Which conformation form of cyclohexane is chiral?

Identify the geometrical isomers of the following compounds.

The above two molecules are

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$

Which species exhibits a plane of symmetry?

Assuming the dipole moment of optically inactive isomer of 2,3 -dibromobutane is 0.8 D and the mole fraction of most stable staggered is 0.8.  The approximate value of dipole moment due to less stable staggered form of 2,3 -dibromobutane will be