## Search found 55 matches

Thu Mar 12, 2020 9:59 pm
Forum: Ideal Gases
Topic: Kc vs Kp
Replies: 43
Views: 575

### 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: 19
Views: 252

### 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: 19
Views: 252

### 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: 106

### 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: 91

### 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: 113

### 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: 72

### 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: 46

### 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: 56

### 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: 2
Views: 23

### 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: 393

### 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: 54

### 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: 95

### 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: 78

### 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: 94

### 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: 25

### 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: 84

### 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: 65

### 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: 84

### 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: 19

### 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: 65

### 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: 45

### 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: 79

### 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: 38

### 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: 19

### 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: 95

### 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: 49

### 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: 48

### 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: 41

### 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: 15

### 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: 63

### 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: 59

### 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: 65

### 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: 90

### 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: 76

### 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: 108

### 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: 78

### 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: 150

### 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: 81

### 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: 46

### 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: 46

### 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: 91

### 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: 45

### 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: 70

### 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: 30

### 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: 81

### 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: 23

### 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: 37

### 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: 65

### 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: 81

### 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: 46

### 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: 79

### 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: 45

### 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: 46

### 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: 81

### Re: Homework for Week 1

The Homework for week 1 is due tomorrow, Friday, at lecture.