A) What assumptions are made about ideal gases. B) if 14g of an ideal gas is added to a 4 dm3 container at 210Kpa pressure and a temperature of 40oc how many moles were added and suggest the identity of the gas.

The two main assumptions that are made about ideal gases are: firstly, that the volume of the gas particles themselves is negligible or zero. So, the entire volume of the container is available. Secondly that there are no interactions or intermolecular forces between the molecules of gas. The first step is to work out what we need and how to calculate it. we can find the identity of the gas by using the mass provided to find its Mr, using n=m/Mr. To do this first we need to find the number of moles of gas in the container (n). This can be done with the ideal gas law PV=nRT if we rearrange this to give the number of moles as PV/RT=n. Next, we must convert the data values we are given to the si units used in the equation. So, Pressure (p)in Kpa must become pa so is times by 1000. Temperature (T) in Celsius must become kelvin so 273.15 must be added. And volume (v) in dm3 must be m3 so is divided by 1000. (the gas constant R remains constant at 8.314). when we input these new values we get (210,0000.004)/(8.314313.15)=0.32 moles. Then to finish off we must rearrange n=m/Mr to find Mr, as Mr=m/n. so we divide our moles (n) by the mass 14g (m) giving 14/0.32= 0.43.75g/mol as our Mr. Then using the atomic weights of elements, we can run through some common gases weights till we find co2 has a Mr of 44 (12+16+16) very close. Making it a likely candidate