There, then, is my list of life chemistries, spanning the temperature range from near red heat down to near absolute zero:
1. fluorosilicone in fluorosilicone
2. fluorocarbon in sulfur
3. nucleic acid/protein (o) in water
4. nucleic acid/protein (n) in ammonia
5. lipid in methane
6. lipid in hydrogen

Asimov suggested the following options, in order of decreasing temperature:

Explanation:

Of this half dozen, the third only is life-as-we-know-it. Lest you miss it, I’ve marked it with an asterisk.

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