## Search found 66 matches

Mon Mar 11, 2019 11:51 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 4D7 temperature
Replies: 2
Views: 151

### Re: 4D7 temperature

I believe it's because it's a constant temperature.
Mon Mar 11, 2019 11:43 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 7th edition 6N.15
Replies: 1
Views: 168

### Re: 7th edition 6N.15

6N.15
Calculate the potential of a cell constructed with two nickel electrodes. The electrolyte in one compartment is 1.0M Ni(NO3)2(aq). In the other compartment, NaOH has been added to a Ni(NO3)2 solution until the pH=11.0 at 298K. See Table 6I.1.
Mon Mar 11, 2019 11:35 pm
Forum: Student Social/Study Group
Topic: Studying for the Final
Replies: 25
Views: 1579

### Re: Studying for the Final

Yeah, I plan on doing the homework problems, the tests and midterm questions.
Sun Mar 10, 2019 8:24 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Final Material
Replies: 4
Views: 222

### Re: Final Material

I think questions that are also brought up on chemistry community.
Wed Mar 06, 2019 7:49 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Disproportionation
Replies: 1
Views: 117

### Re: Disproportionation

I believe disproportionation usually involves redox reaction; disproportionation reactions follow the form: 2A → A' + A"
Wed Mar 06, 2019 7:45 pm
Forum: Student Social/Study Group
Topic: Final
Replies: 24
Views: 1266

### Re: Final

I believe the sessions start Saturday but he has yet to give the times.
Sun Mar 03, 2019 1:27 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Order of Cell Diagrams
Replies: 13
Views: 650

### Re: Order of Cell Diagrams

Solid|ion||ion|solid
Sat Mar 02, 2019 12:22 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6M.3
Replies: 2
Views: 158

### Re: 6M.3

Sorry! What I meant to say was why was C(gr) not included in Sn4+(aq)+2e- → Sn2+(aq) ?
Wed Feb 27, 2019 6:43 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: platinum [ENDORSED]
Replies: 6
Views: 375

### Re: platinum[ENDORSED]

You add Pt to the side that doesn't have a solid.
Wed Feb 27, 2019 6:40 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Standard Cell Potential [ENDORSED]
Replies: 2
Views: 153

### Re: Standard Cell Potential[ENDORSED]

The standard cell potential measures the driving force for a given redox reaction.
Wed Feb 27, 2019 12:25 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6M.3
Replies: 2
Views: 158

### 6M.3

6M.3 Predict the standard potential of each of the following galvanic cells:
For part d, why is C(gr) not included for the anode?
(d) C(gr)|Sn4+ (aq),Sn2+ (aq)||Pb4+ (aq),Pb2+ (aq)| Pt(s)
Wed Feb 27, 2019 12:15 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram
Replies: 3
Views: 173

### Re: Cell Diagram

Okay that makes sense. Thank you!
Tue Feb 26, 2019 10:08 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram
Replies: 3
Views: 173

### Cell Diagram

Why isn't H2O included in the cell diagram?
Tue Feb 26, 2019 10:06 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Pt
Replies: 2
Views: 139

### Re: Pt

I think you include it if you have gases and there's no solids.
Mon Feb 25, 2019 2:15 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Voltage
Replies: 2
Views: 149

### Re: Voltage

If I'm not mistaken, it's just a matter of preference.
Mon Feb 25, 2019 2:13 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: DeltaG at Equilibrium
Replies: 2
Views: 116

### Re: DeltaG at Equilibrium

If the free energy is zero, then the reaction is at equilibrium meaning that an no more work can be done.
Sun Feb 24, 2019 11:52 pm
Forum: Balancing Redox Reactions
Topic: balancing redox reactions
Replies: 2
Views: 185

### Re: balancing redox reactions

I second that, they can get confusing. Tips would be helpful!
Sun Feb 24, 2019 11:51 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridges
Replies: 3
Views: 191

### Re: Salt Bridges

Potassium chloride or sodium chloride are usually used.
Sat Feb 23, 2019 8:13 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: How can a change in entropy be negative?
Replies: 3
Views: 186

### Re: How can a change in entropy be negative?

If there is less disorder in a system, then entropy is negative.
Sat Feb 23, 2019 8:10 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: What is the difference between entropy and free energy?
Replies: 2
Views: 594

### Re: What is the difference between entropy and free energy?

Gibbs free energy is energy available to do work and can be used to determine the spontaneity of a reaction. Entropy is a measure of the molecular disorder of a system.
Sat Feb 23, 2019 3:50 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Test 3
Replies: 14
Views: 599

### Re: Test 3

I believe so since if ΔG=0 then it's at equilibrium.
Sat Feb 23, 2019 3:44 pm
Forum: Van't Hoff Equation
Topic: Van't Hoff Equation
Replies: 2
Views: 390

### Re: Van't Hoff Equation

I'm not too certain but i think you do.
Fri Feb 22, 2019 10:17 pm
Forum: Balancing Redox Reactions
Topic: difference between oxidation and reduction
Replies: 8
Views: 374

### Re: difference between oxidation and reduction

Remember that when an atom gains an electron, its reduction and when it loses electrons its oxidation.
Fri Feb 22, 2019 8:39 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: delta G at equilibrium
Replies: 1
Views: 113

### Re: delta G at equilibrium

Gibbs free energy measures how much potential a reaction has left. Hence if the free energy is zero, then the reaction is at equilibrium, and no more work can be done.
Fri Feb 22, 2019 8:37 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2
Replies: 7
Views: 404

### Re: Test 2

Test 2 covers all topics on Gibbs free energy and electrochemistry up to but not including the Nernst equation!
Thu Feb 21, 2019 10:17 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: electrodes
Replies: 1
Views: 109

### Re: electrodes

https://chem.libretexts.org/Bookshelves ... _Chemistry)/Electrochemistry/Voltaic_Cells/The_Cell_Potential

Thu Feb 21, 2019 10:15 pm
Forum: Van't Hoff Equation
Topic: Practice Problems
Replies: 3
Views: 282

### Re: Practice Problems

I haven't seen any practice problems but do you know if we'll have to have graphical methods for Van't Hoff's equation?
Wed Feb 20, 2019 9:52 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Midterm Question (#3.D)
Replies: 2
Views: 327

### Re: Midterm Question (#3.D)

The solutions for the midterm are posted on the class website!
Wed Feb 20, 2019 9:39 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: entropy
Replies: 4
Views: 354

### Re: entropy

Enthalpy ('H') refers to the measure of total heat content in a thermodynamic system under constant pressure whereas enthalpy is calculated in terms of change. Keep in mind the the SI unit of enthalpy is joules (J).
Wed Feb 20, 2019 9:17 pm
Forum: Balancing Redox Reactions
Topic: Week 7 Homework
Replies: 15
Views: 619

### Re: Week 7 Homework

I included gibbs free energy but also added some material on thermal dynamics.
Wed Feb 20, 2019 9:10 pm
Forum: Balancing Redox Reactions
Topic: 6k.5 7th ed. Writing half reaction for basic solution
Replies: 1
Views: 131

### Re: 6k.5 7th ed. Writing half reaction for basic solution

I'm actually struggling with grasping that subject too. I also thought it was oxidizing.
Sun Feb 03, 2019 10:50 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Midterm
Replies: 12
Views: 495

### Re: Midterm

Yes, doing all of the homework questions help a lot because you'll realize what you need to improve one and by doing so you can seek aid in one or many of the sessions.
Sun Feb 03, 2019 10:49 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Midterm
Replies: 12
Views: 495

### Re: Midterm

Yes, doing all of the homework questions help a lot because you'll realize what you need to improve one and by doing so you can seek aid in one or many of the sessions.
Wed Dec 05, 2018 9:10 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shape
Replies: 5
Views: 281

### Shape

When asked for the shape, are we always supposed to say the molecular geometry rather than the electronic geometry?
Wed Dec 05, 2018 9:08 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent Structures
Replies: 12
Views: 535

### Re: Bent Structures

Yes, they are all polar.
Wed Dec 05, 2018 9:04 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted Versus Lewis
Replies: 4
Views: 230

### Re: Bronsted Versus Lewis

One of the UA told me they were the same thing.
Sun Dec 02, 2018 6:32 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: 4.73
Replies: 2
Views: 403

### 4.73

(a) Draw a Lewis structure for each of the following species: CH3 ; CH4; CH3 ; CH2; CH22 ; CH22 . (b) Identify each as a radical or not.

How do you identify if they're radicals or not?
Thu Nov 29, 2018 9:50 pm
Forum: Naming
Topic: Coordination Number
Replies: 3
Views: 222

### Re: Coordination Number

The coordination number equals the number of ligands.
Thu Nov 29, 2018 9:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.72
Replies: 2
Views: 184

### 4.72

Why is NO3- nonpolar?
Thu Nov 29, 2018 8:56 pm
Forum: Sigma & Pi Bonds
Topic: Sigma bonds
Replies: 6
Views: 406

### Re: Sigma bonds

Thu Nov 29, 2018 8:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 6th edition 4.23
Replies: 3
Views: 358

### Re: 6th edition 4.23

Yes you did but it's not the molecular formula but VSEPR formula.
Thu Nov 29, 2018 8:38 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Determining polar and non polar molecules from a lewis structure
Replies: 8
Views: 538

### Re: Determining polar and non polar molecules from a lewis structure

By the electronegativity difference between the atoms. If they cancel each other then it's non polar.
Tue Nov 27, 2018 11:02 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: 4.46
Replies: 4
Views: 307

### Re: 4.46

KylieY_3B wrote:I believe it's for the entire molecule.

Okay! Thank you!
Tue Nov 27, 2018 11:00 pm
Forum: Resonance Structures
Topic: Bond lengths & number of resonance structures
Replies: 3
Views: 432

### Re: Bond lengths & number of resonance structures

That video might help clarify resonance structures and bond lengths.
Tue Nov 27, 2018 10:45 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: pi bond
Replies: 4
Views: 197

### Re: pi bond

So just to clarify, as long as there's resonance then there's delocalized pi bond?
Tue Nov 27, 2018 10:38 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: 4.17
Replies: 3
Views: 237

### 4.17

Predict the bond angles at the central atom of the following molecules and ions: (a) ozone, O3; (b) azide ion, N3 ; (c) cyanate ion, CNO ; (d) hydronium ion, H3O . For part a.) For the lewis structure of O3, why isn't there double bonds connecting both the oxygen to the oxygen with the lone pair? Al...
Tue Nov 27, 2018 10:21 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: 4.46
Replies: 4
Views: 307

### 4.46

4.46 Describe the structure of the formamide molecule, HCONH2, in terms of hybrid orbitals, bond angles, and sigma and pi bonds. The C atom is bonded to one H atom, a terminal O atom, and the N atom. The N atom is also bonded to two H atoms. Do you get the sigma and pi bonds for the entire molecule ...
Mon Nov 26, 2018 5:01 pm
Forum: General Science Questions
Topic: Test 3
Replies: 4
Views: 287

### Re: Test 3

I heard that today's lecture was also included.
Mon Nov 26, 2018 3:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: CH2CHCN geometry
Replies: 3
Views: 6566

### Re: CH2CHCN geometry

So for this problem we don't describe the hybrid orbitals on each carbon atom? Or by describing the CH2 we identify the hybrid orbital of Acrylonitrile?
Mon Nov 26, 2018 1:38 pm
Forum: Hybridization
Topic: Test 3
Replies: 13
Views: 532

### Re: Test 3

The test covers everything up to Monday's lecture even if your discussion is on Tuesday. Just wanted to clear things up! Since in the past he has put material on the test from the lecture on Monday so now I know to study up to Monday lecture ! Thanks! Are we supposed to know everything he went over...
Sun Nov 25, 2018 11:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape
Replies: 4
Views: 216

### Re: Molecular Shape

I think you should use the formal charge when dealing with Lewis structures so you don't loose the habit.
Sun Nov 25, 2018 10:57 pm
Forum: Lewis Structures
Topic: 4.7A Homework
Replies: 3
Views: 807

### Re: 4.7A Homework

If I'm not mistaken oxygen has a double bond with sulfur.
Sun Nov 25, 2018 10:46 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.5 Bond Angle
Replies: 2
Views: 87

### 4.5 Bond Angle

b) What is the expected OClO bond angle?
Do you go from oxygen to oxygen and say it's less than 120 degrees?
Fri Nov 16, 2018 1:52 pm
Forum: Hybridization
Topic: Describing Hybridization
Replies: 3
Views: 222

### Re: Describing Hybridization

There's a chart in 4.2 that has the electron arrangement, number of atomic orbitals, hybridization of the central atom, and the number of hybrid orbitals. It can be helpful since it gives a breakdown.
Fri Nov 16, 2018 1:44 pm
Forum: Hybridization
Topic: General definition/context
Replies: 2
Views: 173

### Re: General definition/context

You use hybridization to explain molecular geometry hence:
linear → sp
trigonal planar → sp²
tetrahedral → sp³
trigonal pyramidal → sp³d
octahedral → sp³d²
Fri Nov 16, 2018 1:33 pm
Forum: Hybridization
Topic: How to Determine
Replies: 12
Views: 633

### Re: How to Determine

Note:
Single bonds--> one sigma bond
Double bonds--> one sigma and one pie.
Triple bonds--> one sigma and two pies.
Thu Nov 15, 2018 11:49 pm
Forum: Hybridization
Topic: How to Determine
Replies: 12
Views: 633

### Re: How to Determine

I don't think resonance affects it but Im not certain. That being said hybridization to explain molecular geometry.
linear → sp
trigonal planar → sp²
tetrahedral → sp³
trigonal pyramidal → sp³d
octahedral → sp³d²
Thu Nov 15, 2018 11:41 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Molecular Orbital Diagram
Replies: 4
Views: 528

### Re: Molecular Orbital Diagram

So we don't need to know how to draw the 3D shape right?
Sun Nov 11, 2018 9:50 pm
Forum: Dipole Moments
Topic: Dipoles
Replies: 2
Views: 126

### Dipoles

Just for clarification, a partially positive element does not mind sharing electrons while a partially negative receives the electrons?
Sun Nov 11, 2018 9:41 pm
Forum: Dipole Moments
Topic: Bond Lengths
Replies: 5
Views: 313

### Re: Bond Lengths

The atomic size can increase the bond length.
Sun Nov 11, 2018 9:32 pm
Forum: Student Social/Study Group
Topic: Study Group Chat?
Replies: 4
Views: 362

### Re: Study Group Chat?

I do not know if there's a study group but I wouldn't mind forming a study group.
Wed Oct 10, 2018 11:34 pm
Forum: Properties of Light
Topic: Photoelectric effect
Replies: 1
Views: 105

### Re: Photoelectric effect

Wait..I was confused. The work function and avogrado's number is for part b. So it all works out.
Wed Oct 10, 2018 11:30 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical & Molecular Formulas
Replies: 11
Views: 1000

### Re: Empirical & Molecular Formulas

Yes, the empirical and molecular can defiantly be the same.
Wed Oct 10, 2018 11:27 pm
Forum: Properties of Light
Topic: Photoelectric effect
Replies: 1
Views: 105

### Photoelectric effect

28. Light hits a sodium metal surface and the velocity of the ejected electron is 6.61 x 105 m.s-1. The work function for sodium is 150.6 kJ.mol-1. A. What is the kinetic energy of the ejected electron? I used the fromula EK=1/2 MV^2 and got 1.99*10^-19 but I don't understand how to apply the work f...
Fri Oct 05, 2018 4:13 pm
Forum: Properties of Light
Topic: Homework Question
Replies: 2
Views: 170

### Homework Question

For Tuesday, do we have to turn in seven problems that relate to quantum?
Wed Oct 03, 2018 8:39 pm
Forum: SI Units, Unit Conversions