Question

If there is initially 1.334 m o2, how long will it take for the o2 concentration to reach 0.443 m?

Answer 1

To answer, we take it that the rate of the consumption of O2 in this item is directly proportional to its concentration in first degree such that,
-dCa/dt = kCa
Solving,
-dCa/Ca = kt
lnCa - lnCao = -kt
Substituting,
ln(0.443) - ln(1.334) = -k(t)
t = 1.1023/k