Search found 30 matches
- Fri Mar 15, 2019 2:05 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Reaction Mechanisms
- Replies: 2
- Views: 310
Re: Reaction Mechanisms
If you know the spontaneity then you can possibly use the change in moles to assume the enthalpy. I don't think this would ever come up though
- Fri Mar 15, 2019 2:03 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Catalysts in Rate Law
- Replies: 5
- Views: 564
Re: Catalysts in Rate Law
So does an increased concentration of an aqueous catalyst increase the rate of the reaction?
- Fri Mar 15, 2019 2:00 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: K constants
- Replies: 2
- Views: 297
Re: K constants
I think relating big K to the forward and reverse reactions is the only way to connect them.
- Mon Mar 04, 2019 3:31 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Kinetics
- Replies: 7
- Views: 773
Re: Kinetics
if a reaction is thermodynamically favorable doesn't occur because of kinetics, it is a kinetics controlled reaction.
- Mon Mar 04, 2019 3:27 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: difference between chemical reaction and reaction mechanism?
- Replies: 2
- Views: 347
Re: difference between chemical reaction and reaction mechanism?
When are we going over mechanisms?
- Mon Mar 04, 2019 3:24 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Reaction order
- Replies: 4
- Views: 419
Reaction order
How do you get the overall order of a reaction?
- Mon Mar 04, 2019 3:20 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: the phases in a cell diagram
- Replies: 4
- Views: 455
Re: the phases in a cell diagram
Which order do we put the aqueous products in if there are multiple?
- Mon Mar 04, 2019 3:19 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: E cell spontaneity
- Replies: 5
- Views: 605
Re: E cell spontaneity
Is there a quick way to assume the sign of the Ecell?
- Mon Mar 04, 2019 3:18 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Order of Cell Diagrams
- Replies: 13
- Views: 1590
Re: Order of Cell Diagrams
Does anyone know when to use a comma in the cell diagrams?
- Mon Mar 04, 2019 3:16 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: K
- Replies: 5
- Views: 528
Re: K
When delta G is zero the equation is at equilibrium so K=1.
- Mon Mar 04, 2019 3:15 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Delta G rules
- Replies: 8
- Views: 783
Re: Delta G rules
And a negative enthalpy change and positive entropy change increase the spontaneity.
- Mon Mar 04, 2019 3:14 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Melting of ice
- Replies: 9
- Views: 1059
Re: Melting of ice
if you can assume the sign of the enthalpy and entropy you can sometimes use that to determine the sign of delta G.
- Tue Feb 26, 2019 4:45 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: Boltzmann Equation
- Replies: 3
- Views: 697
Re: Boltzmann Equation
I believe W is the number of molecules to the power of the number of micro states
- Tue Feb 26, 2019 4:44 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: Derivations
- Replies: 3
- Views: 689
Re: Derivations
Conceptually, how does a change in temperature effect the equilibrium concentrations?
- Tue Feb 26, 2019 4:43 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: S value
- Replies: 3
- Views: 974
Re: S value
They have a greater number of micro-states, or W in the fundamental entropy equation
- Tue Feb 26, 2019 4:41 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: ln(k2/k1)=(-delta H/R)(1/T2 - 1/T1)
- Replies: 3
- Views: 6596
Re: ln(k2/k1)=(-delta H/R)(1/T2 - 1/T1)
Can anyone provide an example of using this equation?
- Tue Feb 26, 2019 4:40 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Redox Reactions
- Replies: 4
- Views: 549
Re: Redox Reactions
Whichever substance's reduction has the highest potential.
- Tue Feb 26, 2019 4:38 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Delta S Fusion
- Replies: 2
- Views: 1488
Re: Delta S Fusion
The standard entropy of fusion is the standard enthalpy of fusion over the melting point
- Tue Feb 26, 2019 4:37 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Calculating entropy
- Replies: 5
- Views: 438
Re: Calculating entropy
Once you do each, just add the two to get the total change in entropy
- Tue Feb 26, 2019 4:36 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Negative Temperature
- Replies: 5
- Views: 526
Re: Negative Temperature
A positive entropy will always make a reaction more favorable. The temperature can only change by how much.
- Tue Feb 26, 2019 4:34 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: delta S
- Replies: 7
- Views: 767
Re: delta S
When volume is constant, changes in pressure/temperature result in a change in entropy
- Mon Jan 28, 2019 11:15 am
- Forum: Phase Changes & Related Calculations
- Topic: Steam
- Replies: 11
- Views: 1006
Re: Steam
Is this also true for the small amounts of steam that escape even before the boiling point is reached?
- Mon Jan 28, 2019 11:11 am
- Forum: Phase Changes & Related Calculations
- Topic: 3rd method
- Replies: 1
- Views: 188
3rd method
Will we always be given the standard state of each species when we are expected to use the enthalpy of formation to calculate the enthalpy change?
- Mon Jan 28, 2019 11:08 am
- Forum: Phase Changes & Related Calculations
- Topic: Different enthalpy calculation methods
- Replies: 4
- Views: 415
Re: Different enthalpy calculation methods
There will usually be one clear method to used based on the information provided by the problem. If Hess's method can be used, it is the most accurate method.
- Sun Jan 20, 2019 8:55 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: endo/exothermic rxns
- Replies: 5
- Views: 473
Re: endo/exothermic rxns
Can you tell if a reaction is endo/exo just by the number of products vs. reactants?
- Sun Jan 20, 2019 8:52 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Stoichiometric Coefficients
- Replies: 4
- Views: 426
Re: Stoichiometric Coefficients
You just have to add the coefficients to the values in the ice table and the rest is exactly the same
- Sun Jan 20, 2019 8:48 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Temperature's effect on Kc
- Replies: 2
- Views: 270
Re: Temperature's effect on Kc
Consider which side of the reaction equation has heat energy. If heat energy is a reactant, an increase would result in a shift towards the products and vice verse. Essentially treat energy as a part of the reaction and use le chatlier's.
- Thu Jan 10, 2019 11:43 am
- Forum: Ideal Gases
- Topic: use
- Replies: 8
- Views: 267
Re: use
Since we will be using the partial pressures of gasses to find the equilibrium constant of some reactions, we may be asked to calculate partial pressures from a total pressure. This only requires addition and subtraction because the partial pressures of gasses in a system will add up to the total pr...
- Thu Jan 10, 2019 11:39 am
- Forum: Ideal Gases
- Topic: Ideal vs Real Gas
- Replies: 6
- Views: 548
Re: Ideal vs Real Gas
The equation for the ideal gas law can be modified to correct for characteristics of a specific gas. It can incorporate the attraction between gas molecules as well as the volume of the gas molecules.
- Thu Jan 10, 2019 11:29 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Reaction Quotient
- Replies: 5
- Views: 434
Re: Reaction Quotient
Both K and Q represent the ratio of products to reactants, but using Q implies that the reaction is not at equilibrium and the ratio will shift until equilibrium is reached. At this point, the ratio is represented as K