The general answer is the products will minimize the "Gibb's Free Energy". Values for G can be looked up in tables and/or calculated for various pressures, concentrations, etc.
So, if you can't look at the reaction and recognize it (like you can in this example) and it doesn't follow known rules (base+acid = salt+water), then you have to theorize different products (valid chemicals with the valances of each atom considered). Then grind out the deltaGs for each proposed reaction. If it is negative, it can happen with the right pathway. The biggest negative deltaG will be the preferred products.
There are "delta G" reactors in computer-based reactor simulators (available in any Chemistry/ChemEng department at any college). It automatically spits out the % of each compound for the specified conditions.
Some reactions are actually limited by kinetics (at normal pressures graphite is lower energy than diamond but it doesn't happen), but that is a different question
2006-08-24 11:23:05
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answer #1
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answered by David in Kenai 6
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Rule of the thumb in chemical reactions is that, products formed should not be "stronger" than reactants consumed in such reaction.
In your example of NaOH+HCl the product would be NaCl and H2O. Note however that the reverse of such reaction is not plausible, i.e. NaCl+H2O will not yield into NaOH and HCl. The reason behind this is that NaOH is a strong base while HCl is a strong acid.
There are other factors you have to condiser when determining the possible products of a certain reaction. You also need to understand the type of chemical reaction to determine the possible products. In other words, there really is no easy way to determine what the products of chemical reactions would be. You need to have alot of experience with chemical reactions before you can determine the products of a reaction by merely looking at the left hand side of the chemical equation.
Hope this helps. =)
2006-08-21 10:06:17
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answer #2
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answered by Aris 2
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Looks like H20+NaCl... Salty water that is :) There was a rule, there is a list of elements and those at one side can take the place of those further in the list (for metals) when substances with both get in contact... A lot of things are just by memory, I guess... If you have a base and an acid you should get a salt and some other compound. It has been ages since I last studied chemistry, though
2006-08-21 01:01:23
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answer #3
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answered by kichka_2002 4
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Remember 1- Some of the common products that get out of reactions are :
1. Water, H2 O
2. Salts, (Li, Na, K, Rb, Cs) + (F, Cl)
3. Oxides
Remember 2- All the elements on the left hand side of the equation should also appear on the right hand side of the equation too.
So you first try to find out if there is any water molecule forming.
NaOH + HCl surely forms a water molecule. So you get H2 O.
Now, as I said, the elements on LHS should also appear on the elements on RHS, so you have to account for the leftover Na and Cl.
Now, as I also that salts are one of the by products of the reactions, you add the rest of the two elements and you get NaCl.
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One of the answerers correctly said that when Hydroxides ( react with acids then water and salt is formed.
Hydroxides- the name tells you that they have OH in them, hydrogen and oxygen. They are alkalis, also called bases.
Acids- Acids have to have a hyderogen in their formula. Like HN)3, HCl, H2SO4, etc.
Salts- are formed when any of the (Li, Na, K, Rb, Cs) meets any of the (F, Cl, and other halogens)
The H and O of Hydroxides, and one of the H of acid, will always give you water, (H2 0).
2006-08-21 02:00:22
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answer #4
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answered by pranesh81 3
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Generally, an acid reacts with a base to form salt and water.
For example NaOH + HCl --> NaCl + H2O
This is known as nutralisation reaction.
2006-08-21 01:30:32
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answer #5
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answered by dinu 3
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yeah well if you read your gen chem text you'd find this stuff out. it's a double displacement reaction. here's the model
AB+CD ---> AD +BC
so applying that to your reaction
NaOH + HCl ---> NaCl+ H2O
it's also an acid base reaction where neutralization occurs. go back and review the basics.
2006-08-24 13:17:49
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answer #6
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answered by shiara_blade 6
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THE POSSIBILITY OF THE PRODUCTS FORMED CAN BE VISULAISED BY USING HSAB RULE
ACCORDING TO THIS RULE EACH IONS OR ELEMENT OR CLASSIFIED IN TO STRONG AND WEAK ACID OR BASES
STRONG ACID REACT WITH STRONG BASE
WEAK ACID REACT WITH WEAK BASE
EVEN THOUGH SOME EXPECTIONS ARE THERE
THE PRODUCT IS ALSO ANALYSED BY SOME CHEMICAL REEACTION
2006-08-28 10:42:47
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answer #7
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answered by gopi k 1
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yes there are certain rules/methods.... this example is from the double displacement method. you juz basically exchange the partners hence:
NaOH+HCl-->NaCl+H2O. there are other methods too such as the single replacement and watnot.. so juz go check your book or jzu check this out
http://www.dbooth.net/mhs/chem/chemicalreactions.html
2006-08-21 02:01:14
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answer #8
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answered by jaredkomahalko 2
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normally i think they have indicators for indicating the completion of a reaction.
like eg. phenolphthalein is added to determine if acid or base is fully neutralised not..
it takes more on knowledge and experiences..
hope this helps..
:)
2006-08-21 10:48:27
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answer #9
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answered by smelly_ducks 2
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based in ioinc charge and stibilty of the profict
dived the reactants to + & - charge and swach beteen them
2006-08-28 04:16:21
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answer #10
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answered by maherrashdan 2
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