What happens to C u x C l y dot z H2O when it is heated in a crucible at 100 degrees C? options:
a. The sample turns tan as water is absorbed.
b. The sample turns green as water is driven out.
c. The sample turns tan as water is driven out.
d. The sample turns green as water is absorbed.

you need to have a picture of the atom that way we can answer it

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.