Select the correct answer. How can technology negatively impact a guest’s perception of a restaurant? A. The POS system helps the server change a meal quickly when the guest changes their mind. B. It is easy to pay using the kiosks at the table. C. A Yelp search of the restaurant shows only poor, one-star reviews. D. The restaurant offers 10 percent off when returning for the third time.

it's filtration, but this is an assumption so my apologies if i got this

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