In each row check off the boxes that apply to the highlighted reactant. reaction the highlighted reactant acts as (check all that apply) (aq) + (aq) → (aq) + (aq) brønsted-lowry acid brønsted-lowry base lewis acid lewis base (aq) (l) → (aq) brønsted-lowry acid brønsted-lowry base lewis acid lewis base (g) + (g) → (g) + (g)

the answer is option a.

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