(a) Inductive effect:
If more electronegative atom X linked to a carbon atom then the bonded electron pair will be shifted more towards X. So X acquires a small negative charge and carbon get a small charge. So this carbon atom attracts the a bonded electron pair towards its from nearest carbon atom. Therefore the change is transferred from one carbon to other.
Nucleophile : Nucleus loving species negatively charge species like etc. are called nucleophiles.
(b) 2,5,6-Trimethyloctane
(c) (i) Fractional distillation.
(ii) Distillation under reduced pressure.