Non-reversible reactions?

2010-03-24 8:48 pm
what is meant by nonreversibe reaction?
Under what conditions do reactions go to completion?

回答 (2)

2010-03-24 9:56 pm
✔ 最佳答案
Non reversible reactions that go to completion are the norm in inorganic chemistry:
Typically:
NaOH + HCl → NaCl + H2O
At the end of this reaction, if the two reactants are used in 1:1 molar quantities, there will be no HCl or NaOH remaining, but there will be a solution of NaCl You will have an impossible task to adjust conditions such as temperature, pressure etc in order to make the solution of salt in water re- produce HCl and NaOH. This is only possible by complicated electrolysis methods, etc. which hardly make the reaction chemically reversible. This can truly be classified as a nonreversible chemical reaction that goes to completion.
The list of nonreversible inorganic reactions is endless.
But there are some which are reversible, such as the thermal decomposition of CaCO3
CaCO3 +heat → CaO + CO2
The CaO will react with water to form the hydroxide
CaO + H2O → Ca(OH)2 + heat
This in turn will react with CO2 to form the carbonate
Ca(OH)2 + CO2 → CaCO3 + H2O You have reversed the reaction to again form the CaCO3 you started with, and recovered the H2O that was used as an intermediate in the process.
But take note that in each of the three steps shown above, the reactions go to completion, given the correct quantity of reactants
2016-12-13 5:50 am
hi, i'm Dr. Wallace grant. Sodium Acetate produces warmth as much as fifty 8 ranges Celsius while that is utilized in warmth packs. The sodium acetate is inhibited in commercial use. while positioned right into a plastic environment, alongside with a warmth %., the crystallization technique will height at fifty 8 ranges Celsius, or approximately one hundred thirty ranges Fahrenheit. even however, the sodium acetate could be catalyzed to realize a greater suitable temperature while the Van Der Waals forces come into play. by utilising changing the way the molecules connect with a minimum of one yet another on the atomic point, temperatures like a hundred ranges Celsius could be gained.


收錄日期: 2021-04-15 16:57:44
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100324124844AAbH1bx

檢視 Wayback Machine 備份