Question

differentiate between conformation and configuration in open chain molecules by giving one example

Answer 1

Configuration is an arrangement of parts or elements in a particular form, figure, or combination.
e.g. What's the configuration of PC?

Conformation is any of the spatial arrangements which the atoms in a molecule may adopt and freely convert between, especially by rotation about individual single bonds.
e.g. a change of DNA conformation induced by binding of RNA polymerase