Search found 57 matches

by Maria Poblete 2C
Mon Jan 13, 2020 11:45 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5H.3
Replies: 2
Views: 8

5H.3

Use the information in Table 5G.2 to determine the value of K at 300 K for the reaction 2 BrCl(g) + H2(g) = Br2(g) + 2 HCl(g).
I can't quite find this exact reaction in the table. Is there something additional that I should be doing to find K?
This is what Table 5G.2 looks like:
Capture.PNG
by Maria Poblete 2C
Sat Jan 11, 2020 5:16 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: When to use Le Chatelier's
Replies: 4
Views: 26

Re: When to use Le Chatelier's

Le Chatelier's Principle applies whenever an external change is added to the system. This can occur in the form of altering concentration, pressure, or temperature. An exception to this is if an inert gas is added to the reaction, which has no impact on the reaction.
by Maria Poblete 2C
Sat Jan 11, 2020 5:13 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: finding change in concentration in ICE tables
Replies: 3
Views: 19

Re: finding change in concentration in ICE tables

When you don't know the quantitative change in concentration, you can replace the value with variable X. For example, CO and H 2 O would decrease X amount in reaction, while CO 2 and H 2 would increase X amount. By doing this, you can mathematically figure out the actual numerical value of X by usin...
by Maria Poblete 2C
Sat Jan 11, 2020 5:10 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Significance of principle
Replies: 6
Views: 19

Re: Significance of principle

Le Chatelier's Principle is helpful in understanding that changes in concentration or pressure within the system will not affect K, and that the reaction will act accordingly so in order to keep K intact.
by Maria Poblete 2C
Sat Jan 11, 2020 5:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE box
Replies: 9
Views: 28

Re: ICE box

If the solutions to the problem are the direct concentrations of a substance, there is no way the answer can be negative, as you cannot have negative concentration. I'm not really sure if this would ever come up, but the solution could be negative if this results in the desired concentration is stil...
by Maria Poblete 2C
Tue Jan 07, 2020 3:23 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Converting Kc to Keq
Replies: 2
Views: 18

Converting Kc to Keq

Will we ever have to convert between K and Kc? I'm reading Focus 5H in the textbook and I'm kind of confused.
by Maria Poblete 2C
Sat Dec 07, 2019 11:22 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: dentates
Replies: 2
Views: 27

Re: dentates

When there is chelation in a coordinate compound, the ligand attaches multiple times to the central atom. It essentially forms a ring of atoms including the central metal atom. Ligands typically bind at one site of the central atom, making them monodentate. A ligand that binds at two sites is bident...
by Maria Poblete 2C
Sat Dec 07, 2019 1:30 am
Forum: Lewis Acids & Bases
Topic: memorizing ligands
Replies: 5
Views: 78

Re: memorizing ligands

I also don't have a mnemonic but quizlet is actually very helpful! When memorizing CN, NC, SCN, and NCS, I realized that the complementing compound beginning with N will always begin with iso-. For example, CN is cyanate, and NC is isocyanate. SCN is thiocyanate, and NCS is isothiocyanate. Hope this...
by Maria Poblete 2C
Thu Dec 05, 2019 9:22 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: compound names
Replies: 1
Views: 17

Re: compound names

I think that it wouldn't hurt to know the ligand names of each structure. While reviewing, I've done past final exams and I've been asked to identify ligands like ethylenediamine (en) and oxolate.
by Maria Poblete 2C
Thu Dec 05, 2019 10:15 am
Forum: Polyprotic Acids & Bases
Topic: Chelate/polydentate
Replies: 2
Views: 28

Re: Chelate/polydentate

A chelate is a compound with a ligand bonded to a central atom at two or more points. This looks like a ring structure attached to the central atom. A polydentate molecule has multiple ligands of this nature attached to the central atom. So, a chelate can be monodentate, bidentate, tridentate, polyd...
by Maria Poblete 2C
Tue Dec 03, 2019 12:08 pm
Forum: Lewis Acids & Bases
Topic: Products of Lewis Acids and Bases
Replies: 1
Views: 19

Products of Lewis Acids and Bases

I know that Lewis acids accept electron pairs from Lewis bases, but how exactly do you know what the final product looks like? For example, what does the product of Cl - + SO 2 look like, and why? I know that Cl - is the Lewis base, and SO 2 is the Lewis acid, but I'm not exactly sure how the two in...
by Maria Poblete 2C
Tue Dec 03, 2019 11:38 am
Forum: Naming
Topic: Naming Coordination Compounds
Replies: 5
Views: 32

Re: Naming Coordination Compounds

I think it would be really helpful to know the simpler ligands, since I'm pretty confident that we're going to be asked to name some coordination compounds on the final. For the insanely long ligand names, I think it's okay if we don't memorize those haha.
by Maria Poblete 2C
Sun Dec 01, 2019 8:18 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Why sulfuric acid is stronger than phosphoric acid
Replies: 4
Views: 41

Why sulfuric acid is stronger than phosphoric acid

I was just wondering why phosphoric acid is weaker than sulfuric acid. When I tried looking at this online, most sources just listed the pKa's, and I don't think that is a sufficient way to answer my question.
by Maria Poblete 2C
Sun Dec 01, 2019 7:51 pm
Forum: Calculating the pH of Salt Solutions
Topic: PH
Replies: 5
Views: 26

Re: PH

To add onto this, a more visual representation is this:
p[H] = -log10[H3O+]

So, for example, if [H3O+] = 1.0 * 10-7 mol/L, the pH would equal 7.
by Maria Poblete 2C
Sun Dec 01, 2019 7:44 pm
Forum: Naming
Topic: chelating
Replies: 3
Views: 33

Re: chelating

Visually, you can tell if chelation occurs in a molecule if one of the ligands forms a ring of atoms that includes the central atom. In a Lewis structure, it would look like a ring on one of the ligands.
by Maria Poblete 2C
Sun Dec 01, 2019 7:41 pm
Forum: Administrative Questions and Class Announcements
Topic: Past exams
Replies: 7
Views: 72

Re: Past exams

The Community Programs Office in the Student Activities Center on campus has a test bank of previous finals and tests that students may have previously submitted in past quarters. I'm not sure if Lavelle's tests are there, but I feel like there's a good chance especially because this class has been ...
by Maria Poblete 2C
Tue Nov 26, 2019 2:47 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted Acids and Bases
Replies: 6
Views: 35

Re: Bronsted Acids and Bases

Someone else can add onto this, but I think it's helpful to know their exact function and role when reacting with other substances. For example, Bronsted acids are proton donors and Bronsted bases are proton acceptors. Also, it'd probably be helpful to recognize what makes up a strong/weak acid or b...
by Maria Poblete 2C
Tue Nov 19, 2019 10:59 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: induced dipole-induced dipole
Replies: 4
Views: 33

Re: induced dipole-induced dipole

Yes, induced dipole-induced dipole forces can also be considered London forces. They can also be referred to as dispersion forces, or van der Waals forces.
by Maria Poblete 2C
Tue Nov 19, 2019 10:37 pm
Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
Topic: repulsion
Replies: 2
Views: 35

Re: repulsion

Let's take a molecule with tetrahedral electron geometry, for example. If 4 bonded atoms are connected to the central atom, the molecular geometry will also be tetrahedral with bond angles measuring approximately 109.5 degrees. However, if only 3 bonded atoms and one lone pair of electrons are conne...
by Maria Poblete 2C
Mon Nov 18, 2019 9:26 pm
Forum: Dipole Moments
Topic: Net Dipole Moment
Replies: 4
Views: 31

Net Dipole Moment

Does BrF6 have a net dipole moment? I know that F is more electronegative, so the dipole moment travels from the central Br to each F atom. When I draw all of these vectors out, I think they sum up to be 0. Is this correct? Is there another way to look at this?
by Maria Poblete 2C
Mon Nov 18, 2019 7:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Question About Linear Molecules
Replies: 2
Views: 25

Question About Linear Molecules

Let's say we have an ionic compound like ICl 2 - . If you draw the Lewis structure for this, it has two bonded pairs and 3 lone electron pairs, which gives it a linear molecular geometry. Why will the bond angles be 180 o degrees? I thought that lone electron pairs typically repel the bonded atoms' ...
by Maria Poblete 2C
Mon Nov 18, 2019 4:52 pm
Forum: Sigma & Pi Bonds
Topic: E Density
Replies: 1
Views: 17

Re: E Density

The number of regions of electron density help determine the shape of the molecule, concerning both electron and molecular geometry. For example, if the molecule's central atom has 4 regions of electron density surrounding it, you can infer that its electron geometry is tetrahedral. Its amount of lo...
by Maria Poblete 2C
Sat Nov 16, 2019 8:10 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: How to treat Radicals
Replies: 5
Views: 47

Re: How to treat Radicals

Yes, you should treat a single electron as one full region of electron density. However, because there is only one electron compared to two in a lone pair, it most likely has a lower magnitude of electron repulsion.
by Maria Poblete 2C
Sat Nov 16, 2019 8:04 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Tool to Memorize VSEPR
Replies: 3
Views: 32

Re: Tool to Memorize VSEPR

This was really helpful! Thanks for the resource, I'll definitely use this method when memorizing. :)
by Maria Poblete 2C
Sat Nov 16, 2019 8:00 pm
Forum: Bronsted Acids & Bases
Topic: Test2
Replies: 7
Views: 56

Re: Test2

I am not sure if it is required to memorize all of the shapes, but I think it would certainly be extremely helpful. Honestly, bond angles and molecular structure/shape are a large part of the content we learned after the midterm, so I would recommend memorizing them just to be safe before the test.
by Maria Poblete 2C
Sat Nov 16, 2019 7:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Formula
Replies: 7
Views: 31

Re: VSEPR Formula

Yes! One lone pair counts as one region of electron density. Molecular shape should always take into account how many regions of electron density surround the central atom, whether this be a bonded atom or a lone pair.
by Maria Poblete 2C
Sat Nov 16, 2019 7:55 pm
Forum: Dipole Moments
Topic: Dipole Moment
Replies: 3
Views: 29

Re: Dipole Moment

I don't think we will have to calculate any values concerning dipole moments on a test, but I am pretty sure that we will have to recognize and identify which molecules participate in dipole moments with each other by determining relative electronegativity within their atoms.
by Maria Poblete 2C
Sat Nov 16, 2019 7:52 pm
Forum: Bronsted Acids & Bases
Topic: Test2
Replies: 7
Views: 56

Re: Test2

Test 2 should cover everything from after the midterm (around Focus 2D) up to the VSEPR model and bonding angles. Hope this helped!
by Maria Poblete 2C
Sat Nov 16, 2019 7:51 pm
Forum: General Science Questions
Topic: Test 2
Replies: 5
Views: 31

Re: Test 2

I believe Prof. Lavelle said that Test 2 covers everything after the midterm (beginning from Focus 2D) up until the content we learned this Friday, which is the subject of bond angles and the VSEPR model. If I am wrong, someone correct me!
by Maria Poblete 2C
Sat Nov 16, 2019 7:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone pairs and angles
Replies: 1
Views: 18

Re: Lone pairs and angles

The VSEPR model is only able to qualitatively determine the measure of bond angles, but never quantitatively. Because molecules with lone pairs tend to push atoms farther away, the bond angles will always be smaller compared to normal geometric structure. However, it is impossible for us to actually...
by Maria Poblete 2C
Tue Nov 12, 2019 11:31 am
Forum: Administrative Questions and Class Announcements
Topic: Week 7 Homework
Replies: 7
Views: 60

Week 7 Homework

Hi everyone,
From which section on the syllabus does the homework problems begin for the homework due week 7?
by Maria Poblete 2C
Tue Nov 05, 2019 11:33 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 2A5
Replies: 1
Views: 29

2A5

Hi, this should be relatively simple but I'm struggling to understand the reasoning behind the correct answers for this problem: Give the ground-state electron configuration expected for each of the following ions: a) Cu + b) Bi 3+ c) Ga 3+ d) Tl 3+ I got [Ar] 4s 2 3d 8 for both a and c, and [Xe]4f ...
by Maria Poblete 2C
Sun Nov 03, 2019 8:46 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radii
Replies: 9
Views: 75

Re: Atomic Radii

I don't think we'll ever need to calculate the value of an atomic radius, but we should know the trends of increasing/decreasing atomic radii across periods or groups of the periodic table. For example, the atomic radius gets smaller as you go from left to right in a period because the higher positi...
by Maria Poblete 2C
Sun Nov 03, 2019 8:20 pm
Forum: Sigma & Pi Bonds
Topic: Quantum Numbers
Replies: 9
Views: 62

Re: Quantum Numbers

Like Jennifer said, quantum numbers detail the state of an electron. They tell you the overall environment of the orbital, like size/energy (n), shape (l), orientation (ml), and spin state (ms).
by Maria Poblete 2C
Sun Nov 03, 2019 8:18 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Finding electron configurations
Replies: 4
Views: 35

Re: Finding electron configurations

I believe that gallium's electron configuration is [Ar]4s 2 3d 10 4p 1 . To do this, you count the row that the element is in. Gallium is in period 4, so the s-orbital is in the 4th shell with all of its electrons filled (2). Then you enter the 3 d-block, where the maximum number of electrons in the...
by Maria Poblete 2C
Sun Nov 03, 2019 8:10 pm
Forum: SI Units, Unit Conversions
Topic: Do you always convert to SI units for calculations?
Replies: 3
Views: 53

Re: Do you always convert to SI units for calculations?

I think it's important to keep in mind what you are solving for. For example, if you are solving for E, the units for E are Joules, which translates to kg*m 2 *s 2 . Therefore, it's helpful convert your constants and variables to match units of kg and m so that you don't get confused or end up with ...
by Maria Poblete 2C
Sun Nov 03, 2019 11:24 am
Forum: Properties of Light
Topic: n in Rydberg Equation
Replies: 1
Views: 29

n in Rydberg Equation

Hi, can someone please define for me what n actually means in the Rydberg equation? Is it correct that it is the principal quantum number? What does that actually mean?
by Maria Poblete 2C
Sun Oct 27, 2019 6:33 pm
Forum: Properties of Electrons
Topic: Chemical bonds
Replies: 2
Views: 32

Re: Chemical bonds

The formation of ionic compounds involve transferring electrons from a metal to a nonmetal atom, resulting in cations and anions. Covalent bonds bind nonmetal atoms to form molecules. The ionization energies of these atoms are too high to transfer electrons from one atom to another, so they simply s...
by Maria Poblete 2C
Sun Oct 27, 2019 6:29 pm
Forum: General Science Questions
Topic: Study Guides
Replies: 6
Views: 68

Re: Study Guides

I don't believe there is a concrete study guide for the exams in this class. However, the Community Programs Office has a test bank of exams completed by students who took the course in previous quarters. If you're a first-year, you can print out a test without having to turn anything in. But after ...
by Maria Poblete 2C
Sun Oct 27, 2019 6:23 pm
Forum: Lewis Structures
Topic: 2B.7
Replies: 4
Views: 23

Re: 2B.7

Correct; because every element has a unique atomic number that corresponds to their generic number of electrons (no exceptions are stated in this problem), finding the number of valence electrons and identifying the element in the table would get you to your answer.
by Maria Poblete 2C
Sun Oct 27, 2019 6:15 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Using periodic table to find configurations?
Replies: 3
Views: 24

Re: Using periodic table to find configurations?

Yes! The periodic table is actually structured based on these similarities. As you can see in the middle section of the periodic table, all of those elements contain d-orbitals.
by Maria Poblete 2C
Sun Oct 27, 2019 6:12 pm
Forum: Octet Exceptions
Topic: octet rule exception
Replies: 3
Views: 28

Re: octet rule exception

Yes, because the d-orbitals in elements in period 3 or higher are capable of holding up to 10 atoms.
by Maria Poblete 2C
Sun Oct 20, 2019 10:59 pm
Forum: Einstein Equation
Topic: energy emitted by H electrons
Replies: 5
Views: 74

Re: energy emitted by H electrons

Yes, I believe this can only be applied to hydrogen atoms just because multi-electron atoms are more complex in nature and require deeper-level analysis.
by Maria Poblete 2C
Sun Oct 20, 2019 10:58 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Sequence of Orbitals in a Singl
Replies: 3
Views: 19

Re: Sequence of Orbitals in a Singl

Yes, all three orbitals can be generalized together, but like Ethan said, all three must spin up in the same direction before being paired.
by Maria Poblete 2C
Sun Oct 20, 2019 10:55 pm
Forum: Properties of Electrons
Topic: 1A 15
Replies: 4
Views: 64

Re: 1A 15

Thank you everyone! This was really helpful.
by Maria Poblete 2C
Mon Oct 14, 2019 12:20 pm
Forum: Administrative Questions and Class Announcements
Topic: Where are the problems for Quantum World?
Replies: 2
Views: 19

Re: Where are the problems for Quantum World?

Hi! I had a similar problem because I also only have the 6th edition. If you go to Powell Library, you can check out the 7th edition and the solutions manual for 2 hours; the homework problems begin on page 9. I cross referenced the two books and I don't think that the 6th edition has the problems t...
by Maria Poblete 2C
Mon Oct 14, 2019 12:09 pm
Forum: Properties of Electrons
Topic: 1A 15
Replies: 4
Views: 64

1A 15

I'm having trouble with this problem: In the ultraviolet spectrum of atomic hydrogen, a line is observed at 102.6 nm. Determine the values of n for the initial and final energy levels of the electron during the emission of energy that leads to this spectral line. To be quite honest I'm not even sure...
by Maria Poblete 2C
Sun Oct 13, 2019 2:46 pm
Forum: Photoelectric Effect
Topic: Work Function
Replies: 2
Views: 27

Re: Work Function

Yep, and each metal requires a different amount of energy to remove an electron from the surface. I am assuming that if you are solving for another variable like wavelength or the photon energy, the work function will be given but can be calculated manually using the equation @dtolentino4H provided.
by Maria Poblete 2C
Sun Oct 13, 2019 2:34 pm
Forum: Administrative Questions and Class Announcements
Topic: Finding Textbook Questions on the Quantum World
Replies: 4
Views: 46

Re: Finding Textbook Questions on the Quantum World

Thank you everyone! I should have been more clear but I am using the 6th edition and am still struggling to find the questions. I think I'm going to visit the library soon to see how the questions line up.
by Maria Poblete 2C
Sat Oct 12, 2019 10:51 pm
Forum: Balancing Chemical Reactions
Topic: F.3
Replies: 5
Views: 58

Re: F.3

I was also wondering the same thing. I have an easier time deriving formulas for telltale compounds (ex. dihydrogen monoxide, haha) but am not sure if I should remember the methods of deriving for acids or oxides.
by Maria Poblete 2C
Sat Oct 12, 2019 10:49 pm
Forum: DeBroglie Equation
Topic: De Broglie's Equation
Replies: 2
Views: 25

Re: De Broglie's Equation

I believe that De Broglie's Equation can only be used for particles with a mass. I don't think light has a mass, so it wouldn't make sense to use the equation when mass is needed as a variable.
by Maria Poblete 2C
Tue Oct 08, 2019 6:30 pm
Forum: Administrative Questions and Class Announcements
Topic: Finding Textbook Questions on the Quantum World
Replies: 4
Views: 46

Finding Textbook Questions on the Quantum World

I'm having trouble finding the exercises assigned in the syllabus under the Quantum World. One of the first sections of problems is Problems 1A: 3, 5, 7, 9, 11, and 15, but I can't seem to find them in the textbook. Can someone direct me to a page number, please? It would mean a lot! Also, just to c...
by Maria Poblete 2C
Thu Oct 03, 2019 11:42 pm
Forum: SI Units, Unit Conversions
Topic: Formula Units
Replies: 3
Views: 39

Re: Formula Units

Essentially, formula units unnamed variables. There are always 6.022 * 1023 units in one mole of something. This could be atoms or molecules. I would say that you should just know that one mole converts to a quantity of Avogadro's number units.
by Maria Poblete 2C
Thu Oct 03, 2019 11:33 pm
Forum: Molarity, Solutions, Dilutions
Topic: E 27
Replies: 6
Views: 60

Re: E 27

Ok so to answer part a, you want to start with the information they give you (1 molecule water) and you're trying to get to grams of H2O. To get there, you have to convert the 1 molecule of water to moles of water by dividing by Avogadro's number (6.022 x 10^23), since 1 mol = 6.022 x 10^23 molecul...
by Maria Poblete 2C
Thu Oct 03, 2019 10:57 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactant problems
Replies: 4
Views: 33

Re: Limiting Reactant problems

Are you talking about side reactions that are given, or side reactions that occur by chance? I would probably only utilize information that is given in the problem.
by Maria Poblete 2C
Thu Oct 03, 2019 10:55 pm
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student - Part II [ENDORSED]
Replies: 130
Views: 2928

Re: Advice from a Medical Student - Part II [ENDORSED]

Thank you for sharing this information! It gives me hope and affirms that I am not alone in this process.
by Maria Poblete 2C
Thu Oct 03, 2019 10:51 pm
Forum: SI Units, Unit Conversions
Topic: Help on Fundamentals: E21
Replies: 7
Views: 101

Help on Fundamentals: E21

I am just a bit confused when it comes to converting grams of a compound to molecules, or grams to atoms. I know that the first step is to convert the mass to moles: For example, 10.0 g of Al 2 O 3 is 0.0981 mol. However, is converting into molecules the same process as converting to atoms? I know t...

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