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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: zerality on October 01, 2006, 11:26:39 PM

Title: Help completing these reactions
Post by: zerality on October 01, 2006, 11:26:39 PM
Hi

I am supposed to balance these reactions (and write in balance net ionic form if applicable)
Need help to see if i did these correctly

HOAc(aq) + Ba(0H)2 (aq) ---------->
not usre where to start


NH3(aq) + HCl (aq) ---------------->
my ans: N sup (-3) + 3H sup(-) + H sub (-) --------> NH4 sup (+)


NH3(g) + HCL (g) ------------>
my ans: NH3 + HCL --------> NH4Cl (s)
Title: Re: Help completing these reactions
Post by: Donaldson Tan on October 02, 2006, 03:10:42 PM
Quote from: zerality on October 01, 2006, 11:26:39 PM
HOAc(aq) + Ba(0H)2 (aq) ---------->

This is an acid-base reaction. Another way of representing HOAc is H-OAc.

Quote from: zerality on October 01, 2006, 11:26:39 PM
NH3(g) + HCL (g) ------------>
my ans: NH3 + HCL --------> NH4Cl (s) 

Correct!

Quote from: zerality on October 01, 2006, 11:26:39 PM
NH3(aq) + HCl (aq) ---------------->
my ans: N sup (-3) + 3H sup(-) + H sub (-) --------> NH4 sup (+)

Ever consider NH4Cl (aq) ?
Title: Re: Help completing these reactions
Post by: zerality on October 02, 2006, 04:17:28 PM
HOAc(aq) + Ba(0H)2 (aq) ---------->  

I'm still not sure about this reaction. We haven't covered acid base reactions in class yet.
Title: Re: Help completing these reactions
Post by: Donaldson Tan on October 02, 2006, 05:27:28 PM
Quote from: zerality on October 02, 2006, 04:17:28 PM
HOAc(aq) + Ba(0H)2 (aq) ---------->  
We haven't covered acid base reactions in class yet.

The acid-base reaction is called neutraliation. The reaction always produces a salt and water.

eg. HA + NaOH -> NaA + H2O where HA is a monoprotic acid.
Title: Re: Help completing these reactions
Post by: Mitch on October 02, 2006, 05:42:58 PM
Water is made as a product from most acid-base reactions. For the first reaction water(H2O) is a product, try to deduce what the other products should be.
Title: Re: Help completing these reactions
Post by: english on October 02, 2006, 05:55:50 PM
Whatever is your stronger acid will act as your acid.
Title: Re: Help completing these reactions
Post by: zerality on October 02, 2006, 07:23:20 PM
2HOAc(aq) + Ba(0H)2 (aq) ---------->  2H20 + BaAc2 + 02


Does this look correct?
Title: Re: Help completing these reactions
Post by: Dan on October 02, 2006, 07:33:33 PM
Not quite...

HOAc <----> H+ + ___________

hint:

general scheme

HA <----> H+ + A-
Title: Re: Help completing these reactions
Post by: zerality on October 02, 2006, 08:02:02 PM
HOAc(aq) + Ba(0H)2 (aq) ---------->  H20 +  H+  +Ba0 +AcO-

How does that look?
Title: Re: Help completing these reactions
Post by: english on October 02, 2006, 09:28:14 PM
Quote from: zerality on October 02, 2006, 08:02:02 PM
HOAc(aq) + Ba(0H)2 (aq) ----------> H20 + H+ +Ba0 +AcO-

How does that look?

Not quite..

You are creating a proton out of nowhere....

H+ from acetic acid will neutralize HO- from Ba(OH)2 to from H2O.  You are overlooking something very simple here. Is your reaction balanced?
Title: Re: Help completing these reactions
Post by: zerality on October 02, 2006, 09:51:03 PM
2HOAc(aq) + Ba(0H)2 (aq) ----------> 2H20 + Ba + 2AcO-


How about now?
Title: Re: Help completing these reactions
Post by: english on October 02, 2006, 09:57:31 PM
Quote from: zerality on October 02, 2006, 09:51:03 PM
2HOAc(aq) + Ba(0H)2 (aq) ----------> 2H20 + Ba + 2AcO-


How about now?

Your net ionic should only include those reactants/products involved in the reaction itself:

2H+ + 2HO- ---------> 2H2O
Title: Re: Help completing these reactions
Post by: constant thinker on October 03, 2006, 03:41:07 PM
Try writing acetic acid as HAc. That'll be less confusing, and that's how I usually see it abbreviated in acid-base reactions. If you write it this way for acid-base reactions you won't get confused.

HAc + Ba(OH)2 --> H2O + ________

H+ + Ac-  <- That's your acid as you know.
2OH- + Ba2- <- That's your base as you also know.