Search found 104 matches

by Anna Chen 1K
Tue Mar 17, 2020 7:20 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Ecell vs Eocell
Replies: 2
Views: 14

Re: Ecell vs Eocell

I agree the only difference is that Ecell does not require standard conditions like Excel.
by Anna Chen 1K
Tue Mar 17, 2020 7:18 pm
Forum: General Science Questions
Topic: Final chem
Replies: 3
Views: 33

Re: Final chem

We should be given results back by the end of this week. It should come pretty soon since it was taken online.
by Anna Chen 1K
Tue Mar 17, 2020 7:16 pm
Forum: Student Social/Study Group
Topic: Class Grading
Replies: 44
Views: 842

Re: Class Grading

I agree, you will get a C- if you get at least 250 points.
by Anna Chen 1K
Tue Mar 17, 2020 7:12 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Grades
Replies: 6
Views: 71

Re: Final Grades

Yes, I agree that it will be soon since the final was taken online.
by Anna Chen 1K
Tue Mar 17, 2020 7:11 pm
Forum: Administrative Questions and Class Announcements
Topic: Grading
Replies: 3
Views: 43

Re: Grading

I think each person will get the grade they deserve.
by Anna Chen 1K
Sun Mar 08, 2020 10:05 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Cell Diagram
Replies: 16
Views: 43

Re: Cell Diagram

If cell potential is not given, the oxidation half-reaction should be on the left/anode, while the reduction half-reaction should be on the right/cathode. You should look at how electrons are transferred to verify though.
by Anna Chen 1K
Sun Mar 08, 2020 10:02 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Platinum
Replies: 10
Views: 27

Re: Platinum

You add platnium, or another solid metal conductor, whenever there is no solid on either side of the cell diagram.
by Anna Chen 1K
Sun Mar 08, 2020 9:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Exam Material Distribution
Replies: 6
Views: 39

Re: Final Exam Material Distribution

Yes, it should be evenly distributed. However, there is a possibility specific topics will be emphasized like in the midterm.
by Anna Chen 1K
Sun Mar 08, 2020 9:57 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2 Grades
Replies: 22
Views: 182

Re: Test 2 Grades

Yes, test 1 will probably be handed back in discussion.
by Anna Chen 1K
Sun Mar 08, 2020 9:57 pm
Forum: Administrative Questions and Class Announcements
Topic: 100 or 50 posts?
Replies: 8
Views: 35

Re: 100 or 50 posts?

I believe leaving all 100 posts is fine, too.
by Anna Chen 1K
Sun Mar 01, 2020 10:41 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Degree symbol
Replies: 10
Views: 62

Re: Degree symbol

The degree symbol indicates the reaction is at standard conditions (298 K, 1 atm)
by Anna Chen 1K
Sun Mar 01, 2020 10:39 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cathode/Right & Anode/Left
Replies: 7
Views: 34

Re: Cathode/Right & Anode/Left

Generally, yes, the cathode is usually on the right and the anode is usually on the left. However, if you want to make sure, the cathode is always the reduction while the anode is always the oxidation. You determine which solution is reduced and oxidized by looking at the transfer of electrons in th...
by Anna Chen 1K
Sun Mar 01, 2020 10:34 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: salt bridge
Replies: 9
Views: 58

Re: salt bridge

A salt bridge prevents ion buildup and helps the electrons transfer from the anode to cathode.
by Anna Chen 1K
Sun Mar 01, 2020 10:32 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: when to use K or Q
Replies: 18
Views: 85

Re: when to use K or Q

K is used when the situation concerns the reaction at equilibrium; Q is used when the situation concerns the reaction at any point besides equilibrium
by Anna Chen 1K
Sun Mar 01, 2020 10:11 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: test 2 topics
Replies: 11
Views: 52

Re: test 2 topics

the second page of thermochemistry and all of electrochemistry
by Anna Chen 1K
Sun Feb 23, 2020 7:27 pm
Forum: Balancing Redox Reactions
Topic: Half Reactions
Replies: 12
Views: 69

Re: Half Reactions

There are two half reactions in a redox reaction. Oxidation is the half reaction involving a loss of electrons; reduction is the half reaction involving a gain of electrons.
by Anna Chen 1K
Sun Feb 23, 2020 7:26 pm
Forum: Balancing Redox Reactions
Topic: spontaneous
Replies: 15
Views: 93

Re: spontaneous

positive standard reduction potential --> spontaneous reduction
by Anna Chen 1K
Sun Feb 23, 2020 7:24 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: chemistry community posts
Replies: 12
Views: 54

Re: chemistry community posts

The weekly posts are due Sunday 11:59 PM.
by Anna Chen 1K
Sun Feb 23, 2020 7:22 pm
Forum: Balancing Redox Reactions
Topic: Balancing Redox EQs
Replies: 10
Views: 75

Re: Balancing Redox EQs

If it is an acidic solution, you add H+; if it is a basic solution, you add OH-.
by Anna Chen 1K
Sun Feb 23, 2020 7:20 pm
Forum: Balancing Redox Reactions
Topic: Half reactions
Replies: 7
Views: 52

Re: Half reactions

Half reactions are the two reactions involved in a redox reaction, oxidation and reduction. Oxidation is the reaction involving a loss of electrons; reduction is the reaction involving a gain of electrons.
by Anna Chen 1K
Sun Feb 16, 2020 9:18 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Delta S
Replies: 8
Views: 56

Re: Delta S

Delta S - regular delta S, usually concerns the system of the reaction
Delta S (surroundings) - usually equals negative delta S (system)
Delta S (total) - equals delta (system) + delta (surroundings)
by Anna Chen 1K
Sun Feb 16, 2020 9:12 pm
Forum: Balancing Redox Reactions
Topic: Seperating Redoz RXNS
Replies: 7
Views: 27

Re: Seperating Redoz RXNS

Half reactions just show the transfer of electrons in oxidation and reduction. Two half reactions, or an oxidation coupled with a reduction, equals the full reaction.
by Anna Chen 1K
Sun Feb 16, 2020 9:10 pm
Forum: Balancing Redox Reactions
Topic: Electrochemisty
Replies: 10
Views: 54

Re: Electrochemisty

Electrochemistry is the study of electricity and how it relates to chemical reactions. In electrochemistry, electricity can be generated by movements of electrons from one element to another in redox reactions.
by Anna Chen 1K
Sun Feb 16, 2020 9:08 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: reaction entropy
Replies: 7
Views: 47

Re: reaction entropy

You can use the equation ΔS° = ΣS°(products) - ΣS°(reactants) to solve for entropy of a reaction since entropy is a state function.
by Anna Chen 1K
Sun Feb 16, 2020 9:05 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Isochoric
Replies: 8
Views: 43

Re: Isochoric

An isochroric process is one where volume stays the same.
by Anna Chen 1K
Sun Feb 16, 2020 9:03 pm
Forum: Balancing Redox Reactions
Topic: Redox Reactions
Replies: 12
Views: 40

Re: Redox Reactions

A redox reaction is a reaction where both reduction and oxidation occur, also known as two half reactions. Oxidation involves the loss of electrons, whereas reduction involves gaining electrons.
by Anna Chen 1K
Sun Feb 09, 2020 10:40 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Gas v Liquids
Replies: 4
Views: 27

Re: Gas v Liquids

S(gas) >> S(liquids) > S(solids)
by Anna Chen 1K
Sun Feb 09, 2020 10:40 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: q rev
Replies: 9
Views: 50

Re: q rev

q is heat while rev refers to a reversible reaction so q rev is used for calculating heat for a reversible reaction.
by Anna Chen 1K
Sun Feb 09, 2020 10:38 pm
Forum: Administrative Questions and Class Announcements
Topic: midterm format
Replies: 8
Views: 53

Re: midterm format

Based on past Lavelle midterms and finals, it will most likely be around 8 free response questions with each question having multiple parts to it.
by Anna Chen 1K
Sun Feb 09, 2020 10:36 pm
Forum: Student Social/Study Group
Topic: Midterm Topics
Replies: 12
Views: 106

Re: Midterm Topics

The midterm will cover up to outline 4: Focus 4F-J. This means 5G.3, 5G.4, and 5J.3, are not on the exam.
by Anna Chen 1K
Sun Feb 09, 2020 10:35 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm dates
Replies: 11
Views: 52

Re: Midterm dates

The midterm will cover up to Focus 4F-J.
by Anna Chen 1K
Sun Feb 02, 2020 10:49 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Spontaneous
Replies: 4
Views: 41

Re: Spontaneous

Spontaneous, or favorable, reactions favor the formation of products over reactants and have a negative value in delta G. A reaction's overall entropy, or disorder, also increases.
by Anna Chen 1K
Sun Feb 02, 2020 10:44 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reaction constant P
Replies: 3
Views: 23

Re: Reaction constant P

It is negligible for solids and liquids because they maintain a constant volume.
by Anna Chen 1K
Sun Feb 02, 2020 10:31 pm
Forum: Calculating Work of Expansion
Topic: Force
Replies: 3
Views: 16

Re: Force

Force is (pressure x area). You can derive this from the equation, P = F/A.
by Anna Chen 1K
Sun Feb 02, 2020 10:29 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: q vs H
Replies: 9
Views: 38

Re: q vs H

This is referring to q.
by Anna Chen 1K
Sun Feb 02, 2020 10:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Test 1
Replies: 3
Views: 25

Re: Test 1

I also received mine back during Week 4's discussion section.
by Anna Chen 1K
Sun Jan 26, 2020 10:00 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Partial Pressure vs Pressure
Replies: 7
Views: 57

Re: Partial Pressure vs Pressure

Partial pressure is the pressure of one gas but pressure is the pressure of the whole system. All the partial pressures added together equals pressure.
by Anna Chen 1K
Sun Jan 26, 2020 9:57 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Gas Constant
Replies: 13
Views: 49

Re: Gas Constant

The value for the gas constant depends on the units used in the specific question.
by Anna Chen 1K
Sun Jan 26, 2020 9:56 pm
Forum: Ideal Gases
Topic: Determining N
Replies: 9
Views: 50

Re: Determining N

You should only use it for calculating the moles of gases.
by Anna Chen 1K
Sun Jan 26, 2020 9:54 pm
Forum: Ideal Gases
Topic: R Constant
Replies: 18
Views: 134

Re: R Constant

The R constant is the gas constant. Its value is determined by the units in the specific problem.
by Anna Chen 1K
Sun Jan 26, 2020 9:51 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Midterm
Replies: 8
Views: 67

Re: Midterm

Yes, it is Week 6.
by Anna Chen 1K
Sun Jan 19, 2020 9:56 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: H20 in the ICE table
Replies: 26
Views: 136

Re: H20 in the ICE table

Yes H2O is not included in the ICE tables along with solids and liquids.
by Anna Chen 1K
Sun Jan 19, 2020 9:55 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Not including solids and liquids
Replies: 7
Views: 45

Re: Not including solids and liquids

Solids and liquids equal 1 so they are neglected when calculating K.
by Anna Chen 1K
Sun Jan 19, 2020 9:54 pm
Forum: Ideal Gases
Topic: Kp given instead of Kc
Replies: 8
Views: 56

Re: Kp given instead of Kc

Use PV=nRT to convert moles to pressure. Moles is represented by n and pressure is represented by P.
by Anna Chen 1K
Sun Jan 19, 2020 9:51 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K vs Q
Replies: 14
Views: 51

Re: K vs Q

K is used when a reaction is at equilibrium while Q is used when a reaction is at any point.
by Anna Chen 1K
Sun Jan 19, 2020 9:49 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Relationship between pressure and volume
Replies: 10
Views: 37

Re: Relationship between pressure and volume

I agree that PV=nRT proves that pressure and volume have an inverse relationship.
by Anna Chen 1K
Sun Jan 12, 2020 5:30 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction shifts right or left?
Replies: 14
Views: 86

Re: Reaction shifts right or left?

If a reaction shifts to the right, then the forward reaction is favored and more products will be produced.
If a reaction shifts to the left, then the reverse reaction is favored and more reactants will be produced.
by Anna Chen 1K
Sun Jan 12, 2020 5:28 pm
Forum: Ideal Gases
Topic: Topics on Test 1
Replies: 37
Views: 240

Re: Topics on Test 1

It will definitely consist of Outline 1 and possibly outline 2 considering tests will begin week 3.
by Anna Chen 1K
Sun Jan 12, 2020 5:26 pm
Forum: Ideal Gases
Topic: Kc vs Kp
Replies: 5
Views: 25

Re: Kc vs Kp

Kc is defined by molar concentrations while Kp is defined by the partial pressures of the gasses.
by Anna Chen 1K
Sun Jan 12, 2020 5:24 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction Q
Replies: 7
Views: 43

Re: Reaction Q

Q determines which direction a reaction will proceed at any time during the reaction. If Q < K at some time during the reaction, then there are more reactants than products and the forward reaction is favored. If Q > K at some time during the reaction, then there are more products than reactants and...
by Anna Chen 1K
Sun Jan 12, 2020 5:21 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Different types of K
Replies: 9
Views: 38

Re: Different types of K

K is the equilibrium constant.
Kc is defined by molar concentrations while Kp is defined by the partial pressures of the gasses.
by Anna Chen 1K
Sun Dec 08, 2019 5:42 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: LDF
Replies: 4
Views: 61

Re: LDF

Yes, all molecules have LDF. Dipole-induced dipole occurs between an ion and non-polar molecule.
by Anna Chen 1K
Sun Dec 08, 2019 5:36 pm
Forum: DeBroglie Equation
Topic: deBroglie derived
Replies: 2
Views: 45

Re: deBroglie derived

De Brogile's equation says that any moving particle with momentum, p, has wavelike properties with wavelength, λ. (λ=h/p --> λ=h/mv)
by Anna Chen 1K
Sun Dec 08, 2019 5:33 pm
Forum: Naming
Topic: NH4[PtCl3(NH3)]
Replies: 5
Views: 63

Re: NH4[PtCl3(NH3)]

The ending of a metal's name always changes to -ate when it the compound is anionic, or has a negative charge.
by Anna Chen 1K
Sun Dec 08, 2019 5:28 pm
Forum: Dipole Moments
Topic: dipole dipole
Replies: 3
Views: 46

Re: dipole dipole

Yes, hydrogen bonds are stronger than dipole-dipole bonds.
by Anna Chen 1K
Sun Dec 08, 2019 5:27 pm
Forum: Dipole Moments
Topic: Hydrogen bonds
Replies: 5
Views: 67

Re: Hydrogen bonds

A hydrogen bond is any bond between H and F, O, or N. You can count the hydrogen bonding sites for these.
by Anna Chen 1K
Sun Dec 01, 2019 9:10 pm
Forum: Bond Lengths & Energies
Topic: Hydrogen Bonding
Replies: 9
Views: 98

Re: Hydrogen Bonding

Hydrogen bondings occurs when H bonds to either F, O, or N.
by Anna Chen 1K
Sun Dec 01, 2019 9:06 pm
Forum: Bronsted Acids & Bases
Topic: Correct equation for 6A.3?
Replies: 4
Views: 44

Re: Correct equation for 6A.3?

I also got the same equations!
by Anna Chen 1K
Sun Dec 01, 2019 9:03 pm
Forum: Student Social/Study Group
Topic: Final Studying
Replies: 8
Views: 69

Re: Final Studying

I suggest attending the review sessions and doing the practice problems.
by Anna Chen 1K
Sun Dec 01, 2019 9:02 pm
Forum: Hybridization
Topic: Order When Writing
Replies: 5
Views: 40

Re: Order When Writing

I agree that both are correct the preferred way is to write it beginning with d.
by Anna Chen 1K
Sun Dec 01, 2019 9:01 pm
Forum: Naming
Topic: Naming of coordination compounds
Replies: 5
Views: 35

Re: Naming of coordination compounds

Yes, I believe we will be given the formula first.
by Anna Chen 1K
Sun Dec 01, 2019 8:56 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Final Study Methods
Replies: 11
Views: 86

Re: Final Study Methods

You should plan to study consistently from this point until the day of the final. You should attend the upcoming review sessions and workshops, review notes, and do the practice problems.
by Anna Chen 1K
Sun Nov 24, 2019 6:00 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2.57
Replies: 1
Views: 19

Re: 2.57

There is a different shape when referring to each central atom.
by Anna Chen 1K
Sun Nov 24, 2019 5:56 pm
Forum: Bronsted Acids & Bases
Topic: Weak vs Strong Acids
Replies: 3
Views: 25

Re: Weak vs Strong Acids

I agree that the strength of an acid is usually determined by its pH or H+.
by Anna Chen 1K
Sun Nov 24, 2019 5:54 pm
Forum: Sigma & Pi Bonds
Topic: Visualizing this
Replies: 4
Views: 69

Re: Visualizing this

We should visualize sigma bonds as the head-to-head overlap of two sp2 orbitals and pi bonds as the side-to-side overlap of two 2p orbitals.
by Anna Chen 1K
Sun Nov 24, 2019 5:49 pm
Forum: Hybridization
Topic: How does hybridization happen?
Replies: 3
Views: 25

Re: How does hybridization happen?

Hybridization happens when an atom bonds using electrons from both the s and p orbitals, creating an imbalance in the energy levels of the electrons. To equalize these energy levels, the s and p orbitals involved between the two atoms are combined to create hybrid orbitals.
by Anna Chen 1K
Sun Nov 24, 2019 5:43 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Use of Bronsted or Lewis Definitions
Replies: 7
Views: 61

Re: Use of Bronsted or Lewis Definitions

Either definition should be fine.
by Anna Chen 1K
Sun Nov 17, 2019 8:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: HW# 2E.26
Replies: 2
Views: 25

Re: HW# 2E.26

Yes, I agree that the symmetry of a lewis structure can sometimes help in determining polarity, but the most accurate way would be to evaluate electronegativity differences.
by Anna Chen 1K
Sun Nov 17, 2019 7:54 pm
Forum: Ionic & Covalent Bonds
Topic: Hydrogen Bonds
Replies: 6
Views: 40

Re: Hydrogen Bonds

N, O, or F can form a hydrogen bond with H.
by Anna Chen 1K
Sun Nov 17, 2019 7:51 pm
Forum: Bond Lengths & Energies
Topic: Bond Length
Replies: 10
Views: 97

Re: Bond Length

Bond length is determined by the bond order, or the number of bonded electrons. This has to be derived from experiments.
by Anna Chen 1K
Sun Nov 17, 2019 7:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.29
Replies: 2
Views: 23

Re: 2E.29

(a) Of the three forms, 1 and 2 are polar. (b) The largest dipole moment occurs in 1.
by Anna Chen 1K
Sun Nov 17, 2019 7:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.29
Replies: 2
Views: 23

Re: 2E.29

(a) Of the three forms, 1 and 2 are polar. (b) The largest dipole moment occurs in 1.
by Anna Chen 1K
Sun Nov 17, 2019 7:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2F.7
Replies: 1
Views: 29

Re: 2F.7

(a) sp^3 (b) sp^3d^2 (c) sp^3d (d) sp^3
by Anna Chen 1K
Sun Nov 10, 2019 10:45 pm
Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
Topic: Viscosity
Replies: 15
Views: 166

Re: Viscosity

When a liquid has high viscosity, it means there is a lot of friction between the adjacent layers of a liquid. This will make the liquid flow slowly.
by Anna Chen 1K
Sun Nov 10, 2019 10:43 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge and Resonance
Replies: 5
Views: 45

Re: Formal Charge and Resonance

Not really, you should pay attention to the kind of bonds in a compounds in a lewis structure. If there are more than one kind, it should have resonance structures.
by Anna Chen 1K
Sun Nov 10, 2019 10:37 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Oxidation Number
Replies: 6
Views: 33

Re: Oxidation Number

An oxidation number is the charge that atom would have if it was made up of ions.
by Anna Chen 1K
Sun Nov 10, 2019 9:33 pm
Forum: Dipole Moments
Topic: Hydrogen Bonds
Replies: 4
Views: 25

Re: Hydrogen Bonds

F, O, N can form a hydrogen bond with H.
by Anna Chen 1K
Sun Nov 10, 2019 9:33 pm
Forum: Sigma & Pi Bonds
Topic: Sigma vs pi bond
Replies: 3
Views: 30

Re: Sigma vs pi bond

Sigma bonds are formed by end-to-end overlapping of atomic orbitals; pi bonds are formed when the lobe of one atomic orbital overlaps another.
by Anna Chen 1K
Sun Nov 03, 2019 9:19 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: L quantum number
Replies: 5
Views: 91

Re: L quantum number

When n = 12, l = 0-11 (12 values).
by Anna Chen 1K
Sun Nov 03, 2019 9:03 pm
Forum: Resonance Structures
Topic: Showing resonance
Replies: 8
Views: 54

Re: Showing resonance

Yes, you can use the double arrows to draw a lewis structure's resonance structures.
by Anna Chen 1K
Sun Nov 03, 2019 9:03 pm
Forum: Electronegativity
Topic: Defining electronegativity
Replies: 2
Views: 30

Re: Defining electronegativity

Electronegativity is the tendency of an atom to attract a bonding pair of electrons.
by Anna Chen 1K
Sun Nov 03, 2019 8:55 pm
Forum: Empirical & Molecular Formulas
Topic: Rounding
Replies: 6
Views: 113

Re: Rounding

You should only round to a whole number when the decimal is extremely close to a whole number. For example, 1.96 to 1.99 can be rounded to 2. However, 1.6 or 1.8 should be multiplied to a whole number.
by Anna Chen 1K
Sun Nov 03, 2019 8:50 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 4s or 3d first?
Replies: 14
Views: 180

Re: 4s or 3d first?

The 4s orbitals have a lower energy than the 3d orbitals, so the 4s orbitals are filled first. However, Lavelle has said to write 3d first.
by Anna Chen 1K
Sat Oct 26, 2019 8:01 pm
Forum: Lewis Structures
Topic: Anion
Replies: 7
Views: 67

Re: Anion

First, add the negative charge to the total number of electrons in order to know how many electrons to represent in the Lewis structure. Second, you can draw brackets around the Lewis structure and write the negative charge besides the top right corner.
by Anna Chen 1K
Sat Oct 26, 2019 7:52 pm
Forum: Ionic & Covalent Bonds
Topic: Ionization Energy
Replies: 5
Views: 48

Re: Ionization Energy

No it technically does both because diagonally down is basically straight down and to the left.
by Anna Chen 1K
Sat Oct 26, 2019 7:36 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 7
Views: 74

Re: Formal Charge

The resonance structure with the lowest formal change is the most stable.
by Anna Chen 1K
Sat Oct 26, 2019 7:16 pm
Forum: Trends in The Periodic Table
Topic: Trends
Replies: 5
Views: 56

Re: Trends

You should be familiar with atomic radius, ionization energy, electron affinity, and electronegativity.
by Anna Chen 1K
Sat Oct 26, 2019 5:59 pm
Forum: Trends in The Periodic Table
Topic: Ionization energy
Replies: 12
Views: 134

Re: Ionization energy

You should understand the trends of ionization energy. It increases going across a period and up a group.
by Anna Chen 1K
Sun Oct 20, 2019 7:19 pm
Forum: Properties of Light
Topic: Next test
Replies: 23
Views: 275

Re: Next test

The same equation sheet used for test 1 will be used for future tests/midterms/finals.
by Anna Chen 1K
Sun Oct 20, 2019 7:12 pm
Forum: Properties of Electrons
Topic: Mass of an Electron
Replies: 14
Views: 173

Re: Mass of an Electron

This is a set mass which will also be given as a constant on the test.
by Anna Chen 1K
Sun Oct 20, 2019 7:10 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration
Replies: 5
Views: 40

Re: Electron Configuration

The order of filling orbitals is: 1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^10, 4p^6, and so on.
by Anna Chen 1K
Sun Oct 20, 2019 7:07 pm
Forum: Properties of Light
Topic: Unit for Wavelength
Replies: 34
Views: 209

Re: Unit for Wavelength

The standard unit for wavelength is meters (m) but it can be converted from nanometers, centimeters, etc.
by Anna Chen 1K
Sun Oct 20, 2019 7:06 pm
Forum: Properties of Light
Topic: Question 1A.3
Replies: 3
Views: 41

Re: Question 1A.3

The answer is c) The extent of the change in the electrical field at a given point decreases. The electrical field corresponds to the amplitude; as the frequency decreases the waves broaden and the extent of the change decreases.
by Anna Chen 1K
Sun Oct 20, 2019 7:02 pm
Forum: Photoelectric Effect
Topic: Speed of Light
Replies: 29
Views: 226

Re: Speed of Light

Yes, the speed of light is always going to be 2.998 x 10^8 m/s. It is always going to be a constant too. Sometimes, it is rounded to 3.00 x 10^8 m/s; however, using 2.998 x 10^8 m/s is recommended for accuracy.
by Anna Chen 1K
Sun Oct 13, 2019 9:46 pm
Forum: Properties of Light
Topic: Week 3 Homework Topics
Replies: 2
Views: 21

Re: Week 3 Homework Topics

Yes, Lavelle said week 3 homework can be on the quantum unit.
by Anna Chen 1K
Sun Oct 13, 2019 9:44 pm
Forum: Significant Figures
Topic: How Many Sig Figs
Replies: 7
Views: 120

Re: How Many Sig Figs

You should follow the standard sig fig rules for multiplication/division and addition/subtraction. For addition/subtraction, the number of sig figs should match the smallest amount of decimals in a given value. For multiplication/division, the number of sig figs should match the smallest amount of s...
by Anna Chen 1K
Sun Oct 13, 2019 9:41 pm
Forum: Properties of Light
Topic: Speed of light.
Replies: 10
Views: 73

Re: Speed of light.

Yes, we will consider the speed of light as a constant that can be expressed as 3.00 x 10^8 m/s^-1.
by Anna Chen 1K
Sun Oct 13, 2019 9:18 pm
Forum: Administrative Questions and Class Announcements
Topic: When do we need our 5 posts done by?
Replies: 4
Views: 78

Re: When do we need our 5 posts done by?

I also support the above post that our 5 posts are due at Sunday 11:19 PM.
by Anna Chen 1K
Sun Oct 13, 2019 9:14 pm
Forum: Limiting Reactant Calculations
Topic: How to find Excess Reactant?
Replies: 5
Views: 77

Re: How to find Excess Reactant?

To find the amount of excess reactant remaining, subtract the mass of excess reagent consumed from the mass of excess reagent given.
by Anna Chen 1K
Thu Oct 03, 2019 11:29 pm
Forum: SI Units, Unit Conversions
Topic: When to use what units
Replies: 5
Views: 93

Re: When to use what units

You should convert to moles and liters, as those are the standard units.

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