Search found 57 matches

by zoedfinch1K
Sat Dec 07, 2019 9:46 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelates
Replies: 5
Views: 176

Re: Chelates

Naren_Ramesh_4D wrote:I think the best way to approach this if you are having difficulty is to memorize the common polydentates like oxalate and ethylenediamine.


What are the common polydentates that we need to know?
by zoedfinch1K
Sat Dec 07, 2019 9:38 pm
Forum: Biological Examples
Topic: chemotherapy drugs
Replies: 4
Views: 43

Re: chemotherapy drugs

Because the Cl is on the same side, it can bind at two adjacent Guanine bases on the DNA. This makes it an effective blocker of DNA polymerase so that DNA replication cannot occur. Compared to trans-platin, one binding site to the guanine base isn't an effective blocker of DNA polymerase.
by zoedfinch1K
Sat Dec 07, 2019 9:29 pm
Forum: Lewis Structures
Topic: ClF4+ Lewis Structure
Replies: 2
Views: 586

Re: ClF4+ Lewis Structure

Callum Guo 1A wrote:I think F only forms only single bonds because of its electronegativity


Additionally, emember that F isn't one of the atoms that can have an expanded octet so moving a lone pair from Cl to form a double bond with F wouldn't work.
by zoedfinch1K
Sat Dec 07, 2019 9:24 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone pairs location
Replies: 3
Views: 135

Re: Lone pairs location

Trigonal pyramidal is derived from the tetrahedral shape. Remember that in a tetrahedron, the bond angles are all set at an equal distance apart: 109.5 degrees. Thus, no matter where you place the lone pairs, the shape will always look the same. The see-saw shape is derived from a trigonal bipyramid...
by zoedfinch1K
Sat Dec 07, 2019 9:12 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: QUESTION 4 ON MIDTERM
Replies: 1
Views: 126

QUESTION 4 ON MIDTERM

Does anyone have the solutions to question 4 on the midterm? I am re-doing the problems and want to check my answers. Thanks!
by zoedfinch1K
Sun Dec 01, 2019 11:23 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pka v. ka
Replies: 4
Views: 73

Re: pka v. ka

KA is the equilibrium constant with the formula:
KA= [products]/[reactants]

pKA is just the -log of the KA:
pKA= -log[KA]
by zoedfinch1K
Sun Dec 01, 2019 11:18 pm
Forum: Lewis Acids & Bases
Topic: Difference between Lewis and Bronsted
Replies: 4
Views: 35

Re: Difference between Lewis and Bronsted

viewtopic.php?f=56&t=53694

Here's a link to a similar question that answers yours that you might not have seen from earlier. Hope this helps!
by zoedfinch1K
Sun Dec 01, 2019 11:15 pm
Forum: Amphoteric Compounds
Topic: Amphoteric Examples
Replies: 3
Views: 48

Re: Amphoteric Examples

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=imgres&cd=&ved=2ahUKEwiUscKRxpDmAhUmIDQIHbCoACcQjRx6BAgBEAQ&url=https%3A%2F%2Fchem.libretexts.org%2FBookshelves%2FGeneral_Chemistry%2FMap%253A_General_Chemistry_(Petrucci_et_al.)%2F18%253A_Solubility_and_Complex-Ion_...
by zoedfinch1K
Sun Dec 01, 2019 11:12 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Relative Acidity
Replies: 4
Views: 68

Re: Relative Acidity

He said that any mechanism that delocalizes charge makes it more stable. This is due to the electron pulling ability of the delocalization mechanism, giving it a higher electronegativity. The higher electronegativity makes it a more stable anion.
by zoedfinch1K
Sun Dec 01, 2019 11:09 pm
Forum: Biological Examples
Topic: Vitamin B12
Replies: 3
Views: 61

Re: Vitamin B12

I remember Dr. Lavelle mentioning that we should be familiar with any of the biological examples he mentions during lecture.
by zoedfinch1K
Sun Dec 01, 2019 11:05 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: "electron-withdrawing atoms" - stability & acidity
Replies: 2
Views: 49

Re: "electron-withdrawing atoms" - stability & acidity

I think its because when the anion is stable by the process you mentioned below, oxoacids readily lose H+. If you remember, stronger acids dissociate completly in water so the more H+ given off would correlate to a stronger acid.
by zoedfinch1K
Sun Dec 01, 2019 10:56 pm
Forum: Lewis Acids & Bases
Topic: Conjugates
Replies: 3
Views: 29

Re: Conjugates

The conjugate base is the species formed after the Bronsted acid has donated a proton. The conjugate acid is the species formed after the Bronsted base accepts a proton. Here is a picture if it helps you to visualize. https://qph.fs.quoracdn.net/main-qimg-95dd29dc9674e0c9c148b1a4fb325682.webp
by zoedfinch1K
Sun Nov 24, 2019 4:16 pm
Forum: Naming
Topic: Prefixes
Replies: 5
Views: 77

Prefixes

When do we use the bis-, tris-, tetrakis-, pentakis-, etc. prefixes?
by zoedfinch1K
Sun Nov 24, 2019 3:59 pm
Forum: Biological Examples
Topic: Porphyrin ligand
Replies: 1
Views: 34

Re: Porphyrin ligand

This "cage" is the heme complex. The heme complex and protein make up myoglobin where the central Fe atom can bind to O2. This is biologically significant because it facilitates O2 transport in muscle cells.
by zoedfinch1K
Sun Nov 24, 2019 3:54 pm
Forum: Biological Examples
Topic: Transition metals and their biological importance
Replies: 2
Views: 32

Transition metals and their biological importance

Dr. Lavelle listed a few transition metals in the first d-block that we had to know the importance of but I didn't get them all down in my notes. Does anyone have the rest of the transition metals he mentioned in lecture and their biological function?
by zoedfinch1K
Sun Nov 24, 2019 3:47 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelating ligands and cations
Replies: 1
Views: 30

Chelating ligands and cations

I know Dr. Lavelle mentioned that chelating ligands can bind cations tightly, but how do they do this? Is it due to the properties of the ring structure?
by zoedfinch1K
Sun Nov 24, 2019 3:32 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: How to draw dipoles
Replies: 7
Views: 92

Re: How to draw dipoles

The head of the arrow points towards the more electronegative atom. I like to remember is at the "plus sign" looking part of the arrow is near the more electropositive atom.
by zoedfinch1K
Sun Nov 17, 2019 7:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Repulsion strength and Bond Angles
Replies: 12
Views: 117

Re: Repulsion strength and Bond Angles

If one of the molecules has a lone pair, there would be an electron repulsion between the lone pair and the other atoms in the molecule. This would make the resulting bond angle become smaller than the bond angle in the molecule with no lone pairs. This would also change the molecular structure from...
by zoedfinch1K
Sun Nov 17, 2019 7:08 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Electronic arrangement vs molecular shape
Replies: 4
Views: 33

Re: Electronic arrangement vs molecular shape

It's hard to put into words but I hope these pictures help clarify my answer.
by zoedfinch1K
Sun Nov 17, 2019 7:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Electronic arrangement vs molecular shape
Replies: 4
Views: 33

Re: Electronic arrangement vs molecular shape

The electronic shape would be the VSEPR shape you would get if you included the lone pair electrons. The molecular structure is the "actual" structure of the molecule. The actual structure is ONLY dependent on bonds in the molecule, not lone pairs.
by zoedfinch1K
Sun Nov 17, 2019 6:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Angles
Replies: 4
Views: 47

Re: VSEPR Angles

I think for the general shapes we are expected to know the bond angles but for cases where there are lone pairs on the central atom, we just need to know what the impact on the original bond angle would be.
by zoedfinch1K
Sun Nov 17, 2019 6:41 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Angles
Replies: 4
Views: 70

VSEPR Angles

How do factors like atomic radii determine the bond angles in the VSEPR model?
by zoedfinch1K
Mon Nov 11, 2019 3:52 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Equation
Replies: 3
Views: 54

Re: Formal Charge Equation

One way that I like to think about it is subtracting the valence electrons of the atom in the ground state from the number of electrons it has around it. For bonds, this would mean only one electron in that bond is coming from the atom you're calculating the formal charge for.
by zoedfinch1K
Mon Nov 11, 2019 3:48 pm
Forum: Resonance Structures
Topic: What is a Resonance "Structure"
Replies: 12
Views: 336

Re: What is a Resonance "Structure"

The "structure" that we are talking about refers to all the possible Lewis structures that could be correct for and atom (the ones with low formal charge).
by zoedfinch1K
Mon Nov 11, 2019 3:46 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: types of intermolecular forces
Replies: 5
Views: 41

Re: types of intermolecular forces

In addition, when checking with the molecular shape, an overall rule that can help you is checking whether or not the shape is symmetric and the charges on the atoms.
by zoedfinch1K
Mon Nov 11, 2019 3:42 pm
Forum: Bond Lengths & Energies
Topic: Shorter bond lengths
Replies: 12
Views: 118

Re: Shorter bond lengths

The bonds become shorter because there are more chared electrons in a double bond versus a single bond and the two atoms are closer togther.
by zoedfinch1K
Mon Nov 11, 2019 3:40 pm
Forum: Dipole Moments
Topic: Dipoles
Replies: 3
Views: 40

Dipoles

Do all molecules have dipole moments? If not, when do dipole moments occur?
by zoedfinch1K
Mon Nov 11, 2019 3:37 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: london forces
Replies: 6
Views: 54

Re: london forces

All molecules have London forces due to the constant movement of electrons, leaving one part of the molecule slightly more negatively charged and another part of the molecules slightly more positively charged.
by zoedfinch1K
Sun Nov 03, 2019 11:42 pm
Forum: *Shrodinger Equation
Topic: Schrodinger relationships
Replies: 4
Views: 197

Re: Schrodinger relationships

Schrodinger’s equation uses a wave function to describe an electron because of its wavelike properties and indeterminacy in momentum and position. The wave function represents the orbital (position) that and electron can be found.
by zoedfinch1K
Sun Nov 03, 2019 11:34 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 18
Views: 394

Re: Resonance Structures

Basically, they’re Lewis structures that can be written in different ways and still he correct. It’s important to note that the actual structure is actually a hybrid between these bonds.
by zoedfinch1K
Sun Nov 03, 2019 11:16 pm
Forum: *Shrodinger Equation
Topic: effective nuclear charge
Replies: 6
Views: 318

Re: effective nuclear charge

Think of effective nuclear charge as a ‘net charge’ of the valence electrons. It is the charge of the valence electrons after the shielding electrons are accounted for.
by zoedfinch1K
Sun Nov 03, 2019 4:43 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect Equation
Replies: 3
Views: 61

Re: Photoelectric Effect Equation

For analyzing the photoelectric effect, questions can ask you about the kinetic energy of an emitted electron or the wavelength needed to eject the electron. For these problems, you would use the equation for the kinetic energy of the electron E k = 1/2*m e *v 2 = h\nu -\Phi and \lambda = c/\nu .
by zoedfinch1K
Sun Nov 03, 2019 2:48 pm
Forum: Lewis Structures
Topic: Resonance Hybrid
Replies: 2
Views: 28

Re: Resonance Hybrid

I think we just have to know the overall concept of a resonance structure and how they are a hybrid of single and double bonds. As long as we draw one of the resonance structures, we should be fine because there's really no way to accurately draw the Lewis structure of the "real structure"...
by zoedfinch1K
Sun Nov 03, 2019 2:43 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Purpose of Formal Charge
Replies: 6
Views: 69

Re: Purpose of Formal Charge

The purpose is to get the formal charge as closest to 0 as possible in order to find the most "correct" Lewis structure.
by zoedfinch1K
Sun Oct 27, 2019 9:19 pm
Forum: Ionic & Covalent Bonds
Topic: What is the difference between an anion and cation?
Replies: 7
Views: 114

Re: What is the difference between an anion and cation?

Remember an ion is a charged particle. An anion is a negatively charged particle such as Cl-. A cation is a positively charged particle such as Na+.
by zoedfinch1K
Sun Oct 27, 2019 8:37 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 3
Views: 59

Re: Resonance Structures

You don't necessarily "need" to move the location of the bond in the Lewis structure when it comes to resonance structures but its good to know that in resonance structures are hybrids of their single and double bonds.
by zoedfinch1K
Sun Oct 27, 2019 8:13 pm
Forum: Octet Exceptions
Topic: Expanded octet
Replies: 3
Views: 38

Re: Expanded octet

Expanded octets are when an atom can accommodate more than 8 valence electrons. This only happens for P, S, Cl.
by zoedfinch1K
Thu Oct 24, 2019 10:56 pm
Forum: Octet Exceptions
Topic: 2A.21 Ground-state Electron Configuration
Replies: 2
Views: 34

2A.21 Ground-state Electron Configuration

Why is it that the ground-state electron confriguration for Ag+ is [Kr]4d^10 instead of [Kr]5s^2 4d^8?
by zoedfinch1K
Wed Oct 23, 2019 11:40 am
Forum: Trends in The Periodic Table
Topic: Shielding
Replies: 8
Views: 221

Shielding

Can someone explain what shielding is and how it affects ionization energy? When would we see this happen?
by zoedfinch1K
Sun Oct 20, 2019 10:57 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: How to use it
Replies: 5
Views: 87

Re: How to use it

In addition to Brianna Becerra 1F, you would typically use this equation when being asked for the minimum uncertainty in speed/velocity when given the physical constraints or vice versa.
by zoedfinch1K
Sun Oct 20, 2019 10:48 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Hund's Rule
Replies: 5
Views: 75

Re: Hund's Rule

Paired electrons would have a electron-electron repulsion, so electron would naturally want to fill up space where there are fewer repulsions first, before having to be paired.
by zoedfinch1K
Sun Oct 20, 2019 10:43 pm
Forum: Properties of Electrons
Topic: What's the difference between a shell, a subshell, an energy level, and an orbital?
Replies: 8
Views: 141

Re: What's the difference between a shell, a subshell, an energy level, and an orbital?

Shell: the area that an electron can be found; think of it as the electron "cloud". This would be the quantum number n. Subshell: this is the shape of a specific shell (s, p, d, f) and is the quantum number l. Orbital: the specific orientation of the different subshells. Here's a graphic t...
by zoedfinch1K
Sun Oct 20, 2019 10:32 pm
Forum: *Black Body Radiation
Topic: What is it?
Replies: 6
Views: 227

Re: What is it?

I believe he just used black bodies as an example, and we do not need to know about it in detail.
by zoedfinch1K
Sun Oct 20, 2019 10:27 pm
Forum: Quantum Numbers and The H-Atom
Topic: Quantum Numbers: Size of An Atom
Replies: 4
Views: 49

Re: Quantum Numbers: Size of An Atom

If you think about what n, represents, it is the shell of an atom. When the shell is increasing, there are now a great number of electrons (or places where electrons could be). In a neutral atom, the number of protons and electrons are the same so this increase in electrons correlates to an increase...
by zoedfinch1K
Sun Oct 20, 2019 10:21 pm
Forum: Photoelectric Effect
Topic: Chemistry Equations
Replies: 2
Views: 45

Re: Chemistry Equations

As far as figuring out which time to use each equation, a method that helps me is deciding which variables I am given and the variable I am solving for in each problem. Then, I would use the equation that contains those variables. Also, it would help if you studied which equations can be used in spe...
by zoedfinch1K
Sun Oct 20, 2019 10:14 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Writing Electron configurations
Replies: 2
Views: 28

Re: Writing Electron configurations

You would use the noble gas before that element in the brackets.

For example, if the element you are writing an electron configuration for Mg is [Ne] 3s^2 because the noble gas before Mg on the periodic table is Ne.
by zoedfinch1K
Mon Oct 14, 2019 7:25 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbital equation
Replies: 3
Views: 45

Re: Orbital equation

I don't believe rho has a numerical value here but instead refers to the space that an electron can be found. In the entire slide, Dr Lavelle stated \Psi ^{2} related to the electron- \rho distribution. Remember that \Psi ^{2} represents the probability of finding an electron in a given space. In ot...
by zoedfinch1K
Mon Oct 14, 2019 7:03 pm
Forum: *Shrodinger Equation
Topic: Hamiltonian
Replies: 5
Views: 81

Re: Hamiltonian

Additionally, a Hamiltonian represents a change on (x, y, z) but I believe we won't be expected to explain in depth what the Hamiltonian is, just in the context of Schrodinger's wave function equation.
by zoedfinch1K
Mon Oct 14, 2019 6:54 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Shells, Subshells, Orbitals
Replies: 4
Views: 1322

Re: Shells, Subshells, Orbitals

So is the 1s orbital completely separate from the 2s orbital then? Yes. When n=1 (the first shell), the only possible subshell is the 1s subshell. In the second shell, or when n=2, there are now two possible subshells: 2s and 2p. Another thing to note is the orbital refers to the shape of the area ...
by zoedfinch1K
Mon Oct 14, 2019 6:35 pm
Forum: Properties of Light
Topic: Variables and Constants for this Unit
Replies: 2
Views: 33

Re: Variables and Constants for this Unit

= wave function where:
represents the height of a wave at position (x, y, z) and
represents the probablity of finding an electron
by zoedfinch1K
Fri Oct 04, 2019 9:05 am
Forum: SI Units, Unit Conversions
Topic: Why do we always need grams when solving a problem?
Replies: 6
Views: 103

Re: Why do we always need grams when solving a problem?

eduardomorales5 wrote:It is the accepted base SI unit that helps to standardize measurements so that scientists can more easily compare their findings using the same unit measurement.

Even more, think about the lab setting. Chemists will typically measure the amount of substance needed in grams.
by zoedfinch1K
Wed Oct 02, 2019 6:14 pm
Forum: Balancing Chemical Reactions
Topic: H13 Is there a good step by step way to balance this?
Replies: 4
Views: 61

Re: H13 Is there a good step by step way to balance this?

For this problem, it asks for first the reaction between nitrogen and oxygen gases to form nitric oxide gases. SO you know that nitrogen and oxygen gases are diatomic so you would get 2 NO as your product. Then you would use 2NO and O2 as your reactants in your second equation, which makes it easier...
by zoedfinch1K
Wed Oct 02, 2019 6:01 pm
Forum: Properties of Light
Topic: Electromagnetic Radiation and Light
Replies: 2
Views: 65

Re: Electromagnetic Radiation and Light

Electromagnetic radiation includes light. The EM spectrum includes visible light as well as other waves like radio waves or gamma rays. It is a form of energy produced by oscillating electric and magnetic fields. For our purposes, we pay attention to the oscillating electric fields, which are caused...
by zoedfinch1K
Wed Oct 02, 2019 5:52 pm
Forum: SI Units, Unit Conversions
Topic: rounding of the elements. [ENDORSED]
Replies: 6
Views: 97

Re: rounding of the elements. [ENDORSED]

Personally, I save rounding as the very last step and make sure to use the appropriate amount of sig figs according to the question. As Claire said, make sure you are using 4-5 decimal points when doing your calculations to be as precise as possible. I'm sure that as long as the steps to get to your...
by zoedfinch1K
Wed Oct 02, 2019 5:45 pm
Forum: Balancing Chemical Reactions
Topic: Combustion [ENDORSED]
Replies: 3
Views: 125

Re: Combustion [ENDORSED]

TarynD_1M wrote:Just making sure: when writing out combustion reactions, it's implied that we add oxygen as a reagent and CO2 and H20 as products, right?


Yes! This is for all combustion reactions. Additionally, this can sometimes be referred to as burning or oxidative metabolism in some word problems.

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