Tính năng lượng liên kết O – H trong phân tử H2O, biết các dữ kiện sau: H2O(l) → H2O(k) ; H1 = 40,6 kJ/mol
2H
(k) → H2 (k) ; H2 = – 435 kJ/mol

wher is the rest of the question

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

answerlinnaeus;