A $7\mathrm{.}00-$L vessel contains $3\mathrm{.}50$ moles of gas at a pressure of $1\mathrm{.}60106$Pa $.$ Find

$($a$)$

the temperature of the gas and

$($b$)$

the average kinetic energy of the gas molecules in the vessel.

$($c$)$

What additional information would you need if you were asked to find the average speed of the gas molecules?