Question

What is the density at 105 m above the ground (which is at sea level) if the temperature at this height is 315 K, assuming you can use the ideal gas law?

Answer 1

Because only one gas is mentioned and because there are no changing properties, we recognize this as an ideal gas equation problem. Density is mass divided by volume. Using variables from the expanded form of the ideal gas equation,

it can be expressed as g/V.

g /V = ?

P = 105 kPa

T = 315 K

PV = RTg/ M

To save a little time, we can use the value for R that contains the pressure unit given in the problem, kPa.

g/ V = PM /RT

P=105

M=39.948

R=8.314

T=315

Density=1.601g/L