A bulb of constant volume is attached to a manometer tube open at other end as shown in figure. The manometer is filled with a liquid of density `(1//3)^("rd")` that of mercury. Initially h was 228 cm.

Through a small hole in the bulb gas leaked assuming pressure decreases as `(dP)/(dt)=-kp.`If value of h is 114 cm after 14 minutes, what is the value of k (in `"hour"^(-1)`)?
[ Use : In (4/3) =0.28 and density of Hg =13.6 g/mL.].