For a first order decomposition of `N_(2)O_(5)(g)` to give `NO_(2)(g)` and `O_(2)(g)`, what will be the rate constant if at initial instant, after 10 minutes and after a very long time, tolal pressure is 200 mm of Hg, 325 mm of Hg and 450 mm of Hg?
A. 0.693min^(-1)`
B. `6.93min^(-1)`
C. `6.93xx10^(-2)min^(-1)`
D. `(6.93)/(2)xx10^(-2)min^(-1)`