1. Were you able to correctly identify all of the minerals on the first try? 2. Which identification test did you enjoy most? Why? 3. Which identification test did you think was least helpful for identification? Why? ​

i think the answer is terrae but not 100 percent sure. ▓▬▬ §

level 4 to level 2 : ))

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