A scuba tank has a pressure of 195 atm at a temperature of 10 degree Celsius. The volume of the tank is 350 L. How many moles of air are in the tank?

To determine the number of moles of air present in the tank, we assume that air is an ideal gas in order for us to use the following equation,

n = PV/RT

Substituting the known values,

n = (195 atm) (350 L) / (0.0821 L. atm/mol. K) (10 + 273.15 K)

n = 2935.91 moles

Thus, the number of moles of air is approximately 2935.91 moles.