## Search found 100 matches

Mon Mar 09, 2020 5:05 pm
Forum: *Enzyme Kinetics
Topic: Catalyst Practice
Replies: 3
Views: 68

### Re: Catalyst Practice

The organic chemistry tutor usually has really good videos you could check there on youtube.
Mon Mar 09, 2020 5:02 pm
Forum: General Rate Laws
Topic: Pseudo Rate Laws
Replies: 1
Views: 36

### Pseudo Rate Laws

What does the word pseudo denote in the context of pseudo rate laws?
Mon Mar 09, 2020 4:59 pm
Forum: First Order Reactions
Topic: Half Life Equations
Replies: 10
Views: 95

### Half Life Equations

Do we need to memorize the half life equations for zeroth and second order rate laws? Will they be given on the equation sheet for the final?
Mon Mar 09, 2020 4:53 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Pre-Equilibrium Approach Constants
Replies: 1
Views: 23

### Pre-Equilibrium Approach Constants

When using the pre equilibrium approach and using the equilibrium constant to rearrange the rate law for the slow step and make it match the overall rate law, what is the "constant" with (k1 * k2)/k1prime? How do you know this matches the k value for the original rate law of the overall re...
Mon Mar 09, 2020 4:50 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Other ways to find rate determining step
Replies: 1
Views: 43

### Other ways to find rate determining step

Is there any other way to determine the rate determining step if the rate laws aren't given?
Mon Mar 02, 2020 4:33 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Acidic and Basic Solutions
Replies: 1
Views: 27

### Acidic and Basic Solutions

When dealing with acidic or basic solutions, how do you know which half reaction/where in the half reaction to include H3O or OH?
Mon Mar 02, 2020 4:31 pm
Forum: First Order Reactions
Topic: order of reaction equations
Replies: 6
Views: 88

### order of reaction equations

Do we need to know how to show to get from the derived rate law to the integral rate law or can we just know one or the other?
Mon Mar 02, 2020 4:29 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Delta G derivations
Replies: 1
Views: 25

### Delta G derivations

Do we need to know how to derive any of the delta G equations? Will we need to show this on the test?
Mon Mar 02, 2020 4:28 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: delta G equations
Replies: 3
Views: 66

### delta G equations

Are all of the delta G equations that we could possibly use on the test 2 on the formula sheet or are some missing?
Mon Feb 24, 2020 9:19 pm
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: Charging
Replies: 2
Views: 28

### Charging

Can someone explain the idea of charging being a way to overcome what wouldn't normally be a spontaneous reaction in a galvanic cell? How does this work?
Mon Feb 24, 2020 9:16 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Difference in G's
Replies: 2
Views: 51

### Difference in G's

What is the actual difference between G and Go besides the fact that Go is at "standard" conditions?
Mon Feb 24, 2020 9:14 pm
Forum: Balancing Redox Reactions
Topic: redox reactions
Replies: 5
Views: 59

### Re: redox reactions

Which ever is happening at the anode is oxidation, and which ever is happening at the cathode is reduction.
Mon Feb 24, 2020 9:13 pm
Forum: Balancing Redox Reactions
Topic: Reactions with compounds
Replies: 1
Views: 33

### Reactions with compounds

How do you deal with half reactions where one of the things being oxidized/reduced is a part of a larger compound and not isolated? How does this change the two half reactions and the full one?
Mon Feb 24, 2020 9:11 pm
Forum: Balancing Redox Reactions
Topic: Flipping Reactions
Replies: 4
Views: 70

### Flipping Reactions

When writing out half reactions, how do you know which one to flip to get the full balanced reaction?
Wed Feb 19, 2020 5:36 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Potentials
Replies: 2
Views: 53

### Re: Cell Potentials

Reduction potential refers to the electrodes potential in a given cells and it will be different in every cell. Standard reduction potential refers to this value in a standardized cell in which the cathode is always made up of hydrogen to keep it standardized.
Wed Feb 19, 2020 5:33 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge
Replies: 2
Views: 28

### Salt Bridge

I understand that the salt bridge ensures that the cell doesn't reach equilibrium, but how is that achieved through the transfer of ions?
Wed Feb 19, 2020 5:32 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Potential Energy Scenario
Replies: 1
Views: 20

### Potential Energy Scenario

Could there ever be a situation in which the potential energy of the left side of the cell (anode) was greater than that of the right (cathode)? if so what would happen?
Wed Feb 19, 2020 5:24 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: midterm Q1A
Replies: 7
Views: 80

### Re: midterm Q1A

Since it is an anabolic reaction that builds up a more complex molecule it is an endothermic reaction so adding heat will favor the forward reaction and create more products which means you will have an bigger equilibrium constant value.
Wed Feb 19, 2020 5:18 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: galvanic cell structure
Replies: 8
Views: 51

### Re: galvanic cell structure

Generally, the cathode is more positive and the anode is more negative. This means the anode would want to give off electrons and the cathode would attract them.
Wed Feb 19, 2020 5:16 pm
Forum: Balancing Redox Reactions
Topic: Understanding Half-Reactions
Replies: 11
Views: 160

### Re: Understanding Half-Reactions

It shows you the oxidation and reduction reactions separately that are occurring together in the full redox reaction.
Wed Feb 19, 2020 5:14 pm
Forum: Balancing Redox Reactions
Topic: Balancing Redox
Replies: 5
Views: 63

### Re: Balancing Redox

You should probably be familiar with the basic polyatomic ions, a list can be found online but I think they will usually be given or made obvious.
Wed Feb 19, 2020 5:13 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs free energy
Replies: 4
Views: 75

### Re: Gibbs free energy

It means that the reaction is not favorable/spontaneous and would probably require energy to happen
Wed Feb 19, 2020 5:11 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2
Replies: 10
Views: 175

### Re: Test 2

It will cover the second page of outline 4: thermodynamics and all of outline 5: electrochemistry and its applications
Wed Feb 19, 2020 5:09 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Derivations
Replies: 5
Views: 68

### Derivations

Do we need to be able to derive all the different gibbs free energy equations or just know them/look at equation sheet?
Tue Feb 04, 2020 7:48 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Equations
Replies: 4
Views: 56

### Equations

Do we have to memorize all the equations Dr. Lavelle has covered in class? Will they be given? Do we have to know how to derive any of them?
Tue Feb 04, 2020 7:46 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 1/2kt
Replies: 1
Views: 21

### 1/2kt

What does 1/2kt actually reference? How is it used conceptually and in equations?
Tue Feb 04, 2020 7:45 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: W
Replies: 2
Views: 36

### W

What is degeneracy (W) actually a measure of?
Tue Feb 04, 2020 7:43 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Negative Work Equation
Replies: 1
Views: 33

### Negative Work Equation

Why do both work equations have a negative sign at the start?
Tue Feb 04, 2020 7:42 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: Boltzman Constant
Replies: 4
Views: 50

### Boltzman Constant

What are the units of the boltzman constant?
Mon Jan 27, 2020 4:27 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: delta U
Replies: 4
Views: 42

### delta U

What does delta U represent? What are the units?
Mon Jan 27, 2020 4:26 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Specific Heat and Molar Heat Capacity
Replies: 4
Views: 47

### Re: Specific Heat and Molar Heat Capacity

You would make this decision based on what the question was asking for/whether you were given moles or grams.
Mon Jan 27, 2020 4:24 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: q vs. delta H
Replies: 6
Views: 112

### q vs. delta H

What is the difference between q and delta H? What are the units?
Mon Jan 27, 2020 4:22 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Calorimeter
Replies: 3
Views: 25

### Calorimeter

In the context of a calorimeter, what do the terms system and surroundings refer to?
Mon Jan 27, 2020 4:20 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Reversible and Irreversible Expansion
Replies: 2
Views: 19

### Reversible and Irreversible Expansion

What are reversible and irreversible expansion? What do they mean?
Wed Jan 22, 2020 8:09 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Approximation
Replies: 5
Views: 44

### Re: Approximation

If the k value is less than 10^-3 then you can approximate.
Wed Jan 22, 2020 8:08 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Approximation
Replies: 2
Views: 19

### Re: Approximation

In general, I think you can find the percent pronation, and if this value is less than 5%, then your approximation was valid.
Wed Jan 22, 2020 8:04 pm
Forum: Student Social/Study Group
Topic: midterm/final
Replies: 12
Views: 190

### Re: midterm/final

In my experience, the final and midterm are not only longer, but also feature more challenging application type problems. The tests are usually much more straight forward than these bigger exams.
Wed Jan 22, 2020 8:03 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homework week 3
Replies: 1
Views: 23

### Re: Homework week 3

I believe they can be from any section you want, so either one would work.
Wed Jan 22, 2020 8:02 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy
Replies: 4
Views: 86

### Enthalpy

Does enthalpy have to be related to a change in temperature, or can it just be a measure of heat?
Tue Jan 14, 2020 8:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Acid and Base Equilibrium
Replies: 2
Views: 34

### Acid and Base Equilibrium

Will we have to know how to work with acids and bases at equilibrium? If so, is there anything that makes them different when it comes to ICE tables and other calculations we have been doing with regular equations?
Tue Jan 14, 2020 8:53 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K cutoff
Replies: 5
Views: 47

### K cutoff

What is the cutoff value for k that makes it small enough to use the approximation for the ICE table equation as opposed to actually having to solve for x the long way?
Tue Jan 14, 2020 8:52 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: When to approximate
Replies: 5
Views: 54

### When to approximate

I know that when your ICE equation ends up cubed, you can usually use the approximation rules to solve. Can you do this for squared equations as well as long as the k value is small enough?
Tue Jan 14, 2020 8:48 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Including gasses for Q vs K
Replies: 2
Views: 33

### Re: Including gasses for Q vs K

Usually the question will tell you, or it will be clear which form of Q they expect: partial pressures or concentration.
Tue Jan 14, 2020 8:44 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Acids and Bases
Replies: 6
Views: 78

### Acids and Bases

Are all acid and base reactions at equilibrium?
Thu Jan 09, 2020 3:21 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K expression
Replies: 6
Views: 66

### Re: K expression

Solids are not included because you can't have a concentration of a solid. Liquids aren't included because they often act as a solvent whose concentration changes so minimally that it isn't worth noting.
Thu Jan 09, 2020 3:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Q vs K
Replies: 7
Views: 51

### Re: Q vs K

K is the ratio of products to reactants at equilibrium, while Q is the ratio of products to reactants at any given point in the reaction (not necessarily equilibrium).
Thu Jan 09, 2020 3:15 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q
Replies: 10
Views: 101

### Re: Q

Yes, I believe it can be applied to both.
Thu Jan 09, 2020 3:14 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE Table Ratios
Replies: 7
Views: 79

### ICE Table Ratios

When doing an ice table and filling in the middle row for change, does it matter what ratio of coefficients we use as long as it fits the equation? For example, would both 2:1 and 1:.5 be acceptable?
Thu Jan 09, 2020 3:06 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Units
Replies: 4
Views: 45

### Units

Do we write in the units on the partial pressure or concentration of a certain reactant or product we are solving for when given a K value and all other pressures or concentrations?
Wed Dec 04, 2019 1:43 pm
Forum: Conjugate Acids & Bases
Topic: Conjugate Acids and Bases (Uses)
Replies: 1
Views: 41

### Conjugate Acids and Bases (Uses)

What are the applications/uses of knowing conjugate bases and acids? How do you use this information?
Wed Dec 04, 2019 1:42 pm
Forum: Conjugate Acids & Bases
Topic: Conjugate Acids and Bases
Replies: 6
Views: 72

### Conjugate Acids and Bases

How can you tell if compounds are conjugate acids or bases? Will they always both be in the chemical equation?
Wed Dec 04, 2019 1:39 pm
Forum: Conjugate Acids & Bases
Topic: Oxoacids
Replies: 4
Views: 135

### Oxoacids

What is an oxoacid?
Wed Dec 04, 2019 1:38 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted Acids and Bases
Replies: 1
Views: 29

### Bronsted Acids and Bases

How do Bronsted acids and bases transfer electrons? How does this work?
Tue Dec 03, 2019 7:08 pm
Forum: Lewis Acids & Bases
Topic: HCl and HI
Replies: 10
Views: 118

### HCl and HI

Which is the stronger acid: HI or HCl? Why?
Tue Nov 26, 2019 5:01 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Compound Drawings
Replies: 2
Views: 48

### Coordination Compound Drawings

Will we need to know how to draw coordination compounds on the final if given a chemical formula?
Tue Nov 26, 2019 4:57 pm
Forum: Naming
Topic: Testing on Coordination Compounds [ENDORSED]
Replies: 1
Views: 53

### Testing on Coordination Compounds[ENDORSED]

Since the homework problems for the coordination compound section were mainly focused on just the naming of coordination compounds is that the only thing we should be expected to see on the final exam? Or do we need to know other details about these compounds?
Tue Nov 26, 2019 4:55 pm
Forum: Lewis Acids & Bases
Topic: Lewis Acid Lone Pairs
Replies: 2
Views: 28

### Lewis Acid Lone Pairs

I understand that lewis acids and bases involve the donation and accepting of lone pairs but I still don't fully understand what this actually means? How do they donate or accept lone pairs? What does this look like?
Tue Nov 26, 2019 4:53 pm
Forum: Lewis Acids & Bases
Topic: Identifying Lewis Acids and Bases
Replies: 3
Views: 37

### Identifying Lewis Acids and Bases

Can you tell just by looking at two compounds which is the lewis acid and which is the lewis base? Or do you have to look at the equilibrium equation? Or do you have to draw the lewis structures? What is easiest?
Tue Nov 26, 2019 4:50 pm
Forum: Amphoteric Compounds
Topic: Amphoteric
Replies: 8
Views: 108

### Amphoteric

How can you tell just by looking at a compound that it is amphoteric?
Sun Nov 24, 2019 11:29 am
Forum: Lewis Acids & Bases
Topic: Acid and Base Strength
Replies: 7
Views: 116

### Acid and Base Strength

How can you tell is something a strong acid vs. a weak acid? What about strong bases vs. weak bases?
Sun Nov 24, 2019 11:27 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelating Ligands
Replies: 3
Views: 39

### Chelating Ligands

Can someone explain chelating ligands/how they work? Will we need to be able to recognize them when looking at a structure?
Sun Nov 24, 2019 11:20 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Transition Metals
Replies: 3
Views: 54

### Transition Metals

Does the central atom of a coordination compound always have to be a transition metal? Why or why not?
Sun Nov 24, 2019 11:17 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Compounds
Replies: 3
Views: 38

### Coordination Compounds

What makes something a coordination compound compared to a regular molecular or ionic compound? Why are they important/what can they do?
Sun Nov 24, 2019 11:14 am
Forum: Biological Examples
Topic: Biological Examples
Replies: 3
Views: 40

### Biological Examples

To what extent to we need to know the structures and functions of different biological examples? Which examples should we know best?
Sat Nov 16, 2019 3:54 pm
Forum: Determining Molecular Shape (VSEPR)
Replies: 5
Views: 81

### Re: How to treat Radicals

yes, i believe that radicals are still treated as lone pairs they just have slightly lower abilities to repulse the electrons around them
Sat Nov 16, 2019 3:53 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Equatorial/Axial Lone Pairs
Replies: 3
Views: 30

### Re: Equatorial/Axial Lone Pairs

equatorial because otherwise the space between electrons would not be maximized and the repulsion between electrons would be too much.
Sat Nov 16, 2019 3:50 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: Bond Strengths in order?
Replies: 2
Views: 37

### Re: Bond Strengths in order?

i believe all of these other interactions have similar enough bond strengths that there isn't a clear distinction between which are stronger and which are weaker. i don't believe dr. lavelle expects us to know such a thing.
Sat Nov 16, 2019 3:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: polar vs nonpolar
Replies: 6
Views: 80

### Re: polar vs nonpolar

usually it is best to always draw the lewis structure, unless it is a vary simple compound, in which case you might be able to tell by looking at the formula. but in general i would say always draw it out just to make sure.
Sat Nov 16, 2019 3:45 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR
Replies: 3
Views: 55

### Re: VSEPR

honestly its mostly just memorization of the different shapes, taking into consideration the number of electron dense areas, and whether or not those areas involve lone pairs or not.
Sun Nov 10, 2019 9:03 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: polarizability/polar power and bonds
Replies: 2
Views: 119

### polarizability/polar power and bonds

what do polarizability and polar power have to do with bonds/how do they affect them?
Sun Nov 10, 2019 8:57 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: polarizability v. polar power
Replies: 1
Views: 45

### polarizability v. polar power

what exactly is the conceptual difference between polarizability and polar power? how do the two terms relate to electrons?
Sun Nov 10, 2019 8:55 pm
Forum: Octet Exceptions
Topic: incomplete octet
Replies: 6
Views: 190

### incomplete octet

how do we know when an element can have an incomplete octet with less than 8 electrons in its lewis structure?
Sun Nov 10, 2019 8:51 pm
Forum: Dipole Moments
Topic: Identifying dipoles
Replies: 3
Views: 50

### Re: Identifying dipoles

In general, you should use both the electronegativity and the lewis structure to determine dipoles. You look at the structure and then use electronegativity to determine which way the electrons are being pulled.
Sun Nov 10, 2019 8:46 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polar vs covalent
Replies: 7
Views: 104

### Re: Polar vs covalent

You can tell if a bond is ionic if the two elements involved have a large difference in electronegativity. Basically, you can just look at the periodic table and if the two elements are on far, opposite ends, it is likely ionic.
Sun Nov 03, 2019 6:27 pm
Forum: DeBroglie Equation
Topic: Does something have wavelike properties?
Replies: 3
Views: 58

### Re: Does something have wavelike properties?

A wavelength of 10^-15m was the cutoff for detectable wave like qualities.
Sun Nov 03, 2019 6:25 pm
Forum: Trends in The Periodic Table
Replies: 11
Views: 294

A couple things atomic radii is useful in: determining bond length, determining periodic trends such as ionization energy and electron affinity, determining compound size, etc.
Sun Nov 03, 2019 6:21 pm
Forum: Lewis Structures
Topic: resonance hybrid
Replies: 1
Views: 34

### Re: resonance hybrid

A resonance structure is a possible way of drawing the distribution of electrons around a compound. However, in such drawings, none of them represent the actual distribution. That actual distribution can be described as a resonance hybrid, in which the bond length between a central atom to neighbori...
Sun Nov 03, 2019 6:17 pm
Forum: Lewis Structures
Topic: formal charge
Replies: 6
Views: 46

### Re: formal charge

I don't think it is required for every single structure, only on ones where explicitly asked or where multiple resonance structures are possible. In such cases, writing out the formal charges as a way of showing work as to how you reached the correct structure is probably advisable.
Sun Nov 03, 2019 6:15 pm
Forum: Ionic & Covalent Bonds
Topic: Lewis Acids and Bases
Replies: 2
Views: 39

### Re: Lewis Acids and Bases

By definition, a Lewis base is a species that donates an electron pair, while a Lewis acid is a species that accepts an electron pair. In relation to bonds, coordinate covalent bonds can sometimes be described using the notion of one compound being the Lewis acid and one compound being the Lewis base.
Sun Oct 27, 2019 6:08 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: p-orbitals
Replies: 11
Views: 129

### Re: p-orbitals

In general, I believe you can use the simplified form without being so specific, unless Dr. Lavelle specifies otherwise.
Sun Oct 27, 2019 6:06 pm
Forum: Resonance Structures
Topic: Ideal Lewis Structure
Replies: 4
Views: 66

### Re: Ideal Lewis Structure

Calculate the formal charges of all the atoms involved. Whichever molecule has the closest overall charge to 0, the better that resonance structure is.
Sun Oct 27, 2019 6:04 pm
Forum: Properties of Electrons
Topic: Determining Number of Valence Electrons
Replies: 2
Views: 50

### Re: Determining Number of Valence Electrons

You can usually identify the number of valence electrons by looking at the periodic table, which will be given on exams. All you have to do is count the groups leading up to the atom. In other words, know how many electrons are in the outer shell of the electron configuration of the atom.
Sun Oct 27, 2019 5:52 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge and Lone Pairs
Replies: 4
Views: 71

### Re: Formal Charge and Lone Pairs

It is the number of electrons in the bonds, not the number of pairs.
Sun Oct 27, 2019 5:51 pm
Forum: Properties of Electrons
Topic: Formal Charge of an Atom
Replies: 5
Views: 111

### Re: Formal Charge of an Atom

To find the formal charge of an atom, you use the formula, valence electrons = total valence electrons - lone pair electrons - bonding electrons/2.
Sun Oct 27, 2019 5:35 pm
Forum: Trends in The Periodic Table
Topic: Zeff and ionization energy
Replies: 4
Views: 74

### Re: Zeff and ionization energy

As you move across a period, there are more protons in the nucleus of each atom which creates a greater pull on electrons. This in turn causes the ionization energy to increase as well.
Sat Oct 19, 2019 10:07 pm
Topic: Applying Wein's Law
Replies: 3
Views: 165

### Re: Applying Wein's Law

I am pretty sure we don't have to know about this content because it is excluded from the unit syllabus.
Sat Oct 19, 2019 9:39 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Purpose of the Equation
Replies: 9
Views: 118

### Re: Purpose of the Equation

The equation is based on the idea that the exact speed of a particle and the exact position of a particle cannot be known exactly at the same time. However, this equation can be used to determine the uncertainty of one or the other, when the opposite is given.
Sat Oct 19, 2019 9:31 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Letter Names
Replies: 4
Views: 68

### Letter Names

Does anyone know if there is a significance to the use of the specific s, p, d and f letters for the shells? If so, what is that significance?
Sat Oct 19, 2019 9:24 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Effective Nuclear Charge
Replies: 2
Views: 30

### Re: Effective Nuclear Charge

As stated above, the effective nuclear charge is the net attraction a negatively charged electron experiences with the positively charged nucleus, taking into account any shielding that occurs from inner electrons. The equation for effective nuclear charge might help you visualize that. The equation...
Sat Oct 19, 2019 9:07 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Two electrons per orbital
Replies: 2
Views: 25

### Re: Two electrons per orbital

As stated above, there are only two electrons in each due to the repulsion of negatively charged electrons and their opposite spins. It is also important to remember that the "shape" of the orbitals is not actually a true shape, but rather a representation of a math function showing the pr...
Sat Oct 12, 2019 6:04 pm
Forum: Properties of Electrons
Topic: Diffraction
Replies: 4
Views: 66

### Re: Diffraction

Diffraction refers to the pattern created by by two waves interacting. Since light displays such a pattern, it can be inferred that it has wave like properties.
Sat Oct 12, 2019 6:01 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation
Replies: 2
Views: 42

### Rydberg Equation

I remember in class Dr. Lavelle explaining that he didn't want us to use the Rydberg equation because he thought it would confuse us. What exactly is wrong/confusing with the Rydberg equation?
Sat Oct 12, 2019 5:36 pm
Forum: Properties of Electrons
Topic: Electron Excitation
Replies: 6
Views: 89

### Re: Electron Excitation

An electron becomes excited when it absorbs energy from a photon, causing it to move from its original energy level to a higher energy level within the atom. This energy can then be released later on in the form of a photon when the electron drops back to its starting energy level.
Sat Oct 12, 2019 5:31 pm
Forum: Properties of Electrons
Topic: Lyman and Balmer Series
Replies: 4
Views: 96

### Re: Lyman and Balmer Series

The Lyman and Balmer series refer to wavelengths that quantify a transition to a specific energy level. The Lyman series refers to transitions of an electron from one energy level to the n=1 energy level. The Balmer series refers refers to transitions of an electron from one energy level to the n=2 ...
Fri Oct 11, 2019 4:51 pm
Forum: Properties of Light
Topic: Quanta vs Photon
Replies: 4
Views: 53

### Re: Quanta vs Photon

Quanta is simply a word used to describe a unit of something that is discrete and measured. A photon is a unit of light that can be described as a quanta.
Tue Oct 01, 2019 8:28 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Chemical unit vs. Formula unit
Replies: 6
Views: 132

### Re: Chemical unit vs. Formula unit

Another way to think about the formula unit is just as the single, smallest unit of whatever you are dealing with. It is similar to the concept of a single atom or a single molecule.
Tue Oct 01, 2019 8:25 pm
Forum: Molarity, Solutions, Dilutions
Topic: Dilution and Molarity Questions
Replies: 8
Views: 94

### Dilution and Molarity Questions

Whenever I first look at the more complex dilution questions, I tend to feel lost and not sure where to start. Does anyone have any tips as to where to start when you first look at these types of questions? Once I figure out how to start them I am usually fine.
Thank you!
Tue Oct 01, 2019 8:18 pm
Forum: Limiting Reactant Calculations
Topic: Other Way to Find the Limiting Reactant [ENDORSED]
Replies: 3
Views: 96

### Other Way to Find the Limiting Reactant[ENDORSED]

When trying to find the limiting reactant, I understand that Dr. Lavelle taught us to find the moles of one reactant and use the molar ratio with the other reactant to see if it is the limiting reactant or the reactant in excess. Is it also possible to just convert the moles of each reactant separat...
Tue Oct 01, 2019 8:03 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Replies: 12
Views: 418