Acetaldehyde (C₂H₄O) is produced by oxidation of ethane (C₂H₆): 

C₂H_{6 +} O₂ --> CH₃CHO + H₂O

 

Since air is supplied at 20% excess, two side reactions occur:

 

2C₂H_{6 +} 7O_{2    -->} 4CO₂ + 6H₂O

2CH₃CHO + O₂        --> 2CH₃COOH (acetic acid)

In a process to produce 1000 kgmol/h acetaldehyde, ethane is fed to the reactor at 1500 kgmol/h and the fractional conversion is 0.8. The product stream contains 2 mol% CO₂. Calculate the molar composition of the product stream and the fractional selectivity of ethane to acetaldehyde. Assume that air is composed of 79 mol% N₂ and 21 mol% O₂.