Search found 40 matches
- Fri Mar 16, 2018 1:44 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3998436
- Fri Mar 16, 2018 1:43 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3998436
Re: Post All Chemistry Jokes Here
Q. Is silicon spelled the same in Spanish?
A. Si!
A. Si!
- Fri Mar 16, 2018 1:41 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3998436
Re: Post All Chemistry Jokes Here
Did you know you could cool yourself to -273 degrees celsius and still be 0k?
- Fri Mar 16, 2018 1:38 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3998436
- Fri Mar 16, 2018 1:35 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3998436
Re: Post All Chemistry Jokes Here
A photon checks into a hotel and is asked if he needs any help with his luggage. He says, "No, I'm traveling light."
- Fri Mar 16, 2018 1:34 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3998436
Re: Post All Chemistry Jokes Here
Two chemists go into a bar. The first one says "I think I'll have an H2O." The second one says "I think I'll have an H2O too" — and he died.
- Sun Mar 04, 2018 11:53 pm
- Forum: *Free Energy of Activation vs Activation Energy
- Topic: What is Free Energy of Activation
- Replies: 11
- Views: 3628
Re: What is Free Energy of Activation
In regards to gibbs free engery of activation, it will always be positive as energy is usually taken up for the reaction to happen.
- Sun Mar 04, 2018 11:44 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Rate determining reaction
- Replies: 3
- Views: 431
Re: Rate determining reaction
You always calculate based on what you got for the slowest step. The slowest step therefore is your determining rate.
- Sun Mar 04, 2018 11:42 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Friday Lecture
- Replies: 5
- Views: 640
Re: Friday Lecture
CO2 is zero order and is needed
- Sun Feb 25, 2018 10:40 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Diamond and graphite
- Replies: 8
- Views: 3552
Re: Diamond and graphite
Delta H of formation for diamond is higher in energy than it is for graphite and happens at a much slower rate.
- Sun Feb 25, 2018 10:35 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Pressure in calculating Q
- Replies: 4
- Views: 552
Re: Pressure in calculating Q
When calculating Q for a reaction consisting of gases, Molarity and partial pressures are used.
- Sun Feb 25, 2018 10:29 pm
- Forum: General Rate Laws
- Topic: Negative Sign [ENDORSED]
- Replies: 7
- Views: 998
Re: Negative Sign [ENDORSED]
The rate should always be positive, hence the need for the negative sign.
- Sun Feb 11, 2018 11:37 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation
- Replies: 5
- Views: 880
Re: Oxidation
Exactly, charges within a compound have oxidation numbers that contribute to the overall state of the compound.
- Sun Feb 11, 2018 11:34 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Electrolysis
- Replies: 5
- Views: 1319
Re: Electrolysis
In a nonspontaneous reaction, an electron current is necessary for a redox reaction to occur.
- Sun Feb 11, 2018 11:27 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: system vs surroundings
- Replies: 6
- Views: 975
Re: system vs surroundings
Your reaction is the system, leaving the beaker and the atmosphere as your surroundings.
- Sun Feb 04, 2018 11:44 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: The Third Law
- Replies: 3
- Views: 507
Re: The Third Law
we know the micro state is w=1 because there exists no movement at 0 Kelvin therefore resulting in entropy equal to 0.
- Sun Feb 04, 2018 11:30 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Sig Figs
- Replies: 6
- Views: 759
Re: Sig Figs
Stick to the amount you are using in your equations and see if your answer matches the ones in the textbook.
- Sun Feb 04, 2018 11:27 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Friday Lecture Concept
- Replies: 2
- Views: 307
Re: Friday Lecture Concept
Same thinking here. Biological systems are at equilibrium and our systems are assumed to be so.
- Sun Jan 21, 2018 8:46 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Radiation vs. Convection
- Replies: 3
- Views: 439
Re: Radiation vs. Convection
Examples of Radiation are: Heat from the sun or feeling heat from a fire. A convection example could be boiling water: heat passes from the flame into a pot which heats the water at the bottom, then the hot water rises and cooler water moves down, resulting in a circular motion.
- Sun Jan 21, 2018 8:38 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated system
- Replies: 8
- Views: 1057
Re: Isolated system
Work cant be done in an isolated system. There is no energy transfer from the system and the surroundings so assume both work and heat exchange are zero.
- Sun Jan 21, 2018 8:05 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Bond Energies Final 2013 #1
- Replies: 2
- Views: 605
Re: Bond Energies Final 2013 #1
Exactly. Since 02 and H20 were the results of your reaction, they are the products.
- Sun Jan 14, 2018 11:56 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Gas molar heat capacity [ENDORSED]
- Replies: 4
- Views: 573
Gas molar heat capacity [ENDORSED]
why does gas have two values for molar heat capacity?
- Sun Jan 14, 2018 11:44 pm
- Forum: Phase Changes & Related Calculations
- Topic: Temperature and Heat
- Replies: 4
- Views: 508
Re: Temperature and Heat
Dr. Lavelle also mentioned there is a device that can be used to keep the substance at a certain temperature
- Sun Jan 14, 2018 11:42 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Standard State
- Replies: 1
- Views: 297
Standard State
Do we always assume an element is in its standard state (surroundings being 25 degrees C and 1atm)?
- Fri Dec 08, 2017 10:51 pm
- Forum: Hybridization
- Topic: Bond Notation
- Replies: 3
- Views: 492
Re: Bond Notation
I remember he initially had C2sp and then erased the 2
- Fri Dec 08, 2017 10:51 pm
- Forum: Hybridization
- Topic: Bond Notation
- Replies: 3
- Views: 492
Re: Bond Notation
Yes I heard that too. But I remember him saying something about omitting it if the question doesn't ask for it. Can someone clarify this part?
- Fri Dec 08, 2017 10:43 pm
- Forum: *Titrations & Titration Calculations
- Topic: HW 13.53
- Replies: 2
- Views: 1384
Re: HW 13.53
Remember we omit liquids from the equation
- Wed Nov 29, 2017 11:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: From the Post-Module Assessment 1A:
- Replies: 3
- Views: 446
Re: From the Post-Module Assessment 1A:
Makes sense thank you!
- Wed Nov 29, 2017 11:09 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: From the Post-Module Assessment 1A:
- Replies: 3
- Views: 446
From the Post-Module Assessment 1A:
what is the difference between when a reaction is said to "Lie to the right " vs when the “equilibrium is shifted to the right” vs with respect to equilibrium constants?
- Mon Nov 20, 2017 1:11 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 4
- Views: 550
Re: Bond Angles
Know its less than (>109.5) and why (possible lone pairs)
- Mon Nov 20, 2017 1:02 am
- Forum: Hybridization
- Topic: Hybrid orbitals
- Replies: 3
- Views: 383
Re: Hybrid orbitals
Each slightly increase.
- Mon Nov 20, 2017 1:02 am
- Forum: Hybridization
- Topic: Hybrid orbitals
- Replies: 3
- Views: 383
Re: Hybrid orbitals
Yes. 1s, 2s,2p,3s,3p...
- Mon Nov 06, 2017 8:46 pm
- Forum: Octet Exceptions
- Topic: Octet Exceptions
- Replies: 8
- Views: 1040
Octet Exceptions
Are the only elements that adhere to the octet rule those with an energy level of 3 and below? Essentially those without access to the d orbital?
- Mon Nov 06, 2017 8:26 pm
- Forum: Student Social/Study Group
- Topic: DOWNLOAD PRACTICE MIDTERM HERE: Lyndon and Michael's session
- Replies: 7
- Views: 1748
Ni3+ electron configuration
For Ni3+, why is the electron configuration [Ar]3d7 as opposed to [Ar]4s^2 3d5
- Thu Oct 19, 2017 9:52 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Homework
- Replies: 3
- Views: 412
Re: Homework
Check your email in the future. Dr. Lavelle this week sent one Monday stating "For the assigned homework it is Chapter 1 questions 3-41." if you are ever confused.
- Thu Oct 19, 2017 9:43 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Equation
- Replies: 7
- Views: 903
Re: Rydberg Equation
Always depends on where it started and ended up. Remember, E(final) - E(initial)
- Thu Oct 12, 2017 7:29 pm
- Forum: Properties of Light
- Topic: 1.27
- Replies: 3
- Views: 488
1.27
I understand you use Avogadro's constant to solve part b, but isn't the constant usually used to find atoms per mol? not photons per mol?
- Thu Oct 12, 2017 7:22 pm
- Forum: Properties of Light
- Topic: the quantum world [ENDORSED]
- Replies: 2
- Views: 420
Re: the quantum world [ENDORSED]
also, some problems start in (for example) milligrams or picometers. make sure you convert them to grams/meters before you begin.
- Thu Oct 12, 2017 7:19 pm
- Forum: Properties of Light
- Topic: HW 1.25b
- Replies: 2
- Views: 359
Re: HW 1.25b
Use Avogadro's number to turn grams to atoms!
- Thu Oct 12, 2017 7:11 pm
- Forum: Einstein Equation
- Topic: question 27
- Replies: 2
- Views: 556
Re: question 27
Remember! In E=hv, E is energy PER photon. We have 4.7x10^-19J.photon^-1.
We then multiply 64J (1mole/6.022x10^23J) and get 1.4x10^20 photons (and jewels canceled out).
We then multiply 64J (1mole/6.022x10^23J) and get 1.4x10^20 photons (and jewels canceled out).