Calculate standard molar entropy `O_(2)(g)` from the following thermodynamics data at 300 K :
`4Cr(s)+3O_(2)(g)to2Cr_(2)O_(3)(s),DeltaG^(@)=-2093.4 " kJ"//mol`
`DeltaH_(f)^(@)Cr_(2)O_(3)(s)=-1129.05" kJ"//"mole"`
`S_(m)^(@)Cr(s)=24" J"//K" mole"`
`S_(m)^(@)Cr_(2)O_(3)(s)=81" J"//K" mole"`