The rate constant for the first-order reaction, 2N2O5 → 4NO2 + O2 is 3.0 × 10−5 s−1. If the rate is 2.40 × 10−5 molL s−1, then the initial concentration of N2O5 (in molL) is
0.8
Rate = K[N2O5 ]
2.40 × 10−5 = 3.0 × 10−5 × [N2O5]
[N2O5] = 2.40× 10−53.0× 10−5 = 0.8 molL