An ideal gas has a density of 1.25×10−6 g/cm3 at 1.00×10−3 atm and 40.0 ∘c. identify the gas. an ideal gas has a density of 1.25×10−6 at 1.0010 and 40.0 . identify the gas. nitrogen hydrogen oxygen neon chlorine argon

OXYGEN

Explanation:
                   As density is given as,

                                        d  = P M / R T
Solving for M,
                                        M  =  d R T / P      (1)
Data Given:
                   d  =  1.25 × 10⁻⁶ g/cm³  =  0.00125 g/L

                   R  =  0.08206 L.atm.mol⁻¹.K⁻¹

                   T  =  40 °C + 273  =  313 K

                   P  =  1.00 × 10⁻³ atm

Putting values in eq. 1,

   M  =  (0.00125 g.L⁻¹ × 0.08205 atm.L.mol⁻¹.K⁻¹ × 313 K) ÷ 1.0 × 10⁻³ atm

   M  =  32.10 g/mol

Result:
           Molecular Mass of O₂ is 32 g/mol.