A sample of CH$3$CHO is heated to $700$ K and the pressure is measured as $220$ mbar before any reaction takes place. The kinetics of the reaction are then followed by measurements of total pressure and these data are obtained:

t$($s$)0100030007000$ PTotal $($mbar$)$

$220240270310$ Rate $=\backslash$Delta P$($CH$3$CHO$)/\backslash$Delta t$=4\mathrm{.}5\backslash$times $10^4$bar$1$s$1$P$($CH$3$CHO$)^2$ Find total pressure after $6\mathrm{.}00\backslash$times $10^4$s$.$