Question

IS CCI4 polar ?

Answer 1

Not usually, no. It's essentially the same structure as methane except the hydrogen atoms have been replaced with chlorine atoms. Looking at a tetrahedron and asking more specific questions can help me to help you understand better why.

Answer 2

CCl4 has a tetrahedral structure.It has 4 C-Cl polar covalent bonds directed to the four corners of the tetrahedron. All the dipoles cancel each other giving a net dipole moment of zero for the entire molecule. So CCl4 is nonpolar.

Answer 3

yup, pretty much

Answer 4

The reason I said not usually is because this is a real, dynamic object bouncing around in space. When it vibrates it can lose its symmetry and cause it to have a temporary dipole moment and we can use this fact to help identify it with infrared radiation.

Answer 5

but the type that you're talking about is another type of intermolecular force, called London Dispersion, this is TEMPORARY dipole moment.

When I'm reading the word polar, I think of the dipole moment in the molecular is being PERMANENTLY.

Answer 6

I'm not even talking about London Dispersion forces, @alias , I'm talking about the molecule as a simple harmonic oscillator.

Answer 7

To clarify, london dispersion forcces describe the movement of electrons around the molecule and what I'm describing is the movement of atoms.

Check this out: http://courses.chem.psu.edu/chem210/mol-gallery/methane-vib/methane-vibrations.html

Answer 8

@Kainui
Huh... I thought those are the same thing, but apparently I'm wrong :P
Thanks for clarifying

Answer 9

Yeah distinguishing between the electron and the whole electron-atom system is a common problem that pops up in multiple places in chemistry! Like talking about angular momentum in hydrogen atom.

There's the spin of the electron AND the spin of the electron around the atom like this:

It's kind of like how the earth is spinning for day and night and also for how the earth is spinning around the sun once per year.

Although the electron isn't really spinning, if it were it would be moving faster than the speed of light... Which is against the rules lol. Also, the electron isn't exactly spinning around the atom in an orbit, it's in an orbital. And because of the Heisenberg uncertainty principle we can only know certain aspects of its angular momentum, its magnitude and how much of a component it has in one of the 3 spatial dimensions. Usually we just look at the Z direction and forget the X and Y. Not because we want to, but because we can't, their operators don't commute.