CHEMISTRY COMMUNITY

Mei Blundell_1J

Thanks guys, I think that if there are multiple ligands on the metal, though, that the polydentate number of each ligand does not necessarily equal the coordination number of the whole complex. I definitely have to think about this more.

Mei Blundell_1J

Why and how does temperature affect pH?

Mei Blundell_1J

Does the number of coordination bonds in a coordination compound always equal the number of bonds that a ligand makes with the central metal atom (polydentate number)?

Mei Blundell_1J

Hi Melissa,
So pi bonds do have overlaps in 2 places, but these are considered just 2 regions of 1 bond. I guess this is because there are only 2 electrons involved (1 from one p and 1 from the other p).

Mei Blundell_1J

To add on, the "correct" number of hybridization orbitals is a consequence of the atom reaching minimal energy when it forms a bond. Atomic orbitals hybridize when the atom is bonding to other atoms, so that the atom can be less energetic.

Mei Blundell_1J

Thanks Beverly! This sentence "The 2p3 shell is a mix of the 2s shell (1 orbital) and 2p shell (3 orbitals) so it has 4 hybrid orbitals." was particularly helpful. More specifically, I'm wondering why there are necessarily 4 ways (hybrid orbitals) to mix 4 atomic orbitals.

Mei Blundell_1J

I was interested in this fact from Wednesday's lecture. The number of atomic orbitals in an atom is the same as the number of regions of electron density that appear when the atom participates in bonding. Is this just a really cool coincidence? Why is this? A key part in my question is about why the...

Mei Blundell_1J

Also, small and highly charged cations have high polarizing power while large anions have high polarizability (distorted easily).

Mei Blundell_1J

The difference in electronegativity of the atoms involved in the bond determines polarity. Difference in electronegativity means the electrons like to hang out closer to one atom than to the other, and this is called polar. When there is no difference in electronegativity (bond between atoms of the ...

Mei Blundell_1J

Oh that makes sense. When molecules move around they change where attractions and repulsions are located. This changes the orientation of dipoles and causes constant fluctuation. I think I get it, thanks!

Mei Blundell_1J

I'm a bit confused about this phrase "empty d-orbital", because earlier in the course I got the sense that orbitals are states that electrons can be in, rather than locations. My understanding is that when an atom has no electrons in a d-orbital state, then the d-orbital does not exist for...

Mei Blundell_1J

In induced dipole-induced dipole interactions, fluctuations in electron probability cloud density in one molecule causes complementary fluctuations in a nearby molecule. Why are there fluctuations in the electron cloud to begin with, and why doesn't the system equilibrate until both molecules are st...

Mei Blundell_1J

Is it true that cations and anions have opposite polarizability trends?

Mei Blundell_1J

Hi,
High polarizability means more covalent character,which means tighter bonding, and therefore means high boiling point. Please correct me if I'm wrong, I'm not quite sure either.

Mei Blundell_1J

It is possible to have multiple central atoms. Though I'm not sure how you would go about making the lewis structure for that kind of molecule.

Mei Blundell_1J

I'm not sure. I think as long as the formal charges of all the atoms in your structure are as close as possible to zero, you're fine.

Mei Blundell_1J

Hi,
Ionization energy increases across periods and decreases down columns. Keep this in mind when deciding which element has the lowest ionization energy (it will be closer to the lower left corner of the periodic table).

Mei Blundell_1J

Yes, and if the electrons are being added to the same shell (as in moving across the periodic table) then the radius of the atom actually decreases because the electrons are being pulled in by increased effective nuclear charge.

Mei Blundell_1J

So to my understanding, 4s is lower in energy than 3d for s-block elements because the s orbital shape is a sphere and is "simpler" or lower in energy than the complicated energetic shape of the p orbital. 4s electrons are removed first though, because they are farther from the nucleus tha...

Mei Blundell_1J

Hi,
Both are good, it just depends on what information you are given. Typically, questions about the relationship between wavelength and frequency are best solved with c=lambda*nu. And questions about the energy of a photon are best solved with E=h*nu.

Mei Blundell_1J

An important point is that it is the amt. of energy required to remove an electron from an atom such that it comes off with zero kinetic energy. There's no energy left over to move the electron away from the atom, only enough to detach it.

Mei Blundell_1J

The second part just means that the uncertainty in the electron's position is the diameter of the atom. In other words, the electron can occupy any position along this imaginary 350 pm long 1D box (which is a line). The book uses this box analogy that's kind of confusing, but that's what it means fo...

Mei Blundell_1J

l is the angular momentum quantum number and it determines the shape of the orbital. m is the magnetic quantum number and it determines the orientation of the orbital.

Mei Blundell_1J

What Professor Lavelle did was the exact same thing as the Rydberg equation. He took the difference in energies at the two levels. If you look at the Rydberg equation, you'll see that that's what it does. The constants look different just because they're rearranged, but they are the same. I recommen...

Mei Blundell_1J

I'm unclear on why E=h/p can't be used for photons. After all, photons do have momentum p and E=h/p is derived from equations that describe photons, so why doesn't E=h/p also describe photons? Photons don't have mass but they do have momentum, so I don't see why E=h/p can't be used for photons. I'm ...

Mei Blundell_1J

We discussed this in class today, but I'm still unsure of the reason why plastic can't be used for the experiment. Is it because the experimental setup requires a conductive material, or is it because plastics (and other non-conductive materials) don't emit photons? thanks

Mei Blundell_1J

The E-M fields are perpendicular to each other always while they oscillate. The electric field can oscillate up and down if the magnetic field oscillates right and left. These oscillations form the light wave.

Mei Blundell_1J

Fun fact related to this topic: the Sun is a really efficient black body.

Mei Blundell_1J

I also think the answer is D, because it directly relates energy E to frequency $\nu$ .

Mei Blundell_1J

Hi, I think you forgot to balance the equation. With the balanced equation, the limiting reactant will be the same as what you found, but you will have a different molar ratio to work with to find the mass of AgCl.

Mei Blundell_1J

Remember that subscripts indicate that the atoms are bonded to form a molecule while coefficients just count the molecules. For example, 6C₄ represents 6 molecules (or moles) of C₄.

Mei Blundell_1J

Hello!
The definition of a mole is the number of atoms in exactly 12 g of carbon, and it follows that the mass of 1 mole of carbon should be exactly 12g. So, I'm confused about why the molar mass of carbon is 12.011 g/mol. Could anyone help explain this to me?
Thanks,
Mei

CHEMISTRY COMMUNITY

Search found 32 matches

Re: coordination number=polydentate number?

How temperature affects pH

coordination number=polydentate number?

Re: Double bond

Re: Hybridization

Re: Why # regions of e density= # atomic orbitals?

Why # regions of e density= # atomic orbitals?

Re: Polarizing power

Re: Polar Vs. Non-Polar

Re: Why fluctuations? [ENDORSED]

Empty d-orbital?

Why fluctuations? [ENDORSED]

Re: Trends of Polarizing Power

Re: Polarizability and boiling point

Re: Multiple Central atoms

Re: Lewis Structures

Re: 3.33

Re: Exciting Electrons

Re: 4s orbital

Re: Bohr vs Speed of Light Equation

Re: What is work function? [ENDORSED]

Re: 1.43 [ENDORSED]

Re: What do l and m represent? [ENDORSED]

Re: Rydberg’s formula

Re: Photons? [ENDORSED]

Plastic vs Metal [ENDORSED]

Re: Electromagnetic Field [ENDORSED]

Re: Black Body? [ENDORSED]

Re: Post module quiz #25

Re: Module 3: Limiting Reactant Calculations Problem 21 [ENDORSED]

Re: Subscripts [ENDORSED]

Why does carbon have molar mass 12.011g/mol? [ENDORSED]