Question

1. A cubic meter of air sample was sampled at 1.0 atm and 37 C. A Chromatographic analysis of that sample found the air sample to contain 40 micrograms of CH4 .What is the CH4 concentration in the sampled air?

Answer 1

A cubic meter of air sample was sampled at 1.0 atm and 37 C. A Chromatographic analysis of that sample found the air sample to contain 40 micrograms of CH4 .What is the CH4 concentration in the sampled air?

PV = n RT

n / V or concentration = P / RT

now calculate the moles of methane in 40 micrograms =4.0*10^-5 g

number of moles = 4.0*10^-5 g /16.00 g/ mole

=2.5*10^-6 moles CH4

And temperature T= 37 C= 310 K

Therefore;

n / V or concentration = P / RT

= 1.0 atm / 0.08206 L- atm / mole-K *310 K

= 0.0393 mole/ L