(a)[1]
State what the term ideal gas means.
(b(i))[2]
An ideal-gas storage cylinder has a volume of $3.0 \times 10^{-4}\,\text{m}^3$. The gas is at $23^\circ\text{C}$ and under a pressure of $5.0 \times 10^7\,\text{Pa}$. Show that the amount of gas in the cylinder is $6.1\,\text{mol}$.
(b(ii))[4]
Gas leaks gradually out of the cylinder, and after $35$ days the pressure has fallen by $0.40\%$. The temperature stays constant throughout. Calculate the average rate, in atoms per second, at which gas atoms escape from the cylinder.