CHEMISTRY COMMUNITY

Kyla Grunden 1L

How do you determine at what point the nitrogens are too far away to bond to the same metal atom?

Kyla Grunden 1L

The "bis" is there because there are two oxalate ions in the compound.

Kyla Grunden 1L

Will we be required to know some of the common names of complex ions? For example, apparently [Fe(CN)6]4- does not follow the systematic naming of complex ions and is instead known as Ferricyanide.

Kyla Grunden 1L

Will we be asked to find the hybridization of structures with delocalized electron pairs? For example, what would be the hybridization of the nitrogen in amide?

Kyla Grunden 1L

Here's Dr. Lavelle's lesson on naming compounds, hope this helps! https://lavelle.chem.ucla.edu/wp-conten ... pounds.pdf

Kyla Grunden 1L

Like bonded electrons, lone pairs exist in hybrid orbitals. There's no reason, that's just how it works!

Kyla Grunden 1L

Here's a video I think does a good job of explaining it! https://www.youtube.com/watch?v=_gkbxvIo_nw

Kyla Grunden 1L

Yes, they do! I don't think we need to know how, at least at this point in the class. But, here's a website on it if you're curious https://chem.libretexts.org/Courses/Mou ... d_Orbitals

Kyla Grunden 1L

Potential hydrogen bonding sites of a molecule include the Hydrogens on the molecule as well as the lone pairs on hydrogen, oxygen, nitrogen, and fluorine molecules. For example, water has hydrogen bonding sites on the two hydrogen molecules and the two lone pairs on the oxygen, so it has four hydro...

Kyla Grunden 1L

S-character is number of sigma bonds in hybridization. In sp^3, there is 25% s-character and 75% p-character and the bond angle of sp^3 (tetrahedral) is 109.5. In sp^2 there is 33% s-character and 67% p-character and the bond angle (trigonal planar) is 120. In sp, there is 50% s-character and 50% p-...

Kyla Grunden 1L

Hybridization is how bonding works.

Kyla Grunden 1L

I don't think there are any homework questions that don't require the application of sigma and pi bonds in hybridization. I imagine because of this any questions on the test will be conceptual and not application.

Kyla Grunden 1L

Component orbitals are simply what orbitals hybridize when a bond is made.

Kyla Grunden 1L

Yes, I don't think it matters!

Kyla Grunden 1L

The component orbitals of pi bonds are p orbitals. The component orbitals of sigma bonds are s orbitals.

Kyla Grunden 1L

No, I think this is just an average of the strength of hydrogen bonds that Dr. Lavelle uses to show the relative strengths of the different types of bonds.

Kyla Grunden 1L

Bond strength is determined by a number of factors. Bonds are weakened if the atoms involved are large or if there are lone pairs on nearby atoms. Bond strength is also affected by the electronegativities of the atoms involved and their bond lengths (or resonance). Bond multiplicity or order (how ma...

Kyla Grunden 1L

While you can tell if two atoms are more likely to form an ionic or covalent bond based on other factors, I'm sure if we were being asked to determine based specifically on electronegativity, the values would be provided.

Kyla Grunden 1L

No, I believe if we need to determine the differences in electronegativities, a periodic table with electronegativities will be provided.

Kyla Grunden 1L

Bond strength is determined by a number of factors besides the number of bonds. Bonds are weakened if the atoms involved are large or if there are lone pairs on nearby atoms. Bond strength is also affected by the electronegativities of the atoms involved and their bond lengths (or resonance).

Kyla Grunden 1L

He mentioned in a lecture that we weren't going to go over it, so I think we're good!

Kyla Grunden 1L

A) 2
B)2
C)1

Kyla Grunden 1L

I went to a review session today where the TA basically described the hamiltonian as a variable. In the example problem he gave, it told you what the variable stood for (it was a derived equation) and you simply plugged the given equation into Schrodinger's equation and then defined the variables in...

Kyla Grunden 1L

Ionization energy is the energy required to remove an electron from an atom. Electron affinity is the energy released or absorbed when an electron is added to an atom.

Kyla Grunden 1L

Oxygen has a higher electronegativity. Electronegativity increases across the rows of the periodic table and decreases as you move down the table.

Kyla Grunden 1L

Unfortunately, this is just memorization! s has 1 orbital, p has 3, d has 5, and f has 7.

Hope this helps!

Kyla Grunden 1L

Carbon does not have any unpaired valence electrons: it has 4 single bonds with hydrogen atoms, so the hydrogen atoms are spread out equally in the lewis structure.

Kyla Grunden 1L

I'm not sure, I've looked it up and can't find anything, but another good trick is that the least abundant atom is also usually in the middle.

Kyla Grunden 1L

Bromine is an exception to the octet rule because it's in the fourth period (these exceptions occur after the third period). There are a total of 28 electrons in the molecule (7 in Bromine and 7*3 in Fluoride). There is a single bond between the bromine and each of the fluorides, and the fluorides h...

Kyla Grunden 1L

I think we should know the general trends for ionization energy, not only because he went over it in class but because it's useful for drawing Lewis structures and understanding other topics.

Ionization energy increases as you move across a period and decreases as you move down groups.

Kyla Grunden 1L

Hello,

We use this as a shortcut so we don't have to write so much! My high school chem teacher always said chemists are lazy, if there's an easier way to do something, they'll do it :)

Kyla Grunden 1L

Hello, There are several different ways to write electron configuration, but I think the best way if you're just learning this is to think about how many electrons can fit in each shell and subshell. To do this, here's a quick cheat sheet that will help you figure out the order electrons fill. You e...

Kyla Grunden 1L

Hello, I believe there is always a negative sign in Bohr's equation. I looked it up and a previous user on this site said "The negative sign in Bohr's equation is there because E=0 when the electron and neutron are separated completely (when the electron is free). So, as they get closer (or get...

Kyla Grunden 1L

Hello,

For this experiment I think it's better to see it in a video rather than have it explained. Here's a good one: https://www.youtube.com/watch?v=uK60QAKooyM

Hope this helps!

Kyla Grunden 1L

There are several ways to do this, but I think the best way if you're just learning this is to think about how many electrons can fit in each shell and subshell. To do this, here's a quick cheat sheet that will help you figure out the order electrons fill. You end up accidentally memorizing it prett...

Kyla Grunden 1L

In a post from a few years ago a TA said that water molecules in the air can scatter frequencies, which would make the measurements inaccurate.

Hope this helps!

Kyla Grunden 1L

To test that electrons have wave-like properties, they treated an electron like it was light. Essentially, they shot an electron through 2 slits. If the electron behaved like a single particle, it would only make a single spot through one of the slits. However, the electron did not do this, it made ...

Kyla Grunden 1L

https://www.youtube.com/watch?v=h1tflE-L2Dc

Hope this helps!

Kyla Grunden 1L

Remember that s, p, d, and f orbitals are different types of bonds, s orbitals use sigma bonding, p orbitals use pi bonding, and so on. The numbers represent the energy level of the orbital. Within each energy level, there are multiple orbitals. To assign an electron to an orbital and energy level, ...

Kyla Grunden 1L

Yes, molecular spectroscopy is used to identify molecules because of the precise frequencies emitted by different molecules. The process of molecular spectroscopy seems pretty complicated, I'll link an article about it below in case you're curious. Hope this helps! https://www.sciencedirect.com/topi...

Kyla Grunden 1L

Several times I have seen that, when you divide by the smallest molar mass when trying to find the empirical formula, the ratios are not always whole numbers. At what point is it too far to round to find the ratio?

Kyla Grunden 1L

Not sure if this will work for you, but I like to circle all the quantities in the problem and underline key words like "reacts with". It helps me almost visualize the equation in my head. Also, this way I'm not searching through the question to find amounts when I'm doing calculations. Ho...

Kyla Grunden 1L

Because we went over them in lecture, I would definitely memorize them, especially for conversions. I think the only thing being given to us is the formula sheet which can be found on the class website under "Constants, Equations, PT".

Hope this helps!

Kyla Grunden 1L

I had the same question regarding if we have to memorize polyatomic ions, my TA said that they will most likely give us the molecular formulas. But I might review them just because I'm paranoid!

Hope this helps!

Kyla Grunden 1L

A combustion reaction occurs when a compound is reacted with oxygen, releasing heat and light. I don't think there's any way, or reason, to represent that a reaction is combustion, but the second reactant is always oxygen gas.

Hope this helps!

Kyla Grunden 1L

Hello,

The unit for amplitude of wavelength is meters (m). This explains why the unit for speed of light is meters per second (m/s): the equation is c= λv, and λ is m, and v is hertz (1/s), so the speed of light is m/s.

Hope this helps!

Search found 46 matches