Question

What is the limiting reactant of CO + 2H[sub]2[/sub]& --> CH[sub]3[/sub]OH?

Answer 1

The molar mass of CO is 28 g/mol, of H₂ - 2 g/mol.
The ratio of masses of reactants have to be m[CO]/m[H₂] = 28 / 2*2 = 7, hence if m[CO] < 7m[H₂], CO would be the limiting reactant, if m[H₂] < 1/7 m[CO], it should be H₂.