For part (B):
0.951 mol e- * (1 mol O2/4 mol e-) = 0.238 mol O2
V=(0.238 mol O2 * 0.0821 * 298K)/1 atm = 5.82 L / 20% = 29.11 L
But I don't think that's right, because it gives me liters and not liters/second like the problem asks? Where did I go wrong?
edit: Actually my answer doesn't make sense at all. I have no idea how to do part B because it's asking for liters of air and I found liters of oxygen.