Extremely basic chemistry question

[TroutBum]

Hey everyone, I have a general chemistry question. It's so basic, I feel embarassed asking, but it's been years since I've done this and I was trying to help somebody else out but got stuck.

So take these three reactions:

1. NaOH (s) ---> NaOH (aq)
2. NaOH (aq) + HCl (aq) ---> NaCl (aq) + H20 (l)
3. NaOH (s) + HCl (aq) --> NaCl (aq) + H20 (l)

Very basic, yes? Now, show that the algebraic sum of the first two equations equals the third. So, wouldn't that be

NaOH(s)+NaOH(aq)+HCl(aq)-->NaOH(aq)+NaCl(aq)+H20(l)

The NaOH(aq) would cancel on both sides, leaving

NaOH (s) + HCl (aq) --> NaCl (aq) + H20 (l), which is the third equation.

Is this correct?

Now, this is the part that's getting me--the question asks to do the same thing, but using the complete ionic equations. So wouldn't this be:

NaOH(s) --> Na+ (aq) + OH- (aq)
Na+(aq) + OH-(aq) + H+(aq) + Cl-(aq) --> Na+(aq)+Cl-(aq)+H20(l)

The sum of these would then be

NaOH(s)+Na+ (aq)+ OH-(aq)+ H+(aq)+ Cl-(aq) --> Na+(aq) +OH-(aq) + Na+(aq) + Cl-(aq) + H20 (l)

One Na+(aq) and 0H- (aq) would drop out of each side, but so would the Cl-(aq), leaving

NaOH (s) + H+ (aq) -->Na+(aq) + H20 (l), which is not the complete ionic equation for equation #3.

Am I doing something wrong here?

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[geldrop]

yeah thats correct

net ionic equations ignore the pointless ions.


NaOH (s) + HCl (aq) --> NaCl (aq) + H20 (l)
is the net equation but NOT the net ionic equation.

 

[mws99]

lol, I forget how to do that too. But, if my memory serves me correctly I think you did everything right. The final equation you have looks like equation 3, just ignoring the chlorine because it is a spectator ion.

 

[TroutBum]

Thanks for your replies. I think I did it right too, but what's tripping me is the complete ionic equation part--if you use complete ionic equations, you have to show all ions, whether or not they're spectators. But if you add the first two equations, it doesn't make sense to leave the spectators in. Anyways, thanks again. I felt pretty embarrassed when I said I wasn't sure if I had done it right.