Search found 53 matches

by Caroline C 1G
Sat Mar 17, 2018 7:16 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Test 2 Question 2
Replies: 3
Views: 192

Re: Test 2 Question 2

Gwen Peng 1L wrote:Yes it was assumed it was in equilibrium so you could've solved using the equation E standard=(0.05916/n)*log(K) or E standard=(RT/nF)*ln(K)
Hope this helps :)


Would the .05916/n term be negative?
by Caroline C 1G
Sat Mar 17, 2018 5:30 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Test 2 Question 2
Replies: 3
Views: 192

Test 2 Question 2

Question 2 of Test 2 asked "Calculate K for the following redox reaction: Sn^2+(aq)+Pb(s) yields Pb^2+(aq)+Sn(s). I calculated E knot and got -.01V. Was it assumed that the reaction was in equilibrium since we were calculating K, and that therefore, E=0 when using the equation E=Eknot-(.05916/n...
by Caroline C 1G
Fri Mar 16, 2018 10:58 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Transition States
Replies: 1
Views: 89

Transition States

Are all transition states when bonds are breaking and forming simultaneously, or is this only the case for Bimolecular Nucleophilic Substitutions?
by Caroline C 1G
Fri Mar 16, 2018 10:53 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts
Replies: 2
Views: 109

Catalysts

How do catalysts lower the activation energy of a reaction?
by Caroline C 1G
Fri Mar 16, 2018 10:39 pm
Forum: Balancing Redox Reactions
Topic: Balancing Redox Rections in Acidic and Basic Conditions
Replies: 2
Views: 90

Balancing Redox Rections in Acidic and Basic Conditions

Why do you have to add H2O when balancing redox reactions in acidic conditions and H2O and OH- in basic conditions? For redox reactions in basic conditions, how do you know what side of the reaction you add H2O to and which side to add OH?
by Caroline C 1G
Fri Mar 09, 2018 9:03 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Rate Constant of 0 Order Reactions [ENDORSED]
Replies: 1
Views: 218

Rate Constant of 0 Order Reactions [ENDORSED]

Is the magnitude of the rate constant for zero order reactions also influenced by temperature, activation energy, and the frequency factor considering that the reactant concentrations don't affect the rate of the reaction?
by Caroline C 1G
Fri Mar 09, 2018 8:51 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Frequency Factor
Replies: 1
Views: 244

Frequency Factor

I understand that A is the frequency factor and that it involves the number of collisions between reactants in the correct orientation, but what exactly is the correct orientation?
by Caroline C 1G
Fri Mar 09, 2018 8:47 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Activation Energy and Temperature
Replies: 3
Views: 252

Activation Energy and Temperature

What happens to the rate constant if there is a high activation energy and a high temperature? Are these conditions even possible?
by Caroline C 1G
Fri Mar 02, 2018 6:30 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Intermediates [ENDORSED]
Replies: 2
Views: 116

Intermediates [ENDORSED]

Does the concentration of an intermediate always have an affect on the reaction rate?
by Caroline C 1G
Fri Mar 02, 2018 6:24 pm
Forum: Zero Order Reactions
Topic: Zero Order Reactions [ENDORSED]
Replies: 3
Views: 133

Zero Order Reactions [ENDORSED]

Are zero order reactions in equilibrium?
by Caroline C 1G
Fri Mar 02, 2018 6:18 pm
Forum: General Rate Laws
Topic: Half Life [ENDORSED]
Replies: 1
Views: 81

Half Life [ENDORSED]

How would you determine the half life of a reaction that has multiple reactants whose concentrations affect the rate of the reaction?
by Caroline C 1G
Fri Feb 23, 2018 10:38 pm
Forum: General Rate Laws
Topic: Reaction Rate and Spontaneity
Replies: 5
Views: 321

Reaction Rate and Spontaneity

If one reaction occurs at a faster rate than another reaction, is the faster reaction considered to be more spontaneous; or is there no connection between spontaneity and reaction rate?
by Caroline C 1G
Fri Feb 23, 2018 10:27 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Differential Rate Law
Replies: 3
Views: 119

Differential Rate Law

Is it possible for none of the reactant concentrations to affect the initial rate? If so, what would the rate equation look like?
by Caroline C 1G
Fri Feb 23, 2018 10:22 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Order
Replies: 5
Views: 184

Order

What exactly is the order of a reactant or a reaction?
by Caroline C 1G
Fri Feb 16, 2018 5:41 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Equilibrium
Replies: 4
Views: 113

Equilibrium

When a reaction reaches equilibrium does the electric current completely stop flowing between the anode and cathode?
by Caroline C 1G
Fri Feb 16, 2018 5:35 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Potential in Galvanic/Voltaic Cells
Replies: 2
Views: 50

Potential in Galvanic/Voltaic Cells

In the lecture notes, there was a statement that said "because cell potential is sensitive to [R] and [P] make galvanic/voltaic cells with same components at different concentrations". Could someone explain what this means?
by Caroline C 1G
Fri Feb 16, 2018 5:31 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic/Voltaic
Replies: 2
Views: 86

Galvanic/Voltaic

What do the terms galvanic and voltaic mean?
by Caroline C 1G
Fri Feb 09, 2018 2:38 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy
Replies: 1
Views: 68

Gibbs Free Energy

Could someone explain why wmax=delta G?
by Caroline C 1G
Fri Feb 09, 2018 2:14 pm
Forum: Balancing Redox Reactions
Topic: Salt Bridges and Porous Disks
Replies: 2
Views: 88

Salt Bridges and Porous Disks

Does the material that makes up salt bridges and porous disks affect their ability to transfer ions?
by Caroline C 1G
Fri Feb 09, 2018 2:05 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Concentration and Cell Potential
Replies: 1
Views: 80

Concentration and Cell Potential

Could someone explain how you would use Le Chatelier's principle to find that: increasing [Mn 2+]>1 M gives Ecell>E knot and increasing [Al 3+]> 1M gives Ecell< E knot from the reaction 3Al(s)+ 3Mn 2+(aq) yields 2Al 3+(aq)+ 3Mn(s)?
by Caroline C 1G
Fri Feb 02, 2018 12:18 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: entropy
Replies: 4
Views: 172

Re: entropy

deltaS=q/T, therefore, a greater entropy change occurs in systems at lower temperatures when energy is transferred than in systems at higher temperatures where the same amount of energy is transferred. Gases have a higher entropy than liquids and liquids have a higher entropy than solids as gases ca...
by Caroline C 1G
Fri Feb 02, 2018 12:05 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Using the Kan't Hoff Equation to Calculate the Change in Concentration
Replies: 1
Views: 67

Using the Kan't Hoff Equation to Calculate the Change in Concentration

When using the Kan't Hoff equation to calculate the change in concentrations of a reaction at different temperatures, it is assumed that deltaS and deltaH are constant. What do you do if deltaS and deltaH aren't constant?
by Caroline C 1G
Fri Feb 02, 2018 12:02 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Van't Hoff Equation
Replies: 2
Views: 203

Van't Hoff Equation

Could someone explain the steps involved in deriving lnK=(-deltaH/RT)+(deltaS/R) from deltaH-TdeltaS=-RTlnK?
by Caroline C 1G
Thu Jan 25, 2018 8:49 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Entropy of an Ideal Gas
Replies: 2
Views: 119

Re: Entropy of an Ideal Gas

When there is a change in volume during isothermal expansion, the entropy of an ideal gas is related to its volume by the equation: delta S=nRln(V2/V1).
by Caroline C 1G
Thu Jan 25, 2018 8:40 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Formulas Under Different Conditions
Replies: 2
Views: 95

Re: Formulas Under Different Conditions

In a reversible isothermal reaction, there is no change in the internal energy of the system. In other words, delta U=0. Therefore, using the equation, delta U=q+w, q=-w or w=-q.
by Caroline C 1G
Thu Jan 25, 2018 8:36 pm
Forum: Calculating Work of Expansion
Topic: Work Equation
Replies: 3
Views: 129

Work Equation

Does w=integralPdv have the same meaning as w=-PdeltaV? What do each of the variables in w=integralPdV signify?
by Caroline C 1G
Thu Jan 18, 2018 8:29 pm
Forum: Phase Changes & Related Calculations
Topic: 8.37
Replies: 3
Views: 128

Re: 8.37

I had the same question on this problem, but I looked up the enthalpy of vaporization formula online and found that it is equal to heat (q)/the moles of substance.
by Caroline C 1G
Thu Jan 18, 2018 8:16 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Reaction Enthalpy v. Enthalpy of Formation
Replies: 4
Views: 98

Reaction Enthalpy v. Enthalpy of Formation

How do you know when to use reaction enthalpy instead of enthalpy of formation and vice versa?
by Caroline C 1G
Thu Jan 18, 2018 8:12 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Work Equation
Replies: 4
Views: 213

Work Equation

What is the significance of the negative sign in the work equation (w=-PdeltaV)?
by Caroline C 1G
Wed Jan 10, 2018 8:39 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Systems
Replies: 3
Views: 150

Systems

I'm a little confused regarding the classification of systems. What is the difference between an open, closed, and isolated system, and what are some examples of each?
by Caroline C 1G
Wed Jan 10, 2018 8:25 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law
Replies: 8
Views: 327

Hess's Law

When using Hess's Law, is there ever a chance that none of parts of the involved reactions will cancel each other out? If so, how would you write the net reaction?
by Caroline C 1G
Wed Jan 10, 2018 8:16 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Method 2 for Calculating Net Enthalpy
Replies: 2
Views: 98

Method 2 for Calculating Net Enthalpy

When calculating net enthalpy using Method 2 (not Hess's Law), are the bonds of the reactants always broken and the bonds of the products always formed? Or can the bonds of the products be broken and the bonds of the reactants be formed?
by Caroline C 1G
Fri Dec 08, 2017 10:17 pm
Forum: Hybridization
Topic: Composition of a Bond
Replies: 6
Views: 382

Re: Composition of a Bond

The composition of the OH bond would be sigma(H 1s, O 2sp^3). The oxygen has 4 areas of electron density (two single bonds and two lone pairs), and that is why the composition of the OH bond includes "2sp^3".
by Caroline C 1G
Fri Dec 08, 2017 10:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Dipole Moment
Replies: 2
Views: 174

Re: Dipole Moment

Dipole moments cancel out when the dipoles are of the same magnitude and are moving in opposite directions. For example, in the linear molecule, CO2, the oxygen atoms lie on either side of the carbon atom. Oxygen is more electronegative than carbon, so dipoles of the same magnitude point in opposite...
by Caroline C 1G
Wed Nov 29, 2017 2:40 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Mole Ratios in ICE Tables
Replies: 2
Views: 630

Re: Mole Ratios in ICE Tables

When using an ICE table, and the equilibrium concentration isn't given for one of the species, you would use x. The change in concentration for the reactants would be -x and the change in concentration for the products would be +x as the reactants are being disassociated to form the products. If any...
by Caroline C 1G
Wed Nov 29, 2017 2:30 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Delocalized pi bond
Replies: 1
Views: 202

Re: Delocalized pi bond

Delocalized pi bonds are pi bonds that can be moved around as a result of resonance structures. Resonance structures have double and triple bonds in different locations, causing the pi bonds to be delocalized. An example of a molecule with delocalized pi bonds is benzene (C6H6) as its double bonds c...
by Caroline C 1G
Wed Nov 22, 2017 5:23 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE Box [ENDORSED]
Replies: 1
Views: 116

ICE Box [ENDORSED]

I know we went over this in lecture, but could someone remind me of how the different elements change in an ICE box when none of the equilibrium moralities are given and there are stoichiometric coefficients greater than one?
by Caroline C 1G
Wed Nov 22, 2017 5:11 pm
Forum: Naming
Topic: Oxidation State [ENDORSED]
Replies: 1
Views: 94

Oxidation State [ENDORSED]

What exactly is the oxidation state of a cation and how do you find it?
by Caroline C 1G
Wed Nov 15, 2017 4:10 pm
Forum: Hybridization
Topic: Sigma and Pi Bonds [ENDORSED]
Replies: 1
Views: 95

Sigma and Pi Bonds [ENDORSED]

Do unhyrbridized orbitals only form pi bonds with each other? Do hybridized orbitals only form sigma bonds with each other?
by Caroline C 1G
Wed Nov 15, 2017 4:01 pm
Forum: Hybridization
Topic: Benzene Hybridization [ENDORSED]
Replies: 4
Views: 692

Benzene Hybridization [ENDORSED]

Today in lecture we talked about the hybridization of benzene, and determined that each carbon forms three sigma bonds. However, one of the slides stated that benzene has a total of 12 sigma bonds. If there are six carbon atoms in benzene shouldn't there be a total of 18 sigma bonds?
by Caroline C 1G
Wed Nov 08, 2017 3:21 pm
Forum: Ionic & Covalent Bonds
Topic: 3.101
Replies: 1
Views: 152

Re: 3.101

We never covered isolobal analogy in lecture or discussion, so we shouldn't need to know it for the midterm.
by Caroline C 1G
Wed Nov 08, 2017 3:08 pm
Forum: Resonance Structures
Topic: double headed arrow for resonance [ENDORSED]
Replies: 1
Views: 171

Re: double headed arrow for resonance [ENDORSED]

You draw the double headed arrows whenever a molecule or ion has resonance. A molecule or ion has resonance when more than one Lewis Structure can be drawn to represent it. You would draw the arrows between each structure.
by Caroline C 1G
Wed Nov 01, 2017 6:14 pm
Forum: Octet Exceptions
Topic: Octet Exceptions
Replies: 4
Views: 212

Octet Exceptions

Do you automatically add any extra electrons to the atoms that are exceptions to the octet rule? For example, when oxygen and sulfur bond to form sulfur dioxide, 18 electrons are involved. However, when you draw the bonds, only 16 electrons are used. In lecture, we added the two extra electrons to s...
by Caroline C 1G
Wed Nov 01, 2017 5:31 pm
Forum: Bond Lengths & Energies
Topic: Bond Length
Replies: 5
Views: 270

Bond Length

Is there a way to calculate bond length, or is it a given value?
by Caroline C 1G
Wed Oct 25, 2017 10:14 pm
Forum: Lewis Structures
Topic: Lewis Dot Structure Example
Replies: 3
Views: 99

Lewis Dot Structure Example

In lecture we drew the Lewis Dot structure for Ammonium Sulfate by drawing two diagrams, one for NH4, and the other for SO4. Is it possible to draw one diagram for Ammonium Sulfate as a whole? In other words, are NH4 and SO4 bonded in anyway?
by Caroline C 1G
Wed Oct 25, 2017 10:04 pm
Forum: Quantum Numbers and The H-Atom
Topic: Values of Quantum Numbers
Replies: 3
Views: 240

Re: Values of Quantum Numbers

a. l=0,...n-1 So for this question you should list the integers ranging from 0 to n-7. b. d is associated with l=2; and -l is less than or equal to m, and l is greater than or equal to m. Therefore, ml= -2,-1,0,1,2. c. p is associated with l= 1; and -l is less than or equal to m, and l is greater th...
by Caroline C 1G
Wed Oct 25, 2017 9:53 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity and Ionization Energy
Replies: 4
Views: 315

Re: Electron Affinity and Ionization Energy

Ionization energy is the energy needed to remove an electron from an atom in the gas phase. Electron affinity is the amount of energy that is released or acquired when an electron is added to an atom in the gas phase. The trends of electron affinity aren't as obvious as those of ionization energy on...
by Caroline C 1G
Thu Oct 19, 2017 7:53 pm
Forum: *Shrodinger Equation
Topic: Schrodinger Equation
Replies: 3
Views: 178

Schrodinger Equation

I understand that you can solve for the quantum numbers, but can you solve the equation HΨ=EΨ numerically, or is it just an abstract model of how electrons behave?
by Caroline C 1G
Thu Oct 19, 2017 7:39 pm
Forum: *Shrodinger Equation
Topic: The "H" Term in the Schrodinger Equation
Replies: 2
Views: 231

The "H" Term in the Schrodinger Equation

In lecture we talked about how the "H" term is a double derivative. Could someone explain what exactly this means?
by Caroline C 1G
Fri Oct 13, 2017 3:58 pm
Forum: Properties of Light
Topic: Chapter 1 problem 7a
Replies: 1
Views: 220

Re: Chapter 1 problem 7a

I actually got 420 nm for 1.7a in the textbook. The solutions manual also gives 420 nm as the solution for this problem, so we might be looking at different questions. The question I am looking at is "The frequency of violet light is 7.1 x 10^14 Hz. What is the wavelength (in nm) of violet ligh...
by Caroline C 1G
Fri Oct 13, 2017 3:46 pm
Forum: Photoelectric Effect
Topic: Difference Between Work Function and the Energy Required to Remove an Electron from one Atom [ENDORSED]
Replies: 4
Views: 327

Difference Between Work Function and the Energy Required to Remove an Electron from one Atom [ENDORSED]

One of the questions in the "Photoelectric Effect" post module assessment included, "How much energy is required to remove an electron from one sodium atom?" The statements before the question disclosed that the work function of sodium is 150.6 kJ/mol. I assumed that the question...
by Caroline C 1G
Wed Oct 04, 2017 4:13 pm
Forum: Limiting Reactant Calculations
Topic: Problem M11 part a
Replies: 5
Views: 372

Re: Problem M11 part a

By using P4, you eventually discover that oxygen is the limiting reactant of the second equation. This means that oxygen controls the amount of P4O10 produced, not P4O6.
by Caroline C 1G
Wed Oct 04, 2017 3:45 pm
Forum: Limiting Reactant Calculations
Topic: Net Ionic Equation
Replies: 4
Views: 614

Net Ionic Equation

Fundamentals M M.9 Copper (II) nitrate reacts with sodium hydroxide to produce a precipitate of light blue copper (II) hydroxide. a. Write the net ionic equation for the reaction. I know we haven't done net ionic equations in class yet, but this question came up in one of the fundamental sections. D...

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