Chemistry help?Ambiguity in question?
My question is, that when I was doing a past paper, it asked me to identify whether the forward reaction is exothermic or endothermic. The thing is that they never mentioned that the heat of combustion[∆H] was for the forward or backward. So, I just randomly guessed the forward reaction was exothermic, and as a matter of fact , I was right. But, when another question comes up, like this one, how do I know which ones exo or endothermic when the question itself is this ambiguous.