Search found 72 matches

by Porus_Karwa_2E
Sat Mar 16, 2019 8:43 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Final
Replies: 3
Views: 34

Re: Final

Homework questions and skimming over lecture notes always help me
by Porus_Karwa_2E
Sat Mar 16, 2019 8:38 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: k(1)/k(-1)
Replies: 4
Views: 42

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

k(1)/k' =K (equilibrium constant)
k' is the reverse or second process
by Porus_Karwa_2E
Mon Mar 11, 2019 7:38 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: equations for q
Replies: 9
Views: 93

Re: equations for q

We use q=mCdeltaT when mass is given in grams. q=nCdeltaT when moles are given
by Porus_Karwa_2E
Mon Mar 11, 2019 7:32 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Y-Axis Units
Replies: 2
Views: 29

Y-Axis Units

When graphing Kinetics what should we look for on the y-axis for the different orders. Also what units do we use for each
by Porus_Karwa_2E
Mon Mar 11, 2019 7:28 pm
Forum: General Rate Laws
Topic: Unique Rate Law
Replies: 4
Views: 34

Unique Rate Law

What exactly does Unique Rate Law mean?
by Porus_Karwa_2E
Mon Mar 11, 2019 7:27 pm
Forum: Experimental Details
Topic: Fast vs Slow
Replies: 2
Views: 27

Re: Fast vs Slow

Normally, the problem will tell you what the rate determining reaction is.
by Porus_Karwa_2E
Mon Mar 11, 2019 7:24 pm
Forum: General Science Questions
Topic: Final
Replies: 7
Views: 121

Re: Final

There is no curve, but Dr.Lavelle does adjust the grades a bit so everyone benefits.
by Porus_Karwa_2E
Mon Mar 11, 2019 7:20 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Meaning of k
Replies: 4
Views: 27

Re: Meaning of k

k is the rate constant, K is the equilibrium constant
by Porus_Karwa_2E
Sat Mar 02, 2019 10:55 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Test #2
Replies: 10
Views: 124

Re: Test #2

We should get it back in section next week.
by Porus_Karwa_2E
Sat Mar 02, 2019 10:55 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: finding DeltaG
Replies: 6
Views: 63

Re: finding DeltaG

There are multiple methods, but deltaG=deltaH-TdeltaS is a powerful equation. Also, we can do G=-nFE
by Porus_Karwa_2E
Sat Mar 02, 2019 10:54 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Order of Cell Diagrams
Replies: 13
Views: 121

Re: Order of Cell Diagrams

I put in order of the reaction. So for Fe2+ to Fe3+ on the anode side would go in that order.
On the reduction (cathode) we would write in order Fe3+,Fe2+
by Porus_Karwa_2E
Sat Mar 02, 2019 10:52 pm
Forum: Ideal Gases
Topic: pV=nRT
Replies: 12
Views: 148

Re: pV=nRT

We can use it to solve for variables that might be unknown to us from the problem.
by Porus_Karwa_2E
Sun Feb 24, 2019 5:31 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2
Replies: 7
Views: 111

Re: Test 2

Gibbs free energy up to Friday's lecture
by Porus_Karwa_2E
Sun Feb 24, 2019 5:26 pm
Forum: Student Social/Study Group
Topic: How are you guys going to study for Test 2?
Replies: 10
Views: 101

Re: How are you guys going to study for Test 2?

I think Homework problems are the best indicator of what's going to be on the exam.
by Porus_Karwa_2E
Sun Feb 24, 2019 5:26 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Spontaneous?
Replies: 6
Views: 53

Re: Spontaneous?

If the change in DeltaG is negative then the forward reaction will be spontaneous, but if deltaG is positive then the reverse reaction is spontaneous.
by Porus_Karwa_2E
Sun Feb 17, 2019 8:52 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 802210

Re: Post All Chemistry Jokes Here

Q: Why was the mole of oxygen molecules excited when he walked out of the singles bar?
A: He got Avogadro's number!
by Porus_Karwa_2E
Tue Feb 12, 2019 1:49 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Acid Base
Replies: 3
Views: 47

Re: Acid Base

Ka is equal to 10^-pka. Once you find the Ka value you can solve for [H+] using the reaction equation. From that we can find pH.
In other words, yes you're correct
by Porus_Karwa_2E
Tue Feb 12, 2019 1:43 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Heating Curve
Replies: 3
Views: 57

Heating Curve

Can someone please explain how to calculate the entropy through different phase changes using the heating curve as a guide?
Thanks!
by Porus_Karwa_2E
Fri Feb 08, 2019 7:17 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Ideal Gas Laws
Replies: 4
Views: 35

Re: Ideal Gas Laws

The ideal gas laws go with PV=nRT where P is 1atm n is 1 mole of gas.
by Porus_Karwa_2E
Fri Feb 08, 2019 7:14 pm
Forum: Calculating Work of Expansion
Topic: Conversions to joules?
Replies: 4
Views: 64

Re: Conversions to joules?

m^3 is equal to about 1000 L so you'd need to do the conversion of that to give you atm x L. 101.325 atmXL is equal to 1 joule. I believe this conversion is somewhere on the formula sheet for 14B.
by Porus_Karwa_2E
Fri Feb 08, 2019 7:12 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Study Guides
Replies: 15
Views: 244

Re: Study Guides

The online modules might be able to help you understand concepts, but for study guides I would go to TA run review sessions since they typically show problems from past Midterms.
by Porus_Karwa_2E
Sat Feb 02, 2019 9:16 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Angles
Replies: 5
Views: 57

Re: Bond Angles

The formation of bonds is exothermic, thus we place a negative sign.
by Porus_Karwa_2E
Sat Feb 02, 2019 9:16 pm
Forum: Calculating Work of Expansion
Topic: SI unit for P
Replies: 6
Views: 61

Re: SI unit for P

Our textbook uses bar mostly, but atm is technically the proper SI unite for pressure. Since there is only a 1% difference between bar and atm they are interchangeable though.
by Porus_Karwa_2E
Sat Feb 02, 2019 9:14 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: U=q+w
Replies: 3
Views: 37

U=q+w

What exactly is delta U and what does the equation for it mean?
by Porus_Karwa_2E
Sat Feb 02, 2019 9:10 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: calorimeters
Replies: 7
Views: 79

Re: calorimeters

When we are given questions on exams I believe everything we need to know will be provided to us.
by Porus_Karwa_2E
Sat Jan 26, 2019 7:20 pm
Forum: Phase Changes & Related Calculations
Topic: Modules
Replies: 17
Views: 158

Re: Modules

No they are not required but they are good practice
by Porus_Karwa_2E
Sat Jan 26, 2019 7:18 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Signs in bond enthalpies
Replies: 4
Views: 41

Re: Signs in bond enthalpies

Yes, just add up the enthalpies of prods-reactants
by Porus_Karwa_2E
Sat Jan 26, 2019 7:17 pm
Forum: Phase Changes & Related Calculations
Topic: Sublimation
Replies: 6
Views: 85

Re: Sublimation

This does not effect solids or liquids
by Porus_Karwa_2E
Sun Jan 20, 2019 4:58 pm
Forum: Student Social/Study Group
Topic: test 1
Replies: 10
Views: 147

Re: test 1

Karyn Nguyen 1K wrote:Will we be tested on concepts (like multiple choice or short answers) or will it just be math problems?


Based on what happened last quarter in 14A, Dr. Lavelle's style is having mostly math problems with a sprinkling of concept questions throughout the exam.
by Porus_Karwa_2E
Sun Jan 20, 2019 4:57 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatelier's Principle
Replies: 3
Views: 29

Re: Le Chatelier's Principle

Changing the concentration doesn't change K because if we take out more reactants the equation will shift in order to make up for the deficient amount of reactants to make the K ratio the same.
by Porus_Karwa_2E
Sun Jan 20, 2019 4:53 pm
Forum: Student Social/Study Group
Topic: test 1
Replies: 10
Views: 147

Re: test 1

It is outline 1 with acids and bases
by Porus_Karwa_2E
Sun Jan 13, 2019 12:09 pm
Forum: Ideal Gases
Topic: bar or atm
Replies: 8
Views: 102

Re: bar or atm

Both are approximately the same thing, but atm is the SI unit for pressure so I'd put your answer in atm if not stated otherwise.
by Porus_Karwa_2E
Sun Jan 13, 2019 12:06 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: solids & liquids
Replies: 5
Views: 38

Re: solids & liquids

Solid and liquids don't have concentrations so no reaction would really occur
by Porus_Karwa_2E
Sun Jan 13, 2019 12:05 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Using variables in ICE tables
Replies: 2
Views: 45

Re: Using variables in ICE tables

To add onto the above comment the X variable is much easier to use as after you are done assigning variables we would just need to use the quadratic equation.
by Porus_Karwa_2E
Sat Dec 08, 2018 6:06 pm
Forum: Electronegativity
Topic: Exceptions
Replies: 3
Views: 69

Re: Exceptions

The trend is that across (left to right) a group electronegativity increases and up a period it also increases.
I am unaware of any exceptions to this trend.
by Porus_Karwa_2E
Sat Dec 08, 2018 6:05 pm
Forum: Lewis Acids & Bases
Topic: Trends of Acids and Bases
Replies: 2
Views: 53

Re: Trends of Acids and Bases

I just came out of a chem review session and I was told that on the exam we will have to order from most to least acidic, but they will never make it so that we must confirm an oxoacid with a non-oxoacid. It is always comparing oxoacids with oxoacids and non with non. Just know longer the atomic rad...
by Porus_Karwa_2E
Sat Dec 08, 2018 6:01 pm
Forum: Identifying Acidic & Basic Salts
Topic: salts of weak acids and bases
Replies: 4
Views: 84

Re: salts of weak acids and bases

Will this be on the chem14A final?
by Porus_Karwa_2E
Sat Dec 08, 2018 6:00 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Oxyacids
Replies: 4
Views: 77

Re: Oxyacids

If the central atom is not the same in a set of oxoacids then the molecule with the central atom with the highest electronegativity will be the most acidic. If the central atoms are the same for a group of oxoacids then we must see the number of Oxygens that are attached to the central atom. The mor...
by Porus_Karwa_2E
Sun Dec 02, 2018 8:20 pm
Forum: Coordinate Covalent Bonds
Topic: Oxidation states "()" in naming coord compounds
Replies: 4
Views: 78

Re: Oxidation states "()" in naming coord compounds

Yes the central atoms is always positively charged.
by Porus_Karwa_2E
Sun Dec 02, 2018 8:19 pm
Forum: Hybridization
Topic: Double and Triple Bonds
Replies: 17
Views: 140

Re: Double and Triple Bonds

No they do not. The only thing that matters is the areas of electron density.
by Porus_Karwa_2E
Sun Dec 02, 2018 8:06 pm
Forum: Hybridization
Topic: Sigma bonds
Replies: 9
Views: 88

Re: Sigma bonds

3 pi bonds and 1 sigma bond means its a quadruple bond.
by Porus_Karwa_2E
Mon Nov 26, 2018 4:46 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 3 Content
Replies: 3
Views: 102

Test 3 Content

According to Dr. Lavelle, the test will be on Chapter 3 (3.12 6th edition) and all of chapter 4, but my TA and I believe other TA's did review content in their sections that is outside of this text (like Acids and Bases and Intermolecular forces). Will this additional content also be included on Tes...
by Porus_Karwa_2E
Fri Nov 23, 2018 2:22 pm
Forum: Lewis Structures
Topic: Homework #4.13 (C)
Replies: 2
Views: 51

Re: Homework #4.13 (C)

It is more stable in terms of formal charge like this. Plus this doesn't break the octet rule.
by Porus_Karwa_2E
Fri Nov 23, 2018 2:20 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR RULE 3
Replies: 4
Views: 93

Re: VSEPR RULE 3

A double bond will count as one electron density so it doesn't affect the shape of the molecule.
by Porus_Karwa_2E
Fri Nov 23, 2018 2:19 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 3
Replies: 10
Views: 190

Re: Test 3

Test 3 will be more conceptual based rather than calculations.
by Porus_Karwa_2E
Sat Nov 17, 2018 9:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Shapes
Replies: 4
Views: 62

Re: VSEPR Shapes

The amount of lone pairs around the central atom also matters as in a T Shape there are 2 lone pairs on the central atom that makes the other atoms move over. On Trigonal Planer the lone pairs of the other atoms push eachother to make a triangle
by Porus_Karwa_2E
Sat Nov 17, 2018 9:14 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: AXE
Replies: 7
Views: 127

Re: AXE

Well X is the number of possible bonds and E is the number of lone pairs. So you'd have to memorize this combination for each shape.
by Porus_Karwa_2E
Sat Nov 17, 2018 9:13 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Model
Replies: 3
Views: 44

Re: VSEPR Model

Technically no you would just need to memorize the shapes and when each geometrical figure should be applied. I will admit though that the formula will definitely help.
by Porus_Karwa_2E
Sat Nov 10, 2018 2:08 pm
Forum: Electronegativity
Topic: Electronegativity
Replies: 8
Views: 119

Re: Electronegativity

More electronegative means that the element more greatly wants another electron to fill its octet.
by Porus_Karwa_2E
Sat Nov 10, 2018 2:06 pm
Forum: Ionic & Covalent Bonds
Topic: Hydrogen bonding
Replies: 7
Views: 144

Re: Hydrogen bonding

The increased bond length makes the bonds stronger.
by Porus_Karwa_2E
Sat Nov 10, 2018 2:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape
Replies: 2
Views: 91

Re: Molecular Shape

We won't be required to draw a VSEPR model, but a tetrahedral model doesn't have any lone pairs as exhibited in CH4.
by Porus_Karwa_2E
Sat Nov 10, 2018 2:03 pm
Forum: Bond Lengths & Energies
Topic: MIDTERM Bond Length Question
Replies: 15
Views: 224

Re: MIDTERM Bond Length Question

I got 130 pm because I took the average of the 140pm and 120pm.
by Porus_Karwa_2E
Sun Nov 04, 2018 1:35 am
Forum: General Science Questions
Topic: Midterm
Replies: 3
Views: 115

Re: Midterm

The difficulty level should be comparable to the homework problems
by Porus_Karwa_2E
Sat Nov 03, 2018 11:49 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: s-block, p-block, d-block
Replies: 3
Views: 54

s-block, p-block, d-block

Hi just confirming for the midterm we'll only have to be responsible for the configuration of all of the s-block, all the p-block, and just the first row of the d-block?
by Porus_Karwa_2E
Sat Nov 03, 2018 4:38 pm
Forum: Student Social/Study Group
Topic: Sig Figs on Midterm
Replies: 13
Views: 433

Sig Figs on Midterm

My TA wasn't particularly strict on SigFigs on Tests #1 and #2. Will it be more of a factor for the midterm?
by Porus_Karwa_2E
Sat Oct 27, 2018 10:10 pm
Forum: Lewis Structures
Topic: Periodic Table Trends
Replies: 3
Views: 32

Re: Periodic Table Trends

Both are 2 different things but the trend is the same.
by Porus_Karwa_2E
Sat Oct 27, 2018 7:46 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Delta X relationship with Delta P
Replies: 3
Views: 101

Re: Delta X relationship with Delta P

I believe that deltaP and deltaX are inversely proportional. A good rule of thumb is that variables on the same side of an equation are inversely proportional, while variables on different sides of an equation are directly proportion. For example, in p=mv, p and v are directly proportional (p and m ...
by Porus_Karwa_2E
Sat Oct 27, 2018 7:35 pm
Forum: Ionic & Covalent Bonds
Topic: Bond
Replies: 9
Views: 138

Re: Bond

I believe the bond is stronger when there are more bonds. So in terms of energy needed to break the bonds single<double<triple. Also, interestingly, for the length of a bond the more bonds an atom has the shorter the bond. So a triple bond is shorter than a double bond and a double bond is shorter t...
by Porus_Karwa_2E
Sun Oct 21, 2018 1:25 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Lecture Question on Orbitals
Replies: 4
Views: 71

Lecture Question on Orbitals

During the lecture, Dr.Lavelle gave an example where n=2, l=1, and m=-1

From this, he told us this is an electron in 2px state. I don't exactly understand how he got the "x" from this information.
by Porus_Karwa_2E
Sun Oct 21, 2018 1:20 pm
Forum: Quantum Numbers and The H-Atom
Topic: Where does this section end in the textbook? [ENDORSED]
Replies: 2
Views: 48

Re: Where does this section end in the textbook? [ENDORSED]

For the exam, we will only need to go up to Quantum Numbers and Orbitals.
by Porus_Karwa_2E
Sun Oct 21, 2018 1:16 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Test 2 Material
Replies: 9
Views: 77

Re: Test 2 Material

Dr.Lavelle said that everything in Quantum World up to the information presented on Friday's lecture is what we will be tested on. In other words, the lecture from Friday is the cutoff.
by Porus_Karwa_2E
Sun Oct 21, 2018 1:15 pm
Forum: Properties of Light
Topic: TEST 2
Replies: 7
Views: 120

Re: TEST 2

It is confirmed that we won't need to memorize any of them
by Porus_Karwa_2E
Sun Oct 21, 2018 1:11 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenbergy Uncertainty Equation
Replies: 3
Views: 71

Re: Heisenbergy Uncertainty Equation

The equation he gave in class is correct.
by Porus_Karwa_2E
Sat Oct 13, 2018 1:19 pm
Forum: Limiting Reactant Calculations
Topic: Test 1
Replies: 5
Views: 191

Re: Test 1

On the exam, we were supposed to box our answers, so I'm pretty sure that if you boxed the right answer it would negate the "doodles"
by Porus_Karwa_2E
Sat Oct 13, 2018 1:15 pm
Forum: Limiting Reactant Calculations
Topic: Test 1
Replies: 5
Views: 159

Re: Test 1

It would make sense to get our grades back next time we go into discussion yes.
by Porus_Karwa_2E
Sat Oct 13, 2018 1:15 pm
Forum: Properties of Light
Topic: Grades
Replies: 2
Views: 57

Re: Grades

I believe the syllabus does state that we won't know our grades until the end of the quarter since the class is set up on a bell curve of some sorts (only meant to help your grade).
by Porus_Karwa_2E
Sun Oct 07, 2018 5:08 pm
Forum: Properties of Light
Topic: Chapter 1 Homework
Replies: 6
Views: 129

Chapter 1 Homework

Is Chapter 1 homework due in our next discussion period or is it due on the one after that?
by Porus_Karwa_2E
Sun Oct 07, 2018 3:04 pm
Forum: Empirical & Molecular Formulas
Topic: Molecular Formula
Replies: 12
Views: 112

Re: Molecular Formula

All you have to do is count the atoms out for the molecular formula.
by Porus_Karwa_2E
Sun Sep 30, 2018 5:03 pm
Forum: SI Units, Unit Conversions
Topic: Length Units
Replies: 15
Views: 439

Re: Length Units

Typically, yes we should just infer that we are supposed to use SI units
by Porus_Karwa_2E
Sun Sep 30, 2018 5:01 pm
Forum: SI Units, Unit Conversions
Topic: Avogadro #
Replies: 9
Views: 346

Re: Avogadro #

Avogadro's number is pretty much just "things." So for instance, if you want to turn moles to molecules you'd multiply the moles you have by 6.022x10^23 molecules
by Porus_Karwa_2E
Sun Sep 30, 2018 4:58 pm
Forum: General Science Questions
Topic: First Homework
Replies: 3
Views: 130

Re: First Homework

Remember we only have to do 7 problems from the hw list on the syllabus

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