(a) - We have 2.4 moles of C and 3.1 moles of H2O, so we have extra steam.
The limiting reagent is the carbon; when it is used up we have 0.7 mole H2O
(b) - If we begin with 2.4 moles of C and extra water, we can only form 2.4
moles of each product, so we get 2.4 moles of CO and 2.4 moles of H2.
(c) - The molecular weight of CO is 28, so we get 2.4 * 28, or 67.2 gm. of CO