Arigid stainless steel chamber contains 140 torr of methane, ch4, and excess oxygen, o2, at 160.0 °c. a spark is ignited inside the chamber, completely combusting the methane. what is the change in total pressure within the chamber following the reaction? assume a constant temperature throughout the process.

The variation of pressure is 0.

Explanation:

Methane combustion reaction:

The pressure change in gaseous state reactions at constant T y V is proportional to the change in the number of mol of gas in total.

As can be seen in the reaction above we have 3 moles of gas in the reactants and 3 in the products, so the variation of moles is 0. Therefore, the variation of pressure is also 0.

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol