the balanced equation for the above reaction is as follows;
C + Hâ‚‚O ---> Hâ‚‚ + CO
stoichiometry of C to Hâ‚‚O is 1:1
1 mol of C reacts with 1 mol of Hâ‚‚O
we need to find which is the limiting  reactant
2 mol of C and 3.1 mol of Hâ‚‚O
therefore C is the limiting reactant and Hâ‚‚O is in excess.
stoichiometry of C to Hâ‚‚ is 1:1
then number of Hâ‚‚ moles formed are equal to C moles reacted
number of Hâ‚‚ moles formed = 2 mol
