Search found 40 matches

by Miguel Velasco 2J
Fri Mar 16, 2018 1:43 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 908316

Re: Post All Chemistry Jokes Here

Q. Is silicon spelled the same in Spanish?
A. Si!
by Miguel Velasco 2J
Fri Mar 16, 2018 1:41 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 908316

Re: Post All Chemistry Jokes Here

Did you know you could cool yourself to -273 degrees celsius and still be 0k?
by Miguel Velasco 2J
Fri Mar 16, 2018 1:35 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 908316

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."
by Miguel Velasco 2J
Fri Mar 16, 2018 1:34 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 908316

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.
by Miguel Velasco 2J
Sun Mar 04, 2018 11:53 pm
Forum: *Free Energy of Activation vs Activation Energy
Topic: What is Free Energy of Activation
Replies: 5
Views: 739

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.
by Miguel Velasco 2J
Sun Mar 04, 2018 11:44 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Rate determining reaction
Replies: 3
Views: 126

Re: Rate determining reaction

You always calculate based on what you got for the slowest step. The slowest step therefore is your determining rate.
by Miguel Velasco 2J
Sun Mar 04, 2018 11:42 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Friday Lecture
Replies: 5
Views: 158

Re: Friday Lecture

CO2 is zero order and is needed
by Miguel Velasco 2J
Sun Feb 25, 2018 10:40 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Diamond and graphite
Replies: 8
Views: 601

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.
by Miguel Velasco 2J
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: 158

Re: Pressure in calculating Q

When calculating Q for a reaction consisting of gases, Molarity and partial pressures are used.
by Miguel Velasco 2J
Sun Feb 25, 2018 10:29 pm
Forum: General Rate Laws
Topic: Negative Sign [ENDORSED]
Replies: 7
Views: 271

Re: Negative Sign [ENDORSED]

The rate should always be positive, hence the need for the negative sign.
by Miguel Velasco 2J
Sun Feb 11, 2018 11:37 pm
Forum: Balancing Redox Reactions
Topic: Oxidation
Replies: 5
Views: 262

Re: Oxidation

Exactly, charges within a compound have oxidation numbers that contribute to the overall state of the compound.
by Miguel Velasco 2J
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: 625

Re: Electrolysis

In a nonspontaneous reaction, an electron current is necessary for a redox reaction to occur.
by Miguel Velasco 2J
Sun Feb 11, 2018 11:27 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: system vs surroundings
Replies: 6
Views: 327

Re: system vs surroundings

Your reaction is the system, leaving the beaker and the atmosphere as your surroundings.
by Miguel Velasco 2J
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: 127

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.
by Miguel Velasco 2J
Sun Feb 04, 2018 11:30 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Sig Figs
Replies: 6
Views: 137

Re: Sig Figs

Stick to the amount you are using in your equations and see if your answer matches the ones in the textbook.
by Miguel Velasco 2J
Sun Feb 04, 2018 11:27 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Friday Lecture Concept
Replies: 2
Views: 78

Re: Friday Lecture Concept

Same thinking here. Biological systems are at equilibrium and our systems are assumed to be so.
by Miguel Velasco 2J
Sun Jan 21, 2018 8:46 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Radiation vs. Convection
Replies: 3
Views: 162

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.
by Miguel Velasco 2J
Sun Jan 21, 2018 8:38 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated system
Replies: 8
Views: 271

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.
by Miguel Velasco 2J
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: 322

Re: Bond Energies Final 2013 #1

Exactly. Since 02 and H20 were the results of your reaction, they are the products.
by Miguel Velasco 2J
Sun Jan 14, 2018 11:56 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Gas molar heat capacity [ENDORSED]
Replies: 4
Views: 235

Gas molar heat capacity [ENDORSED]

why does gas have two values for molar heat capacity?
by Miguel Velasco 2J
Sun Jan 14, 2018 11:44 pm
Forum: Phase Changes & Related Calculations
Topic: Temperature and Heat
Replies: 4
Views: 170

Re: Temperature and Heat

Dr. Lavelle also mentioned there is a device that can be used to keep the substance at a certain temperature
by Miguel Velasco 2J
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: 92

Standard State

Do we always assume an element is in its standard state (surroundings being 25 degrees C and 1atm)?
by Miguel Velasco 2J
Fri Dec 08, 2017 10:51 pm
Forum: Hybridization
Topic: Bond Notation
Replies: 3
Views: 208

Re: Bond Notation

I remember he initially had C2sp and then erased the 2
by Miguel Velasco 2J
Fri Dec 08, 2017 10:51 pm
Forum: Hybridization
Topic: Bond Notation
Replies: 3
Views: 208

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?
by Miguel Velasco 2J
Fri Dec 08, 2017 10:43 pm
Forum: *Titrations & Titration Calculations
Topic: HW 13.53
Replies: 2
Views: 514

Re: HW 13.53

Remember we omit liquids from the equation
by Miguel Velasco 2J
Wed Nov 29, 2017 11:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: From the Post-Module Assessment 1A:
Replies: 3
Views: 167

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?
by Miguel Velasco 2J
Mon Nov 20, 2017 1:11 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 4
Views: 197

Re: Bond Angles

Know its less than (>109.5) and why (possible lone pairs)
by Miguel Velasco 2J
Mon Nov 20, 2017 1:02 am
Forum: Hybridization
Topic: Hybrid orbitals
Replies: 3
Views: 157

Re: Hybrid orbitals

Each slightly increase.
by Miguel Velasco 2J
Mon Nov 20, 2017 1:02 am
Forum: Hybridization
Topic: Hybrid orbitals
Replies: 3
Views: 157

Re: Hybrid orbitals

Yes. 1s, 2s,2p,3s,3p...
by Miguel Velasco 2J
Mon Nov 06, 2017 8:46 pm
Forum: Octet Exceptions
Topic: Octet Exceptions
Replies: 8
Views: 409

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?
by Miguel Velasco 2J
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: 1112

Ni3+ electron configuration

For Ni3+, why is the electron configuration [Ar]3d7 as opposed to [Ar]4s^2 3d5
by Miguel Velasco 2J
Thu Oct 19, 2017 9:52 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Homework
Replies: 3
Views: 168

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.
by Miguel Velasco 2J
Thu Oct 19, 2017 9:43 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation
Replies: 7
Views: 350

Re: Rydberg Equation

Always depends on where it started and ended up. Remember, E(final) - E(initial)
by Miguel Velasco 2J
Thu Oct 12, 2017 7:29 pm
Forum: Properties of Light
Topic: 1.27
Replies: 3
Views: 179

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?
by Miguel Velasco 2J
Thu Oct 12, 2017 7:22 pm
Forum: Properties of Light
Topic: the quantum world [ENDORSED]
Replies: 2
Views: 166

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.
by Miguel Velasco 2J
Thu Oct 12, 2017 7:19 pm
Forum: Properties of Light
Topic: HW 1.25b
Replies: 2
Views: 162

Re: HW 1.25b

Use Avogadro's number to turn grams to atoms!
by Miguel Velasco 2J
Thu Oct 12, 2017 7:11 pm
Forum: Einstein Equation
Topic: question 27
Replies: 2
Views: 238

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).

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