Question

I posted this question before and the answer is suppose to be 6.8 L but I keep getting 6.12 L
dinitrogen pentoxide n2o5 decomposes by a first-order decomposition in chloroform solvent to yield NO2 and O2. The rate constant at 45°C is 6.2 x 10^-4 mins^-1. Calculate the volume of O2 obtained from the reaction of 1.00 mol N2O5 at 45°C and 770 mmHg after 20.0 hours.
N2O5 = 2 NO2 + 1/2 O2

Answer 1

I think the problem is this.
I believe you have calculated N for N2O5 correctly. That's N2O5 LEFT. Then 1-N = mols N2O5 that decomposed to form O2, take 1/2 that and convert to V using PV = nRT
If I do that I obtain 6.76 which rounds to 6.8L. I don't remember but I may have omitted that 1-N step when I responded to your earlier post.

Answer 2

dinitrogen pentoxide n2o5 decomposes by a first-order decomposition in chloroform solvent to yield NO2 and O2. The rate constant at 45°C is 6.2 x 10^-4 mins^-1. Calculate the volume of O2 obtained from the reaction of 1.00 mol N2O5 at 45°C and 770 mmHg after 20.0 hours. Calculate the volume of 1 L of 0.600 M solution at 45°C