Number of structural isomers possible with the formula, C7H16 is ‘X’. Number of structural isomers possible with the formula, C8H18 is ‘Y’. Difference between X and Y is
Number of structural isomers (all chain isomers) :
C4H10 — 2 ; C5H12 — 3 ; C6H14 — 5 ; C7H16 — 9 ; C8H18 — 18 ; C9H20 — 35 ; C10H22 — 75 ;