Search found 63 matches

by MichelleRamirez_2F
Sat Mar 16, 2019 8:58 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Bimolecular
Replies: 13
Views: 262

Re: Bimolecular

Bimolecular means that for a certain reaction there are two reactants. There's also unimolecular where there is only 1 reactant in the reaction and termolecular for three reactants.
by MichelleRamirez_2F
Sat Mar 16, 2019 8:54 pm
Forum: Zero Order Reactions
Topic: third order
Replies: 6
Views: 155

Re: third order

The textbook says their are mostly uncommon. It may be useful to know because they may appear when asked for overall reaction order.
by MichelleRamirez_2F
Sat Mar 16, 2019 8:45 pm
Forum: Administrative Questions and Class Announcements
Topic: LYNDON'S PORK RAMEN REVIEW
Replies: 37
Views: 2379

Re: LYNDON'S PORK RAMEN REVIEW

For Q7, how come we don't the number of electrons for the half reactions given when adding them to get the overall reaction?
by MichelleRamirez_2F
Sat Mar 16, 2019 8:41 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Endergonic
Replies: 2
Views: 43

Re: Endergonic

Yes, endergonic is deltaG>0 and exergonic is deltaG<0.
by MichelleRamirez_2F
Sat Mar 16, 2019 8:39 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: k(1)/k(-1)
Replies: 4
Views: 141

Re: k(1)/k(-1)

k' is referring to the reverse reaction.
by MichelleRamirez_2F
Sat Mar 16, 2019 8:18 pm
Forum: General Science Questions
Topic: Midterm
Replies: 1
Views: 107

Re: Midterm

It has to do with the temperature. SInce we are increasing the temperature, and the reaction in endothermic this will accelerate the reaction meaning more product will form, so the equilibrium would shift to the right.
by MichelleRamirez_2F
Sat Mar 16, 2019 8:11 pm
Forum: General Science Questions
Topic: Midterm
Replies: 1
Views: 104

Re: Midterm

This is the link to the midterm solutions: https://lavelle.chem.ucla.edu/wp-conten ... am_ans.pdf
by MichelleRamirez_2F
Sat Mar 16, 2019 8:10 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Approaches to mechanisms
Replies: 2
Views: 45

Re: Approaches to mechanisms

In lecture professor Lavelle mentioned that we only need to focus on the Pre-Equilibrium approach.
by MichelleRamirez_2F
Sat Mar 16, 2019 8:09 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: FORMULAS
Replies: 2
Views: 98

Re: FORMULAS

I know that in the 14B website there is a link to the equation list we are given for the test.
by MichelleRamirez_2F
Sat Mar 16, 2019 1:50 pm
Forum: Ideal Gases
Topic: Bar for partial pressure [ENDORSED]
Replies: 4
Views: 188

Re: Bar for partial pressure [ENDORSED]

Bar is the proper unit for partial pressure for equilibrium constant calculations.
by MichelleRamirez_2F
Sat Mar 16, 2019 1:38 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Final [ENDORSED]
Replies: 9
Views: 146

Re: Final [ENDORSED]

I think they did mention we would be given a sheet like the one for test 2.
by MichelleRamirez_2F
Sat Mar 16, 2019 1:37 pm
Forum: Student Social/Study Group
Topic: Solutions for Tests 1 and 2
Replies: 7
Views: 236

Re: Solutions for Tests 1 and 2

I don't think they post the solutions for the tests because there is usually a review session by a TA where they go over the solutions.
by MichelleRamirez_2F
Sat Mar 16, 2019 1:36 pm
Forum: Balancing Redox Reactions
Topic: How to tell if its in acidic or basic
Replies: 6
Views: 82

Re: How to tell if its in acidic or basic

The problem would state whether it is in a basic or acidic solution.
by MichelleRamirez_2F
Sat Mar 16, 2019 11:30 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: K'
Replies: 4
Views: 68

K'

What is k' and when are we supposed to use it?
by MichelleRamirez_2F
Fri Mar 15, 2019 5:24 pm
Forum: Balancing Redox Reactions
Topic: Test 2
Replies: 2
Views: 109

Test 2

Help with the question: rank in order of increasing oxidation power going from their second oxidation state to neutral: Ti2+, Sn2+, Mg2+.
What lets us know their rank?
by MichelleRamirez_2F
Fri Mar 15, 2019 5:22 pm
Forum: Balancing Redox Reactions
Topic: Test 2
Replies: 5
Views: 74

Test 2

Can someone help with this question from test 2.
Rank the following species in order of increasing reducing power going from their neutral to second oxidation state: Pt, Pb, Cu.
How do we know this?
by MichelleRamirez_2F
Fri Mar 15, 2019 11:23 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: DeltaS Total
Replies: 2
Views: 137

Re: DeltaS Total

I believe it is when it's at equilibrium.
by MichelleRamirez_2F
Fri Mar 15, 2019 11:21 am
Forum: First Order Reactions
Topic: Doubling Concentrations
Replies: 3
Views: 51

Re: Doubling Concentrations

If you are talking about a first order reaction the doubling of a reactant means the reaction rate is doubled. If it's a second order reaction then the reaction rate is increase by a factor of x^2, where x would be your reaction rate.
by MichelleRamirez_2F
Fri Mar 15, 2019 11:16 am
Forum: Second Order Reactions
Topic: units of K
Replies: 3
Views: 123

Re: units of K

For a second order reaction k is Lx mol^-1x s^-1.
by MichelleRamirez_2F
Fri Mar 15, 2019 11:15 am
Forum: First Order Reactions
Topic: Reaction Orders
Replies: 1
Views: 26

Re: Reaction Orders

In the textbook it is mentioned how the reaction order can be a negative number=negative order . This would signify that the concentration value of the species is in the denominator of the rate law. The species in this case is usually a product and it represents the reverse reaction.
by MichelleRamirez_2F
Fri Mar 15, 2019 11:11 am
Forum: Zero Order Reactions
Topic: Zero-order reactions
Replies: 4
Views: 132

Zero-order reactions

What are the units for a zero order reaction, if any?
by MichelleRamirez_2F
Tue Feb 26, 2019 11:22 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Agents and Species
Replies: 3
Views: 56

Agents and Species

What is the difference between a reducing agent and a reduced species? And an oxidizing agent vs a oxidized species?
by MichelleRamirez_2F
Tue Feb 26, 2019 10:48 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Question for Test 2
Replies: 4
Views: 81

Re: Question for Test 2

Since that was part of the last lecture covering the topics of test 2 I would assume we do need to know it.
by MichelleRamirez_2F
Tue Feb 26, 2019 7:41 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Cell potential
Replies: 2
Views: 53

Cell potential

Does the value of the cell potential/E change if the value of your stoichiometric coefficient of one reactant changes?
by MichelleRamirez_2F
Tue Feb 12, 2019 2:34 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Example 8.3 sixth edition
Replies: 3
Views: 76

Example 8.3 sixth edition

In the sixth edition textbook the example problem for specific heat and molar heat states that the temperature changes from 20C to 100C. In their work however they treated the deltaT as 80.K. My question is why they didn't convert 80C to 353K?
by MichelleRamirez_2F
Tue Feb 12, 2019 2:29 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: q=mCdeltaT
Replies: 11
Views: 442

Re: q=mCdeltaT

If you are given moles then use n and molar heat capacity, nad if you are given mass (g) then use m and specific heat capacity of the substance.
by MichelleRamirez_2F
Sun Feb 10, 2019 3:43 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Clarifying about Midterm
Replies: 4
Views: 75

Re: Clarifying about Midterm

I would say that it is only focused on the topics covered in class and if you are using the textbook to only focus on the section of the chapters that come before the Gibbs Free energy section. In the case of the 6th edition it would be to only go up to section 9.11 from Chapter 9.
by MichelleRamirez_2F
Sun Feb 10, 2019 3:39 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Converting Celsius to Kelvin
Replies: 7
Views: 100

Re: Converting Celsius to Kelvin

In the examples we have done in class we have added 273K.
by MichelleRamirez_2F
Sun Feb 10, 2019 3:38 pm
Forum: Ideal Gases
Topic: pH and pOH
Replies: 18
Views: 365

Re: pH and pOH

Usually the problem you are solving will tell you which one to solve for. In some occasions you may have to solve for both for the same problem.
by MichelleRamirez_2F
Fri Dec 07, 2018 8:30 pm
Forum: Lewis Structures
Topic: Lone electrons and polarity
Replies: 1
Views: 78

Re: Lone electrons and polarity

I don't think that lone pairs affect the polarity of an atom. Instead its electronegativity and the atomic radius would affect how likely it would be able for its electron cloud to be distorted.
by MichelleRamirez_2F
Fri Dec 07, 2018 8:28 pm
Forum: Naming
Topic: Naming
Replies: 3
Views: 74

Re: Naming

You have to see what the charge would be on the compound to figure out how many potassium molecules would neitralize that charge.
by MichelleRamirez_2F
Fri Dec 07, 2018 8:20 pm
Forum: General Science Questions
Topic: what specifically makes thymine a base.
Replies: 2
Views: 209

Re: what specifically makes thymine a base.

Following the answer above, the nitrogen would make the thymine the base because it has a lone pair electrons.
by MichelleRamirez_2F
Fri Dec 07, 2018 8:16 pm
Forum: Lewis Acids & Bases
Topic: Why is water always a lewis base?
Replies: 2
Views: 63

Re: Why is water always a lewis base?

It depends on the reaction because water is considered to be amphoteric meaning it can be an acid or base.
by MichelleRamirez_2F
Fri Dec 07, 2018 8:15 pm
Forum: General Science Questions
Topic: PH3 or NH3
Replies: 2
Views: 233

Re: PH3 or NH3

NH3 would have a higher boiling point because the nitrogen forms bonds with H. Remember that for intermolecular forces it goes from Van der Waals, dipole-dipole to H-binding as the strongest.
by MichelleRamirez_2F
Fri Dec 07, 2018 8:13 pm
Forum: Amphoteric Compounds
Topic: What makes something amphoteric?
Replies: 6
Views: 186

Re: What makes something amphoteric?

H2O is amphoteric because it can be an acid or base. This means is can either accept an electron or donate an electron.
by MichelleRamirez_2F
Fri Dec 07, 2018 8:11 pm
Forum: General Science Questions
Topic: what determines boiling point
Replies: 2
Views: 178

Re: what determines boiling point

Boiling point from least to greatest is Van der Walls, dipole-dipole and H-bonds.What helps determine boiling point can also be the size of the molecule because the bigger the molecule, the more London forces which also leads to a higher boiling point.
by MichelleRamirez_2F
Fri Dec 07, 2018 8:09 pm
Forum: General Science Questions
Topic: Finals
Replies: 4
Views: 229

Re: Finals

All topics will be covered in the syllabus, so you should be able to understand quantum as equally as the other topics.
by MichelleRamirez_2F
Fri Dec 07, 2018 8:08 pm
Forum: General Science Questions
Topic: amphiprotic
Replies: 3
Views: 209

Re: amphiprotic

Amphiprotic is when the compound can either donate or accept a hydrogen.
by MichelleRamirez_2F
Fri Dec 07, 2018 8:06 pm
Forum: Administrative Questions and Class Announcements
Topic: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
Replies: 118
Views: 4961

Re: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]

Can someone explain why hemogrlobin is tetradentrate but cisplatin is monodentrate?
by MichelleRamirez_2F
Thu Dec 06, 2018 8:25 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: How to tell if something is a chelate
Replies: 6
Views: 122

Re: How to tell if something is a chelate

I think that a chelate is when the ring structured compound binds a central metal at two or more places.
by MichelleRamirez_2F
Thu Dec 06, 2018 8:20 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pH calculation
Replies: 4
Views: 86

pH calculation

When we are loking for pH why is pH= log10[H30]? How do we know what the value of [H3O] is?
by MichelleRamirez_2F
Tue Dec 04, 2018 11:01 pm
Forum: Biological Examples
Topic: Ligands
Replies: 6
Views: 200

Ligands

When given a chemical formula how do we know which one is the cetral metal atom or ion?
by MichelleRamirez_2F
Tue Dec 04, 2018 9:51 pm
Forum: Lewis Structures
Topic: Lewis Structure bonds
Replies: 3
Views: 91

Re: Lewis Structure bonds

So to make sure we have the correct Lewis structure we calculate the formal charge of the possible structures we have drawn?
by MichelleRamirez_2F
Tue Dec 04, 2018 9:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pairs
Replies: 11
Views: 169

Re: Lone Pairs

Lone pairs affect the structure of the VSEPR model beacues they have the highest repulsion so they try to be fathest apart from each other. Also they cause repulsion with the other atoms bonded with the central atom which is why the angles of some shapes turn out to be slightly smaller than the orig...
by MichelleRamirez_2F
Tue Dec 04, 2018 9:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pairs
Replies: 11
Views: 169

Re: Lone Pairs

Arlene Linares 3A wrote:Can someone explain lone pairs to me?
Lone pairs are the pair of electrons that do not get shared with another atom in the molecule.
by MichelleRamirez_2F
Tue Dec 04, 2018 9:36 pm
Forum: General Science Questions
Topic: Can We Take The Final In Pencil?
Replies: 8
Views: 332

Re: Can We Take The Final In Pencil?

I think you are only allowed to write the tests in pen. Atleast for the midterm they mentioned that only what was written in pen would be graded. This seems reasonable to since we receive our tests back after they are graded and things written in pencil can easily be erased.
by MichelleRamirez_2F
Tue Dec 04, 2018 9:31 pm
Forum: Lewis Structures
Topic: Lewis Structure bonds
Replies: 3
Views: 91

Lewis Structure bonds

How do you know when. you need to form a double bond or if the bond between the atoms must stay as single bonds?
by MichelleRamirez_2F
Tue Dec 04, 2018 9:28 pm
Forum: Sigma & Pi Bonds
Topic: Number of sigma and pi bonds
Replies: 5
Views: 253

Re: Number of sigma and pi bonds

You would still have to draw the Lewis structure ( with help of the hybridization) to see whether the bonds are single, double and triple bonds. Once you know the structure the number of sigma bonds are the number of. single bonds and the pi bonds are any bonds starting from the second bond. This me...
by MichelleRamirez_2F
Thu Nov 29, 2018 12:16 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 1
Views: 27

Bond Angles

When we are considering the bond angles, for molecules with lone pairs do we consider the bond lengths of the electron arrangement or of the molecular shape?
by MichelleRamirez_2F
Wed Nov 28, 2018 4:20 pm
Forum: Electronegativity
Topic: Ionic Character
Replies: 7
Views: 306

Re: Ionic Character

Electronegativity decreases down a group since Cl is lower than O, I want to.say that O is more electronegative than Cl.
by MichelleRamirez_2F
Wed Nov 28, 2018 4:14 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw Bond Angles
Replies: 6
Views: 5133

Re: Seesaw Bond Angles

The lone pair is placed on the axis of the molecule. This is the Axail lone pair and it is placed in this position because of the repulsion of the atoms from the electron pair.
by MichelleRamirez_2F
Wed Nov 28, 2018 4:10 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar and Non-Polar
Replies: 2
Views: 60

Polar and Non-Polar

When we are trying to answer whether a molecule is polar or non polar how do we determine the direction of the bond?
by MichelleRamirez_2F
Wed Nov 28, 2018 4:09 pm
Forum: Hybridization
Topic: Polar Power
Replies: 5
Views: 92

Re: Polar Power

The atomic radii helps you understand why the polarizing power increases or decreases since the size of the radius correlates with how much power the nucleus has on the valence electrons.
by MichelleRamirez_2F
Wed Nov 28, 2018 4:06 pm
Forum: Lewis Structures
Topic: Lewis structures vs VSEPR
Replies: 2
Views: 54

Re: Lewis structures vs VSEPR

For VSEPR since the central atom is the "important atom" we only focus on the shared electron it has with the other atoms. Because of this it is not necessary to dram the valence electrons of the other atoms.
by MichelleRamirez_2F
Sat Nov 03, 2018 10:19 pm
Forum: Quantum Numbers and The H-Atom
Topic: Quantum number Ms
Replies: 3
Views: 207

Quantum number Ms

How do we know when the Ms quantum number should be -1/2, or 1/2?
by MichelleRamirez_2F
Thu Oct 25, 2018 6:37 pm
Forum: Quantum Numbers and The H-Atom
Topic: Quantum numbers
Replies: 3
Views: 136

Quantum numbers

What is the difference between principal quantum number and magnetic quantum number?
by MichelleRamirez_2F
Thu Oct 25, 2018 6:35 pm
Forum: Photoelectric Effect
Topic: unit conversion hw Q 1.3
Replies: 2
Views: 117

Re: unit conversion hw Q 1.3

You should convert the given values to the required SI units before plugging them into the equation you are using (like e=hv etc) that way when you are solving the problem you are able to "cross out" the units that you don't need in your final answer. At the end, if they are asking for a c...
by MichelleRamirez_2F
Thu Oct 25, 2018 6:29 pm
Forum: Administrative Questions and Class Announcements
Topic: Constants and Equations
Replies: 2
Views: 106

Re: Constants and Equations

The front page of every exam should gave the general equations and constants that you will need.
by MichelleRamirez_2F
Thu Oct 04, 2018 8:22 pm
Forum: Significant Figures
Topic: Determining Sig Figs
Replies: 6
Views: 87

Re: Determining Sig Figs

You may also want to refer to Dr. Lavelle's "Math Assistance" section where he has two documents that goes over the use of significant figures thoroughly!
by MichelleRamirez_2F
Thu Oct 04, 2018 8:19 pm
Forum: Significant Figures
Topic: Determining Sig Figs
Replies: 6
Views: 87

Re: Determining Sig Figs

When you are multiplying you must use the smallest number of significant figures in your data to be the number of significant figures in your answer. For example, if you are multiplying 6.18165 x 3.56=22.0 your answer must only have 3 significant figures since that is the smallest number of signific...
by MichelleRamirez_2F
Thu Oct 04, 2018 8:13 pm
Forum: Balancing Chemical Reactions
Topic: Net number of molecules
Replies: 3
Views: 89

Re: Net number of molecules

The net number of molecules would be the difference between the number of moles produced minus the number of moles you began with. You will know the number of moles of your reactants and products by adding the given coefficients in front of their respective molecules form the reaction. (Make sure yo...
by MichelleRamirez_2F
Thu Oct 04, 2018 8:06 pm
Forum: SI Units, Unit Conversions
Topic: How does grading for discussion posts work?
Replies: 73
Views: 2195

Re: How does grading for discussion posts work?

Raquel Rodriguez wrote:Do you guys know when our first test is?

It would be during your discussion section in week 2.

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