PV = nRT
where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature.
We can rearrange the equation to solve for n:
n = PV/RT
Substituting the given values into the equation, we get:
n = (2 atm)(8.96 L)/(0.08206 L*atm/mol*K)(273 K)
n = 0.118 mol
The number of moles of X2O3 gas is equal to half the number of moles of X atoms, so the molar mass of X atom is:
Molar mass of X = (30.4 g)/(2 * 0.118 mol)
Molar mass of X = 128 g/mol
Therefore, the molar mass of X atom is 128 g/mol.
