If a mixture of iodomethane and iodoethane is treated with sodium metal in presence of dry ether it forms

Identify the decreasing order of boiling point of alkanes

(i) $\mathrm{n}$-pentane

(ii) Isopentane

(iii) Neopentane

Identify the product $\mathrm{X}$ obtained in following reaction

${\mathrm{CH}}_3-{\left({\mathrm{CH}}_2\right)}_4-{\mathrm{CH}}_3\underset{773 \mathrm{K}, 10-20 \mathrm{atm}}{\overset{{\mathrm{Cr}}_2{\mathrm{O}}_3}{\to }} \mathrm{X}$