The following data were obtained during the first order thermal decomposition of $ ext{N}_2 ext{O}_5 ext{ (g)}$ at constant volume : $2 ext{N}_2 ext{O}_5 ext{ (g)} \longrightarrow 2 ext{N}_2 ext{O}_4 ext{ (g)} + ext{O}_2 ext{ (g)}$ | S.No. | Time/s | Total Pressure/atm | | :---: | :---: | :---: | | 1 | 0 | $0.5$ | | 2 | 100 | $0.625$ | Calculate rate constant. [ Given : $\log 2 = 0.3010$, $\log 10 = 1$ ]