

A. They have identical boiling points
B. They rotate plane polarized light in opposite directions
C. They react at identical rates with chiral reagents
D. They have identical melting points
Answer» C. They react at identical rates with chiral reagents
13.

Which of the following is the definition for enatiomerism?

A. A pair of stereoisomers each of which has two chirality centres
B. A pair of stereoisomers that are not mirror images of one another
C. A pair of stereoisomers that are non-superimposable mirror images of one another
D. Any pair of stereoisomers
Answer» D. Any pair of stereoisomers