During a reaction, the enthalpy of formation of an intermediate is 34 kJ/mol. During the reaction, 4 moles of the intermediate are produced. What is the
enthalpy value for this step of the reaction?
O A. 34 kJ
B. 136 kJ
C. -136 kJ
D. 34 kJ

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

it would only be the stuff in module eight so you need to study all the lessons in that you also could check the flvs

hope this : )