Search found 68 matches
- Sun Mar 17, 2019 5:55 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2761548
- Sun Mar 17, 2019 5:53 pm
- Forum: Balancing Redox Reactions
- Topic: How to balance half reaction
- Replies: 5
- Views: 788
Re: How to balance half reaction
what i do is add the h2o to balance out the Os, then add H to balance H, then for the amount of H you add, add the same amount of OH to each side. The oh and h should combine to form h2o with can be added to/subtracted. just simplify from there!
- Sun Mar 17, 2019 5:47 pm
- Forum: Van't Hoff Equation
- Topic: neutral pH not 7?
- Replies: 6
- Views: 984
Re: neutral pH not 7?
its different at varying temperatures
- Sun Mar 17, 2019 5:46 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Ecell
- Replies: 5
- Views: 648
Re: Ecell
theyre dependent on what youre given/what you want to find
- Sun Mar 17, 2019 5:44 pm
- Forum: *Enzyme Kinetics
- Topic: Catalysts
- Replies: 8
- Views: 1040
Re: Catalysts
so does that mean the amount of product and reactant is or isnt affected by adding a catalyst?
- Sun Mar 17, 2019 5:43 pm
- Forum: *Enzyme Kinetics
- Topic: How do you tell if something is a catalyst vs an intermediate?
- Replies: 16
- Views: 5615
Re: How do you tell if something is a catalyst vs an intermediate?
catalysts are in the reactant and intermediate is in the product side
- Sun Mar 17, 2019 5:42 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: U=0
- Replies: 6
- Views: 3144
Re: U=0
yes! deltaU= 0 for isothermal reversible expansion
- Sun Mar 17, 2019 5:40 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: DeltaU = 3/2 nRT
- Replies: 3
- Views: 886
Re: DeltaU = 3/2 nRT
for monatomic gases!
- Sun Mar 17, 2019 5:37 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Saying Thank You to Dr. Lavelle
- Replies: 490
- Views: 504086
Re: Saying Thank You to Dr. Lavelle
Thank you Dr. Lavelle for being so kind and very interested in what you're teaching! it makes learning more engaging! I am glad to have had you as a professor for 2 quarters!
- Sun Mar 17, 2019 5:34 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: tripotic acid
- Replies: 2
- Views: 1459
Re: tripotic acid
polyprotic acids contain more than one acidic proton. three acidic protons make it triprotic
- Sun Mar 17, 2019 5:32 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: w=-PdeltaW
- Replies: 5
- Views: 687
Re: w=-PdeltaW
you use it for irreverible reactions. usually youre given the external pressure pushing onto the system and you need to find the work of the systemm pushing out against the external pressure. and its w = -pdeltav
- Sun Mar 17, 2019 5:30 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: pKa vs. pH
- Replies: 15
- Views: 2913
Re: pKa vs. pH
pka is in reference to ka whereas ph is in reference to H+
- Sun Mar 17, 2019 5:27 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Bimolecular
- Replies: 13
- Views: 2149
Re: Bimolecular
Henry Dudley 1G wrote:Can a bimolecular reaction be third order if one of the reactants is second order?
no i believe theyre directly related so thats not possible
- Sat Mar 16, 2019 11:37 am
- Forum: Student Social/Study Group
- Topic: class pictures
- Replies: 15
- Views: 3918
Re: class pictures
Here’s another set!
- Sat Mar 16, 2019 11:36 am
- Forum: Student Social/Study Group
- Topic: class pictures
- Replies: 15
- Views: 3918
Re: class pictures
Here are more pictures!
- Fri Mar 15, 2019 12:05 pm
- Forum: Student Social/Study Group
- Topic: class pictures
- Replies: 15
- Views: 3918
Re: class pictures
David Sarkissian 1K wrote:How do you post pictures? I have a decent one from up front, but I don’t know how to post it.
Refer to this: viewtopic.php?f=176&t=3916
- Sun Feb 24, 2019 5:10 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Spontaneous?
- Replies: 6
- Views: 698
Re: Spontaneous?
when its negative its spontaneous. when its positive its not spontaneous.
- Sun Feb 24, 2019 5:09 pm
- Forum: Balancing Redox Reactions
- Topic: TEST
- Replies: 7
- Views: 812
Re: TEST
material up to but not including nernst equation
- Sun Feb 24, 2019 5:08 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Test 3
- Replies: 14
- Views: 2244
Re: Test 3
MichaelMoreno2G wrote:Up to what section of electrochemistry do we need to study? I'm still a little confused so if someone can clarify that would be greatly appreciated.
up to but not including nernst
- Sun Feb 24, 2019 5:04 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation
- Replies: 4
- Views: 535
Re: Oxidation
this is what i found: https://socratic.org/questions/why-is-l ... -oxidation
it had to do with what they thought in the early days of chemistry
it had to do with what they thought in the early days of chemistry
- Sun Feb 24, 2019 5:01 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Regrades
- Replies: 2
- Views: 344
Re: Midterm Regrades
I would ask your ta
- Sun Feb 24, 2019 4:56 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing Redox equations in Basic conditions
- Replies: 3
- Views: 308
Re: Balancing Redox equations in Basic conditions
they both go on the left side
- Sun Feb 24, 2019 4:47 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy
- Replies: 2
- Views: 349
Re: Gibbs Free Energy
gibbs free energy of formation is the change of Gibbs free energy that accompanies the formation of 1 mole of a substance in its standard state.
- Sun Feb 10, 2019 3:36 pm
- Forum: Calculating Work of Expansion
- Topic: Real processes
- Replies: 2
- Views: 302
Re: Real processes
heres some examples: The simplest examples given in thermodynamics texts are the reversible and irreversible expansion of a gas. If you have a gas in a container connected to an evacuated container, and you open the stop-cock between them, the gas will expand without doing any work. This process is ...
- Sun Feb 10, 2019 3:31 pm
- Forum: Calculating Work of Expansion
- Topic: Reversible vs Irreversible
- Replies: 9
- Views: 785
Re: Reversible vs Irreversible
In a irreversible reaction, the reactants react to form the products, which cannot revert back into reactants. In reversible reactions, as the reactants react with other reactants to form products, the products are reacting with other products to form reactants. Combustion cannot be undone. i am not...
- Sun Feb 10, 2019 3:29 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: types of reversible processes
- Replies: 1
- Views: 1535
Re: types of reversible processes
i think thats all we need to know
- Fri Feb 01, 2019 8:25 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Different Kinds of Symptoms
- Replies: 6
- Views: 1202
Re: Different Kinds of Symptoms
open system: glass of tea evaporating
closed system: boba drink with the plastic seal
isolated system: calorimeter
closed system: boba drink with the plastic seal
isolated system: calorimeter
- Fri Feb 01, 2019 8:20 pm
- Forum: Calculating Work of Expansion
- Topic: Isolated System
- Replies: 5
- Views: 2846
Re: Isolated System
no you shouldnt consider the heat of the surroundings in an isolated system
- Fri Feb 01, 2019 8:13 pm
- Forum: Ideal Gases
- Topic: pV=nRT
- Replies: 12
- Views: 1989
Re: pV=nRT
is is a given constant! should be in the equations sheet or in the problem
- Sat Jan 26, 2019 4:31 pm
- Forum: Phase Changes & Related Calculations
- Topic: work and heat
- Replies: 2
- Views: 258
Re: work and heat
because a state property's value is determined by its current state and not dependent on the path taken to obtain that state
- Sat Jan 26, 2019 4:26 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bonds being broken in reaction
- Replies: 4
- Views: 337
Re: Bonds being broken in reaction
the stronger the bond, the more energy it requires to break it
- Sat Jan 26, 2019 4:25 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Ka
- Replies: 6
- Views: 640
Re: Ka
strong acids dont have ka values. if you see a ka value, its most likely a weak acid
- Mon Jan 21, 2019 4:36 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Pressure
- Replies: 7
- Views: 613
Re: Pressure
dont include solids and liquids. only include gases and aqueous solutions
- Mon Jan 21, 2019 4:35 pm
- Forum: Administrative Questions and Class Announcements
- Topic: TA posted slides (dis 1B)
- Replies: 1
- Views: 225
Re: TA posted slides (dis 1B)
its under Board index > Chem 14B > Administrative Questions and Class Announcements > Yekan Discussion slides (1B, 1H, 1J)
- Mon Jan 21, 2019 4:31 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Strong and Weak Acids
- Replies: 3
- Views: 290
Re: Strong and Weak Acids
At equal concentrations, a strong acid will typically have a lower pH than a weak acid, since the strong one will donate more protons to the solution.
- Fri Jan 11, 2019 4:39 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Q and K
- Replies: 13
- Views: 1169
Re: Q and K
When comparing the two, usually you’ll be given K and you’ll have to calculate Q.
- Fri Jan 11, 2019 4:35 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle [ENDORSED]
- Replies: 3
- Views: 275
Re: Le Chatelier's Principle [ENDORSED]
In lecture today, Professor Lavelle gave us the reaction N2(g) + 3H2(g) --> 2NH3(g) and described what would happen if we increased N2, increased NH3, and decreased H2. Can someone please explain to me each scenario, I am a bit confused still. If you increased N2, which is the reactant, a forward r...
- Fri Jan 11, 2019 4:27 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Expression K
- Replies: 3
- Views: 166
Re: Equilibrium Expression K
Actually I found out that it’s most likely a TB error and the 7 N2 should have been a 5 N2
- Wed Jan 09, 2019 10:38 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Expression K
- Replies: 3
- Views: 166
Re: Equilibrium Expression K
Jessica Chen 1F wrote:The equation definitely has to be balanced before you plug things in to solve K because the stoichiometric coefficients matter as the exponents.
does that mean the solution manual is wrong then?
- Wed Jan 09, 2019 10:30 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Expression K
- Replies: 3
- Views: 166
Equilibrium Expression K
I noticed that for 11.3 in the 6th edition that the equation isn't balanced. In the solutions manual, the answer is from the original/given equation. I thought we always had to balance equations... Are we supposed to leave the equation as it is when writing the equilibrium expression K? 11.3 Write t...
- Sun Dec 02, 2018 10:05 pm
- Forum: Dipole Moments
- Topic: Strength of intramolecular forces due to polarity
- Replies: 5
- Views: 587
Re: Strength of intramolecular forces due to polarity
If you have a substance with nonpolar molecules , the only Intermolecular Forces of Attraction that exist are London-Dispersion forces, which are very weak. Therefore, a polar substance will have a stronger attraction between its molecules than a substance with nonpolar molecules.
- Sun Dec 02, 2018 9:57 pm
- Forum: Lewis Acids & Bases
- Topic: Determining Acidity or Basic
- Replies: 2
- Views: 348
Re: Determining Acidity or Basic
To determine whether a substance is an acid or a base, count the hydrogens on each substance before and after the reaction. If the number of hydrogens has decreased that substance is the acid (donates hydrogen ions). If the number of hydrogens has increased that substance is the base (accepts hydrog...
- Sun Dec 02, 2018 9:55 pm
- Forum: Bronsted Acids & Bases
- Topic: Bronsted Acid vs Lewis Acid
- Replies: 2
- Views: 332
Re: Bronsted Acid vs Lewis Acid
the Bronsted definition: an acid is a proton (H+ ion) donor, and a base is a proton acceptor
the Lewis definition: an acid is an electron acceptor, and a base is an electron donor.
the Lewis definition: an acid is an electron acceptor, and a base is an electron donor.
- Sun Nov 25, 2018 7:44 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic bonds
- Replies: 1
- Views: 255
Re: Ionic bonds
when the electronegativity difference is greater than 2.0, the bond is considered ionic.
- Sun Nov 25, 2018 7:42 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: bonding vs anti bonding orbitals
- Replies: 2
- Views: 326
Re: bonding vs anti bonding orbitals
Electrons in bonding orbitals stabilize the molecule because they are between the nuclei. Antibonding orbitals place less electron density between the nuclei. The nuclear repulsions are greater, so the energy of the molecule increases. Antibonding orbitals are at higher energy levels than bonding or...
- Sun Nov 25, 2018 7:39 pm
- Forum: Student Social/Study Group
- Topic: Final
- Replies: 12
- Views: 1614
Re: Final
I’d assume so
- Sun Nov 18, 2018 7:44 pm
- Forum: Dipole Moments
- Topic: Dipoles
- Replies: 3
- Views: 461
Re: Dipoles
in a non-polar molecule, the whole molecule has zero dipole moment but bonds are polar. When two non-polar molecules comes closer to each other, the negative part (electrons) of one molecule attract the positive part (nucleus) of another molecule. As a result, two dipoles are induced.
- Sun Nov 18, 2018 7:40 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Determining Shape
- Replies: 5
- Views: 548
Re: Determining Shape
yes i believe so
- Sun Nov 18, 2018 7:38 pm
- Forum: Resonance Structures
- Topic: Bond Length
- Replies: 4
- Views: 718
Re: Bond Length
im not quite sure what your question is but i believe you are asking about the bond lengths of resonance and non resonance structures? what do you mean by in what context do we discuss them in?
- Thu Nov 08, 2018 6:00 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm [ENDORSED]
- Replies: 14
- Views: 1418
Re: Midterm [ENDORSED]
our ta will hand it to us after lecture
- Thu Nov 08, 2018 5:59 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: HW for discussion
- Replies: 9
- Views: 976
Re: HW for discussion
chapter 3!
- Thu Nov 08, 2018 5:57 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Test Quantum Numbers
- Replies: 4
- Views: 507
Re: Test Quantum Numbers
l= 0,1,2,3
orbitals: s,p,d,f
since l is i that means its in the p orbital which can hold up to 6 electrons (two on each __ __ __)
orbitals: s,p,d,f
since l is i that means its in the p orbital which can hold up to 6 electrons (two on each __ __ __)
- Sat Nov 03, 2018 11:17 am
- Forum: Lewis Structures
- Topic: Electron Affinity
- Replies: 2
- Views: 285
Re: Electron Affinity
i know thar electron affinity and ionization energy are related. But i know that from lecture it was mentioned that elements towards the right have a lower ionization energy and elements towards the left have a higher ionization energy. When drawing the lewis dot structures, the element with the lea...
- Sat Nov 03, 2018 11:13 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Negative Energy
- Replies: 1
- Views: 204
Re: Negative Energy
all energys on the energy levels are negative. its just a matter of becoming less negative when it moves down an energy level
- Sat Nov 03, 2018 11:10 am
- Forum: Trends in The Periodic Table
- Topic: Metals, metalloids, and nonmetals
- Replies: 3
- Views: 482
Re: Metals, metalloids, and nonmetals
you should know by the placement on the periodic table. just search it up and youll find images! when i went to the periodic trends review session the ta said we should know stuff like that
- Fri Oct 26, 2018 8:35 pm
- Forum: Lewis Structures
- Topic: writing the structure
- Replies: 5
- Views: 528
Re: writing the structure
start off wherever you want. It completely up to you but try to make it balanced in a way i guess
- Fri Oct 26, 2018 8:24 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Using Heisenberg's Equation
- Replies: 3
- Views: 411
Re: Using Heisenberg's Equation
they are both the same! they are just written differently! the h over 2 pi is call h bar and it yields the same result!
- Fri Oct 26, 2018 8:21 pm
- Forum: Properties of Light
- Topic: Is light in waves or photons?
- Replies: 10
- Views: 878
Re: Is light in waves or photons?
Light has both wave and photon/particle properties!
- Fri Oct 26, 2018 8:20 pm
- Forum: Properties of Light
- Topic: Quantum Test
- Replies: 11
- Views: 1170
Re: Quantum Test
since lavelle will not be posting anymore modules, I heard the course reader helps alot!
- Thu Oct 18, 2018 11:16 pm
- Forum: Properties of Light
- Topic: Test 2 [ENDORSED]
- Replies: 15
- Views: 1135
Re: Test 2 [ENDORSED]
yeah just chapter 1 and 2 for quantum world
- Thu Oct 18, 2018 11:14 pm
- Forum: Properties of Light
- Topic: Do I have to memorize the spectrum?
- Replies: 20
- Views: 1479
Re: Do I have to memorize the spectrum?
I think during lecture he said we should just know the general order of the spectrum.
- Thu Oct 18, 2018 11:01 pm
- Forum: Einstein Equation
- Topic: Homework Question 1.55 (6th edition)
- Replies: 2
- Views: 339
Re: Homework Question 1.55 (6th edition)
You would use v/c=3600 cm^-1 v=frequency and c=speed of light
from there just plug in the speed of light and solve for v which is the frequency
from there just plug in the speed of light and solve for v which is the frequency
- Fri Oct 12, 2018 5:27 pm
- Forum: DeBroglie Equation
- Topic: Negative Sign
- Replies: 4
- Views: 335
Re: Negative Sign
joonsoo explained it right! Because we are going from a higher energy level to a lower energy level, the change in energy is negative since we are going down energy levels.
- Fri Oct 12, 2018 3:40 pm
- Forum: Properties of Light
- Topic: Plack's constant
- Replies: 2
- Views: 200
Re: Plack's constant
I'm not entirely sure. But i assume it cannot be any other value other than what it already is since it is a 'constant'
- Fri Oct 12, 2018 3:38 pm
- Forum: Significant Figures
- Topic: Calculators
- Replies: 20
- Views: 1691
Re: Calculators
I like my calculator because you can scroll and use the last answer to solve another problem! So if you calculate the molar mass of a compound you don't have to re type it! It's the Ti-30xs! I really recommend it!
- Thu Oct 04, 2018 12:56 pm
- Forum: Balancing Chemical Reactions
- Topic: Formula for nitric acid
- Replies: 3
- Views: 368
Re: Formula for nitric acid
I'd say just search up the formulas for the review. He will probably tell us later which ones to memorize if we ever need to. I wouldn't worry about memorizing for the test too if he specifically said we don't need to memorize them yet.
- Thu Oct 04, 2018 12:45 pm
- Forum: Limiting Reactant Calculations
- Topic: Fundamentals 7th Edition M1
- Replies: 2
- Views: 472
Re: Fundamentals 7th Edition M1
As per what the instructions on page F97 say: Since we are given the actual yield (25.2 g N2H4), we need to calculate the theoretical yield. 1) Start with the given mass of the reactant : 35.0 g NH3 2) Divide the mass by the molar mass of reactant NH3 to get the amount (mol) of reactant : 35.0 g NH3...
- Wed Oct 03, 2018 9:48 pm
- Forum: Empirical & Molecular Formulas
- Topic: Homework
- Replies: 2
- Views: 313
Re: Homework
I'm guessing just maybe the date the assignment is due? Other than that I think what you posted is good!