Answer: approximately 52.6989 moles
Work Shown:
PV = nRT
97.5*1250 = n*8.31446261815324*(273.15+5)
121875 = n*2312.66777723932
n = 121875/2312.66777723932
n = 52.6988792767652
n = 52.6989
Side notes:
- 1 mole = 6.02 * 10^23 molecules approximately
- I converted from Celsius to Kelvin when computing the 273.15+5 portion
- The approximate value R = 8.31446261815324 is one variation of the ideal gas constant. It comes in other variations depending on what units you're working with.