Question $2($a$)$ Calculate the density, specific weight, and specific volume of methane at $25C$ and pressure of $1013\mathrm{.}25$hPa. $($b$)$ What would be the temperature and pressure of this gas if we compressed it isentropically to $40\%$ of its original volume? $($c$)$ If the process described in $($b$)$ had been isothermal, what would the temperature and pressure have been? Given the molar mass of methane is $16\mathrm{.}04,$ and the specific heat ratio $k=1\mathrm{.}3.$