Would someone mind helping me? I really need this answer but I'm so confused. I would appreciate any help :) and if you get the answer right, ill give you brainliest.

A

Explanation:

liquids thake the shape of what holds them so shape is changing and volume is the same

the answer is barium and copper bromide

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