The density of nitric oxide (no) gas at 0.970 atm and 39.9 °c is g/l.

            Density  =  1.13 g/L

Solution:

Data Given;
                  Pressure  =  P  =  0.97 atm

                  Temperature  =  T  =  39.9 °C + 273  =  312.9 K

                  M.mass of NO  =  M  =  30 g/mol

                  Gas Constant  =  R  =  0.0821 atm.L.mol⁻¹.K⁻¹

Formula Used,

                      Density  =  P M / R T

Putting values,

     Density  =  (0.97 atm × 30 g.mol⁻¹) ÷ (0.0821 atm.L.mol⁻¹.K⁻¹ × 312.9 K)

     Density  =  1.13 g/L

Elements would be the right answer