The volume of 2.4 moles of chlorine gas can be calculated using the ideal gas law, PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature.

At standard temperature (0 degrees Celsius or 273.15 Kelvin) and pressure (1 atmosphere), the ideal gas constant is approximately 0.08206 liters-atmosphere / mole-Kelvin.

Substituting the given values into the ideal gas law, we have:

V = (2.4 moles) x (0.08206 L-atm / mole-K) x (273.15 K) / (1 atm)

V = 53.03 liters

Therefore, the volume of 2.4 moles of chlorine gas at standard temperature and pressure is approximately 53.03 liters.