Hf < 0 implies which of the following?

A. The temperature decreases
B. The temperature remains the same
C. A bond-forming process
D. A bond-breaking process

I think the answer is a.

2 answers

Do you mean delta Hf? If dHf<0 doesn't that mean dHf = negative and doesn't that mean it is exothermic and wouldn't that mean it gets hotter?
The answer is C