Question

Is condensing water vapor an exothermic process or an endo process?

Answer 1

Well condensation is the reverse of vaporization, so it is clearly exothermic.

Explanation:

When we boil water, we put heat into the system:

`H_2O(l) + Delta rarr H_2O(g)`

Now this physical process as written is clearly ENDOTHERMIC. And it makes sense intuitively.

Given this, the reverse process must clearly be EXOTHERMIC:

`H_2O(g) rarr H_2O(l) + Delta`

When you include the `Delta` symbol in your reactions, this can help to rationalize the direction of energy transfer, and whether a process is exothermic etc.