How many grams of gas are present in a sample that has a molar mass of 70.0 g/mol and occupies a 2.00 l container at 117 kpa and 35.1 degrees celsius?

The ideal gas law of gases states that the volume occupied by certain moles  of a gas has a pressure at a temperature in kelvin. The law combines both boyle's law and the charle's law. Therefore, PV=nRT where P is the pressure, V is the volume, n is the number of moles, T is the temperature and R is the gas constant. 1 atm = 101.325 kPa, therefore; 117kPa = 1.155 atm , 35.1 °c = 308.25 Kelvin and R = 0.0821
PV=nRT
n = PV/RT
   = (1.155 × 2)/ (0.0821 × 308.25)
  =  0.0913 moles
But, 1 mole = 70 g
Therefore, 0.0913 moles × 70 = 6.39 g

1) according to the law of conservation of mass ,in all chemical reactions total mass is unchanged

What are the options? physical property can be color, smell, opacity, viscosity, density, infra red spectrum, melting and boiling points, attraction and repulson to magnets, etc.