The molecules and atoms of n-pentane are non-polar and thus there is no chance of any dipole –dipole interaction between the molecules of n –pentane. There exists repulsion between the electrons moving in near to each other in respective orbits. The molecule of n-pentane processes instantaneous dipole moment due to instantaneous distribution of electrons and since the molecules are very close to each other instantaneous dipole moment in one molecule induces instantaneous dipole moment in the other molecule and thus there exists an attractive force between the non polar molecules of n –pentane known as Dispersion Forces
It wouldn’t be hydrogen bonding because hydrogen bonding takes place with highly electronegative elements like N,O & F being the most electronegative. It’s not ion - dipole because there is no ion present. So I’m sure it is dispersion
In a redox reaction electrons are lost and gained in equal numbers. The species that is oxidized gives electrons to the species that is reduced. I hope this helps. Let me know if anything is unclear.