Question

First, you name both the compounds. Yes, both of them have the same name. Yet, are they really the same structure, or they are somehow different? Careful inspection should convince you that they are indeed different. Now, how their physical and chemical properties differ? Generally,
i) Cis-isomer has more dipole moment than trans-isomer.
ii) Cis is less stable than trans.
iii) The boiling points of cis isomers are more than those of trans isomers (remember boiling points are directly related to polarity which is determined by dipole moment).
iv) Chemical reactivities of cis and trans also differ from each other.
The number of diastereomeric pairs and enantiomeric pairs respectively, in the set of stereoisomers of the compound $CHCl=CH-CH\left(C{H}_3\right)C_2{H}_5$ are :

• A. 2, 2
• B. 1, 1
• C. 1, 2
• D. 2, 1

Answer 1

Answer: (B)

1, 1

The number of diastereomeric pairs and enantiomeric pairs respectively, in the set of stereoisomers of the compound are 1,1 respectively.
The compound contains 1 chiral C atom. Hence, there are 2 enantiomers.
The compound contains 1 double bond. Hence, there are 2 diastereomers.