The energy changes in two partial reactions are 225.3 kj and -432.0 kj. Using Hess's law, determine the combined energy change of these two partial reactions. Is the combined reaction endothermic or exothermic?

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.

2b2t

explanation:

2b2t