Search found 62 matches

by Albert_Luu3K
Fri Mar 15, 2019 1:04 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Reducing/Oxidizing Power
Replies: 7
Views: 80

Re: Reducing/Oxidizing Power

More positive E value means it will have a higher oxidizing power.
More negative E value means it will have a higher reducing power.
by Albert_Luu3K
Fri Mar 08, 2019 11:57 am
Forum: *Free Energy of Activation vs Activation Energy
Topic: Definition of Transition State
Replies: 1
Views: 40

Re: Definition of Transition State

The transition state of a chemical reaction is a particular, short lived configuration of the reacting atoms along the reaction coordinate. It is defined as the state corresponding to the highest potential energy along this reaction coordinate.
by Albert_Luu3K
Thu Mar 07, 2019 9:24 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Inert Electrode
Replies: 2
Views: 50

Re: Inert Electrode

I feel as if there probably is, but Pt(s) is what we've been taught and told to use. So I wouldn't worry about knowing other possible inert electrodes.
by Albert_Luu3K
Tue Mar 05, 2019 9:09 pm
Forum: General Rate Laws
Topic: Unique rate of reaction
Replies: 2
Views: 53

Re: Unique rate of reaction

The unique rate of a reaction is not the same as the differential rate law. Check notes from last Friday because that's when we learned about the unique rate of a reaction. Also on page 613 of the sixth edition textbook, they introduce the unique rates. Hope this helps!
by Albert_Luu3K
Sun Mar 03, 2019 11:56 pm
Forum: General Rate Laws
Topic: Reaction Rates
Replies: 2
Views: 28

Re: Reaction Rates

Hi Shirley! I can understand why this may seem confusing upon first glance because it may seem that the 2 in front of [O2] means that it's increasing two times as fast (or at least that is how it confuses me sometimes). I just think of it this way: since [O2] increases half as fast [NO2] and in orde...
by Albert_Luu3K
Sun Mar 03, 2019 11:44 pm
Forum: Balancing Redox Reactions
Topic: Ecell
Replies: 4
Views: 60

Re: Ecell

Usually, one would have to flip the anode reaction! That is because the anode side is always an oxidation reaction where electrons are always on the products side being given off. The cathode/reduction reaction should have electrons on the reactants side. Then, you will have electrons on either side...
by Albert_Luu3K
Thu Feb 28, 2019 1:33 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: anode and cathode placement
Replies: 3
Views: 32

Re: anode and cathode placement

Yes, when writing out cell diagrams, the anode should be the left of the salt bridge and the cathode should be to the write of the salt bridge. This convention also works with porous discs/walls as well.
by Albert_Luu3K
Thu Feb 28, 2019 1:31 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Organization of cell diagrams
Replies: 9
Views: 70

Re: Organization of cell diagrams

Yes, you do! An inert electrode such as Pt is necessary for gas/ion electrode reactions.
by Albert_Luu3K
Thu Feb 28, 2019 1:29 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: delta G
Replies: 1
Views: 23

Re: delta G

Delta G is the change of the overall free energy, whereas delta Gr is the change of free energy of a reaction. I guess both could mean the same thing depending on the context of the question. Do you have an example of where you are seeing both being used?
by Albert_Luu3K
Thu Feb 28, 2019 1:41 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Strength of Reducing Agents
Replies: 1
Views: 38

Re: Strength of Reducing Agents

What I would is make sure all the half reaction reduction potential numbers are coming from similar set up equations, meaning that make sure all the equations start off with same neutral element and it goes to the same oxidation state. For example Fe^2+ + 2e- --> Fe and Cu^2+ + 2e- ---> Cu. That mak...
by Albert_Luu3K
Thu Feb 28, 2019 1:27 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram
Replies: 2
Views: 46

Re: Cell Diagram

For that instance, my TA Jack Fuller said that they are both interchangeable, since they're the same state. If the one of them was a solid and the other aqueous, the solid would be closer to the electrode (outside) and the aqueous would be closest to the salt bridge. Hope this helps!
by Albert_Luu3K
Thu Feb 28, 2019 1:18 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell potential
Replies: 2
Views: 28

Re: Cell potential

From looking at the cell diagram, you should be able to determine which is the anode and the cathode. Once you figure that out and you figure out the half reactions of those molecules, you can search up the E cell / reduction potential of each half reaction. With that information, you should be able...
by Albert_Luu3K
Thu Feb 28, 2019 1:15 am
Forum: Balancing Redox Reactions
Topic: Oxidation Numbers
Replies: 3
Views: 44

Re: Oxidation Numbers

For elements like O2 and Cl2, they will always have an oxidation state of zero because they are neutral diatomics. One oxygen atom can't be a negative 2 charge and the other atom be a positive 2 charge. If the elements are solids, liquids, or it is some sort of diatomic molecule, the oxidation state...
by Albert_Luu3K
Thu Feb 28, 2019 1:12 am
Forum: Balancing Redox Reactions
Topic: Oxidation Numbers
Replies: 3
Views: 53

Re: Oxidation Numbers

What Meachelle said above hits the spot perfectly. We will not be expected to know all of the oxidation states of elements, but know a few general rules for certain columns in the periodic table will help definitely.
by Albert_Luu3K
Thu Feb 28, 2019 1:01 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic Cell E not
Replies: 1
Views: 22

Re: Galvanic Cell E not

I believe from what we learned in class so far, it should be. Knowing that a galvanic cell should have a positive potential difference can help you figure out which side is the cathode/anode and what species are being oxidized or reduced.
by Albert_Luu3K
Wed Feb 27, 2019 1:58 pm
Forum: Balancing Redox Reactions
Topic: Oxidized vs oxidizing agent
Replies: 6
Views: 73

Re: Oxidized vs oxidizing agent

Remembering the difference between being oxidized and being the oxidizing agent AND being reduced and being the reducing agent can be confusing.You just got to remember that if a molecule is being oxidized, then it is the reducing agent because it is the one losing and transferring the electrons ove...
by Albert_Luu3K
Wed Feb 27, 2019 5:15 am
Forum: Balancing Redox Reactions
Topic: redox homework question
Replies: 3
Views: 36

Re: redox homework question

Oxygen is not being oxidized here. It remains (-2) on both sides. Carbon is being oxidized here.
by Albert_Luu3K
Wed Feb 27, 2019 5:13 am
Forum: Balancing Redox Reactions
Topic: 6K.3 7th edition
Replies: 1
Views: 42

Re: 6K.3 7th edition

I was stuck on this problem for a while as well! I believe that there's a typo in the problem. It should be Cl2 (g) ---> HClO (aq) + Cl- (aq).
Hope that helps! That would the answer looks like it came from in the solutions.
by Albert_Luu3K
Wed Feb 27, 2019 5:11 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: 6th ed. 14.23: value of n
Replies: 2
Views: 46

Re: 6th ed. 14.23: value of n

What Jonas said was spot on. The safest bet is to write out the half reactions, balance them, and combine them to see what the total number of electrons that cancel out each other is because that is your n. But you can also use your intuitition if you look at the equation they give you. See how much...
by Albert_Luu3K
Wed Feb 27, 2019 5:07 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: n
Replies: 8
Views: 94

Re: n

What Subhani said above is correct. I would just write the balanced half reactions and combine them to see what the number of electrons that cancel out each other is. That is your n. Hope that helps!
by Albert_Luu3K
Wed Feb 27, 2019 5:05 am
Forum: Balancing Redox Reactions
Topic: Problem 6k3 part d seventh edition
Replies: 1
Views: 32

Re: Problem 6k3 part d seventh edition

I was staring at this problem too, but I believe there's a typo in the problem. It should be Cl2(g) ---> HClO(aq) + Cl-(aq). Hope that helps you solve it!
by Albert_Luu3K
Wed Feb 27, 2019 5:02 am
Forum: Balancing Redox Reactions
Topic: 6K. 5
Replies: 1
Views: 46

Re: 6K. 5

For the reduction, you should end up with : 12e- +12H2O + P4 ---> 4PH3 + 12OH- You got the start correct but you just got to keep going and trying out different things to balance. First I saw that there were 12 H on the right side, so I needed to balance that. All I can add is H2O to add more H but ...
by Albert_Luu3K
Wed Feb 27, 2019 4:55 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: moles of electrons of reaction
Replies: 3
Views: 35

Re: moles of electrons of reaction

Not sure if I understand your question, but you should look at both! For example if 2Ce^4+(aq) --> 2Ce^3+(aq), then n should equal 2. Even though one electron was needed to lower the charge, there were two moles of the ions.
by Albert_Luu3K
Wed Feb 27, 2019 4:52 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: HW 6th edition 14.29
Replies: 2
Views: 36

Re: HW 6th edition 14.29

I believe you have to look at each couple's reduction potential. The couple that has the more positive reduction potential will be the one being reduced aka the oxidizing agent.
by Albert_Luu3K
Wed Feb 27, 2019 4:49 am
Forum: Balancing Redox Reactions
Topic: Oxidizing and Reducing Agent
Replies: 4
Views: 59

Re: Oxidizing and Reducing Agent

I wouldn't be surprised if it is included on the test. An example of this is the reaction of chlorine in water: Cl2 (g) -> HClO(aq) + Cl-
Cl2 acts as the oxidizing agent and reducing agent.
by Albert_Luu3K
Wed Feb 27, 2019 4:47 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Week 6 Friday Lecture Notes
Replies: 2
Views: 40

Re: Week 6 Friday Lecture Notes

Here you go, this is what I got.
by Albert_Luu3K
Mon Feb 25, 2019 1:13 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: DeltaG at Equilibrium
Replies: 2
Views: 33

DeltaG at Equilibrium

Why is deltaG at equilibrium equal to zero?
by Albert_Luu3K
Thu Feb 21, 2019 7:23 pm
Forum: Balancing Redox Reactions
Topic: Finding Charge
Replies: 3
Views: 53

Re: Finding Charge

Usually if the charge is not given, that means the molecule is a neutral charge (0). Using that knowledge, you should be able to use the periodic table to find the oxidation state of one of the elements and deduct the oxidation state of the other.
by Albert_Luu3K
Thu Feb 21, 2019 7:08 pm
Forum: Balancing Redox Reactions
Topic: H2O
Replies: 3
Views: 57

Re: H2O

What do you do if the solution is basic? Adding OH- would add more oxygen and hydrogen.
by Albert_Luu3K
Thu Feb 21, 2019 7:04 pm
Forum: Balancing Redox Reactions
Topic: H+ vs H3O+
Replies: 10
Views: 99

Re: H+ vs H3O+

H+ is better because it's easier to write and you might get H3O+ confused with H2O.
by Albert_Luu3K
Sat Dec 08, 2018 10:11 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pH to salt solution
Replies: 1
Views: 42

Re: pH to salt solution

Given the molarity and volume of the basic solution, you find the concentration of OH- ions. With that information, you can find the pOH and subtract that from 14, and you will have the pH. Hope this basic skeleton of how to solve it helps. Basically find out how many moles of the molecule there is ...
by Albert_Luu3K
Sat Dec 08, 2018 10:02 pm
Forum: Identifying Acidic & Basic Salts
Topic: What are salts...
Replies: 4
Views: 81

Re: What are salts...

Salts are basically just ionic compounds such as NaCl. They raise or lower pH by ionizing in solution and either creating more hydronium or hydroxide ions. An example of an acidic salt would be NH4Cl. In solution, the NH4 would donate its H proton to H20 creating H30+. more acidic!
by Albert_Luu3K
Sat Dec 08, 2018 9:57 pm
Forum: Sigma & Pi Bonds
Topic: Churro 17
Replies: 2
Views: 102

Re: Churro 17

Yes it is asking for pi and sigma as well as the hydridization. There is an example given of what they are asking for: sigma(C2sp^2, C2sp^2).
by Albert_Luu3K
Sat Dec 08, 2018 9:55 pm
Forum: Bronsted Acids & Bases
Topic: Strong acid
Replies: 5
Views: 101

Re: Strong acid

It is a strong acid because it fully ionizes and dissociates in water. That means there are more hydronium ions in solution making it more acidic.
by Albert_Luu3K
Sat Dec 08, 2018 9:51 pm
Forum: Bronsted Acids & Bases
Topic: Strong base
Replies: 5
Views: 129

Re: Strong base

NaOH is a strong base because it fully dissociates in water. That means there are more OH- ions floating in solution making it more basic.
by Albert_Luu3K
Sat Dec 08, 2018 6:29 pm
Forum: Calculating the pH of Salt Solutions
Topic: Ph to salt solution
Replies: 2
Views: 60

Re: Ph to salt solution

This is what Lyndon did to himself for one of the problems in his review session, but NO it is not needed to know how to do for the final.
by Albert_Luu3K
Sat Dec 08, 2018 6:28 pm
Forum: Naming
Topic: Common Ligands
Replies: 2
Views: 50

Re: Common Ligands

I think it'll be useful to have memorized for when you encounter any problems with naming. Do enough practice problems and the names should be committed to memory.
by Albert_Luu3K
Sat Dec 08, 2018 6:25 pm
Forum: Conjugate Acids & Bases
Topic: NH3, acid or base?
Replies: 2
Views: 81

Re: NH3, acid or base?

I think for almost all the reactions we've worked with, NH3 acts a Bronsted base because it accepts the proton.
by Albert_Luu3K
Sat Dec 08, 2018 6:22 pm
Forum: Dipole Moments
Topic: Forces Present in molecules
Replies: 3
Views: 97

Re: Forces Present in molecules

You can know what type of intermolecular forces a molecule goes through by know its shape and polarity. By knowing that there is a dipole in a molecule, you will know that opposite dipoles of molecules with attract.
by Albert_Luu3K
Sat Dec 08, 2018 6:20 pm
Forum: Electronegativity
Topic: Exceptions
Replies: 3
Views: 97

Re: Exceptions

Not sure if there are any exceptions to this trend, but it might be a good idea to take a quick look at the electronegativity periodic table. You'll be able to see for yourself the electronegativites of each element and be able to see the trends.
by Albert_Luu3K
Sat Dec 08, 2018 6:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent
Replies: 1
Views: 77

Re: Bent

I believe including the angle would be enough since that would specify which bent shape it is.
by Albert_Luu3K
Tue Dec 04, 2018 10:42 pm
Forum: Naming
Topic: Knowing oxidation states
Replies: 11
Views: 120

Re: Knowing oxidation states

I'm not sure about the textbook, but there's this sheet on Professor Lavelle's website:
https://lavelle.chem.ucla.edu/wp-conten ... pounds.pdf
by Albert_Luu3K
Tue Dec 04, 2018 10:32 pm
Forum: Hybridization
Topic: S character
Replies: 3
Views: 107

Re: S character

Oh okay, I was just overthinking it. Thank you!
by Albert_Luu3K
Tue Dec 04, 2018 10:28 pm
Forum: Naming
Topic: Difference between cis and trans
Replies: 4
Views: 63

Re: Difference between cis and trans

If you need help visualizing cis vs trans, take a look at the molecules cis-dichloroethene and trans-dichloroethene!
by Albert_Luu3K
Thu Nov 29, 2018 5:57 pm
Forum: Hybridization
Topic: S character
Replies: 3
Views: 107

S character

In 6th edition textbook, question 4.43, it talks about s-character in regards to hybridization. What is s character?
by Albert_Luu3K
Thu Nov 29, 2018 4:44 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: trans/cis
Replies: 4
Views: 63

Re: trans/cis

Hello, The way I imagine trans/cis molecules is that there are two different lewis structures that the molecule would be. To differentiate, which lewis structure is correct and what the molecule they are asking for is, trans or cis is added to the front. Cis molecules like cis-dichloroethene are pol...
by Albert_Luu3K
Sun Nov 04, 2018 9:33 pm
Forum: Properties of Electrons
Topic: Electron Configuration
Replies: 9
Views: 208

Re: Electron Configuration

Very interesting, Melissa. I googled this phenomenon, and it says that this is the electron configuration because experiment has shown. Our usual methods don't apply to this Pd because it's an exception due to what has been found in experiment. I doubt this we will need to know this. We'll only need...
by Albert_Luu3K
Sun Nov 04, 2018 9:21 pm
Forum: Administrative Questions and Class Announcements
Topic: Question from textbook
Replies: 2
Views: 76

Re: Question from textbook

First, use the 2.111g Na2CO3 and the 250.0mL and find the molarity. I got .07980mol/L. For part a, take the 2.15mmol Na+ ion and convert into moles. There are two Na+ ion per Na2CO3 molecule, so using dimensional analysis you find out how many moles of Na2CO3 you need. Using the molarity we found, w...
by Albert_Luu3K
Sun Nov 04, 2018 8:27 pm
Forum: Administrative Questions and Class Announcements
Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
Replies: 121
Views: 4918

Re: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]

Thank you so much, Lyndon. These are going to help me a lot as I'm last minute cramming.
by Albert_Luu3K
Sun Oct 28, 2018 10:19 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 4
Views: 55

Re: Atomic Radius

What Ana said above is correct. Adding another electron to the outer shell would increase the electron to electron repulsion, thus making the shell and atomic radius increase ever so slightly.
by Albert_Luu3K
Sun Oct 28, 2018 10:15 pm
Forum: Trends in The Periodic Table
Topic: Lewis Structures
Replies: 7
Views: 126

Re: Lewis Structures

I'm not sure if they can just go anywhere. Just make sure the dots/electrons are paired up and the sides surrounding the atom (where there's not a bond).
by Albert_Luu3K
Sun Oct 28, 2018 10:01 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Energy Release in Electron Affinity
Replies: 1
Views: 56

Re: Energy Release in Electron Affinity

The way I'd rationalize this is knowing that electron affinity, or the energy being released after an electron is added to a neutral atom, is opposite to ionization energy. It takes energy to be put in to break the bonds and release an electron from an atom, so it would only make sense that energy w...
by Albert_Luu3K
Sun Oct 28, 2018 9:51 pm
Forum: Trends in The Periodic Table
Topic: Question 2.81 (Sixth Edition)
Replies: 2
Views: 80

Re: Question 2.81 (Sixth Edition)

I remember learning this somewhat in AP Chemistry. The way that I'd rationalize it is that Nitrogen's orbital is half filled. They are all spinning the same way. Orbitals that are completely filled as well as half filled are relatively stable. Of course the fully filled orbital is more stable than t...
by Albert_Luu3K
Mon Oct 22, 2018 12:09 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Molecular Shape
Replies: 2
Views: 143

Re: Molecular Shape

We need to know the difference because the topic of electron configuration will be a large topic to be discussed later. We will probably be asked later to figure the different orbitals and shapes of different things.
by Albert_Luu3K
Mon Oct 22, 2018 12:07 am
Forum: Bond Lengths & Energies
Topic: Bond length Correlation
Replies: 2
Views: 134

Re: Bond length Correlation

I think there is a relationship between the two because for a bond length to be shorter, there needs to be more bonded electrons between the two. The energy is bond will be higher with more bonded electrons because it will take more energy to break the bond since the bond is shorter and stronger.
by Albert_Luu3K
Thu Oct 11, 2018 11:45 pm
Forum: Balancing Chemical Reactions
Topic: L.5 Part B Sixth Edition [ENDORSED]
Replies: 5
Views: 174

L.5 Part B Sixth Edition [ENDORSED]

I can't seem to get the correct answer for part b. I converted 3.500x10^3 kg Al to g and then to moles by dividing by its molar mass. Then I used molar ratios to find out how many moles of Al2O3 is made, turned that to g and then to kg. My answer doesn't seem to match. Am I making any wrong steps?
by Albert_Luu3K
Thu Oct 11, 2018 10:43 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: molar masses on the test
Replies: 7
Views: 229

Re: molar masses on the test

Even though we'll be given molar masses from the periodic table, it doesn't hurt to memorize some of the more common elements! After doing a whole bunch of practice problems, molar masses of common elements used will just be ingrained in your memory. Oxygen, Carbon, Hydrogen, and Nitrogen are nice o...
by Albert_Luu3K
Thu Oct 11, 2018 10:36 pm
Forum: Properties of Light
Topic: Black Body Radiation
Replies: 4
Views: 66

Re: Black Body Radiation

The previous reply already explained what black body radiation is, but I believe during lecture that Professor Lavelle said that we don't need to worry ourselves with knowing and remembering about what black body radiation does because we will not be tested on it.
by Albert_Luu3K
Thu Oct 04, 2018 5:28 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: diatomic molecules
Replies: 5
Views: 70

Re: diatomic molecules

Dear friend, There is a beautiful computer website and even smartphone application called Quizlet! You are able to make flashcards for anything and test yourself anywhere at any time as long as you have your mobile device or computer. There are even games and tests that Quizlet can do for you. The b...
by Albert_Luu3K
Thu Oct 04, 2018 5:18 pm
Forum: SI Units, Unit Conversions
Topic: Homework: E1, 6th Ed.
Replies: 4
Views: 120

Re: Homework: E1, 6th Ed.

Dear Michelle Bui, I also had trouble with this question because my answer was always far off from the actual answer. Soon I came to realize my mistake. You start off by multiplying Avogadro's number to the amount of moles of Ag to the get the number of atoms you have in the fiber. Once you have tha...
by Albert_Luu3K
Thu Oct 04, 2018 5:10 pm
Forum: Molarity, Solutions, Dilutions
Topic: Fundamental G, Number 5 6th Edition
Replies: 1
Views: 59

Re: Fundamental G, Number 5 6th Edition

Hello dear classmate, Your method of solving the problem would exactly what I would do. The beautiful thing about chemistry is that there are multiple ways about solving a problem. However, there is a mistake in one of your steps which is why your answer is off from the solutions manual. When you mu...

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