Chemistry question! Help!

Question

During an experiment, a metal and an excess of fluorine gas were placed into a combustion chamber at a temperature of 1800°C. The temperature in the sealed chamber continued to rise to 2100°C. After the reaction stopped, a brittle white substance, which dissolved in water, was extracted from the chamber. From this evidence one could conclude that this reaction can be classified as:

a. endothermic formation reaction

b. exothermic formation reaction

c. endothermic decomposition reaction

d. exothermic decomposition reaction

Answer 1

The temperature rose so the reaction gave out heat.  You started with the two elements, and ended with a compound (which you were told was soluble in water, but that doesn't really have anything to do with it).

You now have enough information to solve the problem, if you just think about the meanings of the different choices.

Answer 2

So based on the explanation above, the answer is exothermic formation reaction.

Decomposition reactions are when one compound breaks into two different compounds.

Formation is when two or more compounds form one compound. So since metal and fluorine formed a new "something".

Hope it adds on to what he said.