Search found 55 matches
- Thu Mar 12, 2020 9:59 pm
- Forum: Ideal Gases
- Topic: Kc vs Kp
- Replies: 109
- Views: 4274
Re: Kc vs Kp
Kc deals with concentrations and Kp deals with atm and torr.
- Thu Mar 12, 2020 9:49 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: n in NFE
- Replies: 64
- Views: 2687
Re: n in NFE
n is the whole number mole value of electrons that were shared in the half reactions.
- Thu Mar 12, 2020 9:49 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: n in NFE
- Replies: 64
- Views: 2687
Re: n in NFE
n is the whole number mole value of electrons that were shared in the half reactions.
- Thu Mar 12, 2020 9:44 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: E potential
- Replies: 8
- Views: 507
Re: E potential
Yes, a higher E value means that its is a very strong oxidizing agent, meaning that it is the cathode as it is reduced.
- Thu Mar 12, 2020 9:43 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram
- Replies: 4
- Views: 370
Re: Cell Diagram
commas are used to notify the audience that the half reaction are the same phases. | are used to indicate change in phases or an inert metal acting as a neutral electrode.
- Thu Mar 12, 2020 9:38 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Activation Energy vs Free Energy of Activation
- Replies: 6
- Views: 529
Re: Activation Energy vs Free Energy of Activation
The activation energy is the energy barrier or energy needed to process the reaction through.
- Sun Mar 08, 2020 5:32 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Arrhenius Equation
- Replies: 4
- Views: 331
Re: Arrhenius Equation
You can determine the activation energy given the rate constant, temperature, and A with the Arrhenius equation
- Sun Mar 08, 2020 5:29 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: pre-exponential factor
- Replies: 3
- Views: 231
pre-exponential factor
What is the pre-exponential factor A?
- Sun Mar 08, 2020 5:25 pm
- Forum: First Order Reactions
- Topic: Determining order
- Replies: 3
- Views: 244
Re: Determining order
Since orders are independent from stoichiometric coefficients, you can find the order via experimental data. If the initial concentration doubles and the initial rate quadruple, it is a second order rxn. If the initial concentration doubles and the initial rate doubles, it is a first order rxn. If t...
- Sun Mar 08, 2020 5:22 pm
- Forum: First Order Reactions
- Topic: 1st order equation
- Replies: 8
- Views: 436
Re: 1st order equation
It depends on the equation as the integrated rate of k[A] is ln[A]=-kt+ln[A], which we use to find {A} at a given time.
- Sun Mar 08, 2020 5:19 pm
- Forum: Second Order Reactions
- Topic: Non-integer orders
- Replies: 7
- Views: 1089
Re: Non-integer orders
There will be no noninteger orders as Lavelle said most calculations are centered in whole number calculations and they arent common in nature.
- Fri Feb 28, 2020 10:52 am
- Forum: General Rate Laws
- Topic: Unique Rate
- Replies: 4
- Views: 333
Re: Unique Rate
The Unique rate is the same for all reactants and products on the unique reaction regardless of concentration.
- Fri Feb 28, 2020 10:47 am
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Diamond Reaction
- Replies: 4
- Views: 366
Re: Diamond Reaction
Since Kinetics dictates the speed of chemical reactions, the diamond reaction is very very slow due to high energy activation barrier.
- Fri Feb 28, 2020 10:42 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Why is E Standard=0 in a concentration cell?
- Replies: 4
- Views: 351
Why is E Standard=0 in a concentration cell?
Question above
- Fri Feb 28, 2020 10:39 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt Bridge
- Replies: 4
- Views: 867
Re: Salt Bridge
Salt Bridges serve as a means to keep the overall charges in each solution neutral via ions that do not affect the reaction. By keeping it neutral, the reaction continues to proceed.
- Fri Feb 28, 2020 10:36 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Presence of current
- Replies: 1
- Views: 113
Presence of current
Why do some redox reactions produce electric current?
- Sat Feb 22, 2020 12:10 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: How to write Cell Diagrams
- Replies: 5
- Views: 400
Re: How to write Cell Diagrams
The || represents the salt bridge and | is the interphase between phases in contact. The basic structure is cathode(REDUCTION)||anode(OXIDATION).
- Sat Feb 22, 2020 12:05 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Concentration effect on E
- Replies: 4
- Views: 357
Concentration effect on E
Why is that if you increase the concentration of product, E is smaller than E standard?
- Fri Feb 21, 2020 11:48 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: relevance of salt bridge
- Replies: 9
- Views: 555
relevance of salt bridge
Why do we put a porous/salt bridge in beakers that have the cathode and anode?
- Fri Feb 21, 2020 11:45 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: measuring electron transfer
- Replies: 2
- Views: 172
measuring electron transfer
Why do we compare electron transfer of all cells?
- Fri Feb 21, 2020 11:43 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: property of E
- Replies: 6
- Views: 392
property of E
Why does E stay the same when the reaction it relates to is multiplied by a coefficientt
- Sun Feb 16, 2020 11:25 pm
- Forum: Van't Hoff Equation
- Topic: Entropy in Van't Hoff Equation
- Replies: 3
- Views: 203
Entropy in Van't Hoff Equation
Why is the difference in entropy the same when temperatures are increased?
- Sun Feb 16, 2020 11:23 pm
- Forum: Van't Hoff Equation
- Topic: Van't Hoff Equation
- Replies: 3
- Views: 285
Re: Van't Hoff Equation
We use Van't Hoff equation if we want to solve for the K at a differnet temperature if we are given the standard enthalpy, original temperature, and k value.
- Sun Feb 16, 2020 11:18 pm
- Forum: Balancing Redox Reactions
- Topic: Rules for oxidation numbers
- Replies: 6
- Views: 312
Rules for oxidation numbers
Why are pure elements zero but ions of said elements not zero?
- Sun Feb 16, 2020 11:16 pm
- Forum: Balancing Redox Reactions
- Topic: 2-14-2020 lecture question
- Replies: 1
- Views: 109
2-14-2020 lecture question
Why were electrons in the 2 half-reactions?
- Sun Feb 16, 2020 11:15 pm
- Forum: Balancing Redox Reactions
- Topic: Whats the difference between oxidizing agent and oxiadation
- Replies: 6
- Views: 304
Whats the difference between oxidizing agent and oxiadation
Question above
- Fri Feb 07, 2020 11:42 am
- Forum: Calculating Work of Expansion
- Topic: Reversible process and greatest work
- Replies: 5
- Views: 158
Re: Reversible process and greatest work
Since reversible processes use infinitesimally small changes, which leads to more work done.
- Fri Feb 07, 2020 11:38 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: state occupation of phases
- Replies: 7
- Views: 254
state occupation of phases
Why do gas molecules occupy more space then liquid and solid phases?
- Fri Feb 07, 2020 11:36 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Entropy
- Replies: 4
- Views: 157
Entropy
Why is Entropy an extensive property and not an intensive property?
- Fri Feb 07, 2020 11:32 am
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: spontaneous process
- Replies: 1
- Views: 45
spontaneous process
why does gas expand when the change in volume is zero?
- Fri Feb 07, 2020 11:28 am
- Forum: Calculating Work of Expansion
- Topic: Difference in Wirr and Wrev
- Replies: 4
- Views: 212
Difference in Wirr and Wrev
Why are Reversible processes do more work than irreversible processes?
- Fri Jan 31, 2020 10:35 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: state property
- Replies: 8
- Views: 254
Re: state property
A state property is not dependent on the path taken to obtain that state, meaning the end result is what matters and not the intermediate steps
- Fri Jan 31, 2020 10:32 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess' Law
- Replies: 7
- Views: 213
Hess' Law
Why can we add or subtract enthalpy changes?
- Fri Jan 31, 2020 10:29 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: hess's law
- Replies: 13
- Views: 286
Re: hess's law
It does matter for the molecules to have the same amount on the product and reactant side as they are intermediates in the reaction that get canceled.
- Fri Jan 31, 2020 10:27 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: H and q
- Replies: 7
- Views: 184
Re: H and q
delta h is the amount of heat released or absorbed at a constant pressure, which is also enthalpy. whereas q is the heat being transferred. they are equal to each other if they are at the same pressure.
- Fri Jan 31, 2020 10:25 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: accuracy of bond enthalpies
- Replies: 8
- Views: 340
accuracy of bond enthalpies
Why is it that using bond enthalpies is the least accurate method to calculate energy transfer?
- Thu Jan 23, 2020 11:25 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Molar concentration of H3O
- Replies: 6
- Views: 510
Re: Molar concentration of H3O
How do we calculate the molar concentration of H3O given just the Kw? Assuming that you are calculating the [h3o+] of pure water and it is at 25 degrees Celcius, the concentration of H3O+ be 1.0*10^-7.
- Thu Jan 23, 2020 11:19 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ignoring solids & liquids for K
- Replies: 7
- Views: 503
Re: ignoring solids & liquids for K
The Calcium Hydroxide is dissolved in water making it an aqueous solution.
- Thu Jan 23, 2020 11:11 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Partial Pressure vs Pressure
- Replies: 7
- Views: 208
Re: Partial Pressure vs Pressure
The summation of partial pressure gives the total pressure.
- Thu Jan 23, 2020 10:45 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Value of Ka, Kw, Kb
- Replies: 5
- Views: 129
Re: Value of Ka, Kw, Kb
At 25 degrees Celcius, Kw is measured to be 1.0*10^-14. Ka,Kb, and Kw varies by temperature.
- Thu Jan 23, 2020 10:45 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Value of Ka, Kw, Kb
- Replies: 5
- Views: 129
Re: Value of Ka, Kw, Kb
At 25 degrees Celcius, Kw is measured to be 1.0*10^-14. Ka,Kb, and Kw varies by temperature.
- Thu Jan 23, 2020 10:40 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Q<K
- Replies: 11
- Views: 211
Re: Q<K
When Q<K, this signifies that there are more reactants than the product currently at the system. Since there are more reactants than products, the reaction will go forward.
- Fri Jan 17, 2020 12:12 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Stress
- Replies: 4
- Views: 101
Re: Stress
Types of stress on a system consist of: the addition/removal of a component in a reaction at equilibrium, compression or expansion, and change in temperature
- Fri Jan 17, 2020 12:10 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ICE tables
- Replies: 3
- Views: 112
Re: ICE tables
If K is smaller than 10^-3, you can assume and approximate that there is no change to the reactant. This, in turn, will enable you to calculate the X amount gained much easier.
- Fri Jan 17, 2020 12:07 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Heat
- Replies: 3
- Views: 79
Re: Heat
With regards to the effect of changing temperature in a reaction, it depends whether if said reaction is exothermic or endothermic. If exothermic and the temperature rises, the reaction will favor the formation of reactants. If endothermic and the temperature rises, the reaction will favor the forma...
- Fri Jan 17, 2020 12:04 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Inert Gas
- Replies: 7
- Views: 277
Re: Inert Gas
Typically Inert gases are Noble gases, which do not react with other molecules or atoms due to the fact that they contain a complete valence shell. Since they do not react, they do not interact with the components of an equilibrium mixture when added. Thus, they do not contribute to Equilibrium cons...
- Fri Jan 17, 2020 12:01 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Changes in K and Q
- Replies: 2
- Views: 156
Re: Changes in K and Q
Since the equilibrium constant is dependent on temperature, changing temperature will change K. A change in the equilibrium concentrations will arise the reaction quotient, Q, until the system reaches K again.
- Thu Jan 09, 2020 10:08 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: liquids and aqueous solutions
- Replies: 4
- Views: 103
Re: liquids and aqueous solutions
Only pure solids and liquids can't be used to determine K. Aqueous solutions on the other hand can be used as they are not pure liquids and since they have a molar concentration.
- Thu Jan 09, 2020 9:59 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Meaning of equilibrium constant
- Replies: 5
- Views: 203
Meaning of equilibrium constant
If Equilibrium sits to the left when K<10^-3 and sits to the right when K>10^3, the what does 10^-3<k<10^3 signify?
- Thu Jan 09, 2020 9:47 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Effect of Inert Gases
- Replies: 9
- Views: 288
Re: Effect of Inert Gases
Inert Gases have no effect on the equilibrium reaction because they do not interact with either the reactants and products undergoing equilibrium. They do not interact with them because noble gases are extremely stable.
- Thu Jan 09, 2020 9:44 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K and Q Values
- Replies: 5
- Views: 172
Re: K and Q Values
No. If Q>K at some point in the reaction, the reverse reaction is favored and more reactant will form so that the system will go towards equilibrium.
- Thu Jan 09, 2020 9:36 pm
- Forum: Ideal Gases
- Topic: Difference between K and Q
- Replies: 9
- Views: 244
Re: Difference between K and Q
Although K, the equilibrium constant, and Q, the reaction quotient, uses the same formula to find the value, they are not the same. The concentrations of reactant and product in K are in equilibrium, while the concentrations of reactant and product in Q have yet to reach equilibrium.
- Thu Jan 09, 2020 9:33 pm
- Forum: Ideal Gases
- Topic: eq constant
- Replies: 4
- Views: 118
Re: eq constant
We ignore the terms that are solids when calculating the equilibrium constant because solids do not have concentration. Since it does not have a concentration, it can not be implemented in solving for the Reaction Quotient, Q, or Equilibrium constant, K.
- Thu Jan 09, 2020 9:28 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Unites for K
- Replies: 2
- Views: 143
Re: Unites for K
K does not have units because it is a ratio of chemical activity of product to reactant. Chemical activities have no units and they are the product of the activity constant and the concentration of either reactant/product.
- Thu Jan 09, 2020 9:23 pm
- Forum: Student Social/Study Group
- Topic: Homework for Week 1
- Replies: 6
- Views: 334
Re: Homework for Week 1
The Homework for week 1 is due tomorrow, Friday, at lecture.