What is the average rate of the reaction?

Question

Consider the following reaction:

2 N2O(g) → 2 N2(g)+O2(g)

In the first 12.0 seconds of the reaction, 1.9×10⁻² mol of O₂ is produced in a reaction vessel with a volume of 0.320 L. What is the average rate of the reaction over this time interval?

Answer 1

1.9x10^-2 mol / 12.0 sec = 1.58x10^-3 mol/sec

To put this is terms of M/sec, we divide by 0.320 L to arrive at ...

1.58x10^-3 mol/sec / 0.320 L = 4.9x10-3 M/s O₂ production or - 9.8x10^-3 M/sec disappearance of N₂O