Since there are given data of two reagents, we need to obtain which of reagents are surplus.
0.3618 mol C4H4 - x mol O2
1 mol C4H4 - 5 mol O2
that means that there are too much O2 gas (by 0.009 mol)
so we continue counting using C4H4 data
0.3618 mol C4H4 - x mol H2O
1 mol C4H4 - 2 mol H2O
Mw(H2O)=2×1+16=18 g/mol
n=m/Mw
m=n×Mw
answer:13.0248 grams of H2O
A cation is an atom or group of atoms that have a positive charge.