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

That result from subduction of oceanic plates beneath lighter continental plates. most of the earth's volcanoes are located around the pacific ring of fire because that the location of most of the earth's subduction zones.