CHEMISTRY COMMUNITY

Kellylin_4D

would we need to know isomers? Such as geometrical and optical? I know we never discussed it in lecture but it's in the book so I want to make sure

Kellylin_4D

405310750 wrote:I thought we use bis tris etc when naming multiple of the same polydentate? or is this the same thing?

yes, since all chelates are polydentate

Kellylin_4D

you should know that their naming convention would be different. Instead of using di, tri, etc, you would use bis, tris, tetrakis, etc. Should also know that they form rings when bonded to the central atom, and that they are polydentate

Kellylin_4D

If single bonds can rotate, and double bonds can’t rotate, do resonance rotate?

Kellylin_4D

other than when the question gives you the mole, how do you find pH? For example, how would you get pH from pKa? What are other question formats that leads to pH?

Kellylin_4D

if the question gives you the wavelength for an object, that would clue you to de Broglie, and if it gives you wavelength of a light or radiation, it would be the speed of light equation.

Kellylin_4D

What does it mean when the acid is neutral or negatively charged? Where does this charge come from? How can I tell whether it's charged or not? Do bases get charged as well?

Kellylin_4D

how do you get pH from pKa and vice versa? Also, what is their relationship and why is it possible to get pH from pKa

Kellylin_4D

For Acid and Base reactions, how many protons and oh- gets transferred?

Kellylin_4D

Are we supposed to be able to identify polydente compounds by the formula? Or do we have to draw it out.

Kellylin_4D

What are the differences between inorganic vs organic acids and bases?

Kellylin_4D

What are conjugates exactly and how do I identify them? I have never heard of this except when Dr. Lavelle briefly touched on it in class

Kellylin_4D

First, we can look at when it is just a hydrogen with the halogen elements, which are F, Cl, Br, and I. When it is just a hydrogen atom with one of the halogens, you can look at the distance between the bonds. Since fluorine has a smaller atomic radius, the hydrogen is bonded closer, since it is clo...

Kellylin_4D

It is covalent because the electrons are still shared between the two atoms, one atom is not giving away both their atoms. For example, a kid with two snacks do not give away both their snacks, they share their snack with the kid with no snacks.

Kellylin_4D

They can happen in all molecules. Basically, electrons move around all the time so at a certain time, there can be a lot of electrons towards one side, so it would be partially negative there at that moment, temporarily.

Kellylin_4D

I learned in a step up that you continue to put it on the equatorial plane so that the trigonal part of the structure is now gone. The shape becomes linear, with the two bonded pairs as far as possible, which is 180 degrees.

Kellylin_4D

I believe it is because in both, they are bigger, therefore, more polarizable and the interactions are stronger

Kellylin_4D

Are there always dipole moments in a molecule? How do we know when they cancel out and become nonpolar, esp if the shape also affects whether it’s nonpolar or not?

Kellylin_4D

How exactly does polarizability and the size of the atom make the interactions stronger?

Kellylin_4D

What is this equation exactly and do we need it for the test this week?

Kellylin_4D

What is this equation? Was it in lecture or the textbook? Any help would be great please.

Kellylin_4D

electrons are always moving around, therefore, it also moves the charges around. For example, there may be more electrons on the left at one instance and there is temporarily a partial negative charge on the left, at another instance there can be a bunch of electrons on the bottom, so there will be ...

Kellylin_4D

It is not something we will solve but will be given to us. In relation to bonding, the states have to do with polarizability and bond strength. As we go down a row, the polarizability increases because the size increase, and there's more electrons that is farther from the nucleus, which makes an ato...

Kellylin_4D

induced dipole is basically London and dispersion. According to my ta, it is basically caused by the constant movement of electrons, so the partial charges will be at different places as well.

Kellylin_4D

I'm not sure if I heard correctly during lecture that lone pairs repel more in VSEPR. If that is true, why is that so?

Kellylin_4D

KBELTRAMI_4I wrote:it says on the syllabus that 50% in the class is a C-, is this true?

I went to his office hours awhile back and that is what he said, however, that is only the bare minimum to pass. I believe you still have to get 450/500 points to get an A in the class.

Kellylin_4D

There is dipole moment when the electronegativity difference is big enough, and when the structure is not symmetrical

Kellylin_4D

Hi guys, what are some tips and tricks for making Lewis Structure bonds? I still get confused on when it is better to respect octet rule vs formal charge, or where the charges should be, etc. Any tips or tricks will help, thank you so much!

Kellylin_4D

Yes, as stated above, use de Broglie's

frequency=planks constant/weight of ONE particle in kg*speed/velocity in m.s

Kellylin_4D

so this is a diagram on the order to fill in the orbitals
1s
2s 2p
3s 3p 3d
4s 4p 4d 4f

then you would cross it out, downwards, diagonally, from right to left, for example, it is
2p, 3s, and another example on the order is 3d, then 3d

Kellylin_4D

How come in some bondings, such as CN minus, you put the extra electron with the C, even though the N is more electronegative, just because the N fulfilled the octet rule already, but in N2O, it is better to make O the negative charge, rather than the N? How do I know? And don't Oxygen prefer double...

Kellylin_4D

What are the least to most important steps for drawing Lewis structures? For example, is it more important to do formal charges first, or moving electrons first, etc.

Kellylin_4D

When doing Lewis structures, are electrons able to just "leave" their "home" atoms? Like, they are able to just go to another atom just to fulfill the octet rule?

Kellylin_4D

Furthermore, the atomic radii between the two atoms are generally the same, while in ionic, the two radii are different because they are different elements

Kellylin_4D

Here are some that I got from my plf session

sulfur can have 12 valence e
Nitrogen actually prefers 5
Boron can have 6 valence e

and the ones included by our peers
hopes this helps!

Kellylin_4D

The midterm is covering material from fundamentals, to the end of chemical bonds, as my TA told us

Kellylin_4D

if a compound is negatively charged, where do we put this extra electron?

Kellylin_4D

can someone elaborate more on what dislocation is please?

Kellylin_4D

What did you plug in for Plank's, and c?
Recheck calculations maybe?

Kellylin_4D

Shivam Rana 1L wrote:Are you referring to nodes? Electrons exist in hybridized orbitals when molecules form.

the sharing of electrons during covalent bonds

Kellylin_4D

I believe it's because you have to remove electrons from the highest energy first, even though it is not like that in this case when electrons are being added.

Kellylin_4D

That would depend on the principal quantum number, n, because each shell have a different number of subshells. For example, in n=1 where s is the only orbital, the max electrons would be 2. However, in n=3, where it has s, p, and d, then the max would be 18. s=2 p=6 d=10 add them up and you get 18 v...

Kellylin_4D

For week 4's homework, do we still do Quantum questions, or did we move onto questions from the new unit, since we just started on it.

Kellylin_4D

Can someone elaborate more on how the electrons are shared on the internuclear axis, I'm having trouble visualizing it.

Kellylin_4D

That would be extremely helpful, but they are pretty clear on the periodic table, which will be given to us on every test. Just remember that s is on the left, p is on the right, and d is in the middle

Kellylin_4D

The ground state is when all the electrons are in the lowest energy level possible.

Kellylin_4D

Hi, this may seem like a silly question by what does the symbol that looks like a fish mean? To be clearer, it is like an infinity sign but one side of it is unfinished. Thank you!

Kellylin_4D

In what context will we be using shrodinger's equation and what is it for? What does it tell us and what does it solve?

Kellylin_4D

Can someone explain exactly what Black Body Radiation is and what is it for?

Kellylin_4D

I talked to him during his office hours and he said we should know the two most common ones, which is
visible light 700nm-400nm
UV 400nm-100nm

I would learn xray also just in case

Kellylin_4D

First, convert wavelengths to photons. Since in one second, 32W is emitted, how many W is emitted in 2 seconds? Also, one photon is like one atom, or one molecule, or one electron, you can use Avogadro's number to convert number of photons to moles. Hope that helps!

Kellylin_4D

Perhaps I'm misinterpreting your question, but didn't you say that the wavelengths were already given? If not, what was given to be converted into wavelengths? That's what I assumed, but apparently, that was not the correct answer. The number that was given was 1,614,098 (not exact number) waveleng...

Kellylin_4D

So I was doing the post-module assessment and there was a question about wavelengths of radiation emitted. How do I convert this to wavelengths?

Kellylin_4D

I believe no because Lavelle has been recommending us to do the practice textbook questions but there hasn't been any temperature problems like that.

Kellylin_4D

How I understand it is that the threshold energy is the minimum energy for one photon to remove one electron, that's why there would be no energy left

Kellylin_4D

The work function is the amount of energy needed to remove an electron from a metal. Different metals have different work functions. It can also be denoted as threshold energy, or "energy removed e-." It is in the function, E(photon)-work function=Ek(e-)

Kellylin_4D

They are not multiplied together, but added because they are in separate compounds. When changing gram to moles, the one Cl from each compound is accounted for, then added, so technically, there is two.

Sorry I'm not very good at explanations but hope that made sense!

Kellylin_4D

Also, lights with shorter wavelengths, such as uv, has photons with more energy, therefore, just one of their photons can move one electron. The more intense the light is, the more photons there are. However, in light with shorter wavelength, their photons do not have enough energy to move an electr...

Kellylin_4D

Since we're starting on the Quantum World, when is the homework for this unit due?

Kellylin_4D

There is usually only 1 limiting reactant because you only need one thing to run out for the whole chemical reaction to stop. I'm not sure what it is called when the proportions are perfect and there's no limiting reactant though.

Kellylin_4D

Don't forget to balance the equation first. Hope this helps :)

Kellylin_4D

Hey guys, so I am just having trouble visualizing the stringing of atoms in E1. Since the atom has a radius of 144 pm, does that mean the diameter is 288, and we're just laying the atoms side by side? Thanks for the help!

Kellylin_4D

I would say yes, even if it's just incase to make sure since there's so many students and you want to make sure your points are given to you.

Kellylin_4D

My high school chem teacher used to always stress the importance of significant digits so yes, do keep them in the homework

Kellylin_4D

Hey guys! I was just wondering how everyone is formatting their homework. Are you guys copying down the questions on a binder paper then doing it there?

Kellylin_4D

This is so inspiring and gives me hope. Can I ask what extracurriculars you took part in?

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