(Solved): Cyclopropane (C3H6) reacts to form propene (C3H6) in the gas phase. The reaction is fir ...

Cyclopropane $$\left({\mathrm{C}}_3{\mathrm{H}}_6\right)$$ reacts to form propene $$\left({\mathrm{C}}_3{\mathrm{H}}_6\right)$$ in the gas phase. The reaction is first order in cylclopropane and has a rate constant of $$5.87\times 10^{?4}/\mathrm{s}$$ at $$485^{?}\mathrm{C}$$. It a 2.2 - L, reaction vessel initilly contains 725 torr of cyciopropane at $$485^{?}\mathrm{C}$$, how long will it take for the partial pressure of cylciopropane to drop to below 101 tort?