phases of matter questionWatch
• temperature = 27°C,
• density = 1.2 kgm–3
• pressure = 1.0 × 105 Pa.
At the top of Mount Everest the air is at a temperature of –23°C and pressure of 3.3 × 104 Pa.
(a) What is the volume of 1 kg of air at sea level? [0.83 m3
(b) What is the volume of the same mass of air at the top of Mount Everest? [2.1 m3
(c) What is the density of air at the top of Mount Everest? [0.48 kgm–3
answers in 
need help with part b and c
The volume of gas at sea level is 0.83 m-3 which corresponds to 1 kg.
I called V1 the volume for air for Everest and and the 2 suffix for my ground level variables.
Rearranging for V1 you get
where the units of Kelvin have cancelled. I find it easier to deal in nice fractions, so for my final answer for (b) I can see I have combined two fractions times the pressures (where Pa) cancel, giving the correct answer.
Once you have got the correct answer for (b), the answer for (c) uses the same method as (a) and ICBST kg m-3 to two significant figures.