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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Geddoe on October 14, 2009, 11:39:58 PM

Title: Formation of salts from acid/bases (check)
Post by: Geddoe on October 14, 2009, 11:39:58 PM
Each of the following salts can be prepared from an acid and a base. Write the balanced molecular
equation and the net ionic equation for the preparation of each. Indicate states of the reactants and products
[(aq), (s), (l)]. Review solubility rules if necessary to determine the solubility of the reactants.
(a) Ba(ClO4)2 (aq) (b) CsCH3CO2 (aq) (c) Sr(ClO4)2 (aq)

(a)
Ba(OH)2(aq) + 2HClO4(aq) -----> Ba(ClO4)2(aq) + 2H2O(l)

net: 2OH-(aq) + 2H+(aq) -----> 2H2O(l)

(b)
CsOH(aq) + CH3COOH(aq) ----> CsCH3COO(aq) + H2O(l)

net:
OH-(aq) + CH3COOH(aq) ----> CH3COO-(aq) + H2O(l)

(c)  Sr(OH)2(aq) + 2 HClO4(aq) = Sr(ClO4)2(aq) + 2 H2O(l)
net: 2OH-(aq) + 2H+(aq) ---> 2H2O(l)

Correct?
Title: Re: Formation of salts from acid/bases (check)
Post by: UG on October 15, 2009, 01:06:26 AM
I (think) you have to write the net ionic for the formation of the SALT, ie, Ba2+ + 2ClO4- :rarrow: Ba(ClO4)
Title: Re: Formation of salts from acid/bases (check)
Post by: Borek on October 15, 2009, 03:07:58 AM
Quote from: UG on October 15, 2009, 01:06:26 AM
Ba2+ + 2ClO4- :rarrow: Ba(ClO4)

That would be strange, as technically there is no reaction taking place - correctly written it is

Ba2+(aq) + 2ClO4-(aq) :rarrow: Ba2+(aq) + 2ClO4-(aq)

No idea what will be accepted as a correct answer.

Geddoe: last one doesn't have smallest possible coefficients.
Title: Re: Formation of salts from acid/bases (check)
Post by: UG on October 15, 2009, 03:10:17 AM
Oh, that's funny, why do they not react?
Title: Re: Formation of salts from acid/bases (check)
Post by: Geddoe on October 15, 2009, 01:41:06 PM
The logic of writing the net ionic equations here is leaving what is left after crossing out the spectator ions, correct? They don't react per solubility rules.

Borek: Smallest possible coeff is 2 isn't it? Thus...  Sr(OH)2(aq) + 2 HClO4(aq) => Sr(ClO4)2(aq) + 2 H2O(l) right?
Title: Re: Formation of salts from acid/bases (check)
Post by: Geddoe on October 15, 2009, 05:23:56 PM
Ah or are you referring to the net ionic...

 OH-(aq) + H+(aq) => H2O(l)


would that be correct?
Title: Re: Formation of salts from acid/bases (check)
Post by: Borek on October 15, 2009, 07:38:29 PM
Quote from: Geddoe on October 15, 2009, 05:23:56 PM
OH-(aq) + H+(aq) => H2O(l)

Yes.
Title: Re: Formation of salts from acid/bases (check)
Post by: sjb on October 16, 2009, 02:05:46 AM
Quote from: UG on October 15, 2009, 03:10:17 AM
Oh, that's funny, why do they not react?

It's not a case of not reacting per se, but barium perchlorate is soluble in water, so the net ionic is different say, compared to the case of barium sulfate, where the product is insoluble.