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Topic: Formula unit, total ionic, and net ionic equations  (Read 23898 times)

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Offline Arejenga

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Formula unit, total ionic, and net ionic equations
« on: September 27, 2006, 10:57:27 PM »
The problem is this: Write the formula unit, total ionic and net ionic equations for perchloric acid and aqueous ammonia, and find the oxidation numbers for each element.

So

HClO4 + NH3 ->

I'm not quite sure what the product would be. My best answer would be a guess. This also may be a misunderstanding of the problem on my part and what the problem is actually asking for is this:

HCLO4 -(H20)> H+ + CLO4- and

NH3(aq) -(H20)> H+ + N2-

I understand how formula unit, total ionic, and net ionic equations are each laid out. I just need clarifications on the problem, what the product would be if my first interpretation of the problem is true, and if the second is true, if the ionizations I used are correct. Any help is well appreciated. Thank you!

Arejenga

By the way, if my question is too unclear and you need additional details as to what I need, please do not hesitate to say so.
« Last Edit: September 27, 2006, 11:46:22 PM by Arejenga »

Offline Albert

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Re: Formula unit, total ionic, and net ionic equations
« Reply #1 on: September 28, 2006, 03:21:28 AM »

NH3(aq) -(H20)> H+ + N2-



This is wrong.

Offline Arejenga

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Re: Formula unit, total ionic, and net ionic equations
« Reply #2 on: September 28, 2006, 07:42:42 AM »

NH3(aq) -(H20)> H+ + N2-



This is wrong.

okay, could you explain just a tad bit more? And possibly tell me if the second scenario is even what the problem is asking for? Is there a possible reaction between perchloric acid and ammonia? If there is, please tell me what it is, and I'll work out the formula unit, total ionic, and net ionic equations and post it up. Thanks!

Offline Albert

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Re: Formula unit, total ionic, and net ionic equations
« Reply #3 on: September 28, 2006, 08:08:26 AM »
Perchloric acid and ammonia will certainly react: the former is an acid and the latter a base. The product? A salt.

Now, given that ammonia is a base, how do you think it'll react when you add water?

The first equation

Quote
HCLO4 -(H20)> H+ + CLO4-

is correct.

Offline Arejenga

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Re: Formula unit, total ionic, and net ionic equations
« Reply #4 on: September 28, 2006, 08:27:04 AM »
so... the reaction would be HCLO4 + NH3 -> NCLO4 + H2O?

and ammonia would be NH3(aq) -(H2O)> OH - + N+ ??

Usually Nitrogen would be N2, but that would cause an inbalance ions, I think.

Offline Albert

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Re: Formula unit, total ionic, and net ionic equations
« Reply #5 on: September 28, 2006, 08:34:49 AM »
No, it isn't.

Quote
NH3(aq) -(H2O)> OH - + N+ ??

If ammonia is a base, this means water will act like an acid.

Try looking at the equation this way: NH3+H2O -> 2 products.
« Last Edit: September 28, 2006, 08:50:01 AM by Albert »

Offline Arejenga

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Re: Formula unit, total ionic, and net ionic equations
« Reply #6 on: September 28, 2006, 09:53:32 AM »
No, it isn't.

If ammonia is a base, this means water will act like an acid.

Try looking at the equation this way: NH3+H2O -> 2 products.

By "no, it isn't" do you mean both equations are wrong?

For the second equation, I have NH3 + H2O -> OH- +NH+

Offline Albert

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Re: Formula unit, total ionic, and net ionic equations
« Reply #7 on: September 28, 2006, 09:59:39 AM »
For the second equation, I have NH3 + H2O -> OH- +NH+

It's almost correct. What about NH4+ instead of NH+;)

Offline Arejenga

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Re: Formula unit, total ionic, and net ionic equations
« Reply #8 on: September 28, 2006, 01:27:17 PM »
So if each individual substance were to react with water, Aqueous ammonia would be:

NH3 + H2O -> OH- + NH4+

and perchloric acid would be:

HCLO4 + H20 -> H+ + CLO4-

and if instead the two substances were to react, a salt and water would result:

HCLO4 + NH3 -> NCLO4 + H2O

and the entire formula would not have a charge. Please let me know if I had gathered the information correctly. Thank you for the help so far!
« Last Edit: September 28, 2006, 01:53:08 PM by Arejenga »

Offline Yggdrasil

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Re: Formula unit, total ionic, and net ionic equations
« Reply #9 on: September 28, 2006, 05:38:23 PM »
Chemical reactions need to be balanced.  There must be an equal number of each type of atom on each side of the reaction arrow.  For example,

NH3 + H2O -> OH- + NH4+

Is balanced and correct.  On the reactant side, there are 1 N, 5H, and 1O, and on the product side there are 1N, 5H, and 1O.

Quote
HCLO4 + H20 -> H+ + CLO4-

This, on the other hand, is not balanced.  Here you have 3H, 1Cl, and 5O on the reactant side, but 1H, 1Cl, and 4O on the product side.  There is an imbalance of two hydrogens and one oxygen.  That should give you a clue of how to fix the reaction.

Checking whether your chemical equations are balanced is a good first check on whether your equation will work or not.

Offline Albert

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Re: Formula unit, total ionic, and net ionic equations
« Reply #10 on: September 29, 2006, 04:21:23 AM »

HCLO4 + NH3 -> NCLO4 + H2O


This equation is incorrect: I can't see the salt and I sincerely doubt anything like NCLO4 exists.

Look at products in first two correct equations: how do you think they will react?

Offline Arejenga

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Re: Formula unit, total ionic, and net ionic equations
« Reply #11 on: September 29, 2006, 11:56:55 AM »
Okay, I have the correct answer to the problem and thought I'd post it up for anyone who's curious.

The equation is this:

HCLO4 + NH3 + H2O -> H+ + CLO4- + NH4+

The hydroxide ion that is usually expected from a base like ammonia is left out due to the fact that it is a weak base and most of the hydroxide in fact stays in the left side of the equation. Thus, we are left with one hydrogen with the remainder of the equation acting normally. Ammonia becomes an Ammonia ion and we have CLO4- moving over to the left.

The total ionic equation:

H++ CLO4- + NH3 + H2O -> H+ + CLO4- + NH4+

Net ionic is written without the spectator ions. CLO4- remains unchanged so is ommited.

The result:

H+ + NH3 -> NH4+

To Albert: Please try not to be so critical of my guess. I have asked multiple times as to whether there was fault in my logic and you completely ignored my requests and now you come to me in the manner you just did, as if I should have somehow gained insight on the problem from your silence alone. Thank you for your help in everything else, though. I will post the oxidation numbers later.

Ciao!

Offline Albert

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Re: Formula unit, total ionic, and net ionic equations
« Reply #12 on: September 30, 2006, 04:20:26 PM »
I am really sorry but I never meant to be critical or, even worse, mock you. I tried my best to help you: I thought pointing out what's wrong and what's right would have been the best way of doing it. However, I do apologize if you still believe I was somehow arrogant.
Thing is, once again, I've realized I'm not much of a tutor.  :P

Now, for what concerns your problem, I am not sure that

Quote
HClO4 + NH3 + H2O -> H+ + CLO4- + NH4+

is the right answer.

I would say the right equation is

HClO4 + NH3  -> NH4CLO4

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