Question

The exhaust gas from an automobile contains 1.5 percent by volume of carbon monoxide. What is the concentration of CO in mg/m' at 25°C and 1 atm pressure? What is the concentration in mg/m' in the exhaust pipe if it is at 200°C and 1.1 atm of pressure?

Answer 1

Answer:

(a) 17,178 mg/m3

(b) 11,625 mg/m3

Explanation:

The concentration of CO in mg/m3 can be calculated as

$C (mg/m3) =(P/RT)*MW*C_{ppm}$

For standard conditions (1 atm and 25°C), P/RT is 0.0409.

Concentration of 1.5% percent by volume of CO is equivalent to 1.5*10,000 ppm= 15,000 ppm CO.

The molecular weigth of CO is 28 g/mol.

(1) For 25°C and 1 atm conditions

$C=(P/RT)*MW*C_{ppm}\\\\C=0.0409*28*15,000=17,178$

(b) For 200°C and 1.1 atm,

$P/RT=0.0409*(P/P_{std})*(T_{std}/T)\\P/RT=0.0409*(1.1atm/1atm)*(273+15K/273+200K)=0.0277$

Then the concentration in mg/m3 is

$C=(P/RT)*MW*C_{ppm}\\\\C=0.0277*28*15,000=11,625$