What must be satisfied for a hypothesis to be useful

The following are the desirable features of a hypothesis that makes them useful:  

1. A hypothesis should be susceptible to observation, and it should not be normative.  

2. A good hypothesis should exhibit a generality.  

3. A hypothesis should be specific, that is, the concepts are defined in a careful manner.  

4. A good hypothesis should not defy logic.  

5. And ultimately, a good hypothesis needs to be testable.  

it would be a gas formation

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.