Answer:
7.01 mol CH4
Step-by-step explanation:
STP means standard temperature and pressure, so they are basically telling you that the gas is at 1 atm and 273 K (0 degrees celsius). Now that we have the pressure, volume, and temperature we can use the ideal gas law and solve for n or moles
PV=nRT
n=PV/RT
n=(1)(157)/(0.08206)(273)
n=7.0081 (round to 3 sigfigs)
n=7.01 mol