How do you complete and balance neutralization reactions in aqueous solution?

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In summary: NH3 + HNO3 -> NH4NO3Molecular equation is:NH3 + HNO3 -> NH4NO3Ionic equation is:NH3 + H+ + NO3- -> NH4+ + NO3-So the literal formula would be the same as the molecular formula, NH4NO3. The ions just represent the dissociated molecules.
  • #1
BrainMan
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(Question) Complete and balance each of the following molecular equations (in aqueous solution); include phase labels. Then, for each, write the net ionic equation.

(A) NH3 + HNO3 ->

(Attempt) I thought that the acid HNO3 would just give it's hydrogen to NH3 and make the resulting reaction NH3 + HNO3 -> HNH3 + NO3. However the correct answer is NH3 + HNO3 -> NH4NO3.
 
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  • #2
BrainMan said:
(Question) Complete and balance each of the following molecular equations (in aqueous solution); include phase labels. Then, for each, write the net ionic equation.

(A) NH3 + HNO3 ->

(Attempt) I thought that the acid HNO3 would just give it's hydrogen to NH3 and make the resulting reaction NH3 + HNO3 -> HNH3 + NO3. However the correct answer is NH3 + HNO3 -> NH4NO3.

Your answer appears to me an answer to the second question on the right lines except you seem to have forgotten they asked for the net ionic equation. So if you answer that more carefully that's what what actually happens, is, then this ionic mixture is called ammonium nitrate formally written with the the book answer. I.e you have to represent it as what they thought it was maybe 150 years ago.

It's understanding not so much chemistry as what the questioners want and if you can't grasp this IMHO lose an odd point and live with it. :biggrin:
 
  • #3
epenguin said:
Your answer appears to me an answer to the second question on the right lines except you seem to have forgotten they asked for the net ionic equation. So if you answer that more carefully that's what what actually happens, is, then this ionic mixture is called ammonium nitrate formally written with the the book answer. I.e you have to represent it as what they thought it was maybe 150 years ago.
It's understanding not so much chemistry as what the questioners want and if you can't grasp this IMHO lose an odd point and live with it. :biggrin:
I answered the first part which was to complete the molecular formula. I don't get your explanation.
 
  • #4
Ammonium nitrate is very soluble. You would expect to be able to represent the reaction:


NH3+HNO3 ---------->HNH+4 + NO-3
 
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  • #5
BrainMan said:
(Question) Complete and balance each of the following molecular equations (in aqueous solution); include phase labels. Then, for each, write the net ionic equation.

(A) NH3 + HNO3 ->

(Attempt) I thought that the acid HNO3 would just give it's hydrogen to NH3 and make the resulting reaction NH3 + HNO3 -> HNH3 + NO3. However the correct answer is NH3 + HNO3 -> NH4NO3.


symbolipoint said:
Ammonium nitrate is very soluble. You would expect to be able to represent the reaction:


NH3+HNO3 ---------->HNH+4 + NO-3
BrainMan said:
I answered the first part which was to complete the molecular formula. I don't get your explanation.

You were asked for an ionic equation but there are no ions in your equation. Symbolipoint has give an ionic equation but there is a typo.
It could hardly be simpler - between your two starting molecules a proton, H+ , is transferred.

In solution these ions are all there is. Even when it crystallizes the crystal is a lattice of these ions. It is called ammonium nitrate, think of what any other salt is called, and given the formula in your book. Which is what you will see on a bottle of the crystals like you will see common salt written NaCl and not Na+Cl- which is really what it is.

And then NaCl and NH4NO3 do represent the composition of the salts.

I just remembered the way related salts are described sometimes. Related to ammonia are amines and amino acids. In these one or more H of NH3 are substituted by organic groups. And you will easily see bottles labelled "glycine hyrdrochoride HOOCH2NH3.HCl" or the common buffer salt tris(hydroxymethyl)aminomethane) hydrochloride (HOCH2)3CNH2.HCl. Though I can't remember ever having seen straight ammonium salts described that way.

But this is no big problem, I'm sure you're ready now to re-read your textbook. :biggrin:
 
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  • #6
epenguin is right. I made a typographic mistake.

This, one digit different, is what should have been:


NH3 + HNO3 ---------> HNH3+ + NO3-
 
  • #7
I know that this question asks for the ionic formula but my book actually wants you to find the molecular formula and then find the ionic formula. My problem is I don't understand how to do that with neutralization reactions. The books explanation on how to do this is terrible.
 
  • #8
In terms of a simple Arrhenius theory of acids and bases neutralization reaction is

BOH + HA -> AB + H2O

(where BOH is a base and HA is an acid).

What to do with ammonia depends on whether you are taught only Arrhenius theory, or Bronwsted-Lowry theory as well.
 
  • #9
Borek said:
In terms of a simple Arrhenius theory of acids and bases neutralization reaction is

BOH + HA -> AB + H2O

(where BOH is a base and HA is an acid).

What to do with ammonia depends on whether you are taught only Arrhenius theory, or Bronwsted-Lowry theory as well.

What does that have to do with this (A) NH3 + HNO3 -> ?
 
  • #10
Have you read the very last phrase of my post?

Which theory have you been taught?
 
  • #11
Borek said:
Have you read the very last phrase of my post?

Which theory have you been taught?
I have been teaching myself through a book and it mentions both theories.
 
  • #12
So it will be better to apply Bronsted-Lowry to ammonia, which is a proton acceptor (BL base):

NH3 + H+ -> NH4+

That's net ionic for the ammonia. NO3- is just a spectator (as nitric acid is considered to be strong and always fully dissociated).
 
  • #13
Borek said:
So it will be better to apply Bronsted-Lowry to ammonia, which is a proton acceptor (BL base):

NH3 + H+ -> NH4+

That's net ionic for the ammonia. NO3- is just a spectator (as nitric acid is considered to be strong and always fully dissociated).

OK I understand how to get the ionic formula but how do I get the literal formula with the spectators included. So how do I find the formula before I convert it to the ionic formula? The question in the book only included one side of the equation (A) NH3 + HNO3 -> and left the other side blank. How do I first find what's on the other side?
 
  • #14
Many ways of skinning that cat.

For example: acids react with bases producing salts. What is the acid here, what is the base here, what is the salt that combines them?

Another approach is to go net ionic first, molecular later. HNO3 is 100% dissociated. What do you have in the solution? What reaction do you expect? What ions will be present in the solution? How can you combine them to produce a salt?
 
  • #15
Borek said:
Many ways of skinning that cat.

For example: acids react with bases producing salts. What is the acid here, what is the base here, what is the salt that combines them?

Another approach is to go net ionic first, molecular later. HNO3 is 100% dissociated. What do you have in the solution? What reaction do you expect? What ions will be present in the solution? How can you combine them to produce a salt?

OK then how do I do start this problem (a) the reaction of solid aluminum hydroxide with nitric acid. So I wrote that out in equation form and got AlOH + HNO3 -> and I figured that you would produce AlNO3 + H2O. Turns out the correct answer is Al(NO3)3 + 3H2O. Where did the extra subscript 3 come in?
 
  • #16
Aluminum will react with water to form a hydroxide. However it will react with water in a way in which the net charge is 0. Being on group 13, you know that aluminum will form an ion with a 3+ charge. Hydroxide on the other hand, is an ion with a -1 charge. In order to find the ratio in which the two ions combine, you must find the least common denominator, being 3, and dividing 3 by the two charges to find the respective ratios. So you will end up with Al1(OH)3.
 
  • #17
Teemo said:
Aluminum will react with water to form a hydroxide. However it will react with water in a way in which the net charge is 0. Being on group 13, you know that aluminum will form an ion with a 3+ charge. Hydroxide on the other hand, is an ion with a -1 charge. In order to find the ratio in which the two ions combine, you must find the least common denominator, being 3, and dividing 3 by the two charges to find the respective ratios. So you will end up with Al1(OH)3.

Yeah I just realized that. OK so I think that I have gotten the first step now I am having trouble with the ionic equation. So the equation is 2HCN + Ca(OH)2 -> Ca(CN)2 + 2H2O. So I separated all all the ions except water and canceled out the rest. So I got H+ + OH- -> H2O. The correct answer is HCN + OH- -> H2O +CN-
 
  • #18
BrainMan said:
So I got H+ + OH- -> H2O.

Quite good - that's the essence of most of the neutralization reactions. However, it requires acid and base to be strong enough to be already dissociated. HCN is a very weak acid, and is dissociated in very small degree, so the solution is dominated by the HCN molecules, hence

The correct answer is HCN + OH- -> H2O +CN-
 

1. What is a neutralization reaction?

A neutralization reaction is a chemical reaction in which an acid and a base react to form a salt and water. This reaction occurs when the number of hydrogen ions (H+) from the acid and the number of hydroxide ions (OH-) from the base are equal, resulting in a neutral pH of 7.

2. What are some examples of neutralization reactions?

Some common examples of neutralization reactions include the reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) to form sodium chloride (NaCl) and water (H2O), and the reaction between sulfuric acid (H2SO4) and potassium hydroxide (KOH) to form potassium sulfate (K2SO4) and water (H2O).

3. What is the importance of neutralization reactions?

Neutralization reactions are important because they allow us to control the pH of a solution. Acids and bases are found in many everyday products, and if they are not neutralized, they can be harmful or corrosive. Neutralization reactions also play a crucial role in the digestive system, as stomach acid (hydrochloric acid) is neutralized by the base bicarbonate in the small intestine.

4. How do you calculate the products of a neutralization reaction?

To calculate the products of a neutralization reaction, you need to first identify the acid and base being used. Then, balance the equation by making sure the number of hydrogen ions (H+) and hydroxide ions (OH-) are equal on both sides. The products will always be a salt and water.

5. What factors can affect the rate of a neutralization reaction?

The rate of a neutralization reaction can be affected by several factors, including temperature, concentration of the acid and base, and the presence of a catalyst. A higher temperature can increase the rate of the reaction, while a higher concentration of the acid and base can make the reaction faster. Catalysts can also speed up the reaction by lowering the activation energy required.

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