The elementary gas phase reaction

takes place isothermally in a
flow reactor with no pressure drop. The feed is equal molar in A and B. Write
the rate of reaction, -r_{A}, solely as a function of the conversion, X [i.e. -r_{A}
= f(X)].

Hint 3: What is C_{A}
as a function of X?

Hint 4: What is C_{B}
as a function of X?

Remember that the rate law for gases includes volume change.

What is C_{A} as a function of X?

What is C_{B} as a function of X?

From the stoichiometry: b/a = 1/2

Equal Molar:

We see species A is the limiting reactant as the feed is equal molar in A and B, but one mole of B consumes two moles of A.

Need to put everything in terms of per mole of limiting reactant A.

From the stoichiometry: b/a = 1/2

Equal Molar: