For the first order reaction A(g)→2B(g)+C(g), the initial pressure is PA=90 mm Hg, the pressure after 10 minutes is found to be 180 mm Hg. The rate constant of the reaction is

The reaction is                        A(g)→2B(g)+C(g)at t = 0 pressure                       PA          0           0Pressure after 10 mints               PA−x    2x     x Total pressure after 10 minutes, PT=PA+PB+PC PT=(PA−x)+2x+x=PA+2x=180∵  PA=90 mm90+2x=180    or,    X=45mm∴ PA−x=90−45=45 mmSince, kt=2.303log⁡PAPA−x k×10=2.303log⁡9090−45k×10=0.693 k=0.69310=0.0693 min−1    =0.69310×60 sec=1.155×10−3sec⁡−1