Consider a full $0\mathrm{.}02m^{3}BBQ$ propane tank that is initially at room temperature $(293K)$ and spring$-$loaded so that the pressure is always $400$kPa. When the tank is shaken, no audible sound is heard.

a$.$ If the molar mass of propane is $44k\frac{g}{k}$mol, calculate the mass of propane in the tank. State any assumptions you made in your calculation. Describe how you would check this assumption.

b$.$ The tank is then taken outside in the middle of winter. After some time a swishing is heard when the tank is shook. What is the maximum temperature outside? $($Hint: Look at graph at the back of the worksheet$)$

c$.$ Assuming a constant $c_{p,g}$ of $1\mathrm{.}6794k\frac{J}{kgK}$ and $c_{P,L}$ of $2\mathrm{.}23205k\frac{J}{kgK},$ and $H_v$ of $428k\frac{J}{k}g$; how much energy must the tank lose to reduce its temperature to $263K?$