InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
Which of the following reactions are endothermireactions?a) Combustion of methaneb) Decomposition of water c) Dehydrogenation of ethane to ethened) Conversion of graphite to diamond |
|
Answer» option (d) is correct. Graphite is more stable than diamond and energy is needed to convert graphite into diamond. The extra energy that has to be provided ends up in the tetrahedral structure of diamond.The energy content of diamond is slightly higher than that of graphite. Also the activation energy for this conversion is very high. option (b) is also correct. To decompose requires water to be split into H and O. This is similar to decomposition of any other molecule, to break it apart, to make it no longer what it was before that. Either way, to decompose water would be an endothermic reaction because you need to put a lot of energy into the system to break the H-O bond. The system does not release any energy during this process (making it an endothermic reaction). To decompose water most effectively, electrolysis should be used. |
|