Statement I : Ethyne is more acidic than propyne.

Statement II : 1-butyne is more acidic than propyne.

Acidity tends reduces as alkyl group increases because this group shows +I effect which reduces the acidic character on alkyne.

$\mathrm{CH}\equiv \mathrm{CH} > {\mathrm{CH}}_3 - \mathrm{C} \equiv \mathrm{CH} > {\mathrm{CH}}_3 - {\mathrm{CH}}_2 - \mathrm{C} \equiv \mathrm{CH}$

hence, ethyne is more acidic than propyne and propyne is more acidic than butyne.