Aglass container was initially charged with 4.50 moles of a gas sample at 3.75 atm and 21.7
some of the gas was released as the temperature was increased to 28.1 °c, so the final
pressure in the container was reduced to 0.998 atm. how many moles of the gas sample are
present at the end?

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?