How many moles are in 157 L of CH4 at STP

7.01 mol CH4

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