Dipole moment carbon florides of isotopes of Hydrogen

In summary, the dipole moment of CH3F is greater than that of CD3F due to the longer C-H bond length and the direction of polarization towards the electronegative atoms in each molecule. The sum of the dipole moment in CD3F is also greater than that of CH3F, leading to a conclusion that CD3F has a lower dipole moment than CH3F. This is an advanced question for a high school chemistry class and it is expected that the concept of vibrational potential will be covered in the course.
  • #1
112
34

Homework Statement


Compare Dipole moment of CH3F and and CD3F where D is deuterium.

Homework Equations


Theory questions

The Attempt at a Solution


Our sir had explained that to do this question we muat take into account the vibration of the atom in the respective molecule.
That is that the smaller the molecule is the more easily it can move away from the central atom.
But i don't know how to apply this concept with respect to dipole moment...

The answer given is Dipole moment of CH3F is more than that of CD3F
 
Physics news on Phys.org
  • #2
Your profile says you're 17. This seems like a really advanced question for someone your age. Ergo, I'm not sure at what level to address this.

You don't need to take vibration into account per se, but you do need to understand that the vibrational potential is anharmonic. Since a deuterium nucleus is heavier than a proton, its zero point energy will be lower; therefore, it will (on average) sit deeper in the vibrational potential well and the harmonic approximation will work better for deuterium than a proton. The B-level upshot of all this is that the C-H bond length will be slightly longer than the C-D bond length.

What does this mean for the molecule's dipole moment? Well, take a look at the electronegativities of C, H, and F, and try to predict to what extent, and in which direction, the C-H and C-F bonds will be polarized. What happens to the dipole moment when you stretch or shorten a bond?
 
  • Like
Likes Navin
  • #3
TeethWhitener said:
Your profile says you're 17. This seems like a really advanced question for someone your age. Ergo, I'm not sure at what level to address this

Welcome to the beautiful world of JEE(joint enginearing entrance) Advance and indian Entrance exams !

Okay we have zero idea about the vibrational potential wall, but i won't be surprised if we learn it in our course.(i think our Sir mentioned that we shall go deeper about it later on in the course)

Anyway so yea getting back to the question

So since the C-H bond shall be slightly longer and Dipole moment is directly proptional to distance tween the participating atoms that is Bond lenght

I feel CH should have more dipole moment than CD

Now let's look at CH and CF

In CH the direction of polarisation will towards C as it is more Electro Negative than H

But this Reverses in the Case Of CF
Where the direction will be in the direction of Florine as it is more electronegative .

So far so good ?
 
  • #4
Now if we draw the two tetrahydral structures(i know its frowed upon to send pictures but i really don't know how to draw structures via a keyboard)

We can tell that Since CD has lssser dipole moment than CH ,and CF will have the same dipole moment in both cases,

The sum of the dipole moment in the case of CD3F is more than that of CH3F

Therefore i think
CD3F should have less Dipolemoment than CH3F
 
Last edited:
  • #5
image.jpeg
 

Attachments

  • image.jpeg
    image.jpeg
    47.8 KB · Views: 1,593
  • #6
Navin said:
The sum of the dipole moment in the case of CD3F is more than that of CH3F

Therefore i think
CD3F should have less Dipolemoment than CH3F
This is confusing, but I think it might just be a typo on your part. Everything else looks fine, and is about the level I'd expect from a high school chemistry class.
 
  • #7
TeethWhitener said:
This is confusing, but I think it might just be a typo on your part.

Sorry ! Typo i missed that ! My bad

TeethWhitener said:
is about the level I'd expect from a high school chemistry class.

So much for my hopes of being a genius !
 
  • #8
Thank you so much ! It was really kind of you to help ! Have an awesome day !
 

1. What is a dipole moment?

A dipole moment is a measure of the separation of positive and negative charges in a molecule. It is a vector quantity, meaning it has both magnitude and direction.

2. What are carbon fluorides?

Carbon fluorides are compounds made up of carbon and fluorine atoms. They are commonly used in industrial processes and have a variety of applications, including refrigerants, solvents, and propellants.

3. What are isotopes of hydrogen?

Isotopes of hydrogen are atoms of hydrogen with different numbers of neutrons. The most common isotope, hydrogen-1 or protium, has one proton and no neutrons. The other two stable isotopes are deuterium, with one proton and one neutron, and tritium, with one proton and two neutrons.

4. How does the dipole moment change when isotopes of hydrogen are added to carbon fluorides?

The dipole moment of a molecule is affected by the distribution of charges within the molecule. Adding isotopes of hydrogen to carbon fluorides can change the distribution of charges, and therefore, the dipole moment of the molecule may increase or decrease.

5. What is the significance of dipole moment carbon fluorides of isotopes of hydrogen in scientific research?

The dipole moment of a molecule is an important factor in determining its chemical and physical properties. In the case of carbon fluorides of isotopes of hydrogen, the dipole moment can affect the reactivity, stability, and polarity of the molecules, making them useful in various research areas such as materials science, catalysis, and biochemistry.

Suggested for: Dipole moment carbon florides of isotopes of Hydrogen

Replies
1
Views
701
Replies
2
Views
1K
Replies
9
Views
5K
Replies
1
Views
2K
Replies
4
Views
1K
Replies
6
Views
2K
Back
Top