No, again. Like I said just use the right search engine and there is answer for many things I'm not a Physician or in education age etc.
@Shinchan_Nohara-257 said in #1:
> CaO is stable
> H2O is stable
> Then how CaO +H20 --> Ca(OH)2
Whether or not a chemical reaction occurs (spontaneously) is not a matter of the individual stability of the reactants alone.
Ultimately it's always a question of energetics:
Is the product [Ca(OH)2 in this case] of a chemical reaction in an energetically lower state than the reactants [CaO and H20]?
If so, the process is said to be exothermic: en.wikipedia.org/wiki/Exothermic_process
CaO +H20 <–> Ca(OH)2 is a reversible process with the left-to-right process being exothermic (releasing energy in the form of heat) and the reverse process being endothermic. Exothermic processes can occur spontaneously (upon reactant contact). Endothermic processes require activation energy (and/or a catalyst) to occur.
Here's a very cool example of a potential use (energy storage system on the moon that works during the lunar day and night) for such a reaction:
ntrs.nasa.gov/api/citations/19900016103/downloads/19900016103.pdf
Further reading:
www.youtube.com/watch?v=kZJgJCxcHZE&list=PL36EC6A6180271B0F&index=9
(This video is about ionic crystals like NaCl (table salt) crystals, but it's a very instructive example of the importance of energetics. Note in particular that both sodium and chlorine are stable, but they still react to form an ionic crystal lattice because it's energetically favourable. You only need to know Coulomb's law and a bit of mathematics and geometry for this one. Chemistry at its core is physics.)
> CaO is stable
> H2O is stable
> Then how CaO +H20 --> Ca(OH)2
Whether or not a chemical reaction occurs (spontaneously) is not a matter of the individual stability of the reactants alone.
Ultimately it's always a question of energetics:
Is the product [Ca(OH)2 in this case] of a chemical reaction in an energetically lower state than the reactants [CaO and H20]?
If so, the process is said to be exothermic: en.wikipedia.org/wiki/Exothermic_process
CaO +H20 <–> Ca(OH)2 is a reversible process with the left-to-right process being exothermic (releasing energy in the form of heat) and the reverse process being endothermic. Exothermic processes can occur spontaneously (upon reactant contact). Endothermic processes require activation energy (and/or a catalyst) to occur.
Here's a very cool example of a potential use (energy storage system on the moon that works during the lunar day and night) for such a reaction:
ntrs.nasa.gov/api/citations/19900016103/downloads/19900016103.pdf
Further reading:
www.youtube.com/watch?v=kZJgJCxcHZE&list=PL36EC6A6180271B0F&index=9
(This video is about ionic crystals like NaCl (table salt) crystals, but it's a very instructive example of the importance of energetics. Note in particular that both sodium and chlorine are stable, but they still react to form an ionic crystal lattice because it's energetically favourable. You only need to know Coulomb's law and a bit of mathematics and geometry for this one. Chemistry at its core is physics.)
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