Total number of stereo isomers possible for the given structure :

Solution

Chemistry ma’am · 3 steps

Find every stereo unit, one chiral carbon and two C=C, and since the molecule is unsymmetrical, use 2ⁿ.

1. Read the structure. Number the chain from the left: CH₃-C(Br)=CH-CH₂-CH(Br)-C(CH₃)=C(Br)-CH₃, that is C1 to C8. Now check each double bond and each sp³ carbon for stereo possibility.

   Stereo unit	Groups to compare	Stereo?
   C₂=C₃	C2: CH₃, Br; C3: H, CH₂R	Yes, both ends unlike, so E/Z
   C5 (CHBr)	H, Br, CH₂CH=C(Br)CH₃, C(CH₃)=C(Br)CH₃	Yes, four different groups, so chiral
   C₆=C₇	C6: CH₃, CHBrR; C7: Br, CH₃	Yes, both ends unlike, so E/Z

2. Count them. There are n = 3 stereo units, each with two arrangements. The two ends of the molecule are different, so no meso form or symmetry cuts the count down.

   Stereoisomers = 2ⁿ = 2³ = 8

3. So. The structure has 8 stereoisomers, option (c).

The idea to keep. Count chiral centres and stereo double bonds together as n. If the molecule has no symmetry, the total is 2ⁿ. Only a symmetrical molecule needs the reduced formula.

Answer from the NTA final answer key. Solution by PrepWiser.