For the 1st order reactions,rate constant (k) is mathematically expressed as
k = [tex] \frac{2.303}{t}log \frac{Co}{Ct} [/tex]
where, t = time
Co = initial conc. of reactant
Ct = conc. of reactant after time 't'
Given: k = 2.20 × 10^-5 s-1, t = 2 hours = 7200 s
Therefore, we have
2.20 × 10^-5 = [tex] \frac{2.303}{7200}log \frac{100}{Ct} [/tex]
∴ [tex] log\frac{100}{Ct} [/tex] = 0.06877
∴, [tex] \frac{100}{Ct} [/tex] = 1.1716
∴, Ct = 85.35%
Thus, 85.35 % of the initial amount of SO2Cl2 will remain after 2.00 hours.