Question

a. The gas, hydrogen, is found in dry air at sea level at a concentration of 1.00×10-3 percent by volume. What is the concentration of H2 expressed in ppb? pub bThe gas, carbon dioxide, is found in dry air at sea level at a concentration of 3.30×10-2 percent by volume. What is the concentration of CO2 expressed in ppm? ppm

Answer 1

Hi,

(a) we are given that, (v/V)*100= 1.00*10^-3

v/V= 1.00*10^-5 ...............(1)

where, v= volume of H2 and V= Volume of dry air

therefor ppb= (v/V)*10⁹ ...................(2)

from eq (1) and (2)

ppb= (1.00*10^-5)*10⁹= 1.00*10⁴

(b) we are given that, (v'/V')*100= 3.30*10^-2

v'/V'= 3.30*10^-4 ...............(3)

where, v'= volume of CO2 and V'= Volume of dry air

therefor ppm= (v'/V')*10⁶ ...................(4)

from eq (3) and (4)

ppm= (3.30*10^-4)*10⁶= 3.30*10²