Search found 59 matches
- Sun Mar 10, 2019 10:06 pm
- Forum: Second Order Reactions
- Topic: negative in front of k
- Replies: 1
- Views: 251
Re: negative in front of k
We multiply the other side by the negative to get 1/[A]t - 1/[A]0.
- Sun Mar 10, 2019 10:02 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Electroplating
- Replies: 2
- Views: 468
Re: Electroplating
It utilizes redox reactions to coat a surface.
- Sun Mar 10, 2019 10:00 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Test 2
- Replies: 12
- Views: 1129
Re: Test 2
Also if gibbs free energy is zero, the free energy of the reactants equals that of the products
- Sun Mar 10, 2019 9:59 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Activation Energy
- Replies: 16
- Views: 1521
Re: Activation Energy
Activation energy is the minimum quantity of energy which the reacting species must possess in order to undergo a specified reaction to reach the products and this can be shown in an energy profile diagram by showing the energy of the reactants, the energy needed to overcome the Activation energy, a...
- Sun Mar 10, 2019 9:56 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Final Exam
- Replies: 23
- Views: 1846
Re: Final Exam
One of the TA's said in a review session that there should be one or two problems on it.
- Sun Mar 03, 2019 12:53 pm
- Forum: Zero Order Reactions
- Topic: Reaction Orders
- Replies: 2
- Views: 789
Re: Reaction Orders
Order of a reaction is just the relationship between the rate and the concentration of the reactant. It is calculated utilizing a chart similar to that in the notes where we see how concentration affects the rate of the experiment we are running under different scenarios. A first order reaction is a...
- Sun Mar 03, 2019 12:49 pm
- Forum: Second Order Reactions
- Topic: Reaction orders
- Replies: 3
- Views: 470
Re: Reaction orders
A first order reaction is a reaction based solely on one reactant with order of one, but a second order reaction is either two reactant each with order of one or one reactant with an order of two. Order of a reaction is just the relationship between the rate and the concentration of the reactant. It...
- Sun Mar 03, 2019 12:43 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Purpose of Kinetics
- Replies: 6
- Views: 1728
Re: Purpose of Kinetics
Yeah so pretty much kinetics that we cover attempts to evaluate how different factors such as temperature and concentration affect our reaction rate, and we will probably use this information in 14BL as we conduct different labs.
- Fri Feb 22, 2019 10:17 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Test 2 Help
- Replies: 7
- Views: 758
Re: Test 2 Help
Either way we are covering the nernst equation on Monday so you could ask Ben because he is there at lecture.
- Fri Feb 22, 2019 10:11 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Hw Ch.9 #75 (6th Edition) Residual Entropy
- Replies: 2
- Views: 318
Re: Hw Ch.9 #75 (6th Edition) Residual Entropy
You would have to draw it out. If its cis, the molecules can only be in three positions of the octahedral and the top and bottom and the two diagonals. However, if they are trans, they can be in any of the six positions and there are two molecules that are trans for those six positions so twelve pos...
- Fri Feb 22, 2019 10:09 pm
- Forum: Balancing Redox Reactions
- Topic: Galcanic cell
- Replies: 3
- Views: 397
Re: Galcanic cell
galvanic cell is practically another word for an spontaneous reaction and voltaic is just another name.
- Sat Feb 16, 2019 10:43 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Equilibrium Constant and Gibbs Free Energy
- Replies: 3
- Views: 427
Re: Equilibrium Constant and Gibbs Free Energy
The equilibrium constant only comes into play when we use this equation at equilibrium
- Sat Feb 16, 2019 10:41 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: First Law
- Replies: 3
- Views: 416
Re: First Law
No you just use it when you are given the other variables
- Sat Feb 16, 2019 10:38 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Converting to q rev
- Replies: 4
- Views: 677
Re: Converting to q rev
unless it is isothermal and irreversible, you use the other formulas were change in entropy is =nRlnT2/T1
- Mon Feb 11, 2019 11:22 am
- Forum: Administrative Questions and Class Announcements
- Topic: Thermochemistry Review Packet
- Replies: 4
- Views: 636
Re: Thermochemistry Review Packet
Thank you
- Mon Feb 11, 2019 11:22 am
- Forum: Administrative Questions and Class Announcements
- Topic: Textbook glitch
- Replies: 2
- Views: 338
Re: Textbook glitch
there is also a pdf on Facebook
- Sat Feb 09, 2019 3:22 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Delta H
- Replies: 4
- Views: 429
Delta H
When does delta H = q ?
- Sat Feb 02, 2019 3:37 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Reversible reaction
- Replies: 3
- Views: 404
Re: Reversible reaction
Also, for irreversible reactions, they completely go to products where they do not revert to the reactants
- Sat Feb 02, 2019 3:35 pm
- Forum: Phase Changes & Related Calculations
- Topic: Heat Curve
- Replies: 6
- Views: 641
Re: Heat Curve
I think we just have to know how to read the graph and draw information from it
- Mon Jan 28, 2019 12:06 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat capacity
- Replies: 1
- Views: 219
Heat capacity
What does heat capacity depend on?
- Mon Jan 28, 2019 12:05 pm
- Forum: Phase Changes & Related Calculations
- Topic: 3rd method
- Replies: 1
- Views: 190
Re: 3rd method
yeah or we look it up in the book
- Mon Jan 28, 2019 12:04 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Why Enthalpy Changes Are Additive
- Replies: 2
- Views: 328
Re: Why Enthalpy Changes Are Additive
it is because it is a state function so it can be added
- Mon Jan 28, 2019 12:04 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond Enthalpies of Diatomic Molecules
- Replies: 2
- Views: 311
Re: Bond Enthalpies of Diatomic Molecules
Because the bond enthalpies of other molecules are averages
- Sun Jan 20, 2019 3:12 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 12.25 7th edition
- Replies: 1
- Views: 170
Re: 12.25 7th edition
by using the fact that the [H3O+][OH-]=Kw
- Sun Jan 20, 2019 3:05 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: 6th edition 11.73
- Replies: 1
- Views: 187
Re: 6th edition 11.73
because in the reactants there are less moles of gas because C is a solid so it is more favorable
- Wed Jan 16, 2019 2:22 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Leveled
- Replies: 2
- Views: 230
Leveled
Can anyone explain the concept of a strong acid being leveled?
- Sun Jan 13, 2019 1:03 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: vant Hoff factor and equation
- Replies: 3
- Views: 226
Re: vant Hoff factor and equation
The Van't Hoff equation is practically just the relationship between temperature, the independent value, and the Keq, the dependent value.
- Sun Jan 13, 2019 12:59 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: "bar" meaning
- Replies: 4
- Views: 496
Re: "bar" meaning
bar, atm, and PSI can all be used as a unit for pressure in our Kp values
- Sun Jan 13, 2019 12:57 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Keq
- Replies: 3
- Views: 257
Re: Keq
Kc should be used when talking about concentrations and it is just under the umbrella of Keq which could be either Kp or Kc.
- Sat Dec 08, 2018 10:22 am
- Forum: Bronsted Acids & Bases
- Topic: Arrhenius Acids and Bases
- Replies: 1
- Views: 293
Re: Arrhenius Acids and Bases
CH3COOH is an arrhenius acid because it can act as a proton donor. However, I think that NH3 can be justified as an Arrhenius base because it does increase the [OH-] as a product.
- Sat Dec 08, 2018 10:18 am
- Forum: Empirical & Molecular Formulas
- Topic: Midterm Solution
- Replies: 1
- Views: 539
Re: Midterm Solution
for that question the ratios are not derived from the overall molecules. What you have to do is find the moles of C in CO2, the moles of H in H2O and then add those two together. This number will be subtracted from 1 because that is the weight of your unknown compound, giving you the grams of O whic...
- Sat Dec 08, 2018 10:14 am
- Forum: Properties of Light
- Topic: final Grade
- Replies: 3
- Views: 695
Re: final Grade
also for more practice on naming you can search churro and do Lyndon's practice test which has naming
- Sat Dec 01, 2018 11:59 pm
- Forum: Naming
- Topic: 7th Edit 9C1
- Replies: 2
- Views: 300
Re: 7th Edit 9C1
NH3 actually has a charge of 0 because of the formal charges (all hydrogens=0 and N=0), so like stated, the 2- charge of sulfate would be balanced by a +3 charge of Co to make it +1
- Sat Dec 01, 2018 11:55 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Saying Thank You to Dr. Lavelle
- Replies: 490
- Views: 621809
Re: Saying Thank You to Dr. Lavelle
Dear Dr. Lavelle,
Thank you so much for everything this quarter. Your class has been one of my favorites and I really appreciate your positive attitude and smile you bring to every lecture. Can't wait to have you again next quarter!
Thank you so much for everything this quarter. Your class has been one of my favorites and I really appreciate your positive attitude and smile you bring to every lecture. Can't wait to have you again next quarter!
- Sat Dec 01, 2018 11:51 pm
- Forum: Naming
- Topic: Toolbox 17.1
- Replies: 1
- Views: 102
Re: Toolbox 17.1
I do not think they have a relation you can do either.
- Wed Nov 21, 2018 1:55 pm
- Forum: Electronegativity
- Topic: regions of e- density
- Replies: 4
- Views: 960
Re: regions of e- density
2sp3 is the combination of the s and p orbitals into a hybrid orbital sp3 and it is the s and p orbitals of the molecule's n=2 shell
- Wed Nov 21, 2018 1:53 pm
- Forum: Hybridization
- Topic: Hybridization
- Replies: 6
- Views: 545
Re: Hybridization
Hybridization is the mixture of the different atomic orbitals, so sp3 is a combination of the s orbitals and the p orbitals. Also, the number of atomic orbitals are equal to the hybrid orbitals.
- Wed Nov 21, 2018 1:52 pm
- Forum: Hybridization
- Topic: Help with Confusion
- Replies: 6
- Views: 609
Re: Help with Confusion
I think we just need to understand the premises of pi and sigma bonds and the drawings allow you to see where they exist in 3D space.
- Mon Nov 19, 2018 11:55 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angle
- Replies: 8
- Views: 801
Re: Bond Angle
Like Lavelle said we do not need to memorize the experimental data just that the bond angle is slightly less than what the electron density would suggest.
- Mon Nov 19, 2018 11:52 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Double bonds
- Replies: 8
- Views: 871
Re: Double bonds
For Vespr its more about orientation of the bonds than the type so I don't think there is a way to dictate double bonds. When you draw in lone pairs just show an electron cloud.
- Mon Nov 19, 2018 11:51 am
- Forum: Administrative Questions and Class Announcements
- Topic: Discussion
- Replies: 3
- Views: 503
Re: Discussion
Yeah i think they still have discussion on wednesday
- Fri Nov 09, 2018 12:29 am
- Forum: Bond Lengths & Energies
- Topic: Larger to weaker bond correlation
- Replies: 3
- Views: 369
Re: Larger to weaker bond correlation
The larger the atom, the farther the bond is from the nucleus. This makes the attraction weaker as the inner electrons shield the valence electrons in the bond and they feel less pull to the larger molecules. This causes the bond to be weaker.
- Fri Nov 09, 2018 12:26 am
- Forum: Resonance Structures
- Topic: homework question 3.71 (6th edition)
- Replies: 3
- Views: 439
Re: homework question 3.71 (6th edition)
The resonance structures with the most formal charges equal to or close to 0 are the ones that contribute the most to the resonance hybrid.
- Fri Nov 09, 2018 12:24 am
- Forum: Electronegativity
- Topic: electronegativity trends
- Replies: 6
- Views: 655
Re: electronegativity trends
Electronegativity is the tendency to attract an electron. So, as you move across a period there are more protons, so the electronegativity increases. The electronegativity decreases as you move down because of the increased distance between the electron and the nucleus and more electrons are shieldi...
- Fri Nov 02, 2018 10:58 am
- Forum: Dipole Moments
- Topic: Midterm Dipole Moments?
- Replies: 4
- Views: 439
Midterm Dipole Moments?
Do we need to know today's lecture on dipole moments for the midterm?
- Fri Nov 02, 2018 10:56 am
- Forum: Trends in The Periodic Table
- Topic: Periodic trends
- Replies: 4
- Views: 517
Periodic trends
What periodic trends do we need to know for the midterm?
- Fri Nov 02, 2018 10:55 am
- Forum: Electronegativity
- Topic: Electronegativity calculation
- Replies: 4
- Views: 1686
Electronegativity calculation
How is electronegativity calculated?
- Fri Oct 26, 2018 11:25 am
- Forum: Ionic & Covalent Bonds
- Topic: Chemical Bonding
- Replies: 8
- Views: 830
Re: Chemical Bonding
Yeah we go over bonding. We began from the fundamentals and I think next class we will continue to expand on chemical bonding.
- Fri Oct 26, 2018 11:20 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Covalent Radius
- Replies: 2
- Views: 305
Re: Covalent Radius
The covalent radius is 1/2 the distance between the centers of neighboring atoms and is when two atoms (nonmetals) are joined by covalent bonds.
- Fri Oct 26, 2018 11:17 am
- Forum: Lewis Structures
- Topic: Lewis Dot Order
- Replies: 10
- Views: 1264
Lewis Dot Order
Is there a particular order for Lewis dot structures?
- Fri Oct 19, 2018 1:32 pm
- Forum: *Shrodinger Equation
- Topic: Schrodinger Equation
- Replies: 2
- Views: 312
Re: Schrodinger Equation
For the test, we just have to know of it conceptually because he stated multiple times that we do not have to understand how to calculate anything using it as that is for the physical sciences.
- Fri Oct 19, 2018 1:30 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Equation
- Replies: 7
- Views: 716
Re: Rydberg Equation
For the Rydberg equation, it is usually used when you want to determine the wavelength of the radiation when an electron goes from n-initial to n-final. to do that you find the frequency, nu (the one that looks like a v) and from there you utilize c=lambda/nu to find the wavelength. You can relate t...
- Fri Oct 19, 2018 1:22 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: s, p, d, f subshells in multi-electron atoms
- Replies: 6
- Views: 595
Re: s, p, d, f subshells in multi-electron atoms
Due to the electrostatic interactions between the nucleus and the electrons in the various orbitals, the further the electron is from the nucleus, the higher its energy. Because the s-orbital is shielding the p-orbital in the same shell, the electrons of the p-orbital will have a higher energy becau...
- Fri Oct 12, 2018 11:13 am
- Forum: Properties of Light
- Topic: Kinetic Energy
- Replies: 3
- Views: 281
Re: Kinetic Energy
No, the kinetic energy that you derive from Ek=1/2mv^2 can be related to frequency by using the formula Ek=hv-ϕ. So practically what this equation does is it sets the kinetic energy of the ejected electron equal to the energy supplied by the photon minus the work function (threshold value) that is n...
- Fri Oct 12, 2018 10:59 am
- Forum: DeBroglie Equation
- Topic: Wavelike properties vs classical model
- Replies: 1
- Views: 149
Wavelike properties vs classical model
Does c=Lambda(v) apply in quantum mechanics?
- Wed Oct 10, 2018 1:46 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Going from Spectroscopic line to Energy levels
- Replies: 1
- Views: 135
Re: Going from Spectroscopic line to Energy levels
So conceptually, this problem is similar to the graphs that Dr. Lavelle showed us in class. When the wavelength is shorter, so UV waves, the electron is falling from an elevated state to n=1. However when you go to a larger wavelength, visible light (400nm-700nm), the electron is falling from an ele...
- Wed Oct 03, 2018 11:45 pm
- Forum: SI Units, Unit Conversions
- Topic: formula units [ENDORSED]
- Replies: 69
- Views: 33034
Re: formula units [ENDORSED]
Moles are just a measurement kind of like a dozen. You can define what the moles, or dozen, is of so it could be atoms, molecules, formula units, or donuts. The number is the same regardless of what thing its describing.
- Wed Oct 03, 2018 11:35 pm
- Forum: Balancing Chemical Reactions
- Topic: Order of balancing an equation
- Replies: 8
- Views: 682
Re: Order of balancing an equation
I actually use a different method. I try balancing by matching singular elements and their coefficients to that of a compound because the equation is easier to deal with when it is single elements and not multiple comprising a compound.
- Wed Oct 03, 2018 11:26 pm
- Forum: Limiting Reactant Calculations
- Topic: Combustion Analysis? [ENDORSED]
- Replies: 7
- Views: 450
Re: Combustion Analysis? [ENDORSED]
I think it will be because we discussed it in lecture. The main concept is that you create water and carbon dioxide from the reactant and oxygen, and you balance the equation from there.