Pick the number for the best response. Heat is given off when hydrogen burns in
ID: 485566 • Letter: P
Question
Pick the number for the best response. Heat is given off when hydrogen burns in air according to the equation: 2H2 + O2 2H2O.
a. Which of the following is responsible for the heat?
1. Breaking hydrogen bonds gives off energy.
2. Breaking oxygen bonds gives off energy.
3. Forming hydrogen-oxygen bonds gives off energy.
4. Both (1) and (2) are responsible.
5. (1), (2), and (3) are responsible.
6. None of the above is correct.
b. For each number you did not circle, state why that answer is not the best response; be specific.
Explanation / Answer
Bond beaking is always an energy consuming process and in contrast bond making is an energy releasing process. As given in the question, heat is released during combustion of hydrogen in air is due to formation of hydrogen-oxygen bond.
option 1 & 2 represents breaking of hydrogen bonds and oxygen bonds that are energy consuming process and hence are not good response.