when it is reversible when it can be repeated when it requires heat to make it happen when energy is released by the process
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A student mixed baking soda with vinegar and observed that the reaction was endothermic. When is a reaction endothermic?
Possibilities:
- when it is reversible
- when it can be repeated
- when it requires heat to make it happen
- when energy is released by the process

when it requires heat to make it happen