Answer : The time taken by the reaction is, [tex]2.2\times 10^2hr[/tex]
Explanation :
The expression used for second order kinetics is:
[tex]kt=\frac{1}{[A_t]}-\frac{1}{[A_o]}[/tex]
where,
k = rate constant = [tex]1.6\times 10^{-3}M^{-1}s^{-1}[/tex]
t = time = ?
[tex][A_t][/tex] = final concentration = 1.25 M
[tex][A_o][/tex] = initial concentration = 2.25 M
Now put all the given values in the above expression, we get:
[tex](1.6\times 10^{-3})\times t=\frac{1}{1.25}-\frac{1}{2.25}[/tex]
[tex]t=222.222hr\approx 2.2\times 10^2hr[/tex]
Therefore, the time taken by the reaction is, [tex]2.2\times 10^2hr[/tex]