Physics HELP?

Question

Air is made up of about 80% nitrogen and 20% oxygen by volume. The densities of air and oxygen are 1.29 kg/m^3 and 1.43 kg/m^3 respectively. What is the density of nitrogen?

Workings appreciated

Answer 1

Let the densities of air, oxygen, and nitrogen be A, O, and N respectively. From the problem
A = .8*N + .2*O so
N = (1.29 - .2 *1.43) /.8 = 1.255

HTH

Doug