Pls try to write the 3 facts (answers) shortly and plz don’t miss doing what the role or function is of the eyes (do it shortly like again). This is due today according to my science teacher, thank you so much and god bless all of you :) *spam* ? *may b* have a amazing day!!!

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

answeridentity;