For the reaction pcl3(g) + cl2(g) ⇋ pcl5(g) at a particular temperature, kc = 24.3. suppose a system at that temperature is prepared with [pcl3] = 0.10 m, [cl2] = 0.15 m, and [pcl5] = 0.60 m. which of these statements is true?

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

im doing test rn im going with 2 but ill give answer if itss wrong,   : )