# Why the tetrahedral angle is 109 deg 28 min?

• AlbertEinstein
In summary, the question being addressed is about the calculation of the HCH angle in methane and how it is related to co-ordinate geometry. The conversation also includes links to resources that explain the concept of the tetrahedral angle.
AlbertEinstein
Hope my question is understood.

AlbertEinstein said:
Hope my question is understood.

No it isn't. Please note that if you're too lazy to explain the context of your question, then it is foolish of you to expect people to spend time and effort to give you thoughtful responses.

Zz.

your identifying a special case. You would need to delve into quantum mechanics. In addition, to which molecule are your referring?

To the original poster: try a Google search on "tetrahedral angle" (including the quotes, to keep the words together). Some of the first few hits look like they might be what you're looking for.

As posed, the question in the OP has nothing to do with physics (or chemistry) - it is a standard high school level exercise in either co-ordinate geometry or vectors.

Sorry for forgetting my question for a long time, I am really sorry.
I wanted to ask that in methane the HCH angle is 109 deg 28 min. How in theory is this calculated ? If this has to something with co-ordinate geometry, I would like a bit clarification.I hope my question is clear this time and I'm in the right forum.

Thanks.

Last edited:
http://www.chem.unl.edu/cak/bk5.htm

Last edited by a moderator:
The tetrahedral angle can be formed by taking the midpoint of a cube and drawing four lines from this midpoint out to every other corner. It's then pretty easy to prove the angle.

## 1. Why is the tetrahedral angle 109 deg 28 min?

The tetrahedral angle is 109 deg 28 min because it is the most stable arrangement of four atoms bonded to a central atom. This arrangement minimizes repulsion between the bonding electrons and maximizes the distance between the bonded atoms, resulting in a stable and symmetric structure.

## 2. How was the tetrahedral angle determined to be 109 deg 28 min?

The tetrahedral angle was determined through a combination of theoretical calculations and experimental data. Scientists used molecular orbital theory and quantum mechanics to calculate the most stable arrangement of atoms around a central atom. This calculation resulted in an angle of 109 deg 28 min, which was then confirmed through experimental measurements.

## 3. Does the tetrahedral angle vary in different molecules?

Yes, the tetrahedral angle can vary slightly in different molecules due to differences in bond lengths and types of bonding. However, the average tetrahedral angle of 109 deg 28 min is still the most stable arrangement for most molecules with four bonded atoms and a central atom.

## 4. How does the tetrahedral angle affect molecular properties?

The tetrahedral angle plays a crucial role in determining the shape and properties of a molecule. For example, molecules with a tetrahedral shape tend to have higher boiling points and stronger intermolecular forces due to the compact and symmetrical arrangement of atoms.

## 5. Are there any exceptions to the tetrahedral angle rule?

Yes, there are some exceptions to the tetrahedral angle rule. For example, molecules with lone pairs of electrons on the central atom, such as water and ammonia, have a slightly distorted tetrahedral shape with a smaller bond angle. Additionally, molecules with more than four bonded atoms, such as sulfur hexafluoride, have a more symmetrical octahedral shape with bond angles of 90 degrees.

• General Math
Replies
2
Views
1K
• General Math
Replies
4
Views
356
• Atomic and Condensed Matter
Replies
1
Views
1K
• General Math
Replies
21
Views
2K
• General Math
Replies
5
Views
909
• Atomic and Condensed Matter
Replies
4
Views
3K
• Atomic and Condensed Matter
Replies
2
Views
2K
• Atomic and Condensed Matter
Replies
1
Views
1K
• Calculus and Beyond Homework Help
Replies
2
Views
341
• Chemistry
Replies
2
Views
1K