3.4 moles of an ideal gas occupies volume of 68 mL at 300 K . What would be the pressure of gas? $\left(\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right)$

Which among the following gases is difficult to liquify?

Carbonated water is an example of a solution of

Calculate the partial pressure exerted by dioxygen from a mixture of $32 \mathrm{~g} \mathrm{O}_2, 80 \mathrm{~g} \mathrm{Ar}$ (mol.mass 40 ) and 4 g dihydrogen $\left(\mathrm{P}_{\text {total }}=10 \mathrm{bar}\right)$.