Answer:
k = 2.17E-2 s-1
Explanation:
Initial Concentration [A]o = 0.380 M
Final Concentration [A] = 0.215 M
time, t = 26.3 s
Unit of rate constant = s-1
Rate constant = ?
The units of the rate constant depends on the order of the reaction. This is a first order reaction due to the units.
The integral rate law for a first order reaction is;
ln[A] = ln[A]o - kt
ln(0.215) = ln(0.380) - k(26.3)
ln(0.215) - ln(0.380) = - k(26.3)
- k(26.3) = -0.57
k = 0.57 / 26.3 = 0.02167
Reporting to three significant figures using E notation;
k = 2.17E-2 s-1