What is Conversion?

The conversion of reactant A is $X = (F_{A,0} - F_A)/F_{A,0}$, where $F_{A,0}$ and $F_A$ are the molar flow rates of A entering and leaving the reactor; for a batch reactor, $X = (n_{A,0} - n_A)/n_{A,0}$. At constant density, $X = 1 - c_A/c_{A,0}$.