Answer:
0.01228s⁻¹ = rate constant
Half-life = 56.4s
Explanation:
The first order reaction follows the equation:
ln[A] = -kt + ln[A]₀
Where [A] is amount of reactant after time t = 45.0%, k is rate constante and [A]₀ initial amount of reactant = 100%
ln[45%] = -k*65s + ln[100%]
-0.7985 = -k*65s
0.01228s⁻¹ = rate constant
Half-life is:
Half-life = ln2 / k