Cyclopropane (C3H6) reacts to form propene (C3H6) in the gas phase. The reaction is first order in cylclopropane and has a rate constant of 5.87 x 10^-4/s at 485 degrees Celsius.
If a 2.8 L reaction vessel initially contains 722 torr of cyclopropane at 485 degrees Celsius, how long will it take for the partial pressure of cylclopropane to drop to below 103 torr?