How do you determine which chemicals are dominant in chemical reactions?

 

For example:

 

HCl + Na = NaCl + H2

 

But why does it not go this way:

 

HCl + Na = H2Cl + Na

 

Is there a list that I can learn that tell me which chemical take priority?

 

Another example would be:

 

Na + Cl + HCO3 what would it make and how do we know?

 

NaCl + HCO3 or NaHCO3 + Cl?

 

One of them must have priority over the other.

Check it out from the reduction potential table.

You should work out the Gibbs free energy for each reaction. The one that is most negative will be the one which dominates

My guess is that someon who is asking that question wouldn't know a Gibbs free energy if it bit them

However, it's worth noting that in the examples given the valencies of the elements don't make sense.

 

H2Cl, for example, doesn't exist because it would need a very odd valency for the chlorine.

 

A table of valencies is, imho, probably a lot more use to Lawlord than a discussion of thermodynamics.

Thank you, I have got hold of a standard reduction potential table, but cannot find a valence table... but if it was just going to tell me how many valence electrons an atom has, I won't need it as I know how to use the periodic table to do this.

 

With the standard reduction potential table, is it that the element that's E - naught value closest to zero will be the one that joins?

 

H2Cl is a typo, I meant HCl, sorry.