Answer
$2.25lb/m$
Work Step by Step
The chemical reaction between methane $CH_4$ and oxygen is given as:
$CH_4+2O_2 \rightarrow CO_2+2H_2O$
The molecular weight of $M_{H_2O}$ is:
$M_{H_2O}=2 \times 1+16=18lbm/lbmol$
and
The molecular weight of $M_{CH_4}$ is:
$M_{CH_4}=4 \times 1+12=16lbm/lbmol$
Using molar mass, balance the equation per unit kmol of the chemical reaction as:
$m_{H_2O}=\dfrac{N_{H_2O}}{N_{CH_4}} \cdot \dfrac{M_{H_2O}}{M_{CH_4}} \cdot m_{CH_4}=(\dfrac{2}{1}) (\dfrac{18}{16})(1)=2.25lb/m$
