# Reactions where one product is the reactant for another reaction

1. Oct 28, 2013

Hello

I'm not sure if this belongs in this forum or the homework forum, but I have a quick question about selectivity and yield in reactions where one product is made, and that product returns to one of the reactants to create another separate reaction.

for example:

$C_{6}H_{12} + H_{2}O \Rightarrow 6CO + 12H_{2}$
$C_{6}H_{12} + H_{2} \Rightarrow C_{6}H_{14}$

As you can see, the one of the products in the first reaction is involved with the second reaction. When calculating things such as which is the limiting reagent or which is the excess reagent, do we take the 2nd reaction into account? Given values for number of moles for the reactants from equation 1 and the selectivity and yield of one of the products from equation 1, how can we use these values to find number of moles of product?