## Search found 78 matches

Sat Mar 16, 2019 4:22 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: E equations and when to use them?
Replies: 2
Views: 121

### Re: E equations and when to use them?

Yes and in the event that you are dealing with a concentration cell the E^o becomes 0
Sat Mar 16, 2019 4:21 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst
Replies: 14
Views: 420

### Re: Nernst

do you think we have to know how to derive the nernst equation for our final?
Sat Mar 16, 2019 4:20 pm
Forum: First Order Reactions
Topic: pseudo first order [ENDORSED]
Replies: 5
Views: 548

### Re: pseudo first order[ENDORSED]

You make the other concentrations so big that they are essentially viewed as constant so the rate law becomes "fake" first order
Sat Mar 16, 2019 4:19 pm
Forum: First Order Reactions
Topic: deriving integrated forms
Replies: 1
Views: 274

### deriving integrated forms

Do you think it is necessary to know how to derive the integrated forms of the rate laws for the final?
Wed Mar 13, 2019 8:50 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts
Replies: 6
Views: 224

### Re: Catalysts

Also remember that it is acceptable for a catalyst to appear in the rate law
Wed Mar 13, 2019 8:49 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Exothermic vs. Endothermic
Replies: 10
Views: 491

### Re: Exothermic vs. Endothermic

An endothermic reaction has a higher energy barrier in the forward direction so k forward is greater than k reverse which means that if you heated up a endothermic reaction the k forward would increase so the K overall would also increase and products would be favored For an exothermic reaction, the...
Wed Mar 13, 2019 8:47 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts vs Intermediates
Replies: 4
Views: 137

### Re: Catalysts vs Intermediates

a catalyst is not consumed in a reaction whereas an intermediate is used up in a reaction and you can cancel it out in the elementary steps. This is why it is okay to have a catalyst in your rate law as well.
Wed Mar 13, 2019 8:44 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Arrhenius Equation
Replies: 1
Views: 67

### Re: Arrhenius Equation

use the first one when you are trying to find out K at different temperatures
Wed Mar 13, 2019 8:42 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: k & K
Replies: 18
Views: 870

### Re: k & K

It is also important to note that K can be figured out by taking the ratio of the forward reaction K to the reverse reaction K
Thu Mar 07, 2019 12:21 pm
Forum: First Order Reactions
Topic: First order graph
Replies: 7
Views: 334

### Re: First order graph

If ln(A) vs Time is a straight line, then the reaction is a first order reaction
Thu Mar 07, 2019 12:20 pm
Forum: First Order Reactions
Topic: Pseudo-First-Order Reaction
Replies: 5
Views: 231

### Re: Pseudo-First-Order Reaction

I do not understand, what exactly is a psuedo reaction?
Thu Mar 07, 2019 12:19 pm
Forum: First Order Reactions
Topic: Half-Life 1st Order Reaction
Replies: 6
Views: 226

### Re: Half-Life 1st Order Reaction

Also remember that you can always derive this equation it you have any doubts
Tue Feb 26, 2019 1:32 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Replies: 1
Views: 75

How do you know when to add an inert metal to your cell diagram?
Tue Feb 26, 2019 1:26 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: test 2
Replies: 6
Views: 191

### Re: test 2

do you think we will get a list of redox equations like the appendix in our textbook?
Mon Feb 25, 2019 9:39 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Test 2
Replies: 4
Views: 212

### Test 2

What sections from electrochemistry will be tested on test 2?
Wed Feb 20, 2019 8:15 pm
Forum: Balancing Redox Reactions
Topic: test 2
Replies: 5
Views: 504

### Re: test 2

What sections in the seventh edition will be on the test 2
Wed Feb 20, 2019 8:15 pm
Forum: Balancing Redox Reactions
Topic: determining cathode from anode
Replies: 11
Views: 788

### Re: determining cathode from anode

Also it is just standard for the anode to appear on the left
Wed Feb 20, 2019 8:14 pm
Forum: Balancing Redox Reactions
Topic: flipping the sign of anodes
Replies: 5
Views: 1066

### Re: flipping the sign of anodes

you don't really have to flip the sign of the anode because in the equation you are subtracting the anode so the sign will become positive or favorable automatically just due to the equation we are supposed to use
Wed Feb 20, 2019 8:13 pm
Forum: Balancing Redox Reactions
Topic: Salt Bridge
Replies: 4
Views: 167

### Re: Salt Bridge

Is the salt bridge the same thing as a porous disk?
Wed Feb 13, 2019 2:40 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: difference in states
Replies: 6
Views: 429

### Re: difference in states

Yes for example if the pressure is constant you know that delta h will equal q
Mon Feb 11, 2019 11:02 pm
Forum: Administrative Questions and Class Announcements
Topic: Lyndon's HOTDOG MIDTERM REVIEW SESSION!! FINALLY!
Replies: 49
Views: 4025

### Re: Lyndon's HOTDOG MIDTERM REVIEW SESSION!! FINALLY!

when will you post the answers to hotdog?
Sun Feb 10, 2019 7:56 pm
Forum: Calculating Work of Expansion
Topic: Units
Replies: 7
Views: 264

### Re: Units

Does anyone have a good summary of all the equations we should know? some of them aren't on the equation sheet...
Sun Feb 10, 2019 7:55 pm
Forum: Calculating Work of Expansion
Topic: work equations
Replies: 4
Views: 203

### Re: work equations

irreversible can also be called "constant pressure"
Sun Feb 10, 2019 7:53 pm
Forum: Phase Changes & Related Calculations
Topic: heat of a phase change
Replies: 5
Views: 227

### Re: heat of a phase change

Phase changes occur when the temperature is constant on the flat lines of the heating curve and you use: mass X enthalpy
Sun Feb 10, 2019 7:52 pm
Forum: Phase Changes & Related Calculations
Topic: Negative work
Replies: 11
Views: 414

### Re: Negative work

If the work is negative that means the system DID the work so it lost the energy as work

if the work was positive that means that work was done ON the system so it gained energy as work
Sun Feb 10, 2019 7:51 pm
Forum: Phase Changes & Related Calculations
Topic: Phase change equation
Replies: 1
Views: 127

### Re: Phase change equation

When the temperature is rising you need to use q=mcT (This is on the slanted lines of the heating curve)
When the temperature is constant and the substance is undergoing a phase change you use: mass X enthalpy
Wed Jan 30, 2019 1:40 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Best Method
Replies: 7
Views: 338

### Re: Best Method

DO we have to know how to use every single method? Or, can we just always default to the method we feel most comfortable with?
Wed Jan 30, 2019 1:39 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Replies: 3
Views: 161

So, we have not gone over 4A quite yet?
Wed Jan 30, 2019 1:38 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Isolated systems
Replies: 10
Views: 273

### Re: Isolated systems

A good example of an isolated system would be a bomb calorimeter no energy is exchanged with the surroundings
Wed Jan 30, 2019 1:37 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law
Replies: 4
Views: 218

### Hess's Law

Is there a certain order for approaching a Hess's Law problem that anyone finds useful? For example, is there a certain order in which you choose to balance and compute all the different equations?
Wed Jan 30, 2019 1:35 pm
Forum: Phase Changes & Related Calculations
Topic: Delta Hº versus delta H
Replies: 7
Views: 863

### Re: Delta Hº versus delta H

Does this apply to all other variables as well?
Wed Jan 30, 2019 1:35 pm
Forum: Phase Changes & Related Calculations
Topic: Work
Replies: 5
Views: 253

### Re: Work

Why is work not a state property?
Wed Jan 30, 2019 1:34 pm
Forum: Phase Changes & Related Calculations
Topic: Standard State
Replies: 6
Views: 361

### Re: Standard State

Is the reason that N2 has enthalpy of 0 is because N2 goes to N2 so the change in enthalpy is 0? I am confused how you know it is zero
Wed Jan 30, 2019 1:33 pm
Forum: Phase Changes & Related Calculations
Topic: Standard State
Replies: 6
Views: 361

### Re: Standard State

Why is the enthalpy for something in standard state 0?
Wed Jan 30, 2019 1:32 pm
Forum: Phase Changes & Related Calculations
Topic: State Properites
Replies: 7
Views: 226

### Re: State Properites

I think Lavelle explained this concept well with the analogy of a mountain and hikers. If one group of hikers took a steep path to reach the top of the mountain and another group took a leisure path to the top of the mountain both groups have ended up at the same spot regardless of which path was ta...
Wed Jan 30, 2019 1:31 pm
Forum: Phase Changes & Related Calculations
Topic: Week 4 Homework
Replies: 12
Views: 584

### Re: Week 4 Homework

Why does this section talk about delta U? I don't recall learning about delta U in lecture...
Wed Jan 30, 2019 1:30 pm
Forum: Phase Changes & Related Calculations
Topic: Phase changes
Replies: 14
Views: 650

### Re: Phase changes

Why is it that the phase change for water from a liquid to a gas than from a solid to a liquid has more energy?
Wed Jan 30, 2019 1:29 pm
Forum: Phase Changes & Related Calculations
Topic: Steam
Replies: 11
Views: 432

### Re: Steam

It is because there is more energy released for a gas than a liquid. The reason it burns so much is because the energy is released very quickly. For example, my TA explained it like if you were to punch someone slowly it would not hurt as much but if you punch someone quickly the pain is greater. Si...
Wed Jan 30, 2019 1:27 pm
Forum: Phase Changes & Related Calculations
Topic: Test #1
Replies: 11
Views: 444

### Re: Test #1

Wed Jan 30, 2019 1:26 pm
Forum: Phase Changes & Related Calculations
Topic: Heat Capacity
Replies: 10
Views: 469

### Re: Heat Capacity

Which variable represents heat capacity?
Wed Jan 30, 2019 1:26 pm
Forum: Phase Changes & Related Calculations
Topic: Water phase change graph
Replies: 6
Views: 300

### Water phase change graph

I don't understand the graph Lavelle drew for water's phase change. What is the difference between the straight lines and the slanted lines? Which line represents the phase change?
Tue Jan 08, 2019 11:32 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids do not have concentrations?
Replies: 3
Views: 67

### Solids do not have concentrations?

Is the reason that solids are not considered in the equilibrium constant because they do not have concentrations?
Tue Jan 08, 2019 11:31 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Concentrations
Replies: 5
Views: 299

### Concentrations

Why is it that if you start out with an initial larger value of reactants, the products will be favored at equilibrium?
Tue Jan 08, 2019 11:28 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Water in equilibrium constants
Replies: 4
Views: 113

### Water in equilibrium constants

Is water not counted in the chemical equilibrium constant? And if so, is this why liquids are not considered either since their concentrations are approximately water?
Sat Dec 08, 2018 11:24 pm
Forum: Identifying Acidic & Basic Salts
Topic: Homeword 6D11 7th edition
Replies: 2
Views: 284

### Re: Homeword 6D11 7th edition

what makes F an exception?
Fri Dec 07, 2018 8:31 pm
Forum: Calculating the pH of Salt Solutions
Topic: 6d11 7th edition
Replies: 3
Views: 390

### 6d11 7th edition

I don't understand how to decide whether an aqueous solution of a salt has a pH equal to greater than or less than 7
Fri Dec 07, 2018 7:56 pm
Forum: Calculating the pH of Salt Solutions
Topic: 7th edition 6B number 3
Replies: 1
Views: 260

### 7th edition 6B number 3

I don't understand why when this problem says 200ml of a .025M HCL solution you don't have to divide .025 by 200 to find the Molarity of H
Tue Dec 04, 2018 1:29 pm
Forum: Ionic & Covalent Bonds
Topic: Bond Order
Replies: 4
Views: 279

### Re: Bond Order

Bond order is the number of bonds. For example if there is a triple bond between two nitrogens, the bond order is 3
Sun Nov 25, 2018 9:18 pm
Forum: Electronegativity
Topic: Is it best to memorize electronegativity?
Replies: 8
Views: 743

### Re: Is it best to memorize electronegativity?

I feel like some of the homework problems can only be done when given the exact number for electronegativity. Will it be obvious on the test?
Sun Nov 25, 2018 9:16 pm
Forum: Sigma & Pi Bonds
Topic: Which bond would break first.
Replies: 15
Views: 1041

### Re: Which bond would break first.

So, sigma bond is stronger than pi bond. However, in a double bond there is a pi and sigma bond. I thought double bonds were stronger than single bonds but a single bond would only have a sigma bond. Is the reason that double bonds are stronger than single bonds because double bond has both a sigma ...
Sun Nov 25, 2018 9:13 pm
Forum: Hybridization
Topic: S character
Replies: 4
Views: 203

### Re: S character

What does s character even mean?
Sun Nov 18, 2018 7:45 pm
Forum: Hybridization
Topic: Sigma and Pi Bonds [ENDORSED]
Replies: 12
Views: 509

### Re: Sigma and Pi Bonds[ENDORSED]

Why was doctor Lavelle talking about how sigma and pi bonds rotate and some cannot rotate because they snap? Could someone explain?
Sun Nov 18, 2018 7:42 pm
Forum: Dipole Moments
Topic: Test
Replies: 15
Views: 533

### Re: Test

Will we have to know sigma and pi bonds and how in depth?
Sun Nov 18, 2018 7:41 pm
Forum: Dipole Moments
Topic: Dipoles
Replies: 3
Views: 198

### Re: Dipoles

I was wondering, does every molecule have a dipole moment?
Fri Nov 09, 2018 1:59 pm
Forum: Ionic & Covalent Bonds
Topic: How many forces can bonds have?
Replies: 2
Views: 141

### How many forces can bonds have?

So, do hydrogen bonding just automatically have hydrogen, dipole dipole, and dispersion forces?
And then dipole dipole will have dipole dipole and dispersion?
And then ionic will just have ionic and dispersion?
Fri Nov 09, 2018 1:57 pm
Forum: Ionic & Covalent Bonds
Topic: Chemical Bonds
Replies: 5
Views: 250

### Re: Chemical Bonds

Is this true for every single covalent and ionic bond comparison?
Fri Nov 09, 2018 1:56 pm
Forum: Ionic & Covalent Bonds
Topic: Polarizability
Replies: 9
Views: 415

### Re: Polarizability

Also, will hydrogen, ionic, and dipole dipole bonds always have polarizability?
Fri Nov 09, 2018 1:55 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic vs Covalent Bonds
Replies: 18
Views: 992

### Re: Ionic vs Covalent Bonds

Also, on this topic, do ionic bonds also have dispersion forces?
Sat Nov 03, 2018 10:09 pm
Forum: Electronegativity
Topic: Periodic Trends
Replies: 8
Views: 357

### Re: Periodic Trends

*remember that there are exceptions for other trends like ionization! For example, Nitrogen is higher than Oxygen for first ionization energy!
Sat Nov 03, 2018 10:07 pm
Forum: Electronegativity
Topic: Electron Affinity
Replies: 3
Views: 177

### Re: Electron Affinity

I think these answers were made in relations to the graph in the book that lists specific electron affinities. Otherwise, you would not know the exact value for electron affinities. But, the general trend is to increase towards the right hand side of the table.
Sat Nov 03, 2018 3:30 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Valence Electrons - Are electrons in the d orbitals considered valence?
Replies: 3
Views: 697

### Re: Valence Electrons - Are electrons in the d orbitals considered valence?

I also was wondering how do you find the valence electrons for elements in the d orbitals?
Fri Nov 02, 2018 10:03 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Au question
Replies: 1
Views: 119

### Au question

for Au, why is an electron more likely to be removed from the s orbital than the p orbital? I understand that the half full d orbital is more stable but why remove the electron from the s orbital?
Sat Oct 27, 2018 5:18 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 8
Views: 235

### Re: Electron Affinity

What exactly is electron affinity and WHY does it increase towards the upper right diagonally?
Sat Oct 27, 2018 5:15 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation
Replies: 7
Views: 435

### Re: Rydberg Equation

Does the order of final and initial change if the problem is having to do absorption instead of emission?
Sat Oct 27, 2018 5:13 pm
Forum: Quantum Numbers and The H-Atom
Topic: Degeneracy
Replies: 4
Views: 240

### Re: Degeneracy

Just to clarify, is the degeneracy related to the orbital in an atom?
Sun Oct 21, 2018 8:48 pm
Forum: Properties of Electrons
Topic: Schrodinger question
Replies: 3
Views: 2379

### Schrodinger question

I know we don't have to know the equations for Schrodinger, but I was wondering is this formula responsible for shapes in an atom?
Sun Oct 21, 2018 8:47 pm
Forum: Properties of Electrons
Replies: 2
Views: 107

For the upcoming test, do we have to read everything in the textbook? For example, the sections that were not discussed in class like the history of an electron?
Sun Oct 21, 2018 8:46 pm
Forum: Properties of Electrons
Topic: Electron Spin
Replies: 7
Views: 528

### Re: Electron Spin

I believe you do not need to know the extreme details of spin. Just know that there is a fifty fifty chance of positive one half or negative one half and pick one when asked on a test
Sun Oct 14, 2018 10:59 pm
Topic: What exactly is Black Body Radiation?
Replies: 1
Views: 299

### What exactly is Black Body Radiation?

In class we have established that black body radiation is useful in showing light to have particle light qualities, which is why it is part of the "quantum world". But what exactly is it and how much about this experiment do we need to know?
Sun Oct 14, 2018 10:58 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Test Question
Replies: 3
Views: 196

### Test Question

For the test, will we be given the Balmer series or Lyman series wavelengths? No memorization right...?
Sun Oct 14, 2018 10:56 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Absorption/Emission
Replies: 4
Views: 149

### Absorption/Emission

hey guys, I'm having trouble with the names of things. When is it Spectrum Absorption or Spectrum Emission and when does the term refer to the actual line that shows up. Please help me clear up the vernacular here. Thanks
Tue Oct 09, 2018 9:03 pm
Forum: Photoelectric Effect
Topic: photoelectric experiments EMR spectrum
Replies: 2
Views: 71

### photoelectric experiments EMR spectrum

In photoelectric experiments, typically what part of the EMR spectrum is the incoming light?
Tue Oct 09, 2018 2:51 pm
Forum: Properties of Light
Topic: 1A question 3 7th edition
Replies: 1
Views: 51

### 1A question 3 7th edition

When the frequency of electromagnetic radiation decreases, the extent of the change in the electric field at a given point decreases. I don't understand this completely. I understand that the electrical field corresponds to the amplitude, but do not see how this would make a change at a point decrea...
Mon Oct 08, 2018 6:17 pm
Forum: Empirical & Molecular Formulas
Topic: Mass Percent Composition
Replies: 7
Views: 559

### Mass Percent Composition

For Mass percent composition questions, why doesn't it always add up to 100? What do you do when it doesn't add to 100?
Wed Oct 03, 2018 12:28 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactant Question
Replies: 2
Views: 168

### Limiting Reactant Question

So, in the problems so far we have only had 1 limiting reactant. I think it is unlikely to have more than 1 limiting reactant. However, if there is an equation with 3 reactants, then can there be 2 limiting reactants?
Wed Oct 03, 2018 12:25 pm
Forum: Limiting Reactant Calculations
Topic: Two Limiting Reactants
Replies: 6
Views: 268

### Re: Two Limiting Reactants

Also, if 5g of reactant A react with 7g of reactant B, can this produce 14 grams of product? No, correct?
Wed Oct 03, 2018 12:24 pm
Forum: Limiting Reactant Calculations
Topic: Two Limiting Reactants
Replies: 6
Views: 268

### Re: Two Limiting Reactants

On that same module, can the mass be greater than the total mass of reactants? No and the reason is conservation of mass right?
Tue Oct 02, 2018 11:03 am
Forum: SI Units, Unit Conversions
Topic: Textbook Homework Assignment
Replies: 11
Views: 841

### Textbook Homework Assignment

Are we doing any 7 problems we want that are listed? Or do the problems have to come from all sections?