PLS HELP ME TY Part A
Which statement is a central idea of the text?

A. Scientists usually work in laboratories.

B. Scientists work alone on their research.

C. Scientists work together and report their findings.

D. Scientists mostly work outdoors.

Question 2
Part B

Which detail from the text best supports the answer in Part A?

A. Experiments must be repeatable.

B. Variables change in different experiments.

C. Without sharing results, little progress is made.

D. Often, there is no correct answer in science.

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