CHEMISTRY COMMUNITY

Brynne Burrows 3K

What is the threshold for the bond angle of a chelating molecule? I have heard the term "spacer atom" but am not sure how this relates to whether a molecule can chelate.

Brynne Burrows 3K

Also, this molecule is not likely to gain more protons because of its stability so it cannot be a Bronsted base (proton acceptor). If you look at the conjugate base SO3]2- this is a stable anion with resonance. It is a conjugate base of a strong acid which will completely dissociate in water and giv...

Brynne Burrows 3K

How can we determine if a molecule acts as an acid or a base if there are no hydrogens present in the formula? Is it solely based on the metal or nonmetal present or are there other ways of identifying its characteristics in an aqueous solution?

Brynne Burrows 3K

Amphiprotic means that a substance can both accept and donate a proton or H+. Amphoteric means that a substance can act as both an acid and a base. All amphoteric substances are amphiprotic because if a molecule can either donate or accept a proton, that means it can act as both an acid or a base. H...

Brynne Burrows 3K

You can look at the anion once the acid has lost its proton and see which anion is more stable due to resonance of the structure or electronegativity, and in this case Chlorine is more electronegative than Phosphorus so chlorine stabilizes the anion more since it is able to withdraw the electrons.

Brynne Burrows 3K

Myoglobin has one heme group and primarily stores oxygen while hemoglobin has 4 heme groups and transports oxygen.

Brynne Burrows 3K

So if I am getting my test back in discussion Friday I will have two days to review it before the final?

Brynne Burrows 3K

A Lewis base means that molecule is donating its lone pair, while the Bronsted base accepts a proton. The molecule is still a base either way, it is just the way of wording that changes if its called Lewis or Bronsted.

Brynne Burrows 3K

Strong acids are HCl, H2SO4, HI, HNO3, HBr, and HClO4, weak acids typically have carbon or phosphorus. Some of the strong bases are NaOH, Ba(OH)2, CsOH, and KOH, while weak bases typically have ammines. Nitrogen makes it a weak base because its lone pair can sometimes break the O-H bond in H2O.

Brynne Burrows 3K

I just memorized which elements are amphoteric because the diagonal line is a bit skewed on the periodic table. However elements to the left of that general area are metals and form bases, while elements to the right are nonmetals and form acids.

Brynne Burrows 3K

You would turn in week 9 and 10 at the same time during your next discussion.

Brynne Burrows 3K

Cis means same side and trans means opposite side, which also means that cis are typically polar charged because there is no cancellation of charges as opposed to trans.

Brynne Burrows 3K

What is the correct way to draw the Lewis structure for N2O? There can either be a triple bond between the Nitrogen molecules and a single bond between Nitrogen and Oxygen, or a double bond between both N-N and N-O. Should the -1 formal charge be assigned to the Nitrogen atom or Oxygen?

Brynne Burrows 3K

The lone pair electrons spread out equidistant around the equatorial plane and the atoms, as a result, go to either end of the axial plane, as far away from each other as possible. The electron arrangement would appear trigonal bipyramidal while the molecular shape is linear. This is only possible w...

Brynne Burrows 3K

I think Lavelle's curve will depend on the overall grades of the students in this quarter's 14A class the percent ranges for letter grades will be determined by his curve for this quarter.

Brynne Burrows 3K

Since CO2 is a nonpolar molecule, only London dispersion forces are present and therefore would not have dipole-dipole forces. The behavior of the bonds within the molecule, also known as intramolecular forces, does not determine the type of intermolecular forces.

Brynne Burrows 3K

Just to be safe, I would suggest using bent as he taught us.

Brynne Burrows 3K

I know that grades aren't assigned after everything is in the grade book, meaning that he can curve the grades if the average is low.

Brynne Burrows 3K

Polarizability is the tendency of an anion to be polarized, while polarizing power refers to how much cations can distort the electrons of the anion.

Brynne Burrows 3K

005162520 wrote:How would you draw the resonance structure for SOCl2?

S is the central atom, double bonded to the Oxygen atom, single bonded to both Chlorine's, with a lone pair attached to the sulfur.

Brynne Burrows 3K

Most molecules have London forces, which occur between two dipoles, and are the weakest intermolecular forces relative to the others.

Brynne Burrows 3K

The lone pair counts as an area of electron density which moves the atoms also bonded to the central atom as far away from each other as possible, which changes the molecule's shape.

Brynne Burrows 3K

First make sure the number of lone pairs + bonds on the atom matches the number of valence electrons or is very close so that it results in a low formal charge. Then check if you are maintaining the octet rule on the atoms to know which lone pairs must be taken away.

Brynne Burrows 3K

If the problem doesn't give you the n final if the electron is losing energy, or they don't give you n initial when an electron is going up levels, then you have to know that Balmer signifies n=2 and Lyman signifies n=1. These will then be plugged into the Rydberg formula to calculate the energy of ...

Brynne Burrows 3K

After drawing the Lewis structure of a molecule you can usually identify a radical because one of the atoms has a single electron due to the odd number of valence electrons that must be accounted for.

Brynne Burrows 3K

When writing electron configuration, 3d always preceeds 4s because it is a lower energy level!

Brynne Burrows 3K

Leila_4E wrote:This is really helpful, thank you. I'm also having trouble remembering if the ionic radius trend is different than atomic radius trend?

The ionic radius trend is the same as the atomic radius trend. Decreasing down and to the left.

Brynne Burrows 3K

I don't think the fact that it is a Lithium atom is as significant in this problem as the fact that it is going from the 1s-orbital to the 2p-orbital. This is what tells you that energy will increase, the value of l and n will increase, and the radius will increase because electrons are being added.

Brynne Burrows 3K

I think this partly has to do with an electron being removed from 4s before it would be removed from 3d. The energy level is lower in the 3d shell, so it would come before 4s when 4s has both electrons.

Brynne Burrows 3K

I believe the entire test will be free response questions like the first one, but I am not 100% sure.

Brynne Burrows 3K

aphung1G wrote:Can someone explain how to find the lone pair electrons when trying to find the formal charge?

Whichever pairs of electrons that cannot be replaced by a bond when the Lewis structure is drawn out can be counted as a lone pair. It helps to see the picture in order to determine lone pair electrons.

Brynne Burrows 3K

Atomic radius is half the diameter measured across one ground state atom, while ionic radius is half the distance between the nuclei of two ionically bonded atoms.

Brynne Burrows 3K

De Broglie's Equation proves wavelike properties of electrons by finding wavelength, and the equation is Planck's constant/(mass x velocity) is used for this.

Brynne Burrows 3K

n correlates to the shell; l correlates to the subshell; ml correlates to the orbital.

Brynne Burrows 3K

I love your perspective on being able to take these classes at UCLA and how big of an opportunity this is for us and maybe our last opportunity to learn about this subject material! Thank you so much for sharing and good luck with the rest of your journey!!

Brynne Burrows 3K

The elements in the top right of the periodic table have shells that are nearly full, meaning they need few electrons to complete an octet, whereas elements in the bottom left corner of the periodic table need to gain far more electrons in order to have an octet.

Brynne Burrows 3K

What are the exceptions to the trends in the periodic table when talking about ionization energy?

Brynne Burrows 3K

His equation supports the fact that all matter -- if it is small enough -- has wavelike properties. Using Planck's constant and the momentum (mass*velocity) of the object, the wavelength of that object can be found because it has wavelike properties.

Brynne Burrows 3K

Atomic radii are only measured in the ground state, not in the excited state.

Brynne Burrows 3K

In terms of frequency, a negative value cannot be obtained because it is the number of waves over a given unit of time. Negative values represent the loss or gain of energy in terms of a change in energy under the Bohr frequency condition.

Brynne Burrows 3K

The mass of one electron is 9.109*10^-28 grams

Brynne Burrows 3K

Here is the conversion from keV to J:
E = (140.11*10^3 eV)*(1.6022*10^-19 J/eV) = 2.2513*10^-14 J

Brynne Burrows 3K

I think it is more conceptual, but also has to do with calculating the distances between spectral lines as was explained through the sketch during the last lecture. Visible light has smaller gaps between lines whereas ultraviolet has ones farther apart so the value of change in E is greater.

Brynne Burrows 3K

Both of those equations are referring to v as frequency instead of velocity, but you can use velocity in the equation E=1/2Me*Ve.

Brynne Burrows 3K

E in this equation represents the energy of the photon. In some cases, it could also be equal to the energy required to remove an electron if the kinetic energy is 0. This is shown in the formula E(photon) - work function = Kinetic energy. If the Kinetic energy is 0, then the energy of the photon is...

Brynne Burrows 3K

Formula units are the amount of said material object, such as molecule, atom, compound, etc. The formula units are a quantitative measurement of the amount of any given thing.

Brynne Burrows 3K

The intensity of the photons hitting the metal surface is not as important as the frequency of the photons hitting the metal. Higher energy light results from the increased frequency, in other words a shorter wavelength, because all of these variables have a proportional relationship to one another.

Brynne Burrows 3K

On my paper is name, section and lecture #, date, and UID.

Brynne Burrows 3K

The number of units (atoms, molecules, compounds, etc.) in a mole.

Brynne Burrows 3K

You should use however many sig figs are given in the original problem, even when considering periodic table molar masses.

Brynne Burrows 3K

We will be given the necessary compound names on tests, so no we do not have to memorize them.

Brynne Burrows 3K

There can only be one limiting reactant in a chemical reaction. Sometimes the reactants are present in equal amounts so there would be none in this case.

Search found 52 matches