CHEMISTRY COMMUNITY

Erin Nash - 4G

A ligand has to be able to form coordinate covalent bonds, so often the molecules will have a lone pair of electrons.

Erin Nash - 4G

Ka is the concentrations of the products over the concentration of the reactants, but I'm not sure if we will need to know how to calculate it.

Erin Nash - 4G

A Bronsted acid is one that donates protons and a Bronsted base is one that accepts protons.

Erin Nash - 4G

Since lone pair - lone pair electron repulsion is stronger than electrons in a bond, the angles are slightly smaller than what is experimentally observed such as for tetrahedral, the bond angles are 109.5, but if there is a lone pair, the bond angle is slightly less than 109.5.

Erin Nash - 4G

When deciding whether a molecule is polar or nonpolar you must look at the shape to see the dipoles. If there are no dipoles, then it is nonpolar or if the dipoles cancel out then it is nonpolar. If the dipoles are uneven (large difference in electronegativity) then the molecule is polar.

Erin Nash - 4G

To build off of what other students have answered, sigma bonds are only for single bonds while pi bonds are double bonds and triple bonds. Pi bonds cannot rotate around the bond axis or else the bond will break. A double bonds consists of a sigma bond and a pi bond.

Erin Nash - 4G

Van der Waals is the force that occurs because as we know, electrons are constantly moving and sometimes their movement can create an slightly more negative charge on one side of the molecule.

Erin Nash - 4G

Before, we have just been placing the atoms equally distant from the central atom, but that is not always correct. The VESPR model emphasizes electron repulsion and thus helps us determine what the experimentally observed structure of a molecule is.

Erin Nash - 4G

You should always draw the resonance structures because the true structure of the molecule is a mixture of all of the resonance structures.

Erin Nash - 4G

The VSPER model helps explain the shape of molecules that have been determined by experiments. Previously, we have just been drawing the structures without paying much attention to the distance between the atoms, but using the VSPER model we can find the exact angular distance between each atom.

Erin Nash - 4G

Atoms that are in the 4th period and below are the ones that are able to exceed the octet rule because they have access to their 3d orbitals. The energy difference between the 3d and 4s orbital is much smaller in comparison to other orbitals.

Erin Nash - 4G

Yes! This is because longer bond lengths (single bonds) are only sharing one pair of electrons and therefore the bond is weaker. Double bonds are sharing two pairs of electrons so they are stronger and the distance between them is shorter.

Erin Nash - 4G

I believe that is all we need to know.

Erin Nash - 4G

We will be expected to know how to draw this for the midterm?

Erin Nash - 4G

How can you tell if it is a coordinate covalent bond?

Erin Nash - 4G

For salts, you draw both of the elements separately. An example we did in a review session was (NH4)2CO3 so we drew NH4 and then next to it CO3 with no bonds connecting them.

Erin Nash - 4G

Writing using the inert gases is a short cut to make it easier to write out the electron configuration, since he taught it to us I'm assuming he would accept it as an answer.

Erin Nash - 4G

3d always comes before 4s because it is at a lower energy level than 4s.

Erin Nash - 4G

He emphasized once more during lecture today that only material we covered up until Friday will be on the test.

Erin Nash - 4G

The reason that the configuration is 3d5 4s1 and not the expected 3d4 4s2, if because in the d shell, there are 5 possible pairs of electrons. According to Hund's principle, an electron must spin parallel, until there are no free orbitals left. Thus, an atom would prefer to have all 5 orbitals fille...

Erin Nash - 4G

The Uncertainty Principle states the momentum (delta p) and exact location (delta x) for an electron cannot be known at the same time. Hence the delta symbols indicating a range.

Erin Nash - 4G

The photon energies are always positive, but the negative signs accounts for the bound electron having a lower energy than a free electron.

Erin Nash - 4G

An object that has rest mass is an object that's mass can be calculated when it is in rest. He used this in the context of light, since it is never at rest and therefore does not have rest mass.

Erin Nash - 4G

A black body is a theoretical material that can absorb all wavelengths of light; however, Dr. Lavelle said we didn't need to worry about it.

Erin Nash - 4G

We used the Heisenberg Indeterminacy Equation (delta p)(delta x) > or equal to h/4Pi to find our final answer of 3.4 x 10^10 m/s. Our delta x was 1.7 x 10^-15 m and instead of solving for the momentum right away, we had to find the velocity, since the only other information that we know is the mass ...

Erin Nash - 4G

I would also recommend completing the Audio-Visual Focus Topics on his website to study if you haven't done them already.

Erin Nash - 4G

From my understanding all that he meant by one discrete H2O was a singular molecule of H2O. However, I was confused on whether or not the flow would be continuous if a single molecule was poured out of and why.

Erin Nash - 4G

You would like to get within .1 (or closer) to a whole number before you round so that the empirical formula is all integers. Many times we get answers such as 1.33 so it's easier for us to find the empirical formula (multiplying by 3).

Erin Nash - 4G

So I understand how to use the M1V1 = M2V2 equation but for this specific problem I wasn't sure how to tell that we needed to use it. Could someone explain?

CHEMISTRY COMMUNITY

Search found 29 matches

Re: Ligands

Re: Ka Constant

Re: Distinguishing bronsted acids vs bases

Re: Angle Distorted

Re: Polar vs. Non-polar

Re: Sigma and Pi bonds

Re: London Van Der Waals Force?

Re: VSEPR Model

Re: Drawing resonance

Re: VSPER

Re: Atoms with 8+ valence e-

Re: Bond Length and Bond Strength

Re: Midterm

Re: What each bond refers to

Re: Coordinate Covalent Bond Definition

Re: Lewis Structure for Ionic Bonds

Re: Electron Configuration

Re: s, p, d, f subshells in multi-electron atoms

Re: Test On Tuesday

Re: Confused about Copper and Chromium [ENDORSED]

Re: Uncertainty Principle

Re: Negative sign in front of Bohr Frequency Condition

Re: Rest Mass?

Re: What is a black body? [ENDORSED]

Re: Incorrect Atomic Model

Re: Test 2

Re: Behavior of small objects - clarification

Re: When to double moles

Re: Problem G5