Until recently, medicine and dentistry were thought to be unrelated. Scientists now understand that hundreds of bacteria species live in the human mouth and can enter the bloodstream and travel through
the body. This table describes four bacteria found in the mouth that scientists have linked to conditions
previously thought to be unrelated to oral health.
Bacteria Found in Human Mouth

Lol pls help

i believe the answer is true.

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