Asample of no2(g) is initially placed in a 2.50-l reaction vessel at 300°c. if the half-life and the rate constant at 300°c are 11 seconds and 0.54 m-1 s-1, respectively, how many moles of no2 were in the original sample? nitrogen dioxide decomposes at 300°c via a second-order process to produce nitrogen monoxide and oxygen according to the following chemical equation. 2 no2(g) → 2 no(g) + o2(g). a sample of no2(g) is initially placed in a 2.50-l reaction vessel at 300°c. if the half-life and the rate constant at 300°c are 11 seconds and 0.54 m-1 s-1, respectively, how many moles of no2 were in the original sample? 0.17 mol 15 mol 0.42 mol 5.9 mol