Predicting Bond Enthalpy Trends for Atom-Hydrogen Bonds

In summary, the conversation discusses the search for a trend in predicting the bond enthalpy of atom-hydrogen bonds using Gaussian calculations. The speaker mentions a table that may be helpful in determining the trend for main group elements and transition metals.
  • #1
ReidMerrill
66
2
Is there a period trend for bond enthalpy? Specifically Atom-Hydrogen bonds. Need to find a trend in predicting the bond enthalpy of several atom-hydrogen bonds I calculated using gaussian.

Any help would be appreciated, thanks!
 
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  • #2
ReidMerrill said:
Need to find a trend in predicting the bond enthalpy of several atom-hydrogen bonds I calculated using gaussian.
If you calculated the bond enthalpies, wouldn't you be in a better position to tell us the trend, rather than us telling you?
 
  • #3
TeethWhitener said:
If you calculated the bond enthalpies, wouldn't you be in a better position to tell us the trend, rather than us telling you?
I just wondered if there was supposed to be a trend since they don't appear to follow any pattern.
 
  • #4
Try this table. https://labs.chem.ucsb.edu/zakarian/armen/11---bonddissociationenergy.pdf

For maingroup elements, E-H BDE's are fairly predictable: decrease down the periodic table, and increase across the periodic table.
For transition metals, M-H BDE's increase down the periodic table (1st < 2nd < 3rd). There's not really a clear trend across the periodic table.
 

1. What is bond enthalpy?

Bond enthalpy, also known as bond energy, is the amount of energy required to break a chemical bond between two atoms in a molecule.

2. How is bond enthalpy measured?

Bond enthalpy is typically measured in units of kilojoules per mole (kJ/mol) and is determined experimentally using calorimetry or spectroscopy techniques.

3. What is the periodic trend for bond enthalpy?

The periodic trend for bond enthalpy is that it generally increases as you move across a period from left to right, and decreases as you move down a group on the periodic table. This is due to the increasing electronegativity and decreasing atomic size of elements across a period.

4. How does bond enthalpy affect the stability of molecules?

A higher bond enthalpy indicates a stronger bond, which results in a more stable molecule. This is because it requires more energy to break the bond, making it less likely for the molecule to undergo chemical reactions.

5. Can bond enthalpy be used to predict the strength of a chemical bond?

While bond enthalpy can give an indication of the strength of a chemical bond, it is not the only factor that affects bond strength. Other factors such as bond length, bond angle, and molecular geometry also play a role in determining the overall strength of a bond.

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