Search found 56 matches

by Sara Richmond 1D
Tue Dec 03, 2019 5:02 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Resonance and Formal Charge
Replies: 4
Views: 20

Re: Resonance and Formal Charge

The major contributor is the most stable resonance structure, where the central atom's charge is closest to 0. To determine charge of a molecule add all of the formal charges together.
by Sara Richmond 1D
Tue Dec 03, 2019 5:01 pm
Forum: Biological Examples
Topic: cisplatin
Replies: 5
Views: 78

Re: cisplatin

I have heard on past chem finals, students have had to draw cisplatin. So maybe be familiar with the chemical formula and shape.
by Sara Richmond 1D
Tue Dec 03, 2019 4:58 pm
Forum: Amphoteric Compounds
Topic: Amphoteric, Amphiprotic, Polyprotic
Replies: 2
Views: 42

Re: Amphoteric, Amphiprotic, Polyprotic

amphoteric: Can act as both an acid and a base
amphiprotic: Can donate or accept protons
ionic: has ionic character. Has to do with bonding.
polyprotic: can donate or accept multiple protons
by Sara Richmond 1D
Tue Dec 03, 2019 4:55 pm
Forum: Biological Examples
Topic: Biological Examples
Replies: 4
Views: 35

Re: Biological Examples

What specific biological examples would we know for the final? And what should we know about them?
by Sara Richmond 1D
Tue Dec 03, 2019 4:54 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: 1 B27
Replies: 5
Views: 79

Re: 1 B27

I am so confused by this problem. I have included two photos. One of my work and one of the solution guide's work. Where did the solution guide get the equation they used? What is wrong with the equations I used?
by Sara Richmond 1D
Sun Dec 01, 2019 11:37 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Midterm Problem
Replies: 4
Views: 23

Re: Midterm Problem

Q6.A. Magnesium ions are a known cofactor in over 300 enzymatic reactions. What are the possible angular momentum quantum numbers of the highest energy electrons in these magnesium ions? Indicate the corresponding subshell of each angular momentum quantum number. The electron configuration of Mg is ...
by Sara Richmond 1D
Sun Dec 01, 2019 11:31 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Midterm Problem
Replies: 4
Views: 23

Midterm Problem

Q5C. Calcium ions are important in the process of neurotransmitter release at the neuromuscular junction. Write the full electron-configuration for the ground-state of a calcium ion. Answer: Ca2+ 2pt 1s2 2s2 2p6 3s2 3p6 2pt How would we have know to write the electron configuration of calcium 2+? Wh...
by Sara Richmond 1D
Thu Nov 28, 2019 11:58 am
Forum: Hybridization
Topic: double bonds
Replies: 7
Views: 29

Re: double bonds

Double bonds do not affect hybridization because a double bond still represents a single location of electron density. An easy way to determine what type of hybridization is to use steric numbers. Steric Number= number of bonded atoms + number of lone pairs. Notice that the number of bonds is not in...
by Sara Richmond 1D
Thu Nov 28, 2019 11:52 am
Forum: Lewis Acids & Bases
Topic: Identifying Acids and Bases
Replies: 8
Views: 25

Re: Identifying Acids and Bases

Typically strong acids have a greater difference in electronegativity than weak acids. While weak bases have a smaller difference in electronegativity than strong bases.
by Sara Richmond 1D
Thu Nov 28, 2019 11:48 am
Forum: Amphoteric Compounds
Topic: Amphoteric
Replies: 8
Views: 43

Re: Amphoteric

Yes, by referencing the periodic table you can tell which compounds are amphoteric. Semi metals are typically amphoteric. Meaning that if they lay on the jagged diagonal line they are amphoteric. In addition to this information. We can use the periodic table to determine which elements are solely a...
by Sara Richmond 1D
Thu Nov 28, 2019 11:47 am
Forum: Amphoteric Compounds
Topic: Amphoteric
Replies: 8
Views: 43

Re: Amphoteric

Yes, by referencing the periodic table you can tell which compounds are amphoteric. Semi metals are typically amphoteric. Meaning that if they lay on the jagged diagonal line they are amphoteric.
by Sara Richmond 1D
Sat Nov 23, 2019 4:09 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: AXE formula
Replies: 32
Views: 1442

Re: AXE formula

danielruiz1G wrote:is it possible to determine the shape of a molecule if you're only given the AXE formula, if so how do you do it?


The only real way to do it, is to memorize the chart. This chart is especially helpful because it includes hybridization and shape and polarity.
by Sara Richmond 1D
Sat Nov 23, 2019 4:06 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Denticity
Replies: 2
Views: 23

Denticity

Can someone please explain Denticity to me? I do not understand how we are supposed to be able to determine if a molecule is polydentate, mono dentate, or didentate.
by Sara Richmond 1D
Mon Nov 18, 2019 3:24 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AXE notation
Replies: 10
Views: 39

Re: AXE notation

AXE notation is the same as saying "What is the Vsepr formula?" Each of the letter stand for something: A= the central atom. Some chemistry courses will require you to write the central atom in the formula, but Dr Lavelle does not require this nor does he prefer that you do. On exams just ...
by Sara Richmond 1D
Mon Nov 18, 2019 3:20 pm
Forum: Hybridization
Topic: Hybridization and VSEPR
Replies: 1
Views: 13

Re: Hybridization and VSEPR

I believe hybridization is based on molecular geometry. This chart can help you understand the relationship of hybridization and molecular geometry.
by Sara Richmond 1D
Mon Nov 18, 2019 3:18 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Pi Bond vs Sigma
Replies: 6
Views: 26

Re: Pi Bond vs Sigma

Are one of these bonds stronger than the other? Pi bond vs Sigma? If so, why? Sigma bonds are stronger than pie bonds because the orbitals of a sigma bond overlap more during hybridization than the orbitals of a pie bond. It can be difficult to understand sigma and pie bonds without reading through...
by Sara Richmond 1D
Mon Nov 18, 2019 3:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Pi Bond vs Sigma
Replies: 6
Views: 26

Re: Pi Bond vs Sigma

Sigma bonds are single bonds. Pie bonds are in double and triple bonded atoms. In a double/ triple bonded atom, one bond is always a sigma bond and the others are pie bonds.
by Sara Richmond 1D
Mon Nov 18, 2019 3:14 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSPER
Replies: 7
Views: 42

Re: VSPER

This chart is extremely useful. I would recommend memorizing the sheet for your test 2.
by Sara Richmond 1D
Tue Nov 12, 2019 5:47 pm
Forum: Administrative Questions and Class Announcements
Topic: KAREN SUN 5-7PM WORKSHOP - DOWNLAOD WORKSHEETS HERE
Replies: 53
Views: 2155

Re: KAREN SUN 5-7PM WORKSHOP - DOWNLAOD WORKSHEETS HERE

Will you have a review session this weekend to prepare for Test 2?
by Sara Richmond 1D
Tue Nov 12, 2019 5:46 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR formula for molecules of the same atom
Replies: 3
Views: 19

Re: VSEPR formula for molecules of the same atom

I believe that I read in the textbook that the VSEPR formula for molecules of the same atom result in a linear shape.
by Sara Richmond 1D
Tue Nov 12, 2019 5:44 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR model
Replies: 4
Views: 34

VSEPR model

What does VSEPR stand for? How do we determine a molecules VSEPR formula for a molecule.
by Sara Richmond 1D
Tue Nov 12, 2019 5:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR
Replies: 5
Views: 20

Re: VSEPR

I went to a UA workshop last week. She said that we will be expected to memorize all of the shapes. She also suggests we memorize the VSEPR model.
by Sara Richmond 1D
Tue Nov 12, 2019 5:41 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 3
Views: 15

Test 2

What material will we be tested on for test 2 that occurs during Week 8?
by Sara Richmond 1D
Wed Nov 06, 2019 1:29 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Uncertainty in Speed [ENDORSED]
Replies: 18
Views: 756

Re: Uncertainty in Speed [ENDORSED]

Use these equations:
(delta p)(delta x) = (1/2)(h/4 PIE)
(deltap) = m( delta v)

Sometimes this type of problem can be confusing because they dont give you the delta p equation.

Also remember to multiply the delta v uncertainty by 2 because it is plus or minus a certain amount.
by Sara Richmond 1D
Wed Nov 06, 2019 1:26 pm
Forum: Student Social/Study Group
Topic: Final Jitters
Replies: 90
Views: 19207

Re: Final Jitters

I find it useful to take a nap before a midterm or final. especially when they are night midterms. To be honest after studying for weeks (like I do for chemistry exams), I can be really distracted and nervous before an exam. By taking a nap, I recharge my brain. But really you will need to find what...
by Sara Richmond 1D
Wed Nov 06, 2019 1:22 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Help Calculating
Replies: 3
Views: 46

Re: Help Calculating

Thank you, the process makes more sense now. I was missing the equation for delta P. "ΔP is equal to mΔv because mass is constant and velocity is the only thing that changes. Set up the equation Δp=mΔv on the side to solve for Δp". Now that I know this, it makes more sense.
by Sara Richmond 1D
Wed Nov 06, 2019 1:19 pm
Forum: Administrative Questions and Class Announcements
Topic: Worksheet for 1D/1F 10/16
Replies: 24
Views: 1366

Re: Worksheet for 1D/1F 10/16

For number 4 part b on the extra practice problems, why doesn't boron have to complete it's octet? In your answer key, boron only has 6 electrons accounted for in the lewis structure
by Sara Richmond 1D
Sat Nov 02, 2019 1:59 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Help Calculating
Replies: 3
Views: 46

Help Calculating

I am kind confused when it comes to the Heisenberg uncertainty principle. Can you help me calculate this problem? It is from a worksheet made by the UA Karen Leung
by Sara Richmond 1D
Wed Oct 30, 2019 2:22 pm
Forum: Ionic & Covalent Bonds
Topic: Valence e-
Replies: 3
Views: 33

Re: Valence e-

Usually in terms of Chemical bonds, we usually just include the s and p orbitals when defining the number of valence electrons in the valence shells. You should definitely check out the other posts on this topic.
by Sara Richmond 1D
Wed Oct 30, 2019 2:19 pm
Forum: Lewis Structures
Topic: Homework 2A 12
Replies: 3
Views: 24

Re: Homework 2A 12

M2+ is not actually an element. The problem is asking you to name the 2+ ions with those electron configurations. Imagine M as x in an algebraic function.
by Sara Richmond 1D
Wed Oct 30, 2019 2:17 pm
Forum: Lewis Structures
Topic: Formal charge
Replies: 9
Views: 58

Re: Formal charge

AN easy way to calculate formal charge of an atom is:

# of valence electrons for that element- number of dots-number of lines=formal charge
by Sara Richmond 1D
Wed Oct 30, 2019 2:16 pm
Forum: Lewis Structures
Topic: Bonds:
Replies: 3
Views: 19

Bonds:

Do bonds count as one or two valence electrons in a Lewis Structure?
by Sara Richmond 1D
Wed Oct 30, 2019 2:11 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: S to D orbital?
Replies: 1
Views: 10

S to D orbital?

When do the electrons from a future s orbital transfer to a d orbital to stabilize the electron configuration.
by Sara Richmond 1D
Sat Oct 26, 2019 5:31 pm
Forum: Ionic & Covalent Bonds
Topic: + and - ions
Replies: 3
Views: 56

+ and - ions

I had a questions on a chemistry concept relating to determining the electron configuration of an ion- do you move left or right on the periodic table for charge?  For example:  1. Is the electron configuration of Fe^+ the same as the electron configuration of Mn (move left) or the same as Co (move ...
by Sara Richmond 1D
Wed Oct 23, 2019 5:36 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Subshell vs. Orbital
Replies: 9
Views: 64

Re: Subshell vs. Orbital

Electron shells are divided into subshells and subshells are divided into orbitals. In terms of quantum numbers, n denotes the shell, l denotes the subshell, and ml denotes the orbital. Each orbital typically houses 2 electrons of opposite spin./
by Sara Richmond 1D
Wed Oct 23, 2019 5:31 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration Exceptions:
Replies: 3
Views: 20

Electron Configuration Exceptions:

Why fo the elements of Cr and Cu have different electron configurations than the rest of the elements in the 3d block? For instance why is Cr's electron configuration: [Ar]3d^5 4s^1 instead of [Ar]3d^4 4s^2? What other elements are an exception to the expected electron configuration? Will we need to...
by Sara Richmond 1D
Wed Oct 23, 2019 5:29 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Oribital Notation
Replies: 3
Views: 25

Re: Oribital Notation

Sometimes its difficult to know what order to write the orbitals. The best one to remember which orbitals have higher or lower energy is with this chart. Follow the arrows from bottom to top and when your done return to the bottom of the next arrow.
by Sara Richmond 1D
Wed Oct 23, 2019 5:27 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configurations
Replies: 13
Views: 99

Re: Electron Configurations

Hey the order of electron shell energy is difficult to understand. The only way that I can remember the order of the energy is with this chart. Follow the arrows from bottom to top and then return to the bottom of the next arrow.
by Sara Richmond 1D
Wed Oct 23, 2019 5:21 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration
Replies: 2
Views: 14

Re: Electron Configuration

Hund's rule states that: Every orbital in a sublevel is singly occupied before any orbital is doubly occupied. All of the electrons in singly occupied orbitals have the same spin (to maximize total spin). It is easier to understand if you picture electrons as magnets, two negatively polled magnets w...
by Sara Richmond 1D
Wed Oct 16, 2019 2:18 pm
Forum: Molarity, Solutions, Dilutions
Topic: What is Molarity?
Replies: 11
Views: 71

Re: What is Molarity?

Molarity is a measure of concentration. The higher a substances molarity the more solutes. For example, if one sample of salt water has a molarity of 0.1M and another sample has a molarity of 0.9M, then the 0.1M water would be less. salty than the 0.9M sample.
by Sara Richmond 1D
Wed Oct 16, 2019 2:15 pm
Forum: Administrative Questions and Class Announcements
Topic: KAREN SUN 5-7PM WORKSHOP - DOWNLAOD WORKSHEETS HERE
Replies: 53
Views: 2155

Re: KAREN SUN 5-7PM WORKSHOP - DOWNLAOD WORKSHEETS HERE

I went to your workshop last Sunday, and I found it extremely useful. Thank you for all the help. I will see you next week!
by Sara Richmond 1D
Wed Oct 16, 2019 2:13 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Bohr's Equation
Replies: 5
Views: 49

Bohr's Equation

Will we be expected to derive Bohr's equation on the midterm like Dr. Lavelle did in class?
by Sara Richmond 1D
Wed Oct 16, 2019 2:01 pm
Forum: General Science Questions
Topic: Chemistry Community Registration
Replies: 2
Views: 39

Chemistry Community Registration

Every week my chemistry community account locks me out. I am forced to reset my password each week. Has anyone else experienced this? Each week a reset my password to the same thing and it still locks me out the next week.
by Sara Richmond 1D
Wed Oct 16, 2019 1:59 pm
Forum: Properties of Light
Topic: Midterm- Electromagnetic spectrum
Replies: 3
Views: 30

Midterm- Electromagnetic spectrum

For the first midterm will we need to memorize the electromagnetic spectrum?
by Sara Richmond 1D
Wed Oct 09, 2019 3:18 pm
Forum: *Black Body Radiation
Topic: Wavelength and Temperature
Replies: 2
Views: 36

Re: Wavelength and Temperature

There is a short section in the textbook about Wein's law that helped me better understand this. You should check out section 1B of the textbook.
by Sara Richmond 1D
Wed Oct 09, 2019 3:16 pm
Forum: Properties of Light
Topic: Partical VS Wave
Replies: 2
Views: 30

Partical VS Wave

I am having trouble understanding the difference between when light acts like wave and like a particle. Any advice for reading material/ videos?
by Sara Richmond 1D
Wed Oct 09, 2019 3:05 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Test 1 [ENDORSED]
Replies: 107
Views: 2323

Re: Test 1 [ENDORSED]

VLi_1L wrote:Are there any specific equations we need to memorize for future tests? Or are equation sheets usually provided

The equations are provided on the cover sheet of the exam.
by Sara Richmond 1D
Wed Oct 09, 2019 3:05 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Test 1 [ENDORSED]
Replies: 107
Views: 2323

Re: Test 1 [ENDORSED]

Hey, I just took the Test this morning at 8 am. You do not need to purchase anything for the exam. Your TA will provide you with printed periodic table and a printed version of the exam. There is not a lot of work space on the exam so be aware. Th exam MUST be completed IN PEN, so remember to bring ...
by Sara Richmond 1D
Sun Oct 06, 2019 6:11 pm
Forum: SI Units, Unit Conversions
Topic: Naming Compounds?
Replies: 10
Views: 169

Re: Naming Compounds?

Jielena_Bragasin_LEC4_DIS4G wrote:Hi! I went to office hours today and he said that naming compounds will not be on THIS exam, but future exams will be worded with the compound name (ex. sulfuric acid) without the molecular formula (ex. H2SO4).

Thank You this was extremely helpful.
by Sara Richmond 1D
Tue Oct 01, 2019 7:45 am
Forum: Limiting Reactant Calculations
Topic: Test 1
Replies: 4
Views: 42

Test 1

The first test is in about 1 week. What will the text cover? Will the test take place in discussion sections?
by Sara Richmond 1D
Tue Oct 01, 2019 7:40 am
Forum: Significant Figures
Topic: Decimals After Whole Numbers
Replies: 6
Views: 196

Re: Decimals After Whole Numbers

Do any of you have a video recommendation to review significant figures? It has been a long time since I've looked at significant figures?
by Sara Richmond 1D
Tue Oct 01, 2019 7:36 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Fundamental F Question 1
Replies: 2
Views: 29

Fundamental F Question 1

I do not know why, but I am having a really hard time understanding this problem in the textbook. I've tried looking in the solutions manual, but it doesn't seem to be helping. Maybe its the wording I do not understand, I am not really sure. Please Help, E.1 The field of nanotechnology offers some i...
by Sara Richmond 1D
Tue Oct 01, 2019 7:32 am
Forum: General Science Questions
Topic: Order of Elements When Writing Out a Compound
Replies: 8
Views: 108

Re: Order of Elements When Writing Out a Compound

I am not sure that the order of the elements will matter too much as professor Lavelle has not reviewed this in class. However, in organic chemistry carbon comes first, followed by hydrogen, followed by oxygen, followed by everything else.
by Sara Richmond 1D
Tue Oct 01, 2019 7:29 am
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 168
Views: 101608

Re: Rusty on High School Chem [ENDORSED]

Hello, this is my first time taking a chemistry course since my senior year of high school and I am currently a second year. I was just wondering for someone who is on chem in general, what tips can I use to guide me through this 14A course? Hello, this is also my first time taking chemistry in a w...
by Sara Richmond 1D
Tue Oct 01, 2019 7:22 am
Forum: SI Units, Unit Conversions
Topic: How does grading for discussion posts work?
Replies: 80
Views: 2692

Re: How does grading for discussion posts work?

Is there a minimum number of posts/replies to get full points? I believe each week Dr. Lavelle will give us a minimum number of posts on Chemistry Community. As long as we reach that number of posts (counting both questions and responses) we will receive full points for the week. For example for we...
by Sara Richmond 1D
Tue Oct 01, 2019 7:19 am
Forum: SI Units, Unit Conversions
Topic: Naming Compounds?
Replies: 10
Views: 169

Naming Compounds?

Will we be expected to be able to name compounds on exams like they ask you to in the textbook homework? If so where in the textbook can I find a review of how to name compounds?

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