In a chemical reaction, what happens to the total number of each type of atom? * A. The total number of each type of atom always stays the same.
B. The total number of each type of atom either increases or decreases.
C. The total number of each type of atom always increases.
D. The total number of each type of atom always decreases

yes

ya te ayud espera

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