[Andy1710]

A Mass of gas at a pressure of 400kPa and temp 35°C (308°K) occupies a volume of 0.04m3.If the characteristic gas constant is 0,26kJ/kgK, determine the mass of the gas.  If this mass of gas s now expanded to occupy a volume of 0.16m3 and experiences a temperature increase of 20°C to 55°C (328°K), determine the final Pressure

am stuck o this question and would really appreciate ANY help onit

Andy

[Strudders]

As far as I can see, you need to use the equation pV=nRT which, plugging in the p,V,R and T should give you n, the number of moles of gas (remember to use the right units for p,V,R and T) - how you then determine the mass of the gas is complicated since you are not told what the gas IS. If you were told it was CO2, for example, you know that the molecular weight of CO2 is 44 g/mol so, you know that 44 x n is your mass of gas in grams. I'm nit sure that you have been given enough information to complete this calculation.

For the second part of the questions, you have to assume that P1V1=P2V2 and then work out the answer from that directly substituting in the given volumes and pressures to work out the unknown.

Hope this helps.