Search found 52 matches
- Fri Mar 16, 2018 11:59 pm
- Forum: *Nucleophilic Substitution
- Topic: Transition States
- Replies: 3
- Views: 1987
Transition States
What occurs at a transition state and why is its energy so high?
- Fri Mar 16, 2018 11:53 pm
- Forum: General Rate Laws
- Topic: Coefficients and Exponents
- Replies: 2
- Views: 639
Coefficients and Exponents
In what case can coefficients in reactions be used as exponents for rate laws?
- Wed Mar 14, 2018 1:53 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: 15.63
- Replies: 4
- Views: 544
Re: 15.63
Where does the -0.59 come from?
- Sun Mar 11, 2018 4:38 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Slowest Step
- Replies: 3
- Views: 521
Slowest Step
Why does the slowest step determine the rate of the overall reaction?
- Sun Mar 11, 2018 4:37 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: SN2
- Replies: 1
- Views: 302
SN2
What does the SN2 reaction do?
- Sun Mar 11, 2018 4:35 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Dimerization
- Replies: 2
- Views: 374
Dimerization
What does dimerization mean, and what does it look like in a reaction?
- Sun Mar 04, 2018 1:01 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Independent of rate
- Replies: 3
- Views: 549
Independent of rate
How do you determine if a concentration is independent of the rate?
- Sun Mar 04, 2018 12:50 am
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: K'
- Replies: 7
- Views: 924
K'
Is the slope the only way to determine K'?
- Sun Mar 04, 2018 12:46 am
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Rate Law
- Replies: 2
- Views: 378
Rate Law
When determining the rate law, why do we use the reactant with the smallest concentration?
- Sun Mar 04, 2018 12:38 am
- Forum: First Order Reactions
- Topic: Pseudo-1st-Order
- Replies: 6
- Views: 824
Pseudo-1st-Order
What exactly is a pseudo-1st-order rate law?
- Sun Feb 25, 2018 4:33 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Using K
- Replies: 3
- Views: 508
Using K
When calculating the reaction rate, why is K used instead of Q?
- Sun Feb 25, 2018 4:24 pm
- Forum: General Rate Laws
- Topic: Gas Product
- Replies: 3
- Views: 515
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?
- Sun Feb 25, 2018 4:20 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Kinetic vs. Thermodynamics
- Replies: 3
- Views: 544
Kinetic vs. Thermodynamics
How do you know if kinetics or thermodynamics is controlling a reaction?
- Sat Feb 17, 2018 6:40 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidizing & Reducing Agents
- Replies: 6
- Views: 1196
Oxidizing & Reducing Agents
What exactly are oxidizing and reducing agents?
- Sat Feb 17, 2018 6:36 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Dissolving
- Replies: 2
- Views: 451
Dissolving
When do you know that a gold ring will dissolve based off of delta G standard?
- Sat Feb 17, 2018 6:31 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Negative E
- Replies: 2
- Views: 693
Negative E
What does it mean when E/the standard reduction potential is negative?
- Fri Feb 09, 2018 1:30 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Conducting Metal
- Replies: 3
- Views: 426
Conducting Metal
Is a conducting metal/solid always necessary for half reactions?
- Fri Feb 09, 2018 1:29 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: E and G
- Replies: 2
- Views: 371
E and G
Is there a relationship between the standard reaction potential/E and free energy?
- 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: 679
Porous Disc vs Salt Bridge
What's the main difference between a porous disc and a salt bridge?
- Sat Feb 03, 2018 5:21 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Value of G
- Replies: 4
- Views: 585
Value of G
What is the lowest value that G can be? 0?
- Sat Feb 03, 2018 5:11 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: ΔS(universe)
- Replies: 6
- Views: 915
ΔS(universe)
Can ΔS(universe) decrease? If so, what does that mean?
- Sat Feb 03, 2018 4:56 pm
- Forum: Calculating Work of Expansion
- Topic: Reversible vs Irreversible [ENDORSED]
- Replies: 3
- Views: 684
Reversible vs Irreversible [ENDORSED]
Can someone conceptually explain why a reversible pathway has more work done than an irreversible pathway?
- Sat Jan 27, 2018 2:46 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Utotal of Ideal Gas
- Replies: 3
- Views: 493
Utotal of Ideal Gas
What is the significance of the 3/2 in Utotal=3/2*nRT?
- Sat Jan 27, 2018 2:41 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: Calculating S [ENDORSED]
- Replies: 1
- Views: 268
Calculating S [ENDORSED]
What is Kb in S=Kb*ln(W)?
- Sat Jan 27, 2018 2:29 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: Calculating Degeneracy
- Replies: 1
- Views: 273
Calculating Degeneracy
Is w=states^particles?
- Sat Jan 20, 2018 11:57 pm
- Forum: Calculating Work of Expansion
- Topic: w=-P*deltaV
- Replies: 3
- Views: 394
w=-P*deltaV
Can someone explain why there's a negative sign in the w=-P*deltaV equation?
- Sat Jan 20, 2018 10:58 pm
- Forum: Calculating Work of Expansion
- Topic: Reversible vs Irreversible
- Replies: 4
- Views: 508
Reversible vs Irreversible
What's the difference between reversible work and irreversible work?
- Sat Jan 20, 2018 10:02 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Open Beaker [ENDORSED]
- Replies: 5
- Views: 1578
Open Beaker [ENDORSED]
If a reaction occurs in an open beaker, does that mean it's at constant pressure?
- Fri Jan 12, 2018 1:22 am
- Forum: Sigma & Pi Bonds
- Topic: delocalized pi bond
- Replies: 5
- Views: 2515
Re: delocalized pi bond
If there are double and triple bonds in the structure, there will be delocalized pi bonds.
- 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: 1449
Enthalpy Change Signs
If a reaction is written in reverse, will the sign of the change in enthalpy change to be the opposite sign?
- 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: 194
Most Stable/Pure Form
Are an element's most stable form and most pure form the same thing?
- Fri Dec 08, 2017 10:13 pm
- Forum: Biological Examples
- Topic: Ligand Names
- Replies: 2
- Views: 436
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?
- Fri Dec 08, 2017 10:03 pm
- Forum: Amphoteric Compounds
- Topic: Amphoteric vs amphiprotic
- Replies: 1
- Views: 437
Amphoteric vs amphiprotic
What's the difference between amphiprotic and amphoteric, and can you give an example?
- Tue Nov 28, 2017 12:11 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Solvents
- Replies: 2
- Views: 270
Solvents
Are solvents included in equilibrium constant expressions?
A. No
B. Yes
C. Sometimes
D. Not always
E. None of the above
A. No
B. Yes
C. Sometimes
D. Not always
E. None of the above
- Mon Nov 27, 2017 11:35 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K value
- Replies: 1
- Views: 161
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?
- Mon Nov 27, 2017 11:17 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Product/Reactant Formation
- Replies: 1
- Views: 210
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...
- Fri Nov 24, 2017 1:25 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium constant
- Replies: 4
- Views: 336
Re: Equilibrium constant
When calculating K, you should also include aqueous, but when calculating Kp, only gases are involved.
- Fri Nov 24, 2017 1:22 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Expanded octet
- Replies: 6
- Views: 696
Re: Expanded octet
Anything in the third row and beyond can have an expanded octet.
- Sat Nov 18, 2017 3:30 pm
- Forum: Bond Lengths & Energies
- Topic: Bond length
- Replies: 2
- Views: 335
Re: Bond length
The overall bond length should be between the length of a single bond and a double bond.
- Sat Nov 18, 2017 3:28 pm
- Forum: Bond Lengths & Energies
- Topic: Regions of Electron Density
- Replies: 4
- Views: 842
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.
- Fri Nov 10, 2017 11:49 pm
- Forum: Electronegativity
- Topic: Polar or non polar [ENDORSED]
- Replies: 4
- Views: 909
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...
- Fri Nov 10, 2017 11:37 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Molarity conversions [ENDORSED]
- Replies: 3
- Views: 517
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.
- Thu Nov 02, 2017 10:20 pm
- Forum: Trends in The Periodic Table
- Topic: Logistics
- Replies: 1
- Views: 204
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...
- Thu Nov 02, 2017 10:18 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Uncertainty Principle [ENDORSED]
- Replies: 5
- Views: 685
Re: Uncertainty Principle [ENDORSED]
The uncertainty amount is 4. You don't need to take into account the actual momentum value.
- Wed Oct 25, 2017 10:43 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Homework Question 2.17 part d
- Replies: 5
- Views: 696
Re: Homework Question 2.17 part d
l: 0 1 2 3
orbitals: s p d f
# of orbitals: 1 3 5 7
orbitals: s p d f
# of orbitals: 1 3 5 7
- Wed Oct 25, 2017 10:36 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 2.1 part d
- Replies: 4
- Views: 452
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.
- Sat Oct 21, 2017 2:21 pm
- Forum: Properties of Electrons
- Topic: Electron Configuration [ENDORSED]
- Replies: 3
- Views: 619
Re: Electron Configuration [ENDORSED]
Yeah that's correct. Just not as specific.
- Sat Oct 21, 2017 2:16 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Radial Nodes [ENDORSED]
- Replies: 1
- Views: 305
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).
- Sat Oct 14, 2017 5:24 pm
- Forum: Properties of Electrons
- Topic: Threshold level and Work Function [ENDORSED]
- Replies: 6
- Views: 1083
Re: Threshold level and Work Function [ENDORSED]
Yes. It's also known as the minimum amount of energy needed to remove an electron.
- Sat Oct 14, 2017 12:26 am
- Forum: Photoelectric Effect
- Topic: Photon vs. Energy [ENDORSED]
- Replies: 6
- Views: 776
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.
- Thu Oct 05, 2017 10:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Question about pencils
- Replies: 1
- Views: 338
Re: Question about pencils
Pretty sure you can do them in pencil.
- Thu Oct 05, 2017 10:17 pm
- Forum: Significant Figures
- Topic: Clarification
- Replies: 4
- Views: 601
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.