Question

Question #5ed28

Answer 1

Here's what I get.

Explanation:

For geometric isomerism, you need restricted rotation, usually caused by a double bond or a ring.

(i) 2,3-Dichlorohex-2-ene

`(Z)sf("-2,3-dichlorohex-2-ene") color(white)(m) (E)sf("-2,3-dichlorohex-2-ene")`

Two geometric isomers. The two `"Cl"` atoms can be either cis or trans to each other.

Distinguish by dipole moment. The cis isomer has a dipole moment. The trans isomer should have µ ≈ 0.

(ii) 2,2-Dimethylpropane

No geometric isomers.

(iii) Butan-1,3-diol

No geometric isomers, but there are optical isomers.

(iv) 2,2-Dihydroxy-1-phenylpentan-3-one

No geometric isomers.