Search found 101 matches

by ASetlur_1G
Sun Mar 15, 2020 12:01 am
Forum: Balancing Redox Reactions
Topic: inferring half rxns from equation
Replies: 4
Views: 96

Re: inferring half rxns from equation

I don't know how to infer these sorts of things to balance half rxns. for example 6L.5.c) Cl2 + H2 --> HCl yields the half reactions Cl2 + 2e --> Cl- and H2 + 2e --> H+ but why don't they have products of HCl as that's all that is given in the problem? Why are we, in this one problem, allowed to sp...
by ASetlur_1G
Sat Mar 14, 2020 11:54 pm
Forum: Calculating Work of Expansion
Topic: Multistep Irreversible Expansion
Replies: 4
Views: 118

Re: Multistep Irreversible Expansion

Because entropy is a state function, you can calculate the change in entropy (of the system) as though the expansion occurred reversibly! You would calculate the change in entropy from a change in volume, assuming constant temperature (∆S = nRlnV2/V1), and the change in entropy from the change in t...
by ASetlur_1G
Sat Mar 14, 2020 11:51 pm
Forum: Balancing Redox Reactions
Topic: cathode vs anode
Replies: 11
Views: 191

Re: cathode vs anode

If Ecell is positive, the anode is on the left and the cathode is on the right. If Ecell is negative, the anode is on the right and the cathode is on the left.
by ASetlur_1G
Sat Mar 14, 2020 11:48 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Gibbs free energy
Replies: 8
Views: 139

Re: Gibbs free energy

Standard Gibbs Free Energy is a fixed value for a reaction, but Gibbs Free Energy changes as the reaction progresses.
by ASetlur_1G
Sat Mar 14, 2020 11:47 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Including H2O in Cell Diagram
Replies: 3
Views: 32

Including H2O in Cell Diagram

Just to clarify, do we not add H2O (l) to the cell diagram because it's already implied in the aqueous solution?
by ASetlur_1G
Wed Mar 04, 2020 11:39 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: strength as reducing agents
Replies: 3
Views: 30

Re: strength as reducing agents

The more negative the standard reduction potential, the stronger the reducing agent. The more positive the standard reduction potential, the stronger the oxidizing agent.
by ASetlur_1G
Wed Mar 04, 2020 8:00 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6N.7 (b)
Replies: 2
Views: 28

6N.7 (b)

The question asks to calculate Ecell for the concentration cell:

Pt(s)|H2(g, 1 bar)|H+(aq, pH=4.0)||H+(aq, pH=3.0)|H2(g, 1 bar)|Pt(s).

When calculating Ecell, I thought n = 2 because 2 electrons are transferred. Why is n = 1?
by ASetlur_1G
Wed Mar 04, 2020 2:04 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6M.1
Replies: 1
Views: 30

Re: 6M.1

Because Ecell is negative, the anode is on the right side of the cell diagram instead of the left side, making Cu2+/Cu the anode.
by ASetlur_1G
Tue Mar 03, 2020 12:37 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.5 (d)
Replies: 1
Views: 30

6L.5 (d)

For 6L.5 (d), the cell reaction is:

Au+(aq) --> Au(s) + Au3+ (aq)

Why is the oxidation half-reaction Au(s) --> Au3+(aq) +3e- and not Au+(aq) --> Au3+(aq) + 2e- ?
by ASetlur_1G
Tue Mar 03, 2020 12:31 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.5 D.
Replies: 7
Views: 92

Re: 6L.5 D.

For this specific reaction, Au + acts in both the cathode and anode reaction, so you should see both in each reaction. For cathode, the half reaction is: Au+ + e- -> Au For anode, the half reaction is" Au3+ + 3e- -> Au+ Then, you should multiply the half reaction of cathode by 3 and flip the a...
by ASetlur_1G
Sun Mar 01, 2020 11:24 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Electromotive force
Replies: 2
Views: 24

Re: Electromotive force

How is EMF different from potential difference?
by ASetlur_1G
Sun Mar 01, 2020 11:16 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Ways to calculate Gibbs free energy
Replies: 5
Views: 70

Re: Ways to calculate Gibbs free energy

I think it mostly just depends on what they give you. If you're given a table with delta G of different molecules, then you use the second one.
by ASetlur_1G
Sun Mar 01, 2020 11:14 pm
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: Rust [ENDORSED]
Replies: 2
Views: 160

Rust [ENDORSED]

Can someone explain the rusting process and why it needs to be oxidized by both oxygen and water?
by ASetlur_1G
Sun Mar 01, 2020 10:48 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: When to add Platinum
Replies: 8
Views: 67

Re: When to add Platinum

You add platinum when there's no solid in either the anode or cathode of the cell (like if there's only an aqueous solution). You add it to the side without a solid.
by ASetlur_1G
Sun Mar 01, 2020 10:40 pm
Forum: Balancing Redox Reactions
Topic: Acidic vs. Basic Solutions
Replies: 8
Views: 114

Re: Acidic vs. Basic Solutions

In terms of balancing redox reactions in acidic vs. basic solutions, the only difference is that in basic solutions, for every H+ that you add, you add an OH to the opposite side.
by ASetlur_1G
Sun Feb 23, 2020 11:08 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 5J.15
Replies: 2
Views: 60

Re: 5J.15

They use the standard enthalpies of formation, which is zero for diatomic/pure/elemental gases like H2 and D2.
by ASetlur_1G
Sun Feb 23, 2020 10:58 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: G(not) and G
Replies: 15
Views: 154

Re: G(not) and G

Is it correct to say that G(not) is used at equilibrium (K value) and G is used for other conditions (Q value)?
by ASetlur_1G
Sun Feb 23, 2020 10:56 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Standard Hydrogen Electrode
Replies: 3
Views: 34

Standard Hydrogen Electrode

Why is hydrogen used as a standard electrode? Why do we compare half reactions with respect to the standard hydrogen electrode?
by ASetlur_1G
Sun Feb 23, 2020 10:53 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams
Replies: 4
Views: 39

Cell Diagrams

When do you use Platinum as an inert conductor in cell diagrams?
by ASetlur_1G
Sun Feb 23, 2020 10:45 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: applying gibbs free energy
Replies: 5
Views: 65

Re: applying gibbs free energy

Gibbs free energy tells us if a reaction is spontaneous or not.
by ASetlur_1G
Sun Feb 16, 2020 10:48 pm
Forum: Phase Changes & Related Calculations
Topic: rate of reactions
Replies: 3
Views: 135

Re: rate of reactions

Nathan Rothschild_2D wrote:What is the standard unit of time?


I believe it's seconds.
by ASetlur_1G
Sun Feb 16, 2020 10:47 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Delta H
Replies: 10
Views: 215

Re: Delta H

Manav Govil 1B wrote:Delta H can usually be written as q. This is derived from the equation . , so .


But this is only for when pressure is constant right?
by ASetlur_1G
Sun Feb 16, 2020 10:42 pm
Forum: Calculating Work of Expansion
Topic: Using Calculus to prove the equation
Replies: 4
Views: 121

Re: Using Calculus to prove the equation

ASetlur_1G wrote:You integrate -P delta V from V1 to V2, and because it's referring to an irreversible expansion, the pressure is constant, so you can take out the P, which just gives you w = -P delta V


Actually, sorry you integrate -Pdv, which gives you -P delta V.
by ASetlur_1G
Sun Feb 16, 2020 10:41 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Shift in Equilibrium
Replies: 2
Views: 43

Shift in Equilibrium

What would happen to the equilibrium if a substance that is not involved in the initial reaction is added? Would the equilibrium still shift? Which way?
by ASetlur_1G
Sun Feb 16, 2020 10:32 pm
Forum: Calculating Work of Expansion
Topic: Using Calculus to prove the equation
Replies: 4
Views: 121

Re: Using Calculus to prove the equation

You integrate -P delta V from V1 to V2, and because it's referring to an irreversible expansion, the pressure is constant, so you can take out the P, which just gives you w = -P delta V
by ASetlur_1G
Sun Feb 09, 2020 10:15 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: heat cap for liquid water instead of solid water
Replies: 1
Views: 22

Re: heat cap for liquid water instead of solid water

You first have to calculate the heat for a phase change (ice to liquid water), which is done by multiplying the enthalpy of fusion and the number of moles. Then, you use q = mc delta t, by which time the ice has already changed into liquid water, so you use the specific heat capacity of liquid water.
by ASetlur_1G
Sun Feb 09, 2020 10:10 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Equipartition Therom
Replies: 3
Views: 40

Re: Equipartition Therom

What exactly is the Equipartition Theorem?
by ASetlur_1G
Sun Feb 09, 2020 10:06 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: monoatomic, diatomic, linear, non-linear
Replies: 3
Views: 49

Re: monoatomic, diatomic, linear, non-linear

Do we have to have all the molar heat capacities for the different shapes memorized? I don't think all of them are on the constants and equations sheet...
by ASetlur_1G
Sun Feb 09, 2020 10:05 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Entropy Change with both volume change and temperature change
Replies: 2
Views: 40

Re: Entropy Change with both volume change and temperature change

I think you would calculate the entropy of the temperature change and volume change separately and then add the values together (since entropy is a state function) to calculate the total change in entropy. So for the change in volume you would use the deltaS = nRln(V2/V1) and for the change in temp...
by ASetlur_1G
Sun Feb 09, 2020 9:54 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Intensive vs. extensive, state vs. non state
Replies: 6
Views: 71

Re: Intensive vs. extensive, state vs. non state

Not too sure about the intensive vs. extensive but the state functions are: pressure, density, temperature, volume, enthalpy, internal energy, Gibbs free energy, and entropy.
by ASetlur_1G
Sun Feb 02, 2020 11:41 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 4D.3
Replies: 2
Views: 33

Re: 4D.3

You first find q of the calorimeter (2.058 kJ), and since qcal = -qrxn, qrxn = -2.058 kJ. Then you divide qrxn by the number of moles of CO (convert 1.40 g to moles) to get q for 1 mole of CO, which is equal to delta U.
by ASetlur_1G
Sun Feb 02, 2020 11:13 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 4A.7
Replies: 3
Views: 31

Re: 4A.7

chari_maya 3B wrote:Is it possible to do this problem by finding total mass and only applying mcdeltaT once, or would that not work because of different heat capacities?


I think you have to do them separately because copper and water have different heat capacities.
by ASetlur_1G
Sun Feb 02, 2020 11:10 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Combustion
Replies: 5
Views: 42

Re: Combustion

It depends on what temperature the reaction occurs at. At 25 degrees Celsius, water is produced as a liquid. If the temperature is greater than the boiling point, water is produced as a gas.
by ASetlur_1G
Sun Feb 02, 2020 11:06 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacity at Constant Volume and Pressure
Replies: 1
Views: 27

Re: Heat Capacity at Constant Volume and Pressure

At a constant volume, the system is not able to do work, so all the heat put in goes into raising the temperature (internal energy). Therefore, Cv = delta U/delta T. At constant pressure, some of the energy put in goes into raising the temperature (internal energy) and some of it goes into doing wor...
by ASetlur_1G
Sun Feb 02, 2020 10:57 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat capacities of different compounds
Replies: 3
Views: 25

Re: Heat capacities of different compounds

Generally, the more complex the molecule, the higher the heat capacity. This is because complex molecules have more vibrational motions that can store heat.
by ASetlur_1G
Sun Jan 26, 2020 11:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Negative pH
Replies: 9
Views: 65

Negative pH

Why can the pH sometimes be negative? What's going on conceptually?
by ASetlur_1G
Sun Jan 26, 2020 11:17 pm
Forum: Phase Changes & Related Calculations
Topic: State function
Replies: 4
Views: 32

Re: State function

Heat is the energy transferred between the system and the surroundings during some process. The amount that transfers depends on how the process happens, so it's a state function.
by ASetlur_1G
Sun Jan 26, 2020 11:10 pm
Forum: Phase Changes & Related Calculations
Topic: Solids, liquids, and gases
Replies: 4
Views: 36

Re: Solids, liquids, and gases

Water as a liquid has more directions to move and to absorb the heat applied to it. There's more surface area that needs to be heated for the overall temperature to increase.
by ASetlur_1G
Sun Jan 26, 2020 11:06 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy of Vaporization and Fusion
Replies: 5
Views: 36

Re: Enthalpy of Vaporization and Fusion

Water in its liquid state has strong intermolecular force (hydrogen bonding), but water in its vapor phase has almost no intermolecular force. Thus, it takes a lot of energy to break the hydrogen bonds for water in liquid phase to turn to water in vapor phase. For fusion, the intermolecular forces a...
by ASetlur_1G
Sun Jan 26, 2020 10:54 pm
Forum: Phase Changes & Related Calculations
Topic: Why does steam cause burns?
Replies: 29
Views: 253

Re: Why does steam cause burns?

Omar Selim 1D wrote:Steam causes burns due to the high amount of heat transferred from the steam to skin. It has a large Q and H value.


What do the Q and H values refer to?
by ASetlur_1G
Sun Jan 19, 2020 11:10 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Adding Acid/Base to Neutral Water
Replies: 1
Views: 21

Adding Acid/Base to Neutral Water

Is it safe to assume that if you add an acid/base to neutral water and the H3O+ or OH- concentration of the acid/base is less than 10^-7, then it won't change the pH (pH will still be 7)?
by ASetlur_1G
Sun Jan 19, 2020 11:01 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic and Endothermic Reactions
Replies: 5
Views: 55

Re: Exothermic and Endothermic Reactions

Will we always be give delta H to tell if a reaction is endothermic or exothermic? If not, how do we tell?
by ASetlur_1G
Sun Jan 19, 2020 10:58 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Adding Inert Gas
Replies: 9
Views: 118

Adding Inert Gas

What's the difference between adding an inert gas at constant pressure vs. adding an inert gas at constant volume to a reaction in regards to the effect on equilibrium?
by ASetlur_1G
Sun Jan 19, 2020 10:51 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6B.11B
Replies: 2
Views: 46

Re: 6B.11B

You have to use the original concentration of OH- because they're asking for the initial amount of Na2O. Thus, you want the concentration of OH- before the dilution, which would be 18 M.
by ASetlur_1G
Sun Jan 19, 2020 10:46 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K for Gases
Replies: 12
Views: 96

Re: K for Gases

It probably depends on what you are given in the problem (the partial pressures or the concentrations). You could do either Kp or Kc, as long as you keep track and do not confuse the two because the values will not be the same. And in Wednesday's lecture Lavelle showed us how to convert between Kp ...
by ASetlur_1G
Sun Jan 12, 2020 10:23 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: solids and liquids
Replies: 5
Views: 42

Re: solids and liquids

Solids and liquids don't affect the reactant amount at equilibrium. They don't change in concentration (solids don't really even have "concentrations") so they're not included.
by ASetlur_1G
Sun Jan 12, 2020 10:19 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K Expression for Reverse Reaction
Replies: 3
Views: 38

Re: K Expression for Reverse Reaction

K of the reverse reaction would be the reciprocal of K of the forward reaction so the products and reactants would be flipped.
by ASetlur_1G
Sun Jan 12, 2020 10:17 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Comparing K
Replies: 9
Views: 75

Re: Comparing K

ShastaB4C wrote:Also, Is there a difference between saying the rxn “lies to the right” and “shifts to the right”?


I think they mean the same thing.
by ASetlur_1G
Sun Jan 12, 2020 10:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Comparing K
Replies: 9
Views: 75

Re: Comparing K

ShastaB4C wrote:What if K=0? Does that have an effect?



I don't think K can even be 0 but I might be wrong.
by ASetlur_1G
Sun Jan 12, 2020 10:13 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Partial Pressure
Replies: 19
Views: 131

Re: Partial Pressure

^ Partial pressure is the amount of pressure each gas would exert if it were the only gas in the volume. We express the amount of a gas at equilibrium in terms of its partial pressure.
by ASetlur_1G
Tue Jan 07, 2020 12:08 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW Problem 5G.7
Replies: 4
Views: 59

Re: HW Problem 5G.7

Oh okay I think I just don't have the latest edition
by ASetlur_1G
Mon Jan 06, 2020 9:20 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW Problem 5G.7
Replies: 4
Views: 59

HW Problem 5G.7

For 5G.7, the solutions manual uses Kc instead of Kp. If all of the reactants and products are in the gas phase, why aren't partial pressures used?
by ASetlur_1G
Sun Dec 08, 2019 11:21 am
Forum: Significant Figures
Topic: pH sig figs
Replies: 9
Views: 220

Re: pH sig figs

Basically, the number of digits after the decimal points should match the number of sig figs in the molarity number
by ASetlur_1G
Sun Dec 08, 2019 11:20 am
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge [ENDORSED]
Replies: 1
Views: 101

Formal Charge [ENDORSED]

When drawing resonance structures, is it okay to have ones without optimal formal charges?
by ASetlur_1G
Sun Dec 08, 2019 11:18 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: chelating ligands [ENDORSED]
Replies: 21
Views: 6220

Re: chelating ligands [ENDORSED]

Just to clarify, polydentate ligands are chelating right?
by ASetlur_1G
Sun Dec 08, 2019 11:15 am
Forum: Biological Examples
Topic: b12?
Replies: 3
Views: 142

Re: b12?

What’s the ligand for b12?
by ASetlur_1G
Sun Dec 01, 2019 11:31 am
Forum: Hybridization
Topic: Hybridized vs. Unhybridized Orbitals
Replies: 2
Views: 41

Hybridized vs. Unhybridized Orbitals

When do you place electrons in unhybridized orbitals vs. hybridized orbitals?
by ASetlur_1G
Sun Dec 01, 2019 11:27 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Pka vs Ka
Replies: 10
Views: 173

Re: Pka vs Ka

What is the pKa value actually describing?
by ASetlur_1G
Sun Dec 01, 2019 11:13 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Organic vs. Inorganic Acids
Replies: 2
Views: 48

Organic vs. Inorganic Acids

Why are organic acids weaker than inorganic acids?
by ASetlur_1G
Sun Dec 01, 2019 10:56 am
Forum: Conjugate Acids & Bases
Topic: Conjugate Base
Replies: 5
Views: 77

Conjugate Base

Why don't conjugate bases of strong acids affect the pH?
by ASetlur_1G
Sun Dec 01, 2019 10:51 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Reactions, Equilibrium
Replies: 4
Views: 43

Reactions, Equilibrium

In class, Dr. Lavelle kept mentioning how reactions were favored to the right or left. What does that mean?
by ASetlur_1G
Sun Nov 24, 2019 6:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Radicals and Molecular Shape
Replies: 4
Views: 45

Re: Radicals and Molecular Shape

Would they also make the bond angle smaller then?
by ASetlur_1G
Sun Nov 24, 2019 6:48 pm
Forum: Hybridization
Topic: Hybrid Orbitals
Replies: 2
Views: 29

Re: Hybrid Orbitals

Draw the lewis structure and determine the number of electron domains there are around the central atom (lone pairs + bonding pairs). Then correlate the number of electron domains to the appropriate hybridization scheme (sp: 2 electron domains, sp2: 3 electron domains, sp3: 4 electron domains, sp3d:...
by ASetlur_1G
Sun Nov 24, 2019 6:29 pm
Forum: Biological Examples
Topic: Drawing Structures on Final
Replies: 3
Views: 68

Re: Drawing Structures on Final

I would assume so. Dr. Lavelle emphasized that it was important to know the biological examples like cisplatin
by ASetlur_1G
Sun Nov 24, 2019 6:26 pm
Forum: Hybridization
Topic: Strength of sigma vs pi bonds
Replies: 6
Views: 53

Re: Strength of sigma vs pi bonds

In addition to overlap, the electrons in a sigma bond are directly between the 2 nuclei so the nuclei have a strong hold over the electrons. The electrons in a pi bond are further away from the nuclei, so it's easier to break a pi bond.
by ASetlur_1G
Sun Nov 24, 2019 6:20 pm
Forum: Hybridization
Topic: stability in hybridization
Replies: 4
Views: 47

Re: stability in hybridization

I think sp2 is actually more stable because it has more s character than sp3, which means that the bond is shorter, stronger, and more stable.
by ASetlur_1G
Sun Nov 17, 2019 9:45 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Other VSEPR shapes?
Replies: 2
Views: 36

Re: Other VSEPR shapes?

I would maybe memorize all of them just to be safe.
by ASetlur_1G
Sun Nov 17, 2019 9:40 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: shape
Replies: 3
Views: 51

Re: shape

I think if there's more than one central atom, then technically yes.
by ASetlur_1G
Sun Nov 17, 2019 9:35 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lewis Structures
Replies: 6
Views: 68

Re: Lewis Structures

When you draw the lewis structure, you look at the central atom and count how many atoms it's attached to and how many lone pairs it has. This will give you the AXE notation (A = central atom, X = # of attached atoms, E = # lone pairs). Each AXE notation corresponds to a certain shape that I think w...
by ASetlur_1G
Sun Nov 17, 2019 9:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.13 part a
Replies: 1
Views: 27

Re: 2E.13 part a

It would be linear because the VSEPR notation would be AX2E3 if we're looking at the central I atom (2 bonds, 3 lone pairs).
by ASetlur_1G
Sun Nov 17, 2019 9:23 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar vs. Nonpolar
Replies: 8
Views: 90

Re: Polar vs. Nonpolar

I think it means that even if a molecule has polar bonds, if the dipole moments cancel out (they are symmetrical), then the molecule is considered nonpolar.
by ASetlur_1G
Sun Nov 10, 2019 6:00 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: London dispersion
Replies: 4
Views: 52

Re: London dispersion

All molecules have LDF because all molecules have electrons, which means that they all exhibit dispersion forces to some extent.
by ASetlur_1G
Sun Nov 10, 2019 5:43 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: 3F. 1
Replies: 2
Views: 37

Re: 3F. 1

NH2OH: dipole-dipole
CBr4: London Dispersion
H2SeO4: dipole-dipole, hydrogen bonds, London Dispersion
SO2: dipole-dipole, London Dispersion
by ASetlur_1G
Sun Nov 10, 2019 5:35 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: 51

Re: Polarizability

Electron distortion is proportional to the polarizability of electrons. When there's a greater number of electrons (large anions), electron distortion increases, and polarizability increases, so the strength of interaction also increases.
by ASetlur_1G
Sun Nov 03, 2019 9:34 pm
Forum: Formal Charge and Oxidation Numbers
Topic: formal charge
Replies: 5
Views: 74

Re: formal charge

Minimizing formal charges leads to electrons being more evenly distributed rather than being concentrated in one area which leads to regions of negative charge.
by ASetlur_1G
Sun Nov 03, 2019 9:28 pm
Forum: Trends in The Periodic Table
Topic: Electronegativity
Replies: 3
Views: 63

Electronegativity

Which one has a higher electronegativity? O or Cl?
by ASetlur_1G
Sun Nov 03, 2019 9:20 pm
Forum: Photoelectric Effect
Topic: When energy is equal to work function
Replies: 9
Views: 214

Re: When energy is equal to work function

When the energy of the photon is exactly equal to the work function, the kinetic energy is 0, so the electron will still be ejected, but it won't be able to escape from the nucleus because the velocity is 0. Usually, if the energy of the photon is greater than the work function, the electron is ejec...
by ASetlur_1G
Sun Nov 03, 2019 9:12 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: dino nugget midterm review 10d
Replies: 4
Views: 73

Re: dino nugget midterm review 10d

Is this the case for other elements in those groups as well? Does sulfur have a lower ionization energy than phosphorus?
by ASetlur_1G
Sun Nov 03, 2019 9:08 pm
Forum: *Shrodinger Equation
Topic: Schrondiger's Equation
Replies: 6
Views: 187

Re: Schrondiger's Equation

Essentially it's used to describe orbitals right?
by ASetlur_1G
Sun Oct 27, 2019 5:15 pm
Forum: Lewis Structures
Topic: Ionic vs. Covalent Lewis Structures
Replies: 2
Views: 129

Re: Ionic vs. Covalent Lewis Structures

In ionic bonding, electrons are transferred from one atom to another (adding electron for anion, subtracting electron for cation). In covalent bonding, electrons are shared between atoms.
by ASetlur_1G
Sun Oct 27, 2019 5:05 pm
Forum: Resonance Structures
Topic: Resonance
Replies: 6
Views: 62

Re: Resonance

When electrons have more volume available to them (they're not confined between atoms and are delocalized), they have lower energy. Thus, the molecule is more stable.
by ASetlur_1G
Sun Oct 27, 2019 4:57 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Vs. Oxidation Number
Replies: 4
Views: 75

Re: Formal Charge Vs. Oxidation Number

For formal charge, you're assuming that the bond is fully covalent and attribute one electron to each atom. For oxidation number, you take into account which atom has the highest electronegativity and attribute the whole shared pair to that atom.
by ASetlur_1G
Sun Oct 27, 2019 4:52 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic vs. Atomic Radii
Replies: 4
Views: 56

Re: Ionic vs. Atomic Radii

Cations have smaller radii than parent atoms because with the loss of electrons, the protons pull the remaining electrons more strongly and closely. Anions have larger radii than parent atoms because with the gain of electrons, the electron-electron repulsion increases.
by ASetlur_1G
Sun Oct 27, 2019 4:42 pm
Forum: Lewis Structures
Topic: Clarification
Replies: 6
Views: 81

Re: Clarification

I think he said that lewis structures with an expanded octet have lower energy than the octet structure, and since it's more important to have the lowest energy possible and be more stable, obtaining a formal charge of 0 is more important than following the octet rule.
by ASetlur_1G
Sun Oct 20, 2019 6:21 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodal planes
Replies: 3
Views: 34

Re: Nodal planes

Nodal planes are regions where the probability of finding an electron is 0.
by ASetlur_1G
Sun Oct 20, 2019 6:13 pm
Forum: Quantum Numbers and The H-Atom
Topic: Magnetic Quantum Number ml
Replies: 5
Views: 45

Re: Magnetic Quantum Number ml

The magnetic quantum number divides subshells into orbitals and describes the orientation of the orbitals.
by ASetlur_1G
Sun Oct 20, 2019 6:09 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Stern and Gerlach
Replies: 3
Views: 50

Re: Stern and Gerlach

I'm also having a hard time understanding spin. If the electrons aren't actually physically spinning, what's happening? Also, how exactly did they discover spin through the Stern and Gerlach experiment?
by ASetlur_1G
Sun Oct 20, 2019 5:52 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Ordering of s and d orbitals
Replies: 4
Views: 59

Re: Ordering of s and d orbitals

4s is lower in energy if there are no electrons in the 3d level. Therefore, the 4s level is filled up before 3d because 4s is lower in energy. However, once electrons enter the 3d state, 4s becomes higher in energy than 3d and is then written after 4s.
by ASetlur_1G
Sun Oct 20, 2019 5:38 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 3d vs 4s
Replies: 2
Views: 34

3d vs 4s

Are electrons removed from 3d or 4s first?
by ASetlur_1G
Sun Oct 13, 2019 8:45 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect
Replies: 3
Views: 48

Photoelectric Effect

Can non-metals exhibit the photoelectric effect? If not, why?
by ASetlur_1G
Sun Oct 13, 2019 8:37 pm
Forum: DeBroglie Equation
Topic: Rest Mass
Replies: 1
Views: 40

Rest Mass

Why is it important the De Broglie's Equation only applies to particles with rest mass? Why do particles have a different mass when not at resting state?
by ASetlur_1G
Sun Oct 13, 2019 8:21 pm
Forum: Photoelectric Effect
Topic: Electrons ejected based on wavelength
Replies: 3
Views: 61

Re: Electrons ejected based on wavelength

Light with a longer wavelength has a shorter frequency, and low frequency light has no photons with sufficient energy to eject an electron. Conversely, light with a shorter wavelength has a high frequency and with high frequency light, each photon has sufficient energy to remove each electron.
by ASetlur_1G
Sun Oct 13, 2019 8:03 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect
Replies: 4
Views: 59

Photoelectric Effect

Why does the photoelectric experiment need to be done under a vacuum?
by ASetlur_1G
Sun Oct 13, 2019 7:59 pm
Forum: Photoelectric Effect
Topic: Photoelectric experiment
Replies: 3
Views: 49

Re: Photoelectric experiment

People believed that if the light didn't have enough energy to eject electrons, the intensity of the light would need to increase because they believed that light could be explained by a wave-like model (higher intensity = bigger wave = more energy). However increasing the intensity just increased t...
by ASetlur_1G
Thu Oct 03, 2019 11:02 pm
Forum: Empirical & Molecular Formulas
Topic: What decimal place to round to when taking masses from the Periodic Table?
Replies: 19
Views: 392

Re: What decimal place to round to when taking masses from the Periodic Table?

I would use the entire number and then use sig figs in your final answer.
by ASetlur_1G
Thu Oct 03, 2019 11:00 pm
Forum: SI Units, Unit Conversions
Topic: Memorizing Metric Conversions
Replies: 8
Views: 204

Re: Memorizing Metric Conversions

Will we be required to memorize all of the unit prefixes and their meanings (including fento, atto, angstrom)?
by ASetlur_1G
Thu Oct 03, 2019 10:46 pm
Forum: Significant Figures
Topic: Sig Figs
Replies: 3
Views: 72

Sig Figs

Just to clarify...

400 is different from 400. in terms of sig figs right?
I'm under the impression that 400 is 1 sig fig and 400. is 3 sig figs because there is a decimal point after the 0.

Is this correct?
by ASetlur_1G
Thu Oct 03, 2019 10:29 pm
Forum: Balancing Chemical Reactions
Topic: Question on L.33
Replies: 4
Views: 92

Question on L.33

This isn't a homework problem but I came across it and was wondering how to go about solving it: Barium bromide, BaBrx, can be converted into BaCl2 by treatment with chlorine. It is found that 3.25 g of BaBrx reacts completely with an excess of chlorine to yield 2.27 g of BaCl2. Determine the value ...

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