Search found 78 matches

by Megan_Ervin_1F
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: 44

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
by Megan_Ervin_1F
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: 173

Re: Nernst

do you think we have to know how to derive the nernst equation for our final?
by Megan_Ervin_1F
Sat Mar 16, 2019 4:20 pm
Forum: First Order Reactions
Topic: pseudo first order [ENDORSED]
Replies: 5
Views: 323

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
by Megan_Ervin_1F
Sat Mar 16, 2019 4:19 pm
Forum: First Order Reactions
Topic: deriving integrated forms
Replies: 1
Views: 182

deriving integrated forms

Do you think it is necessary to know how to derive the integrated forms of the rate laws for the final?
by Megan_Ervin_1F
Wed Mar 13, 2019 8:50 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts
Replies: 6
Views: 101

Re: Catalysts

Also remember that it is acceptable for a catalyst to appear in the rate law
by Megan_Ervin_1F
Wed Mar 13, 2019 8:49 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Exothermic vs. Endothermic
Replies: 5
Views: 237

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...
by Megan_Ervin_1F
Wed Mar 13, 2019 8:47 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts vs Intermediates
Replies: 4
Views: 63

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.
by Megan_Ervin_1F
Wed Mar 13, 2019 8:44 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Arrhenius Equation
Replies: 1
Views: 29

Re: Arrhenius Equation

use the first one when you are trying to find out K at different temperatures
by Megan_Ervin_1F
Wed Mar 13, 2019 8:42 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: k & K
Replies: 18
Views: 366

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
by Megan_Ervin_1F
Thu Mar 07, 2019 12:21 pm
Forum: First Order Reactions
Topic: First order graph
Replies: 7
Views: 117

Re: First order graph

If ln(A) vs Time is a straight line, then the reaction is a first order reaction
by Megan_Ervin_1F
Thu Mar 07, 2019 12:20 pm
Forum: First Order Reactions
Topic: Pseudo-First-Order Reaction
Replies: 5
Views: 100

Re: Pseudo-First-Order Reaction

I do not understand, what exactly is a psuedo reaction?
by Megan_Ervin_1F
Thu Mar 07, 2019 12:19 pm
Forum: First Order Reactions
Topic: Half-Life 1st Order Reaction
Replies: 6
Views: 95

Re: Half-Life 1st Order Reaction

Also remember that you can always derive this equation it you have any doubts
by Megan_Ervin_1F
Tue Feb 26, 2019 1:32 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Adding inert metal
Replies: 1
Views: 43

Adding inert metal

How do you know when to add an inert metal to your cell diagram?
by Megan_Ervin_1F
Tue Feb 26, 2019 1:26 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: test 2
Replies: 6
Views: 133

Re: test 2

do you think we will get a list of redox equations like the appendix in our textbook?
by Megan_Ervin_1F
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: 122

Test 2

What sections from electrochemistry will be tested on test 2?
by Megan_Ervin_1F
Wed Feb 20, 2019 8:15 pm
Forum: Balancing Redox Reactions
Topic: test 2
Replies: 5
Views: 359

Re: test 2

What sections in the seventh edition will be on the test 2
by Megan_Ervin_1F
Wed Feb 20, 2019 8:15 pm
Forum: Balancing Redox Reactions
Topic: determining cathode from anode
Replies: 11
Views: 479

Re: determining cathode from anode

Also it is just standard for the anode to appear on the left
by Megan_Ervin_1F
Wed Feb 20, 2019 8:14 pm
Forum: Balancing Redox Reactions
Topic: flipping the sign of anodes
Replies: 5
Views: 420

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
by Megan_Ervin_1F
Wed Feb 20, 2019 8:13 pm
Forum: Balancing Redox Reactions
Topic: Salt Bridge
Replies: 4
Views: 107

Re: Salt Bridge

Is the salt bridge the same thing as a porous disk?
by Megan_Ervin_1F
Wed Feb 13, 2019 2:40 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: difference in states
Replies: 6
Views: 242

Re: difference in states

Yes for example if the pressure is constant you know that delta h will equal q
by Megan_Ervin_1F
Sun Feb 10, 2019 7:56 pm
Forum: Calculating Work of Expansion
Topic: Units
Replies: 7
Views: 118

Re: Units

Does anyone have a good summary of all the equations we should know? some of them aren't on the equation sheet...
by Megan_Ervin_1F
Sun Feb 10, 2019 7:55 pm
Forum: Calculating Work of Expansion
Topic: work equations
Replies: 4
Views: 89

Re: work equations

irreversible can also be called "constant pressure"
by Megan_Ervin_1F
Sun Feb 10, 2019 7:53 pm
Forum: Phase Changes & Related Calculations
Topic: heat of a phase change
Replies: 5
Views: 106

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
by Megan_Ervin_1F
Sun Feb 10, 2019 7:52 pm
Forum: Phase Changes & Related Calculations
Topic: Negative work
Replies: 11
Views: 176

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
by Megan_Ervin_1F
Sun Feb 10, 2019 7:51 pm
Forum: Phase Changes & Related Calculations
Topic: Phase change equation
Replies: 1
Views: 51

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
by Megan_Ervin_1F
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: 148

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?
by Megan_Ervin_1F
Wed Jan 30, 2019 1:39 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Homework/reading
Replies: 3
Views: 66

Re: Homework/reading

So, we have not gone over 4A quite yet?
by Megan_Ervin_1F
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: 142

Re: Isolated systems

A good example of an isolated system would be a bomb calorimeter no energy is exchanged with the surroundings
by Megan_Ervin_1F
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: 70

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?
by Megan_Ervin_1F
Wed Jan 30, 2019 1:35 pm
Forum: Phase Changes & Related Calculations
Topic: Delta Hº versus delta H
Replies: 7
Views: 183

Re: Delta Hº versus delta H

Does this apply to all other variables as well?
by Megan_Ervin_1F
Wed Jan 30, 2019 1:35 pm
Forum: Phase Changes & Related Calculations
Topic: Work
Replies: 5
Views: 101

Re: Work

Why is work not a state property?
by Megan_Ervin_1F
Wed Jan 30, 2019 1:34 pm
Forum: Phase Changes & Related Calculations
Topic: Standard State
Replies: 6
Views: 121

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
by Megan_Ervin_1F
Wed Jan 30, 2019 1:33 pm
Forum: Phase Changes & Related Calculations
Topic: Standard State
Replies: 6
Views: 121

Re: Standard State

Why is the enthalpy for something in standard state 0?
by Megan_Ervin_1F
Wed Jan 30, 2019 1:32 pm
Forum: Phase Changes & Related Calculations
Topic: State Properites
Replies: 7
Views: 123

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...
by Megan_Ervin_1F
Wed Jan 30, 2019 1:31 pm
Forum: Phase Changes & Related Calculations
Topic: Week 4 Homework
Replies: 12
Views: 226

Re: Week 4 Homework

Why does this section talk about delta U? I don't recall learning about delta U in lecture...
by Megan_Ervin_1F
Wed Jan 30, 2019 1:30 pm
Forum: Phase Changes & Related Calculations
Topic: Phase changes
Replies: 14
Views: 181

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?
by Megan_Ervin_1F
Wed Jan 30, 2019 1:29 pm
Forum: Phase Changes & Related Calculations
Topic: Steam
Replies: 11
Views: 200

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...
by Megan_Ervin_1F
Wed Jan 30, 2019 1:27 pm
Forum: Phase Changes & Related Calculations
Topic: Test #1
Replies: 11
Views: 201

Re: Test #1

Yes I had discussion today and received my test in section
by Megan_Ervin_1F
Wed Jan 30, 2019 1:26 pm
Forum: Phase Changes & Related Calculations
Topic: Heat Capacity
Replies: 10
Views: 139

Re: Heat Capacity

Which variable represents heat capacity?
by Megan_Ervin_1F
Wed Jan 30, 2019 1:26 pm
Forum: Phase Changes & Related Calculations
Topic: Water phase change graph
Replies: 6
Views: 93

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?
by Megan_Ervin_1F
Tue Jan 08, 2019 11:32 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids do not have concentrations?
Replies: 3
Views: 56

Solids do not have concentrations?

Is the reason that solids are not considered in the equilibrium constant because they do not have concentrations?
by Megan_Ervin_1F
Tue Jan 08, 2019 11:31 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Concentrations
Replies: 5
Views: 77

Concentrations

Why is it that if you start out with an initial larger value of reactants, the products will be favored at equilibrium?
by Megan_Ervin_1F
Tue Jan 08, 2019 11:28 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Water in equilibrium constants
Replies: 4
Views: 56

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?
by Megan_Ervin_1F
Sat Dec 08, 2018 11:24 pm
Forum: Identifying Acidic & Basic Salts
Topic: Homeword 6D11 7th edition
Replies: 2
Views: 175

Re: Homeword 6D11 7th edition

what makes F an exception?
by Megan_Ervin_1F
Fri Dec 07, 2018 8:31 pm
Forum: Calculating the pH of Salt Solutions
Topic: 6d11 7th edition
Replies: 2
Views: 224

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
by Megan_Ervin_1F
Fri Dec 07, 2018 7:56 pm
Forum: Calculating the pH of Salt Solutions
Topic: 7th edition 6B number 3
Replies: 1
Views: 183

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
by Megan_Ervin_1F
Tue Dec 04, 2018 1:29 pm
Forum: Ionic & Covalent Bonds
Topic: Bond Order
Replies: 4
Views: 143

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
by Megan_Ervin_1F
Sun Nov 25, 2018 9:18 pm
Forum: Electronegativity
Topic: Is it best to memorize electronegativity?
Replies: 8
Views: 379

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?
by Megan_Ervin_1F
Sun Nov 25, 2018 9:16 pm
Forum: Sigma & Pi Bonds
Topic: Which bond would break first.
Replies: 15
Views: 533

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 ...
by Megan_Ervin_1F
Sun Nov 25, 2018 9:13 pm
Forum: Hybridization
Topic: S character
Replies: 4
Views: 94

Re: S character

What does s character even mean?
by Megan_Ervin_1F
Sun Nov 18, 2018 7:45 pm
Forum: Hybridization
Topic: Sigma and Pi Bonds [ENDORSED]
Replies: 12
Views: 243

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?
by Megan_Ervin_1F
Sun Nov 18, 2018 7:42 pm
Forum: Dipole Moments
Topic: Test
Replies: 15
Views: 260

Re: Test

Will we have to know sigma and pi bonds and how in depth?
by Megan_Ervin_1F
Sun Nov 18, 2018 7:41 pm
Forum: Dipole Moments
Topic: Dipoles
Replies: 3
Views: 112

Re: Dipoles

I was wondering, does every molecule have a dipole moment?
by Megan_Ervin_1F
Fri Nov 09, 2018 1:59 pm
Forum: Ionic & Covalent Bonds
Topic: How many forces can bonds have?
Replies: 2
Views: 68

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?
by Megan_Ervin_1F
Fri Nov 09, 2018 1:57 pm
Forum: Ionic & Covalent Bonds
Topic: Chemical Bonds
Replies: 5
Views: 113

Re: Chemical Bonds

Is this true for every single covalent and ionic bond comparison?
by Megan_Ervin_1F
Fri Nov 09, 2018 1:56 pm
Forum: Ionic & Covalent Bonds
Topic: Polarizability
Replies: 9
Views: 181

Re: Polarizability

Also, will hydrogen, ionic, and dipole dipole bonds always have polarizability?
by Megan_Ervin_1F
Fri Nov 09, 2018 1:55 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic vs Covalent Bonds
Replies: 18
Views: 523

Re: Ionic vs Covalent Bonds

Also, on this topic, do ionic bonds also have dispersion forces?
by Megan_Ervin_1F
Sat Nov 03, 2018 10:09 pm
Forum: Electronegativity
Topic: Periodic Trends
Replies: 8
Views: 214

Re: Periodic Trends

*remember that there are exceptions for other trends like ionization! For example, Nitrogen is higher than Oxygen for first ionization energy!
by Megan_Ervin_1F
Sat Nov 03, 2018 10:07 pm
Forum: Electronegativity
Topic: Electron Affinity
Replies: 3
Views: 96

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.
by Megan_Ervin_1F
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: 310

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?
by Megan_Ervin_1F
Fri Nov 02, 2018 10:03 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Au question
Replies: 1
Views: 73

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?
by Megan_Ervin_1F
Sat Oct 27, 2018 5:18 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 8
Views: 146

Re: Electron Affinity

What exactly is electron affinity and WHY does it increase towards the upper right diagonally?
by Megan_Ervin_1F
Sat Oct 27, 2018 5:15 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation
Replies: 7
Views: 265

Re: Rydberg Equation

Does the order of final and initial change if the problem is having to do absorption instead of emission?
by Megan_Ervin_1F
Sat Oct 27, 2018 5:13 pm
Forum: Quantum Numbers and The H-Atom
Topic: Degeneracy
Replies: 4
Views: 142

Re: Degeneracy

Just to clarify, is the degeneracy related to the orbital in an atom?
by Megan_Ervin_1F
Sun Oct 21, 2018 8:48 pm
Forum: Properties of Electrons
Topic: Schrodinger question
Replies: 3
Views: 298

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?
by Megan_Ervin_1F
Sun Oct 21, 2018 8:47 pm
Forum: Properties of Electrons
Topic: Textbook reading Test 2
Replies: 2
Views: 90

Textbook reading Test 2

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?
by Megan_Ervin_1F
Sun Oct 21, 2018 8:46 pm
Forum: Properties of Electrons
Topic: Electron Spin
Replies: 7
Views: 380

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
by Megan_Ervin_1F
Sun Oct 14, 2018 10:59 pm
Forum: *Black Body Radiation
Topic: What exactly is Black Body Radiation?
Replies: 1
Views: 220

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?
by Megan_Ervin_1F
Sun Oct 14, 2018 10:58 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Test Question
Replies: 3
Views: 109

Test Question

For the test, will we be given the Balmer series or Lyman series wavelengths? No memorization right...?
by Megan_Ervin_1F
Sun Oct 14, 2018 10:56 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Absorption/Emission
Replies: 4
Views: 75

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
by Megan_Ervin_1F
Tue Oct 09, 2018 9:03 pm
Forum: Photoelectric Effect
Topic: photoelectric experiments EMR spectrum
Replies: 2
Views: 48

photoelectric experiments EMR spectrum

In photoelectric experiments, typically what part of the EMR spectrum is the incoming light?
by Megan_Ervin_1F
Tue Oct 09, 2018 2:51 pm
Forum: Properties of Light
Topic: 1A question 3 7th edition
Replies: 1
Views: 32

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...
by Megan_Ervin_1F
Mon Oct 08, 2018 6:17 pm
Forum: Empirical & Molecular Formulas
Topic: Mass Percent Composition
Replies: 7
Views: 387

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?
by Megan_Ervin_1F
Wed Oct 03, 2018 12:28 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactant Question
Replies: 2
Views: 64

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?
by Megan_Ervin_1F
Wed Oct 03, 2018 12:25 pm
Forum: Limiting Reactant Calculations
Topic: Two Limiting Reactants
Replies: 6
Views: 159

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?
by Megan_Ervin_1F
Wed Oct 03, 2018 12:24 pm
Forum: Limiting Reactant Calculations
Topic: Two Limiting Reactants
Replies: 6
Views: 159

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?
by Megan_Ervin_1F
Tue Oct 02, 2018 11:03 am
Forum: SI Units, Unit Conversions
Topic: Textbook Homework Assignment
Replies: 11
Views: 533

Textbook Homework Assignment

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

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