Is the oxidization of a substance ever exothermic?

  • Thread starter Thread starter Topher925
  • Start date Start date
  • Tags Tags
    Exothermic
Click For Summary

Discussion Overview

The discussion revolves around whether the oxidation of a substance, specifically hydrogen in the presence of platinum, can be exothermic. Participants explore the nature of reactions involving hydrogen and platinum, including the potential for heat emission and the specifics of the chemical processes involved.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant questions if the reaction of hydrogen with platinum is exothermic or neutral, suggesting that the reaction may occur spontaneously due to the catalyst's effect on bond strength.
  • Another participant clarifies that while the reaction between hydrogen and oxygen is exothermic, the specific reaction involving hydrogen and platinum needs further examination.
  • A participant challenges the initial reaction proposed, stating it does not make sense and asks for references, noting that the interaction may be more about the adsorption of hydrogen on platinum rather than a chemical reaction that produces electrons or acid.
  • One participant suggests that the adsorption of hydrogen on platinum is likely exothermic due to decreasing entropy, but questions the specifics of electron production in the process.
  • A later reply elaborates on the process of hydrogen chem-adsorption on platinum, mentioning the splitting of diatomic hydrogen into monatomic forms and the potential for cation formation in an electrolyte environment, while also offering to provide references for this process.

Areas of Agreement / Disagreement

Participants express differing views on the nature of the reaction between hydrogen and platinum, with some asserting that it is an exothermic process while others question the validity of the proposed reaction and its implications. The discussion remains unresolved regarding the specifics of the reaction and its thermodynamic properties.

Contextual Notes

There are limitations in the clarity of the proposed reaction involving hydrogen and platinum, as well as the definitions and assumptions regarding the terms used, such as "oxidation" and "exothermic." The discussion also highlights the complexity of electrochemical processes that may not be fully addressed.

Topher925
Messages
1,563
Reaction score
7
Like the question states, if you remove the electrons from an atom using some catalyst, will that reaction be exothermic or neutral. For example oxidization of hydrogen using platinum.

H2 + Pt = PtH+2 + 2e-

Would this reaction absorb or emit any heat? I wouldn't think so since I think this reaction can occur almost spontaneously as the Pt reduces the H2 bond strength to 0eV or am I just talking nonsense here?
 
Chemistry news on Phys.org
You are confusing spontaneity with enthalpy. Oxygen and hydrogen spontaneously combine to form water and that reaction is plenty exothermic.
 
chemisttree said:
You are confusing spontaneity with enthalpy. Oxygen and hydrogen spontaneously combine to form water and that reaction is plenty exothermic.

Yes, I realize the reaction between hydrogen and oxygen is exothermic, but what about the reaction of hydrogen with platinum?
 
What reaction is that? The one you show doesn't make any sense. Do you have a reference for it?

I know that platinum oxide is reduced in the presence of hydrogen (producing water) to platinum metal but I have never seen platinum itself reacting with hydrogen to generate acid and 2 electrons (where do they go?). The "reaction" you suggest is simply the adsorption of hydrogen on the surface of platinum. It is likely an exothermic process since it is known to occur and entropy is decreasing. I don't think that any electrons or acid are produced...
 
here's a few exothermic oxidations:

 
Last edited by a moderator:
anthemrider22 said:
here's a few exothermic oxidations:



Hi,

This video is very good to keep all the facts in mind, as this is giving me a pure example of exothermic oxidations which are no doubt very serving.


Thanks!
 
Last edited by a moderator:
chemisttree said:
What reaction is that? The one you show doesn't make any sense. Do you have a reference for it?

I know that platinum oxide is reduced in the presence of hydrogen (producing water) to platinum metal but I have never seen platinum itself reacting with hydrogen to generate acid and 2 electrons (where do they go?). The "reaction" you suggest is simply the adsorption of hydrogen on the surface of platinum. It is likely an exothermic process since it is known to occur and entropy is decreasing. I don't think that any electrons or acid are produced...

Sorry for my nonsense, I should have been more clear. I'm referring to the reaction or maybe you would call it a process, where hydrogen is chem-absorbed by platinum and the hydrogen molecules split from a single diatomic molecule into two monotonic molecules and both are oxidized (no O2 present). If this happens at a three phase region where one of those phases is an electrolyte and the other phase is an electronically conductive material, the electrons have the ability to separate from the hydrogen creating cations. The cations of course can then migrate through the electrolyte. If you need references I can post a few, but I thought this was a rather common process in electrochemistry?

Again, sorry if I'm not making any sense, I'm an ME trying to learn electrochemistry.
 

Similar threads

Detailed electrochemistry question
  • · Replies 5 ·
Replies
5
Views
3K
Understanding Oxidizing Agents in 2CuO + C
  • · Replies 7 ·
Replies
7
Views
10K
Endothermic absorb energy How do they begin in the first place?
  • · Replies 2 ·
Replies
2
Views
3K
Can Chemical Bonds with Nitrogen and Nitric Oxide Mitigate Pollution?
  • · Replies 8 ·
Replies
8
Views
3K
Chemically regenerating my auto's catalytic converter?
  • · Replies 19 ·
Replies
19
Views
10K
Which substance acted as a catalyst?
  • · Replies 2 ·
Replies
2
Views
6K
Can New Reactants Reduce Nitric Oxide Pollution?
  • · Replies 1 ·
Replies
1
Views
2K
Specific Heat and its relevance to Molecular Configuration
  • · Replies 1 ·
Replies
1
Views
5K
Questions from Exam Grade 11 Just Check
  • · Replies 1 ·
Replies
1
Views
5K
What is the most reactive metal and ion based on reduction potentials?
  • · Replies 5 ·
Replies
5
Views
15K