Answer :
For this problem, we assume a first-order kinetics which has a kinetics expression written as:
ln(Ca/Cao) = -kt
We use this formula to solve for time, t. First we list the needed values,
k = 9.2 x 10-3 s-1
Cao = 0.500 M
Xa = 90.8% = 1 - (Ca/Cao)
Ca = 0.046 M
ln(0.046/0.500) = -9.2 x 10-3 s-1(t)
t = 259.34 s
ln(Ca/Cao) = -kt
We use this formula to solve for time, t. First we list the needed values,
k = 9.2 x 10-3 s-1
Cao = 0.500 M
Xa = 90.8% = 1 - (Ca/Cao)
Ca = 0.046 M
ln(0.046/0.500) = -9.2 x 10-3 s-1(t)
t = 259.34 s