Search found 20 matches
- Thu Mar 01, 2018 10:18 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibb's Energy and Work
- Replies: 4
- Views: 787
Re: Gibb's Energy and Work
Gibbs Free Energy measures the useful work obtainable from a thermodynamic system at a constant temperature and pressure.
- Thu Mar 01, 2018 10:12 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: K and Q at equilibrium
- Replies: 5
- Views: 705
Re: K and Q at equilibrium
Is Q = 1 at equilibrium?
- Thu Mar 01, 2018 10:07 am
- Forum: General Rate Laws
- Topic: Differential vs integrated
- Replies: 2
- Views: 374
Re: Differential vs integrated
Differential rate law talks about the overall rate, how long it takes from the beginning (reactants) fully to the end (products). It also tells us how influential or impactful the concentration is to the rate. Integrated rate law discusses how many reactants in the beginning versus a particular mome...
- Sat Feb 10, 2018 8:40 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: negative entropy [ENDORSED]
- Replies: 3
- Views: 520
Re: negative entropy [ENDORSED]
Since entropy measures the disorder or randomness of the particles in a system, negative entropy would mean there is less disorder.
- Sat Feb 10, 2018 8:33 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Delta G
- Replies: 4
- Views: 527
Re: Delta G
Why is a system at equilibrium when G is a minimum? What does the term "minimum" mean in terms of delta G?
- Sat Feb 10, 2018 8:22 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: conceptual entropy questions
- Replies: 5
- Views: 765
Re: conceptual entropy questions
The possible states, known as microstates, all have the same energy as well.
- Sun Jan 28, 2018 11:54 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Entropy vs. Degeneracy [ENDORSED]
- Replies: 5
- Views: 624
Re: Entropy vs. Degeneracy [ENDORSED]
Degeneracy and entropy are also directly related, which means that the higher the entropy, the higher the degeneracy.
- Sat Jan 27, 2018 3:11 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Spontaneous [ENDORSED]
- Replies: 6
- Views: 678
Re: Spontaneous [ENDORSED]
Can someone briefly explain what it means to have a spontaneous process?
- Sat Jan 27, 2018 3:09 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Degeneracy
- Replies: 4
- Views: 541
Re: Degeneracy
Degeneracy is the number of ways of achieving a given energy state. Also, entropy increases dramatically depending on the number of systems.
- Sat Jan 20, 2018 4:45 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Standard Enthalpy of Formation
- Replies: 3
- Views: 373
Re: Standard Enthalpy of Formation
Standard enthalpy of formation of an element in its most stable form is zero.
- Sat Jan 20, 2018 4:10 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Delta U?
- Replies: 7
- Views: 10549
Re: Delta U?
Adding onto the previous posts, if delta u is positive, then u(final) > u(initial). If delta u is negative, then u(final) < u(initial).
- Sat Jan 20, 2018 1:10 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated system
- Replies: 8
- Views: 985
Re: Isolated system
This is why the energy of an isolated system must remain constant because no matter or heat can be transferred and the system cannot be physically changed.
- Sat Jan 13, 2018 11:18 am
- Forum: Phase Changes & Related Calculations
- Topic: Standard Reaction Enthalpy
- Replies: 8
- Views: 770
Re: Standard Reaction Enthalpy
When all reactants and products are in their standard state at 1ATM, rxn enthalpy is called standard reaction enthalpy. However, the standard rxn enthalpy for the formation of one mole of a substance from its elements in their most stable form is called standard enthalpy of formation. By definition,...
- Sat Jan 13, 2018 11:14 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Capacity
- Replies: 3
- Views: 358
Re: Heat Capacity
Will the heat capacity always be the heat required to raise the temperature by 1C only?
- Sat Jan 13, 2018 11:05 am
- Forum: Phase Changes & Related Calculations
- Topic: Methods of Enthalpy
- Replies: 8
- Views: 808
Re: Methods of Enthalpy
Hess's Law (method 1) is a state function, which means it must be additive. The enthalpy change at each step of a multi-step reaction can be added to give the total enthalpy change. Bond enthalpies (method 2) are always positive and endothermic. The reactants (bonds broken) require energy, and the p...
- Tue Nov 14, 2017 11:28 am
- Forum: Hybridization
- Topic: Electrostatic potential
- Replies: 1
- Views: 295
Electrostatic potential
In class, Prof. Lavelle mentioned that polar molecules interact with an electrostatic potential. Can someone expand on this?
- Tue Nov 14, 2017 11:25 am
- Forum: Hybridization
- Topic: Polar/nonpolar [ENDORSED]
- Replies: 14
- Views: 2607
Re: Polar/nonpolar [ENDORSED]
In lecture, Prof. Lavelle discussed that a non-polar molecule must have zero electric dipole movement which is possible if it contains nonpolar bonds, or polar bonds with dipoles that cancel.
- Thu Oct 26, 2017 12:58 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Anion electron configuration [ENDORSED]
- Replies: 3
- Views: 572
Re: Anion electron configuration [ENDORSED]
Can someone also explain why anions are bigger than cations? Is it because of the number of protons?
- Thu Oct 26, 2017 12:56 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Test 3 [ENDORSED]
- Replies: 7
- Views: 2777
Re: Test 3 [ENDORSED]
I just asked my TA today, and he clarified that Test 3 will cover everything after 1.5 and all of chapter 2!
- Mon Oct 16, 2017 11:12 pm
- Forum: Properties of Light
- Topic: Planck's Constant
- Replies: 10
- Views: 1228
Re: Planck's Constant
Whenever you see "h" in a formula! Don't get it confused with "p"!!