Search found 55 matches

by erica thompson 4I
Sat Dec 07, 2019 2:58 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: polydentate
Replies: 3
Views: 63

Re: polydentate

it all depends on the structure of each molecule. like some have multiple potential bonding sites, but the sites aren’t far enough apart that 2 could bind, and some have 2 bonding sites that are far enough apart that it could bind to 2 molecules at the same time.
by erica thompson 4I
Sat Dec 07, 2019 2:26 pm
Forum: SI Units, Unit Conversions
Topic: Test 2 Constants/Equations ERRORS
Replies: 2
Views: 120

Re: Test 2 Constants/Equations ERRORS

I know, hopefully!!

Another error: Ek = mv^2 intead of (1/2) mv^2
by erica thompson 4I
Sat Dec 07, 2019 1:54 pm
Forum: SI Units, Unit Conversions
Topic: Test 2 Constants/Equations ERRORS
Replies: 2
Views: 120

Test 2 Constants/Equations ERRORS

Did anyone else notice that the constants sheet we were given for Test 2 was missing equations and had some inaccuracies? Like it says that ΔpΔx≥π instead of (h/4π), and didn't even have the second half of the equations for λ= , En = -, and En = . Was this intentional/did this happen with anyone els...
by erica thompson 4I
Wed Dec 04, 2019 9:37 pm
Forum: Amphoteric Compounds
Topic: Selecting Which Acid/Base to React Test Oxide With
Replies: 1
Views: 77

Selecting Which Acid/Base to React Test Oxide With

What strategies can you use to figure out which acids/bases are good for reacting with the tested oxide? I understand that you should try to use the oxide in a reaction as both an acid and a base, but how do you figure out which substances to react the oxide with in the first place?
by erica thompson 4I
Wed Dec 04, 2019 9:26 pm
Forum: Amphoteric Compounds
Topic: 6A.17
Replies: 5
Views: 68

Re: 6A.17

saigorijavolu33J wrote:Amphoteric compounds are compounds that can react as an acid and base. If you react them with water, there would be 2 reactions. If you write this out then you can tell. Also it is general pattern. There is chart in the textbook which can help.


Where is this chart in the textbook???
by erica thompson 4I
Wed Dec 04, 2019 7:51 pm
Forum: Balancing Chemical Reactions
Topic: Delta Over Reaction Arrow
Replies: 1
Views: 108

Delta Over Reaction Arrow

What does it mean when there's a delta symbol over the arrow in a chemical equation? As seen in problem 6A.7 b)
by erica thompson 4I
Tue Dec 03, 2019 9:52 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: J.23
Replies: 2
Views: 50

J.23

The answers to parts a) and b) are H2CO3 (carbonic acid) and H2SO4 (sulfuric acid), respectively. Are we just supposed to know beforehand that carbonic acids and sulfuric acids are common/good ones to know? Are we supposed to memorize acids like these? Or are there strategies you could use to figure...
by erica thompson 4I
Tue Dec 03, 2019 9:41 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: J.17
Replies: 4
Views: 55

J.17

What strategies can you use to figure out which part of the given salt is the anion/cation you're dealing with? How are you supposed to know that without looking it up?
by erica thompson 4I
Sat Nov 30, 2019 1:50 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Ka constant
Replies: 5
Views: 57

Re: Ka constant

Ka is the equilibrium constant for a weak acid
by erica thompson 4I
Sat Nov 30, 2019 1:37 pm
Forum: Naming
Topic: Common Names
Replies: 2
Views: 43

Re: Common Names

I would say don't stress yourself out about exceptions unless they are exceptions he specifically named in class.
by erica thompson 4I
Sat Nov 30, 2019 1:36 pm
Forum: Naming
Topic: ethelynediaminetetraaceto
Replies: 2
Views: 35

Re: ethelynediaminetetraaceto

I agree, Google is very helpful! That exact coordination compound is also an example in the resource linked below. You could simply count the atoms (although the image given here doesn't seem to include the carbons or hydrogens). https://lavelle.chem.ucla.edu/wp-content/supporting-files/Chem14A/Nami...
by erica thompson 4I
Sat Nov 30, 2019 1:28 pm
Forum: Naming
Topic: Ligand Order
Replies: 5
Views: 62

Re: Ligand Order

In lecture Lavelle said that the order is: "(Greek prefix)" + "ligand names in alphabetical order" + "transition metal cation name" + "Roman numeral"

If there are anions, it goes: "anion name" + "(Greek prefix)" + "hydrate"
by erica thompson 4I
Sat Nov 30, 2019 1:24 pm
Forum: Naming
Topic: Meaning of Cis and Trans
Replies: 11
Views: 86

Re: Meaning of Cis and Trans

This is a generalization, but many examples we are given include more than one atom of the same type. Adding onto everyone's answers above, oftentimes the same atom (which therefore has the same electronegativity) can be a good distinguisher of cis- vs. trans-. If the same atom types are on the same...
by erica thompson 4I
Sun Nov 24, 2019 10:49 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angle of bent
Replies: 17
Views: 144

Re: Bond Angle of bent

Always start by thinking of the entire electron configuration first! Much easier than memorizing different VSEPR combinations.
by erica thompson 4I
Sun Nov 24, 2019 10:45 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent vs linear
Replies: 56
Views: 747

Re: Bent vs linear

It's helpful to think about how many electron pairs are occupying spots where there may/may not be atoms. Add the Xs and Es together to get the electron configuration, and then subtract as many atoms as there are lone pairs. This way you'll see which molecules should be "bent" down or not.
by erica thompson 4I
Sun Nov 24, 2019 10:43 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Why is CH2Cl2 polar?
Replies: 12
Views: 138

Re: Why is CH2Cl2 polar?

I always find it's easier to think about it visually! I would recommend drawing the Lewis structures, and more importantly the molecular structures, and drawing arrows toward the molecules with more negative charge. Think about the trajectories of the arrows you're drawing!
by erica thompson 4I
Fri Nov 22, 2019 10:50 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Removing Non-Axis Atoms First
Replies: 4
Views: 46

Removing Non-Axis Atoms First

Can someone remind me why we remove the atoms that are NOT on the axis first in order to determine molecular shape?
by erica thompson 4I
Tue Nov 19, 2019 2:22 pm
Forum: Hybridization
Topic: Sigma and Pi Bond Practice Problems
Replies: 1
Views: 36

Sigma and Pi Bond Practice Problems

Does anyone know off-hand which problems from 2F are good for practicing just sigma and pi problems for Test 2?
by erica thompson 4I
Sun Nov 17, 2019 8:04 pm
Forum: Hybridization
Topic: Hybridization
Replies: 3
Views: 51

Re: Hybridization

I think hybridization notation is used to describe how many orbitals of each orbital level/type are occupied by electrons when they're not full?
by erica thompson 4I
Sun Nov 17, 2019 8:01 pm
Forum: Hybridization
Topic: Test 2 Topics
Replies: 11
Views: 125

Re: Test 2 Topics

@DHavo_3H I think it has something to do with it being the most stable organization that requires the least amount of energy.
by erica thompson 4I
Sun Nov 17, 2019 7:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Purpose of electron geometry
Replies: 2
Views: 35

Re: Purpose of electron geometry

Also electron geometry gives you a hint as to whether certain angles are larger/smaller than expected. If there are more lone pairs, they will have more "push" so the angles will likely be smaller than expected.
by erica thompson 4I
Sun Nov 17, 2019 7:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR
Replies: 5
Views: 57

Re: VSEPR

Use the VSEPR formula to determine the number of atoms and lone pairs in a molecule. Add up the Xs and the Es to determine the structure of the electrons (e.g. tetrahedral, octahedral, etc.), then remove as many atoms as there are Es to find the actual molecular shape. For example, tetrahedral molec...
by erica thompson 4I
Sun Nov 17, 2019 7:38 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Linear molecule with lone pairs
Replies: 3
Views: 39

Re: Linear molecule with lone pairs

As Lavelle stated in lecture, although only atom positions are used to name molecular shapes (e.g. linear), lone pairs still influence the molecular shape. Two examples of lone pairs in linear molecules are the trigonal bipyramidal structure with 3 lone pairs, and the octohedral structure with 4 lon...
by erica thompson 4I
Sun Nov 10, 2019 1:47 pm
Forum: Bond Lengths & Energies
Topic: how to determine the energy of a bond
Replies: 6
Views: 72

Re: how to determine the energy of a bond

The formal energy is the difference between the number of valence electrons an atom normally has, and how many it has in a particular molecule. You can just count each dot individually, and then count only one electron for each bond (line).
by erica thompson 4I
Fri Nov 08, 2019 11:57 pm
Forum: Resonance Structures
Topic: resonance hybrid
Replies: 6
Views: 64

Re: resonance hybrid

I think we have to know how to draw and name the different orbitals in the same layout as the "building up" method.
by erica thompson 4I
Fri Nov 08, 2019 11:56 pm
Forum: Resonance Structures
Topic: resonance importance?
Replies: 7
Views: 87

Re: resonance importance?

It's also important to know that electrons don't "jump" from one resonance structure to the other, but rather the different resonance structures show the different placements of electrons as they constantly move about.
by erica thompson 4I
Mon Nov 04, 2019 9:28 pm
Forum: SI Units, Unit Conversions
Topic: Unit Conversion
Replies: 2
Views: 129

Unit Conversion

Does anyone know if we have to include the nano/giga/mega/etc. prefixes in our answers? Or can we just use the basic unit and multiply it by 10^n in our final answer?
by erica thompson 4I
Sun Nov 03, 2019 7:53 pm
Forum: Ionic & Covalent Bonds
Topic: Carbon Bonding
Replies: 5
Views: 56

Carbon Bonding

Does carbon prefer to gain or lose 4 electrons in order to form a full shell? Or is it equally as favorable?
by erica thompson 4I
Sun Nov 03, 2019 7:40 pm
Forum: Ionic & Covalent Bonds
Topic: In what order do electrons get removed?
Replies: 7
Views: 10817

Re: In what order do electrons get removed?

How about when it comes to f-orbitals? Problem 2A.5 b) is making me think that having both a half-full/full d-subshell and a full s-subshell is more important than a full f-subshell.

So then is the order of removal for the electrons in the lower periods: p<f<s<d ??
by erica thompson 4I
Thu Oct 31, 2019 12:45 am
Forum: Ionic & Covalent Bonds
Topic: Valence Electrons?
Replies: 15
Views: 141

Re: Valence Electrons?

Count from the last full period on the periodic table, representing a full electron shell, and that's how many valence electrons there are!
by erica thompson 4I
Thu Oct 31, 2019 12:41 am
Forum: Ionic & Covalent Bonds
Topic: Polarity
Replies: 6
Views: 54

Re: Polarity

Depends on the specific molecule and how much "pull" each element has in it.
by erica thompson 4I
Thu Oct 31, 2019 12:38 am
Forum: Ionic & Covalent Bonds
Topic: Midterm
Replies: 10
Views: 127

Re: Midterm

And bring a pen and a basic calculator! Professor Lavelle said that anything "over $10" is probably not allowed.
by erica thompson 4I
Thu Oct 31, 2019 12:29 am
Forum: Ionic & Covalent Bonds
Topic: Homework for Week 5
Replies: 8
Views: 79

Re: Homework for Week 5

It might be useful to do the most up-to-date problems if you're all caught up on the lectures, but I always just do whatever sections I need to focus more on! Just make sure to pace yourself and actually cover every topic :)
by erica thompson 4I
Thu Oct 31, 2019 12:24 am
Forum: Ionic & Covalent Bonds
Topic: Ionic and Covalent Bonds
Replies: 6
Views: 59

Re: Ionic and Covalent Bonds

A coordinate covalent bond is a covalent bond in which one atom provides both electrons in a pair to another atom.
by erica thompson 4I
Wed Oct 23, 2019 10:02 pm
Forum: Trends in The Periodic Table
Topic: Location of elements
Replies: 12
Views: 175

Re: Location of elements

It would be helpful! In general, metals are the majority of the table on the left side, nonmetals are the upper-right corner, and metalloids sort of form a staircase in between metals and nonmetals.
by erica thompson 4I
Wed Oct 23, 2019 10:00 pm
Forum: Trends in The Periodic Table
Topic: Shielding
Replies: 8
Views: 179

Re: Shielding

Everyone above explained the concept that electrons closer to the nucleus have a stronger pull towards it than the further valence electrons nicely. The important thing to take away is that electrons in further shells are more easy to form bonds with other atoms because there's less pull!
by erica thompson 4I
Wed Oct 23, 2019 9:58 pm
Forum: Trends in The Periodic Table
Topic: bond length
Replies: 9
Views: 106

Re: bond length

I'm not sure I think he said that that's assessed in a formal lab setting? I think talking about the specifics of bond length was more to emphasize that electrons are not bouncing between elements, forming only a few specific double bonds. Electrons are always moving! Can someone elaborate on this? ...
by erica thompson 4I
Wed Oct 23, 2019 9:56 pm
Forum: Trends in The Periodic Table
Topic: Electron affinity
Replies: 5
Views: 42

Re: Electron affinity

Elements on both sides of the periodic table are essentially trying to get "closer to" a noble gas in terms of stability in its electrons. Because elements on the left side want to lose electrons in order to be more stable, they would have less of an affinity, or attraction to, other elect...
by erica thompson 4I
Wed Oct 23, 2019 9:54 pm
Forum: Trends in The Periodic Table
Topic: Exceptions
Replies: 3
Views: 52

Re: Exceptions

It's also interesting to note that elements with low ionization energies typically form cations, which are typically metals. Because metals are grouped on the left side of the periodic table, you can use this as a memory clue to remind you that the ionization energy increases as you move across a pe...
by erica thompson 4I
Sun Oct 20, 2019 5:55 pm
Forum: Properties of Electrons
Topic: 1B. 15C [ENDORSED]
Replies: 4
Views: 109

Re: 1B. 15C [ENDORSED]

To respond to DHavo^^, I thought that you could use the two equations in similar ways because you can isolate and substitute v in both?
by erica thompson 4I
Sun Oct 20, 2019 5:50 pm
Forum: Properties of Electrons
Topic: Energy increasing
Replies: 7
Views: 126

Re: Energy increasing

I thought that the energy levels decreased as you moved further away from the nucleus because there was less electrostatic attraction?
by erica thompson 4I
Sun Oct 20, 2019 5:46 pm
Forum: Properties of Electrons
Topic: Electron structures
Replies: 4
Views: 58

Re: Electron structures

Each orbital can hold a maximum of 2 electrons, and the two electrons in the same orbital have opposite spins.
by erica thompson 4I
Sun Oct 20, 2019 5:44 pm
Forum: Properties of Electrons
Topic: d vs s orbitals
Replies: 6
Views: 77

Re: d vs s orbitals

The reasoning behind the order is that you're supposed to write it in order of lowest energy to highest energy. Because shells that are further away from the nucleus have less electrostatic attraction, further shells have less energy (double-check me on this?).
by erica thompson 4I
Sun Oct 20, 2019 5:41 pm
Forum: Properties of Electrons
Topic: Quantum numbers
Replies: 4
Views: 62

Re: Quantum numbers

To add onto Cassidy's comment above, it's important to know that although each orbital can hold a maximum of 2 electrons, each energy shell can have more than 2 (aside from s) because there are multiple orbitals in each shell.
by erica thompson 4I
Sun Oct 13, 2019 3:12 pm
Forum: Properties of Electrons
Topic: Electron Energy Levels
Replies: 8
Views: 71

Re: Electron Energy Levels

Does the number of energy levels not depend on the number of electrons the atom has? Or was that a simpler way of thinking about it in high school?
by erica thompson 4I
Fri Oct 11, 2019 1:51 pm
Forum: Student Social/Study Group
Topic: Final Jitters
Replies: 118
Views: 31230

Re: Final Jitters

Definitely get a lot of sleep! If you are staying up late studying, you are losing sleep and are most likely not really taking in all the information in the later hours anyways. Also remember to sit back and take a deep breath any time you're feeling overwhelmed. Also, most importantly, put it all i...
by erica thompson 4I
Fri Oct 11, 2019 1:46 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Photoelectric Effect
Replies: 4
Views: 74

Re: Photoelectric Effect

In response to Brooke above, I think he clarified that it's more about the frequency than the amplitude, as you have to think of each atom separately (like the water flowing example).
by erica thompson 4I
Fri Oct 11, 2019 1:45 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg equation [ENDORSED]
Replies: 73
Views: 3120

Re: Rydberg equation [ENDORSED]

Can someone clarify why the Rydberg equation is always negative? Because you're "losing" energy because it's being transferred somewhere else?
by erica thompson 4I
Fri Oct 11, 2019 1:42 pm
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student [ENDORSED]
Replies: 158
Views: 111607

Re: Advice from a Medical Student [ENDORSED]

Thank you for the advice Ashley! How much do you think you specifically reference this information from this class in your work today, and as a medical student?
by erica thompson 4I
Fri Oct 11, 2019 1:40 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 2 Homework Problems [ENDORSED]
Replies: 67
Views: 3187

Re: Week 2 Homework Problems [ENDORSED]

You can do problems from the Review sections, as that is the majority of the content for this week's Test.
by erica thompson 4I
Thu Oct 03, 2019 12:04 am
Forum: Molarity, Solutions, Dilutions
Topic: Empirical and Molecular Formulas
Replies: 13
Views: 208

Re: Empirical and Molecular Formulas

In the simplest terms, the empirical formula is the relative number of atoms, while the molecular formula is the actual number of atoms.
by erica thompson 4I
Thu Oct 03, 2019 12:01 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Units in Answer
Replies: 18
Views: 284

Re: Units in Answer

Like what many people said above, it depends what the problem is asking for. If the problem was asking you to solve for the mass, the answer would be in grams. I believe in lecture today he said that the SI fundamental units were:

- mass = kilograms
- length = meters
- time = seconds
by erica thompson 4I
Wed Oct 02, 2019 11:58 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Balancing Equations [ENDORSED]
Replies: 25
Views: 849

Re: Balancing Equations [ENDORSED]

That was definitely a technique he used for that specific problem! Working with stoichiometry problems will never have the same set of moves for each problem. In this case, we had a coefficient with a denominator of 2, so we had to multiply the entire problem by 2 in order to get rid of the fraction...
by erica thompson 4I
Wed Oct 02, 2019 11:55 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: E1
Replies: 6
Views: 894

Re: E1

Responding to Brenna: The question is essentially telling us that we're lining up Ag atoms in a single-file line. You don't have to "convert" the problem to atoms because it is telling you that the unit we're working with is atoms right from the start.
by erica thompson 4I
Wed Oct 02, 2019 11:47 pm
Forum: SI Units, Unit Conversions
Topic: Can someone tell me where I can access the Solutions Manual?
Replies: 6
Views: 132

Re: Can someone tell me where I can access the Solutions Manual?

As someone mentioned above, the textbook offers solutions to both the self-tests in the readings and the odd-numbered exercise problems. According to the table of contents, both of them should be in the section at the end of the book with page numbers starting with "C."

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