No_2 decomposes by the following reaction: 2 no_2(g) → 2 no(g) + o_2(g) the rate constant at 273 k is 2. 3 x 10^{-12} m^{-1}s^{-1}, and e_a is 111 kj/mol. How many seconds will it take for the partial pressure of no_2(g) to decrease from an initial pressure of 2. 5 atm to 1. 5 atm at 500 k?.