Question

The following data were obtained during the first order thermal decomposition of N2O5(g) at constant volume

2N2O5(g) → 2N2O4(g) + O2(g)

| S.No. | Time/s | Total Pressure/(atm) |
| 1 | 0 | 0.5 |
| 2 | 100 | 0.512 |

Calculate the rate constant

Answer 1

Let the pressure of N2O5(g) decreases by 2x atm. As two ***** of N2O5 decomposes to give twoes of N2O4(g) and one mole of O2(g) ,the pressure of N2O4(g) increases mol by 2x atm and that of O2(g) increases by x atm.

2N2O5(g) → 2N2O4(g) + O2(g)

Start t = 0 0.5 atm. 0 atm 0 atm.

At time t (0.5 – 2x) atm. 2x atm. x atm.