Search found 52 matches

by Janice Xiao 1I
Fri Mar 16, 2018 11:59 pm
Forum: *Nucleophilic Substitution
Topic: Transition States
Replies: 3
Views: 381

Transition States

What occurs at a transition state and why is its energy so high?
by Janice Xiao 1I
Fri Mar 16, 2018 11:53 pm
Forum: General Rate Laws
Topic: Coefficients and Exponents
Replies: 2
Views: 278

Coefficients and Exponents

In what case can coefficients in reactions be used as exponents for rate laws?
by Janice Xiao 1I
Wed Mar 14, 2018 1:53 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.63
Replies: 4
Views: 174

Re: 15.63

Where does the -0.59 come from?
by Janice Xiao 1I
Sun Mar 11, 2018 4:38 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Slowest Step
Replies: 3
Views: 110

Slowest Step

Why does the slowest step determine the rate of the overall reaction?
by Janice Xiao 1I
Sun Mar 11, 2018 4:37 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: SN2
Replies: 1
Views: 70

SN2

What does the SN2 reaction do?
by Janice Xiao 1I
Sun Mar 11, 2018 4:35 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Dimerization
Replies: 2
Views: 75

Dimerization

What does dimerization mean, and what does it look like in a reaction?
by Janice Xiao 1I
Sun Mar 04, 2018 1:01 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Independent of rate
Replies: 3
Views: 92

Independent of rate

How do you determine if a concentration is independent of the rate?
by Janice Xiao 1I
Sun Mar 04, 2018 12:50 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: K'
Replies: 7
Views: 206

K'

Is the slope the only way to determine K'?
by Janice Xiao 1I
Sun Mar 04, 2018 12:46 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: Rate Law
Replies: 2
Views: 88

Rate Law

When determining the rate law, why do we use the reactant with the smallest concentration?
by Janice Xiao 1I
Sun Mar 04, 2018 12:38 am
Forum: First Order Reactions
Topic: Pseudo-1st-Order
Replies: 6
Views: 182

Pseudo-1st-Order

What exactly is a pseudo-1st-order rate law?
by Janice Xiao 1I
Sun Feb 25, 2018 4:33 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Using K
Replies: 3
Views: 106

Using K

When calculating the reaction rate, why is K used instead of Q?
by Janice Xiao 1I
Sun Feb 25, 2018 4:24 pm
Forum: General Rate Laws
Topic: Gas Product
Replies: 3
Views: 93

Gas Product

We were given the reaction NH4+ (aq) + NO2- (aq) --> N2 (g) + 2H2O (l) in class, and told that since N2 is a gas it leaves the solution and the reverse reaction is less likely. Why is the reverse reaction less likely?
by Janice Xiao 1I
Sun Feb 25, 2018 4:20 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Kinetic vs. Thermodynamics
Replies: 3
Views: 131

Kinetic vs. Thermodynamics

How do you know if kinetics or thermodynamics is controlling a reaction?
by Janice Xiao 1I
Sat Feb 17, 2018 6:40 pm
Forum: Balancing Redox Reactions
Topic: Oxidizing & Reducing Agents
Replies: 6
Views: 152

Oxidizing & Reducing Agents

What exactly are oxidizing and reducing agents?
by Janice Xiao 1I
Sat Feb 17, 2018 6:36 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Dissolving
Replies: 2
Views: 87

Dissolving

When do you know that a gold ring will dissolve based off of delta G standard?
by Janice Xiao 1I
Sat Feb 17, 2018 6:31 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Negative E
Replies: 2
Views: 47

Negative E

What does it mean when E/the standard reduction potential is negative?
by Janice Xiao 1I
Fri Feb 09, 2018 1:30 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Conducting Metal
Replies: 3
Views: 86

Conducting Metal

Is a conducting metal/solid always necessary for half reactions?
by Janice Xiao 1I
Fri Feb 09, 2018 1:29 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: E and G
Replies: 2
Views: 88

E and G

Is there a relationship between the standard reaction potential/E and free energy?
by Janice Xiao 1I
Thu Feb 08, 2018 10:49 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Porous Disc vs Salt Bridge
Replies: 2
Views: 215

Porous Disc vs Salt Bridge

What's the main difference between a porous disc and a salt bridge?
by Janice Xiao 1I
Sat Feb 03, 2018 5:21 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Value of G
Replies: 4
Views: 72

Value of G

What is the lowest value that G can be? 0?
by Janice Xiao 1I
Sat Feb 03, 2018 5:11 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: ΔS(universe)
Replies: 6
Views: 187

ΔS(universe)

Can ΔS(universe) decrease? If so, what does that mean?
by Janice Xiao 1I
Sat Feb 03, 2018 4:56 pm
Forum: Calculating Work of Expansion
Topic: Reversible vs Irreversible [ENDORSED]
Replies: 3
Views: 153

Reversible vs Irreversible [ENDORSED]

Can someone conceptually explain why a reversible pathway has more work done than an irreversible pathway?
by Janice Xiao 1I
Sat Jan 27, 2018 2:46 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Utotal of Ideal Gas
Replies: 3
Views: 139

Utotal of Ideal Gas

What is the significance of the 3/2 in Utotal=3/2*nRT?
by Janice Xiao 1I
Sat Jan 20, 2018 11:57 pm
Forum: Calculating Work of Expansion
Topic: w=-P*deltaV
Replies: 3
Views: 121

w=-P*deltaV

Can someone explain why there's a negative sign in the w=-P*deltaV equation?
by Janice Xiao 1I
Sat Jan 20, 2018 10:58 pm
Forum: Calculating Work of Expansion
Topic: Reversible vs Irreversible
Replies: 4
Views: 119

Reversible vs Irreversible

What's the difference between reversible work and irreversible work?
by Janice Xiao 1I
Sat Jan 20, 2018 10:02 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Open Beaker [ENDORSED]
Replies: 5
Views: 230

Open Beaker [ENDORSED]

If a reaction occurs in an open beaker, does that mean it's at constant pressure?
by Janice Xiao 1I
Fri Jan 12, 2018 1:22 am
Forum: Sigma & Pi Bonds
Topic: delocalized pi bond
Replies: 5
Views: 747

Re: delocalized pi bond

If there are double and triple bonds in the structure, there will be delocalized pi bonds.
by Janice Xiao 1I
Fri Jan 12, 2018 12:47 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy Change Signs
Replies: 5
Views: 170

Enthalpy Change Signs

If a reaction is written in reverse, will the sign of the change in enthalpy change to be the opposite sign?
by Janice Xiao 1I
Fri Jan 12, 2018 12:17 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Most Stable/Pure Form
Replies: 2
Views: 84

Most Stable/Pure Form

Are an element's most stable form and most pure form the same thing?
by Janice Xiao 1I
Fri Dec 08, 2017 10:13 pm
Forum: Biological Examples
Topic: Ligand Names
Replies: 2
Views: 229

Ligand Names

When naming the compounds with the ligands ethylenediamine, diethylenetriamine, and ethylenediaminetetraacetato, can we abbreviate them as (en), (dien), and (edta), or should we write out the full name?
by Janice Xiao 1I
Fri Dec 08, 2017 10:03 pm
Forum: Amphoteric Compounds
Topic: Amphoteric vs amphiprotic
Replies: 1
Views: 214

Amphoteric vs amphiprotic

What's the difference between amphiprotic and amphoteric, and can you give an example?
by Janice Xiao 1I
Tue Nov 28, 2017 12:11 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solvents
Replies: 2
Views: 142

Solvents

Are solvents included in equilibrium constant expressions?

A. No

B. Yes

C. Sometimes

D. Not always

E. None of the above
by Janice Xiao 1I
Mon Nov 27, 2017 11:35 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K value
Replies: 1
Views: 91

K value

For which values of K does the equilibrium favor reactants or products? Is it K>1 and K<1, or K>10^3 and K<10^-3?
by Janice Xiao 1I
Mon Nov 27, 2017 11:17 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Product/Reactant Formation
Replies: 1
Views: 77

Product/Reactant Formation

13. When a chemical reaction has reached equilibrium are products and reactants being formed? A. No because the concentrations of the reactants and products do not change. B. No because the forward reaction and reverse reaction don’t occur. C. Yes, the forward reaction and reverse reaction occur but...
by Janice Xiao 1I
Fri Nov 24, 2017 1:25 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium constant
Replies: 4
Views: 140

Re: Equilibrium constant

When calculating K, you should also include aqueous, but when calculating Kp, only gases are involved.
by Janice Xiao 1I
Fri Nov 24, 2017 1:22 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Expanded octet
Replies: 6
Views: 201

Re: Expanded octet

Anything in the third row and beyond can have an expanded octet.
by Janice Xiao 1I
Sat Nov 18, 2017 3:30 pm
Forum: Bond Lengths & Energies
Topic: Bond length
Replies: 2
Views: 154

Re: Bond length

The overall bond length should be between the length of a single bond and a double bond.
by Janice Xiao 1I
Sat Nov 18, 2017 3:28 pm
Forum: Bond Lengths & Energies
Topic: Regions of Electron Density
Replies: 4
Views: 195

Re: Regions of Electron Density

Think of a region of electron density as just areas of electrons bunched together. An electron pair, single bond, double bond, and triple bond all count as 1 region of electron density.
by Janice Xiao 1I
Fri Nov 10, 2017 11:49 pm
Forum: Electronegativity
Topic: Polar or non polar [ENDORSED]
Replies: 4
Views: 238

Re: Polar or non polar [ENDORSED]

Covalent bonds have differences in electronegativity <1.5 and ionic bonds have differences in electronegativity >2. Electronegativity is greatest on the upper right side of the periodic table, so F is the most electronegative element. Ionization energy, electron affinity and electronegativity all ha...
by Janice Xiao 1I
Fri Nov 10, 2017 11:37 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity conversions [ENDORSED]
Replies: 3
Views: 172

Re: Molarity conversions [ENDORSED]

Molarity is equal to number of moles divided by volume in liters. So to find the number of moles, multiply the volume by the molarity.
by Janice Xiao 1I
Thu Nov 02, 2017 10:20 pm
Forum: Trends in The Periodic Table
Topic: Logistics
Replies: 1
Views: 123

Re: Logistics

Pretty much all trends except atomic/ionic radii increase across a period and up a group, so the elements in the top right of the periodic table have high electronegativity, electron affinity, and ionization energy. Atomic radii increase down a group and decrease down a period, so elements on the bo...
by Janice Xiao 1I
Thu Nov 02, 2017 10:18 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Uncertainty Principle [ENDORSED]
Replies: 5
Views: 283

Re: Uncertainty Principle [ENDORSED]

The uncertainty amount is 4. You don't need to take into account the actual momentum value.
by Janice Xiao 1I
Wed Oct 25, 2017 10:43 pm
Forum: Quantum Numbers and The H-Atom
Topic: Homework Question 2.17 part d
Replies: 5
Views: 251

Re: Homework Question 2.17 part d

l: 0 1 2 3
orbitals: s p d f
# of orbitals: 1 3 5 7
by Janice Xiao 1I
Wed Oct 25, 2017 10:36 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 2.1 part d
Replies: 4
Views: 176

Re: 2.1 part d

The radius also increases because the atomic number/number of protons increases, so the number of electrons increases as well.
by Janice Xiao 1I
Sat Oct 21, 2017 2:21 pm
Forum: Properties of Electrons
Topic: Electron Configuration [ENDORSED]
Replies: 3
Views: 247

Re: Electron Configuration [ENDORSED]

Yeah that's correct. Just not as specific.
by Janice Xiao 1I
Sat Oct 21, 2017 2:16 pm
Forum: Quantum Numbers and The H-Atom
Topic: Radial Nodes [ENDORSED]
Replies: 1
Views: 107

Re: Radial Nodes [ENDORSED]

A radial node is a circular ring that occurs as the principal quantum number increases. To determine the number of radial nodes, it is the principal quantum number minus 1 (n-1).
by Janice Xiao 1I
Sat Oct 14, 2017 5:24 pm
Forum: Properties of Electrons
Topic: Threshold level and Work Function [ENDORSED]
Replies: 6
Views: 389

Re: Threshold level and Work Function [ENDORSED]

Yes. It's also known as the minimum amount of energy needed to remove an electron.
by Janice Xiao 1I
Sat Oct 14, 2017 12:26 am
Forum: Photoelectric Effect
Topic: Photon vs. Energy [ENDORSED]
Replies: 6
Views: 252

Re: Photon vs. Energy [ENDORSED]

Energy is made up of discrete units called photons. You can calculate the energy of a photon. They're not exactly interchangeable but they're often associated with each other in photoelectric effect problems.
by Janice Xiao 1I
Thu Oct 05, 2017 10:19 pm
Forum: Administrative Questions and Class Announcements
Topic: Question about pencils
Replies: 1
Views: 173

Re: Question about pencils

Pretty sure you can do them in pencil.
by Janice Xiao 1I
Thu Oct 05, 2017 10:17 pm
Forum: Significant Figures
Topic: Clarification
Replies: 4
Views: 232

Re: Clarification

Use the "answer" button on your calculator so you can use the most accurate numbers in your calculations, and then round to the correct number of sig figs in your final answer.

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