Ca(CH₃COO)₂ + 2NaOH ---> 2CH₃COONa + Ca(OH)₂
or
2CH₃COONa + Ca(OH)₂ ---> Ca(CH₃COO)₂ + 2NaOH

The first reaction takes place. Compare soloubility of Calcium acetate and Calcium hydroxide.

21 hours ago, observer1 said:

Ca(CH₃COO)₂ + 2NaOH ---> 2CH₃COONa + Ca(OH)₂
or
2CH₃COONa + Ca(OH)₂ ---> Ca(CH₃COO)₂ + 2NaOH

You have asked this type of question several times now and the answer has been the same in all cases: consider the solubility of the possible combinations of ions. There is an article in Wiki on this: https://en.wikipedia.org/wiki/Salt_metathesis_reaction Note especially the section on counterion exchange, which is what your questions have been about.

There is also a link in the article to a quite useful solubility chart, which is helpful if one does not know whether a given ionic compound is appreciably water-soluble or not: https://en.wikipedia.org/wiki/Solubility_chart

 

 

 

the first reaction is possible since both disassociate in water

33 minutes ago, observer1 said:

the first reaction is possible since both disassociate in water

That, frankly, is a stupid reply, given everything you have been told.  

That, frankly, is all I understood form the https://en.wikipedia.org/wiki/Solubility_chart link u sent.
I was specifically looking about this reaction and that was the only difference I found(from the table u sent)

if you can, can you pls explain this in a much simpler was or give a video for it?

The table is understandable

If you check Ca with OH it says sS and Ca with CO3 also sS, slightly solouble, if you do it with Na its says s solouble. The same with acetate.

So if you mix sodium carbonate and Calcium acetate , both solouble alone, then you will find a precipitation takes place , because the CaCO3 is formed.

The same takes place  if you take Calcium acetate and sodium hydroxide. Ca(OH)2 is formed. The opposit reaction dont takes place, because one reacting is not good solouble.

that was what I was just telling.
Only the first reaction is possible because both the reactants completely are soluble in water

No its the opposit . Important is which component is not soluble or only slightly soluble.  The reaction takes place where this will be formed if the ions come together.

Edited January 23, 20232 yr by chenbeier

2 hours ago, observer1 said:

That, frankly, is all I understood form the https://en.wikipedia.org/wiki/Solubility_chart link u sent.
I was specifically looking about this reaction and that was the only difference I found(from the table u sent)

if you can, can you pls explain this in a much simpler was or give a video for it?

No need for a video, you just need to be able to read and take in what you have already been told, several times now.

You get a double displacement reaction when one of the possible combinations is insoluble, because it is more stable in the solid state than in solution, and therefore precipitates out. I've told you this, so has @chenbeier, and it is repeated in the Wiki link I went to the trouble of providing. 

In your latest example it is Ca(OH)₂ that is much less soluble than the other possibilities, so it will precipitate from any solution with those ions in it.

 

Edited January 23, 20232 yr by exchemist

so since Ca(OH)₂ is slightly soluble and not completely, the reaction is not possible

10 minutes ago, exchemist said:

You get a double displacement reaction when one of the possible combinations is insoluble, because it is more stable in the solid state than in solution, and therefore precipitates out

now i understand
so, just asking, let's ASSUME Ca(OH)₂ is also soluble, then the reaction will go back and forth?

Let say you mix Calcium acetate and sodium chloride

Both salts are solouble, you will get everything dissolved and have Ca2+ , CH3COO-, Na+ and Cl - in solution. No reaction.

The same you would get if you mix Calciumchloride with sodium acetate.

why does that happen?
is it because here both sides completely dissolved while in the one I gave, Ca(OH)₂ is slightly dissolved in water?

Yes, only the unsoluble compound escapes. The others exist side by side.

so in a reaction, if both the reactants and products are soluble in water, the reaction does not take place while if the product is not completely soluble in water, then the reaction is possible. Also if the reactants are no soluble in water, the reaction does not take place

You start from a situation, where two compounds are soluble.  If a new compound is formed, which  is unsoluble, then the two reactants react each other.  If New compounds also soluble nothing will be observed. If a reactant is not soluble then also no reaction takes place.

For example Ca(CH3COO)2 + NaHCO3 I change my opinion. In long term also a reaction takes place, because NaHCO3 was called sodium bi carbonate, today sodium hydrogen carbonate. Bi means two, what gives the following 2 NaHCO3 => Na2CO3 + H2CO3.

H2CO3 => H2O + CO2

So if this is given to the calcium acetate, then

Ca(CH3COO)2 + 2 NaHCO3 => CaCO3 + 2 CH3COONa + H2O + CO2

 

Edited January 24, 20232 yr by chenbeier

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