Answer:
Time required is 1.33 seconds
Explanation:
For first order reaction, the rate law expression is:
[tex]kt = ln \frac{[A_{0}]}{[A_{t}]}[/tex]
Where
A0 = initial concentration = 0.830 M
At = concentration after time t = 0.260 M
t = time in seconds = ?
k = rate constant = 0.870 s⁻¹
time = [tex][\frac{1}{k}](ln[\frac{0.830}{0.260}])[/tex]
time = [tex]\frac{1}{0.870}(1.16) = 1.33 seconds[/tex]