## Search found 114 matches

Sat Mar 14, 2020 11:21 am
Forum: Administrative Questions and Class Announcements
Topic: online
Replies: 3
Views: 62

### Re: online

I believe he will be sending another conformation email with all the logistics.
Sat Mar 14, 2020 11:20 am
Forum: General Rate Laws
Topic: functional difference
Replies: 1
Views: 29

### Re: functional difference

A differential rate law is the rate dependent on concentration while the integrated rate law is the concentration as a function of time.
Thu Mar 12, 2020 11:12 am
Forum: Administrative Questions and Class Announcements
Topic: Take Home Final
Replies: 16
Views: 308

### Re: Take Home Final

I would be prepared to have to print out a worksheet from online and then scan in your answers and submit it online. There will most likely be a time frame of probably around 3-4 hours.
Tue Mar 10, 2020 6:23 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Using Equilibrium constants to predict solubility
Replies: 4
Views: 69

### Re: Using Equilibrium constants to predict solubility

Both methods will ultimately yield the same answer, but if you are only given equilibrium constants then you would use K=k/k'
Tue Mar 10, 2020 6:21 pm
Forum: Second Order Reactions
Topic: 2nd Order Slope
Replies: 2
Views: 22

### Re: 2nd Order Slope

When plotting a second order reaction, the slope should be positive k.
Tue Mar 10, 2020 6:20 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: reaction mechanism
Replies: 2
Views: 29

### Re: reaction mechanism

There is no way to know for sure the intermediates and all the steps of the reaction based on a single overarching equation.
Tue Mar 10, 2020 6:18 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Replies: 2
Views: 85

### Re: Adiabatic system and entropy

An adiabatic system means that q=0 which does not necessarily connect directly to entropy.
Tue Mar 10, 2020 6:16 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Rate of Change
Replies: 1
Views: 30

### Re: Rate of Change

It depends on the coefficients, order, and whether they are reactants or products.
Mon Mar 09, 2020 10:08 am
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: pH
Replies: 3
Views: 65

### Re: pH

The pH of an electrode can help you find the concentration of H+, if you are trying to find E cell and need to find Q.
Wed Mar 04, 2020 10:38 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6N.13
Replies: 1
Views: 48

### Re: 6N.13

The reaction would be 2H20--> O2 +4H+ + 4e-. You would have to look at the table of reductions to figure this out.
Wed Mar 04, 2020 10:35 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6N5 part a
Replies: 1
Views: 43

### Re: 6N5 part a

I thin you switched reactants and products in Q because [H+] should. be in the numerator and 1 should be in the denominator.
Wed Mar 04, 2020 10:33 am
Forum: Balancing Redox Reactions
Topic: 6K.3 part d
Replies: 1
Views: 47

### Re: 6K.3 part d

I think there is a typo in the textbook and it is supposed to be cl2--> 2cl-, otherwise it wouldn't be a redox reaction.
Wed Mar 04, 2020 10:32 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6M.5
Replies: 2
Views: 49

### Re: 6M.5

The cell potential of Hg2^2+ +2e--> Hg is on the reduction chart and the potential is 0.79 V.
Wed Mar 04, 2020 10:30 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram w/o salt bridge
Replies: 1
Views: 41

### Re: Cell Diagram w/o salt bridge

I think for the purpose of the class, he only is focusing on drawing a cell diagram with a salt bridge, but you should know the function and application of a porous disc.
Wed Mar 04, 2020 10:28 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Writing a redox reaction from a cell diagram
Replies: 1
Views: 35

### Re: Writing a redox reaction from a cell diagram

In the following step they end up multiplying by 2 so I don't think it matters that much which way you attempt it. In the end it the solution is the same.
Wed Mar 04, 2020 10:27 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6.L.5 D
Replies: 2
Views: 43

### Re: 6.L.5 D

I think you would have to look at the reduction table to figure it out. At least that's the way I approached it.
Fri Feb 28, 2020 3:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2
Replies: 5
Views: 95

### Re: Test 2

Yes, I believe the test covers the second page of the thermodynamics outline and all of the electrochemistry outline
Fri Feb 28, 2020 3:58 pm
Forum: General Rate Laws
Topic: Deriving the Rate Equation
Replies: 5
Views: 125

### Re: Deriving the Rate Equation

I do not think he will make us reproduce the derivation for an exam
Fri Feb 28, 2020 3:57 pm
Forum: Balancing Redox Reactions
Topic: Test 2
Replies: 10
Views: 113

### Re: Test 2

Test 2 will cover the second page of thermodynamics as well as all of the electrochemistry outline
Wed Feb 26, 2020 4:37 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6N.7
Replies: 1
Views: 46

### 6N.7

Can someone explain why n=1 in 6N.7, I thought that N should be 2 because there is a transfer of 2 electrons from H2->2H+
Mon Feb 24, 2020 5:19 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Example 6L.2
Replies: 1
Views: 25

### Example 6L.2

In example 6L.2 can someone explain why the Cl- only shows up in the reduction half of the equation and not the oxidation half?
Mon Feb 24, 2020 12:56 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy and K
Replies: 5
Views: 104

### Gibbs Free Energy and K

Can someone explain the free energy depends on pressure and the equilibrium constant
Sat Feb 22, 2020 2:23 pm
Forum: Van't Hoff Equation
Topic: Entropy in Van't Hoff Equation
Replies: 3
Views: 58

### Re: Entropy in Van't Hoff Equation

The change in entropy is constant because the difference in entropy between the reactants and products at 2 different temperatures is the same. The entropy is different at two different temperatures, but for Van't Hoff we are using the net change go entry which is constant.
Sat Feb 22, 2020 2:19 pm
Forum: Van't Hoff Equation
Topic: Entropy in Van't Hoff Equation
Replies: 3
Views: 45

### Re: Entropy in Van't Hoff Equation

The difference in entropy between reactants and products at two different temperatures is the same because despite entropy changing with temperature, you are finding the overall change in entropy, so if reactants entropy goes up then products entropy would do the opposite.
Sat Feb 22, 2020 2:15 pm
Forum: Van't Hoff Equation
Topic: Assumptions
Replies: 3
Views: 55

### Re: Assumptions

Temperature affects entropy because at higher temperature, there are more possible states for particles increasing entropy and vice versa for lower temperatures.
Sat Feb 22, 2020 2:12 pm
Forum: Van't Hoff Equation
Topic: 5G.21
Replies: 4
Views: 152

### Re: 5G.21

Everything given to you in the problem is either a constant or experimentally determined, so when you rearrange the equation to solve for K, you exponentiate the G/-RT, to give you the answer.
Sat Feb 22, 2020 2:09 pm
Forum: Van't Hoff Equation
Topic: Van't Hoff Equation
Replies: 2
Views: 51

### Van't Hoff Equation

Can someone explain when one should use the Van't Hoff Factor, and what it tells us?
Wed Feb 12, 2020 9:27 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Delta U = n*Cv,m*deltaT
Replies: 7
Views: 300

### Re: Delta U = n*Cv,m*deltaT

For constant pressure the Cv would actually be switched to CP.
Wed Feb 12, 2020 9:27 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: deltaU for an ideal gas
Replies: 2
Views: 56

### Re: deltaU for an ideal gas

I do not believe that Lavelle expects us to know them or what they are used for. He used it as an example to show that an isothermal reaction has an internal energy equal to 0.
Wed Feb 12, 2020 9:25 pm
Forum: Calculating Work of Expansion
Topic: Work for an isothermal reversible expansion
Replies: 3
Views: 94

### Re: Work for an isothermal reversible expansion

Pressure is not always used because it is not in the equation, but you can substitute nrt to PV through the ideal gas law.
Mon Feb 10, 2020 8:48 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: 4G.5
Replies: 2
Views: 46

### 4G.5

Can someone explain how the cis has 12 possible orientations while the trans only has 3? I don't understand how they got these numbers.
Mon Feb 10, 2020 8:35 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 4F.17
Replies: 1
Views: 29

### 4F.17

Can someone explain why you have to calculate the entropy to heat up the water and then cool it back down. Why can't you just calculate going from 100 degrees to 85 degrees?
Fri Feb 07, 2020 10:37 am
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: 3rd Law of Thermodynamics
Replies: 2
Views: 30

### Re: 3rd Law of Thermodynamics

It is also states that the sign of entropy is always positive as long as the system is above absolute zero. This means that entropy in increase and the system is spontaneous as long as the the system is above absolute zero.
Fri Feb 07, 2020 10:28 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: negative Delta U
Replies: 5
Views: 59

### Re: negative Delta U

If you burn fuel you have a lot of heat lost, meaning the internal energy decrease, but since the energy is lost as heat it does not increase the capacity to do work.
Fri Feb 07, 2020 10:26 am
Forum: Calculating Work of Expansion
Topic: Understanding equation for work at constant pressure
Replies: 3
Views: 34

### Re: Understanding equation for work at constant pressure

I would not focus as much on how to derive the equation, rather focus conceptually on what the equation means and how to manipulate it.
Fri Feb 07, 2020 10:22 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Cp/Cv
Replies: 7
Views: 68

### Re: Cp/Cv

You must assume that it is constant pressure because otherwise you a reversible system which requires another set of equations.
Fri Feb 07, 2020 10:16 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Isothermal and Isobaric
Replies: 1
Views: 64

### Re: Isothermal and Isobaric

I believe this is possible, but everything would just equal 0. It is not a realistic scenario.
Fri Feb 07, 2020 10:15 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: enthalpy and temperature
Replies: 2
Views: 66

### Re: enthalpy and temperature

I don't believe we have to know this for the midterm.
Sun Feb 02, 2020 8:00 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Constant Pressure
Replies: 2
Views: 25

### Re: Constant Pressure

This is because for reactions with solids or liquids there are no volume changes as compared to a gas that is able to expand and change its volume relatively easily.
Sun Feb 02, 2020 7:54 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: 4A1
Replies: 2
Views: 37

### Re: 4A1

This would be an isolated system because no heat is able to escape the bomb calorimeter and there would be no matter (such as water) able to escape either.
Sun Feb 02, 2020 7:51 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Method 2
Replies: 2
Views: 60

### Re: Method 2

For method two you could assume that all the bonds of the reactants were broken and all the bonds of the products were formed, but the reactant bond enthalpies would be positive and the bond enthalpies of the products would be negative.
Sun Feb 02, 2020 7:48 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: deltaU and deltaH
Replies: 4
Views: 45

### Re: deltaU and deltaH

delta U indicates constant volume while delta H Indicates constant pressure
Sun Feb 02, 2020 10:44 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 4A.7
Replies: 3
Views: 58

### Re: 4A.7

I was also wondering the same thing.
Tue Jan 28, 2020 9:49 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard Enthalpy of Formation
Replies: 4
Views: 63

### Standard Enthalpy of Formation

Can someone explain when the standard enthalpy of formation is equal to 0?
Thu Jan 23, 2020 9:05 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6B.9
Replies: 2
Views: 40

### Re: 6B.9

1.0x10^-14= [H3O+][OH-], from this equation you can find the concentration of either hydronium or hydroxide.
Thu Jan 23, 2020 8:59 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Changing K
Replies: 13
Views: 115

### Re: Changing K

Changing temperature does not make it a different reaction it simply makes the reaction go more to completion which therefore changes K.
Thu Jan 23, 2020 8:56 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: removing H2 from N2 + 3H2 -> 2NH3
Replies: 7
Views: 138

### Re: removing H2 from N2 + 3H2 -> 2NH3

Decreasing H2 would cause there to be less reactants meaning the equilibrium will shift back towards the reactants in order to maintain the value of K.
Thu Jan 23, 2020 8:52 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Partial Pressure vs Pressure
Replies: 7
Views: 80

### Re: Partial Pressure vs Pressure

The partial pressure and total pressure are different things, but they are related. The partial pressure is the pressure of a specific gas while the total pressure is the sum of all the partial pressures.
Wed Jan 22, 2020 2:41 pm
Forum: Phase Changes & Related Calculations
Topic: Heat curve for water
Replies: 2
Views: 37

### Heat curve for water

Can someone explain how the heat curve for water proves steam causes worse burns than water at the same temperature?
Thu Jan 16, 2020 8:36 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6D.3
Replies: 1
Views: 20

### Re: 6D.3

I got those answers as well!
Thu Jan 16, 2020 8:34 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Solids and Liquids in Le Chatelier
Replies: 5
Views: 91

### Re: Solids and Liquids in Le Chatelier

No since solids and liquids are not even used to calculate K they are disregarded in Le Chateliers. Solids and liquids do not affect the equilibrium.
Thu Jan 16, 2020 8:33 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: strong/weak acids and bases
Replies: 2
Views: 24

### Re: strong/weak acids and bases

You must memorize the strong/weak acids and bases in order to figure it out in a problem.
Thu Jan 16, 2020 8:31 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Replies: 11
Views: 99

### Re: ICE and quadratic formula

For some problems you must use the quadratic formula, there is no way around it. Even when you ignore K you must do the 5% approximation check.
Tue Jan 14, 2020 10:04 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 5I.13
Replies: 3
Views: 41

### 5I.13

Can someone explain part C of 5I.13? What would the equilibrium constant tell us in terms of stability?
Fri Jan 10, 2020 7:54 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Graphing K and Q Values
Replies: 4
Views: 51

### Re: Graphing K and Q Values

I think graphing is a very complex way of showing q vs k which is more visually favorable, but is not necessary to determine q vs k. I think due to time constraints it would not be reasonable to graph q vs k.
Fri Jan 10, 2020 7:50 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Pure Substance
Replies: 5
Views: 42

### Re: Pure Substance

The activity of pure substances are actually not equal to zero they are equal to one.
Fri Jan 10, 2020 4:52 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Today's Lecture
Replies: 3
Views: 47

### Today's Lecture

Can someone explain what he was trying to say in todays lecture when he said that simply comparing the mole ratio would give the right answer but the wrong reasoning? What is the proper reasoning to explain change in pressure?
Wed Jan 08, 2020 11:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5G.1
Replies: 1
Views: 44

### 5G.1

Can someone explain part C of 5G.1. The question is talking about pressure but the answer only addresses amount of reactant and product which is confusing.
Wed Jan 08, 2020 11:07 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5G.7
Replies: 2
Views: 48

### 5G.7

In 5G.7 why did they write K in terms of Kc if all the products and reactants are gases? Should it be in terms of Kp?
Sun Dec 08, 2019 10:18 am
Forum: Calculating the pH of Salt Solutions
Topic: 6.13
Replies: 1
Views: 103

### Re: 6.13

I think it is referring to the conjugate seesaw in which a strong acid has a weak conjugate base and vice versa.
Tue Dec 03, 2019 11:32 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: J.23
Replies: 2
Views: 53

### Re: J.23

I think that since these are common acids that you should know them.
Tue Dec 03, 2019 11:28 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Definition of Acid
Replies: 4
Views: 56

### Re: Definition of Acid

A Lewis acid simply includes more molecules than a Bronsted acid. They are both proper definitions for acids, but a Lewis acid is more broad and includes more molecules.
Tue Dec 03, 2019 11:26 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Electronegativity and Acid Strength
Replies: 3
Views: 76

### Re: Electronegativity and Acid Strength

This is because an electronegative atom has a more stable resulting anion. In H-O-F and H-O-Cl the more EN F pulls the charge away from the O delocalizing the electrons and making the resulting anion more stable and HF a stronger acid.
Tue Dec 03, 2019 11:19 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6C17 - strength of bases
Replies: 4
Views: 82

### Re: 6C17 - strength of bases

I remember during lecture he said anything with Nitrogen is usually a weak base. So that is a good rule of thumb.
Tue Dec 03, 2019 11:01 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: acidic trends
Replies: 3
Views: 52

### Re: acidic trends

Another way of thinking about it is the strength of an acid can be related to electronegativity because in the case of H-O-F and H-O-Cl since F is more electronegative it pulls on the oxygen weakening the O-H bond making HF a stronger acid.
Fri Nov 29, 2019 11:00 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Weak Acids and Bases
Replies: 5
Views: 372

### Re: Weak Acids and Bases

Since strong bases fully dissociate a helpful tip is that if Kb is given it is implying a weak base.
Fri Nov 29, 2019 10:55 am
Forum: Bronsted Acids & Bases
Topic: Naming Acids and Bases
Replies: 3
Views: 53

### Re: Naming Acids and Bases

I don't think we need to know any complicated ones, but you should know the rules and the most common acids/bases.
Fri Nov 29, 2019 10:53 am
Forum: Bronsted Acids & Bases
Topic: Difference between bronsted and lewis acid/base?
Replies: 6
Views: 57

### Re: Difference between bronsted and lewis acid/base?

Not a single one is correct to define an acid or base, but you should know the difference between them.
Fri Nov 29, 2019 10:48 am
Forum: Lewis Acids & Bases
Topic: Weak and Strong Acids and Bases
Replies: 3
Views: 41

### Re: Weak and Strong Acids and Bases

For strong acids I had to memorize them as HCl, HBr, HI, HCLO3, HCLO4, HNO3, and H2SO4, but I don't know if Lavelle wants us to know any others.
Fri Nov 29, 2019 10:46 am
Forum: Lewis Acids & Bases
Topic: Weak and Strong Acids and Bases
Replies: 3
Views: 41

### Re: Weak and Strong Acids and Bases

The strong bases are any group I or II oxides and hydroxides and an indication of a weak base is basically anything with N in it.
Fri Nov 22, 2019 8:55 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 2
Views: 32

### Re: Ligands

It might refer to where the ligand makes a coordination bond with the central atom.
Fri Nov 22, 2019 8:52 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Number of Coordination Bonds
Replies: 2
Views: 41

### Re: Number of Coordination Bonds

I think you would have to find the oxidation number on the transition metal first and then from there you can determine how many coordination bonds that can form.
Wed Nov 20, 2019 1:00 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 4
Views: 107

### Cisplatin

Can someone explain how cisplatin stops cell division?
Tue Nov 19, 2019 9:53 am
Forum: Hybridization
Topic: Energy in Hybridization
Replies: 3
Views: 44

### Re: Energy in Hybridization

In class when he was mentioning that energy was increasing he was referring to the original orbitals of 2s and 2p. He drew the arrow of increasing energy next to these orbitals and then put the hybridized orbital in the middle of the 2s and 2p because a hybridized orbital has energy somewhere betwee...
Mon Nov 18, 2019 3:35 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Sigma and Pi Bonds
Replies: 18
Views: 335

### Re: Sigma and Pi Bonds

As long as you state there is one sigma and 2 pi bonds it doesn't matter how you assign them.
Mon Nov 18, 2019 3:32 pm
Forum: Hybridization
Topic: Pi and sigma bonds
Replies: 4
Views: 73

### Re: Pi and sigma bonds

A sigma bond almost always forms first so automatically a multiple bond will have one sigma bond. Since pi bonds overlap side by side that is why they form on multiple bonds. Therefore any multiple bond will have one sigma bond and then either 1 or 2 pi bonds.
Fri Nov 15, 2019 9:19 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Other shapes
Replies: 3
Views: 35

### Re: Other shapes

Yes, I believe we are responsible for knowing all of the shapes for the test.
Fri Nov 15, 2019 9:16 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Determining Bond Angle
Replies: 3
Views: 37

### Re: Determining Bond Angle

It is based on a case by case basis and what shape the lone pairs are affecting. You just have to visualize the effect of the lone pair based on the VSEPR shape you have.
Fri Nov 15, 2019 9:14 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar vs Nonpolar molecules
Replies: 4
Views: 82

### Re: Polar vs Nonpolar molecules

It's helpful remember that the polarity should be based off of the VSEPR model and not the Lewis Structure. Since the VSEPR model is the actual shape and often looks a lot different than the lewis structure, the polarity would be based off of the VSEPR model.
Fri Nov 15, 2019 9:11 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Symmetry and Polarity
Replies: 13
Views: 148

### Re: Symmetry and Polarity

Sometimes symmetry alludes to polarity but since most of the time the lewis structure isn't the actual representation you have to base it off of the VSEPR model. A symmetric Lewis structure does not automatically mean the molecule is non polar because the VSEPR model is the actual shape of the molec...
Fri Nov 15, 2019 9:07 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent or angular?
Replies: 2
Views: 58

### Re: Bent or angular?

I think it should be fine either way because bent and angular refer to the same shape.
Sun Nov 10, 2019 6:29 pm
Forum: Dipole Moments
Topic: Interactions
Replies: 4
Views: 60

### Re: Interactions

For the purposes of this class they are the same, but in induced dipole moments the molecule that induces the dipole moments has a permanent dipole moment while the same does not occur in London Dispersion Forces.
Sun Nov 10, 2019 6:25 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Polarizability
Replies: 3
Views: 55

### Re: Polarizability

With greater polarizability, the electron cloud is able to be distorted more. Therefore it is easier to form IMFs because since the electron cloud can easily be distorted it is more attracted to partial positive charges.
Sun Nov 10, 2019 10:20 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: London vs. dipole-induced-dipole interaction
Replies: 3
Views: 35

### Re: London vs. dipole-induced-dipole interaction

In addition, in dipole-induced-dipole interaction the molecule that induces the dipole moment has a permanent dipole moment while it does not in London Dispersion.
Sun Nov 10, 2019 10:17 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Electrostatic Meaning
Replies: 2
Views: 33

### Re: Electrostatic Meaning

It mainly pertains to electrostatic interaction which is the interaction between objects having electrical charges. These forces are what give rise to IMFs.
Mon Nov 04, 2019 9:58 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polar Covalent VS Ionic
Replies: 11
Views: 198

### Polar Covalent VS Ionic

How do you determine if a bond is polar covalent or ionic without looking at ionization energies?
Wed Oct 30, 2019 1:54 pm
Forum: Electronegativity
Topic: Exceptions to ionization energy trend?
Replies: 2
Views: 41

### Re: Exceptions to ionization energy trend?

There are several transition metals that break the trend in ionization energy, but it depends on a case by case basis. I do not think we are going to be responsible for knowing those.
Wed Oct 30, 2019 1:52 pm
Forum: Electronegativity
Topic: Electronegativity
Replies: 11
Views: 174

### Re: Electronegativity

An easy way to remember the trends is electronegativity, ionization energy, and electron affinity all have the same periodic trend.
Wed Oct 30, 2019 1:50 pm
Forum: Octet Exceptions
Topic: Octet Rule Exceptions
Replies: 4
Views: 67

### Re: Octet Rule Exceptions

If the atom is in a n=3 shell or higher and has an empty d orbital (elements in the p block) it will be able to expand its octet.
Tue Oct 29, 2019 10:09 am
Forum: Ionic & Covalent Bonds
Topic: Midterm
Replies: 28
Views: 428

### Re: Midterm

The midterm covers all the material up to the end of Outline 3: Chemical Bonds.
Mon Oct 28, 2019 10:09 am
Forum: Formal Charge and Oxidation Numbers
Topic: In Class Example, Sulfate
Replies: 3
Views: 79

### In Class Example, Sulfate

When computing the formal charges for SO4^2- in class he said that by adding more bonds and making all the oxygens have a 0 formal charge it would make sulfur have a 2- charge and we would rather have the sulfur have a 0 charge than the oxygens? Why would the compound be more stable with oxygen havi...
Fri Oct 25, 2019 9:37 pm
Forum: Octet Exceptions
Topic: Resonance structures
Replies: 5
Views: 50

### Re: Resonance structures

I think you have to draw out all of the possible resonance structures for a compound to portray all the possible positions for the multiple bonds.
Fri Oct 25, 2019 9:35 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Expanded Valence Shells
Replies: 5
Views: 78

### Expanded Valence Shells

I was confused as to why P,S, and Cl have an expanded octet if they have no electrons in the d orbital?
Fri Oct 25, 2019 9:31 pm
Forum: Resonance Structures
Topic: Lewis Structure vs. Resonance Structure
Replies: 4
Views: 80

### Re: Lewis Structure vs. Resonance Structure

A resonance structure is specifically related towards elements with double and triple bonds. A resonance structure is basically all of the variations of having a double and triple bond. A Lewis Structure is the basic structure of a compound and while it may contain a double or triple bond it does no...
Wed Oct 23, 2019 1:50 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Homework Help
Replies: 5
Views: 72

### Re: Homework Help

One way to look at it would be that the ground state of an electron would be the normal electron configuration. If the electron configuration is off in any way such as electrons being paired while the orbitals are not yet completely filled, then the electron is considered to be in an excited state.
Tue Oct 22, 2019 2:40 pm
Forum: Trends in The Periodic Table
Topic: Ionization Energy for the 2nd Electron
Replies: 3
Views: 27

### Re: Ionization Energy for the 2nd Electron

Yes, the second ionization is always higher regardless of whether the electron would gain a full octet or not. The second ionization is always higher because it takes more energy to remove an electron positively charged ion( since one electron has already been removed) rather than a neutral atom.
Mon Oct 21, 2019 1:26 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Spin
Replies: 8
Views: 97

### Re: Electron Spin

When simply drawing out the configurations once all the oribtals have atleast one electron( at this point they are all parallel to one another) then when more electrons are added, the electrons in the same orbital begin to get paired. All of the orbitals must be filled by at least one electron befor...
Thu Oct 17, 2019 11:31 am
Forum: Properties of Electrons
Topic: The wave property of electrons [ENDORSED]
Replies: 2
Views: 54

### Re: The wave property of electrons[ENDORSED]

In addition if electrons only acted like waves then increasing the intensity of light would yield more electron ejection, but that was not the case.
Thu Oct 17, 2019 11:29 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Spin State
Replies: 17
Views: 150

### Re: Spin State

Calculating spin state is not necessary as it will always be either +1/2 or -1/2. The positives and negatives simply represent whether the electron is spinning clockwise or counterclockwise
Wed Oct 16, 2019 2:42 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodal plane for s-orbitals?
Replies: 3
Views: 52

### Re: Nodal plane for s-orbitals?

S orbitals have no nodal planes simply due to their shape. S orbitals are symmetrical and basically look like a sphere. For this reason they have no nodal planes.