Measuring total pressure is a convenient way to monitor gas

reaction:

$2$NOCl$($g$)->2$NO$($g$)+$ Cl$2($g$).$

The rate of the reaction depends on the concentration of the reactant, which is

proportional to the partial pressure of the reactant. Derive a relation connecting its velocity

above reaction with initial pressure, P$0,$ and total pressure, Pt$,$ at time t$.($Hint: Assume the reaction is $2$nd order. Make a table with initial $($t$0)$ and

final values $($t$)$ of the moles of NOCl, NO$,$ and Cl$2,$ and construct the ideal gas equations

for both cases. Use the ideal gas equation for t$0$ so that

calculate the initial concentration of NOCl and substitute this value into the equation

of ideal gases for t$.)$