Which conformation form of cyclohexane is chiral?

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

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 $100\}$