A LEVEL CHEM 唔識做,急!!!

1)Inside level-one air quality office buildings, the concentration of carbon
dioxide should not exceed 800ppm. Express this concentration in µg m^-3
units at 298K and 1.01*10^5 Nm^-2 pressure.
(You may assume that air behaves as an ideal gas.)


2)At 98.6 kPa and 300 K, the density of a sample of dry air is 1.146dm^-3.
Assuming that dry air contains only nitrogen and oxygen and behaves ideally, calculate the
composition of the sample.