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Topic: Balance equation: NH3 + O2 -> HNO3 + NO + H2O  (Read 1918 times)

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CH3COOH

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Balance equation: NH3 + O2 -> HNO3 + NO + H2O
« on: July 18, 2024, 07:07:06 AM »
Hello,

Based on my own calculation, the equation is baalnced as follow:

10NH3 + 17O2 -> 6HNO3 + 4NO + 12H2O

However, the solution given by the book is:

12NH3 + 21O2 -> 8HNO3 + 4NO +14H2O

How could I decide which one is correct?
Thank you. I am trying to change my career to pharmacy. Any advice on which materials good to read as well?

Hunter2

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Re: Balance equation: NH3 + O2 -> HNO3 + NO + H2O
« Reply #1 on: July 18, 2024, 07:42:02 AM »
Multiple solutions

Simple burning

4 NH3 + 5 O2 => 4 NO + 6H2O

And

NH3 + 2 O2 => HNO3 + H2O

The easiest combination would be add both equation

5 NH3 + 7 O2 => 4 NO + HNO3 + 7 H2O

But to get 6 HNO3 then

10NH3 + 17O2 -> 6HNO3 + 4NO + 12H2O

Get 8 HNO3

12NH3 + 21O2 -> 8HNO3 + 4NO +14H2O

So you can do different additions.

The right one is the book solution, it's the reaction according Ostwald.
There are 3 reactions

1. 4 NH3 + 5 O2 => 4 NO + 6H2O
2. 2 NO + O2 =>  2 NO2
3. 3 NO2 + H2O => 2 HNO3 + NO

The summery gives the book solution.

« Last Edit: July 18, 2024, 08:18:53 AM by Hunter2 »

Borek

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Re: Balance equation: NH3 + O2 -> HNO3 + NO + H2O
« Reply #2 on: July 18, 2024, 02:11:32 PM »
Note: technically none of these reactions is "correct", or, in a way all are "correct", depending on what you mean by "correct". Technically, as Hunter pointed out, this is sum of several processes, this always means more than way of balancing the reaction equation in terms of having the same number of atoms on both sides of the equation. That doesn't mean reaction proceeds following the equation, paper will accept anything you write, reality will do its own thing

The book solution is more or less equation that describes the whole process as performed in the industrial synthesis of the acid. It lets you estimate the process stoichiometry with a reasonable accuracy, but in practice process will never exactly follow the reaction equation, it will be always off.
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