The first-order rate constant for the decomposition of dimethyl etheris 3.2 × 10−4 s−1 at...

The first-order rate constant for the decomposition of dimethyl ether

is 3.2 × 10−4 s−1 at 450°C. The reaction is carried out in a constant-volume flask. Initially only dimethyl ether is present and the pressure is 0.350 atm. What is the pressure of the system after 8.0 min? Assume ideal behavior.