When parasites are found in food, the food has been exposed to contamination.

Coli contamination/ E.coli contamination

Explanation:

When there are harmful substance in, whether microorganisms or chemicals in food which can cause adverse effects on animals, the term for it is called food contamination. Food contamination can be caused contamination by pathogenic bacteria, viruses, and protozoa.

One of the microorganisms that can be found in food and poses threat to animals life is the Escherichia coli. Escherichia is a bacteria. Naturallyy, the Escherichia coli can be found in animals(including humans) intestines. So, some kinds might be harmless.

While some are poisonous and cause food poisoning. Some of the symptoms include: pneumonia, diarrhea, respiratory illness and so on.

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