# How many grams of CO_2 are produced from 125 g of O_2 and excess CH_4 in the equation CH_4 +2O_2-> CO_2 + 2H_2O?

Here $C {H}_{4}$ being excess ${O}_{2}$ will be consumed fully.
2 mole or 64 g ${O}_{2}$ produces 1 mole or 44 g $C {O}_{2}$
So 125 g ${O}_{2}$ will produce $\frac{44}{64} \times 125 = 85.9 g C {O}_{2}$