A bacterial culture isolated from sewage produced 41.3ml of methane at 31 degree C and 753 mm Hg. What is the volume of methane at STP?

Dear student,
At STP, P₁ = 760 mm Hg 
             T₁ = 273 K
            V₁ = ?
P₂ = 753 mm Hg
V₂ = 41.3 mL 
T₂ = 31 + 273 =304 K
According to Gas law,
       P₁V₁/ T₁ = P₂V₂/T₂
        V₁ = 753 * 41.3 *273 / (304 * 760)
       V₁ = 36.7 mL
​So the volume at STP = 36.7 mL
Regards