State what is meant by
the Avogadro constant 
,
the mole.
A container has a volume of 
. The ideal gas in the container has a pressure of 
at a temperature of 
. Show that the amount of gas in the cylinder is 
.
Gas molecules leak from the container in (b) at a constant rate of 
. The temperature remains at . In a time 
, the amount of gas in the container is found to be reduced by 
. Calculate
the pressure of the gas after the time ,
the time .
