Label Each Of The Following Reactions As Exothermic Or Endothermic (“exo” Or “endo”),?

4. Thermo-ExoEndoWork1b-11 match (Points: 1)
Label each of the following reactions as exothermic or endothermic (“exo” or “endo”), and according to whether work is done on or by the system, or no work is done at all (“on”, “by” or “none”)? Note that no “endo-on” cases appear here, as these are always thermodynamically unfavourable. There is no need to do any calculation, use chemical arguments to predict the sign of the enthalpy change.
Matching pairs
CO(g) –> C(g) + O(g) – Select choice -exo-byendo-by
2 H2O(g) –> 2 H2(g) + O2(g) – Select choice -exo-byendo-by
C2H5OH(l) + 3 O2(g) –> 2 CO2(g) + 3 H2O(g) – Select choice -exo-byendo-by
Ca(s) + 2 H2O(l) –> Ca(OH)2(aq) + H2(g) – Select choice -exo-byendo-by
CO2(s) –> CO2(g) – Select choice -exo-byendo-by
I looked up a previos answer that said.
Well lets make some general statements about endo/exothemic.
I always think of exothermic as being an explosion or release of energy, whereas endothermic is when energy is absorbed by the reaction. Also, breaking bonds generally requires the input of energy while forming bonds usually releases energy.
So take 2 H2 + O2—> 2 H2O
Now, what is really happening in this reaction?
1. 2 H2 molecules are broken into 4 H atoms—-Endothermic
2. The O2 molecule is broken into 2 O atoms—-Endothermic
3. An O atom bonds to 2 H atoms—————Exothermic
4. The other O atom bonds to the other H atoms–Exothermic
Now you would need some sort of table telling you how much each step absorbed or released energy. For example, breaking the H-H bond in H2 has a value of +436 kJ/mol, while forming an O-H bond gives -464 kJ/mole. Values are generally negative for exothermic and positive for endothermic. Add these numbers up, and you will find out if the reaction is exo or endothermic. Lets try and do it:
1.H-H bond broken x2……+872 kJ/mole
2. O-O bond broken………+204 kJ/mole
3. O-H bond formed x2….-928 kJ/mole
4. O-H bond formed x2….-928 kJ/mole
Total Energy:…………….-780 kJ/mole
Its a negative value, so you know its exothermic
As for the H2O (l) —> H2O (s) being exothermic, think of it this way:
When you add a cube of ice to a glass of water, what happens? The water becomes cooler. How does this happen? The ice absorbs heat from the water, and in the process melts. Therefore H2O (s)—-> H2O (l) would be an endothermic process, since the solid is absorbing heat, then turning into a liquid. So logically the reverse process, H2O (l) —> H2O (s), would be exothermic.
Given this does that mean that anythin which break bones is Exothermic? or endothermic. I am a bit confused on this process. Can somoeone help?