Search found 30 matches

by Jacob Bershatski 4C
Thu Mar 14, 2019 11:04 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Molecularity
Replies: 5
Views: 91

Re: Molecularity

Molecularity is only concerned with the reactants. It does not matter how much product is formed.
by Jacob Bershatski 4C
Thu Mar 14, 2019 11:03 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Catalysts in Rate Law
Replies: 5
Views: 74

Catalysts in Rate Law

For a given reaction mechanism, can catalysts be included in the rate law?
by Jacob Bershatski 4C
Thu Mar 14, 2019 11:02 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: A in the Arrhenius Equation
Replies: 4
Views: 61

A in the Arrhenius Equation

In the Arrhenius Equation, I'm kinda confused what A means and when to apply it. Can someone help me out plz?
by Jacob Bershatski 4C
Sun Mar 10, 2019 10:58 pm
Forum: Second Order Reactions
Topic: Final
Replies: 30
Views: 481

Re: Final

It is cumulative. Hopefully it wont be too bad :)
by Jacob Bershatski 4C
Sun Mar 10, 2019 10:56 pm
Forum: Zero Order Reactions
Topic: Zero order reactions
Replies: 4
Views: 73

Zero order reactions

I remember in class Dr. Lavelle mentioned that as the order of a reaction increases, the reaction becomes more rare. Does that mean then that zero order reactions are the most common?
by Jacob Bershatski 4C
Sun Mar 10, 2019 10:54 pm
Forum: First Order Reactions
Topic: Rate dependency
Replies: 5
Views: 96

Re: Rate dependency

I think we only consider reactants because we are talking about the initial rate. At that point, there will be minimal products formed so the concentrations of products are not considered.
by Jacob Bershatski 4C
Sun Mar 03, 2019 11:25 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Kinetics
Replies: 7
Views: 116

Re: Kinetics

I think we need to know derivatives for kinetics because we need to be able to calculate the instantaneous rate of change of concentration in a reaction.
by Jacob Bershatski 4C
Sun Mar 03, 2019 11:24 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: how is kinetics different?
Replies: 17
Views: 278

Re: how is kinetics different?

Thermodynamics deals with the amount of energy absorbed or released during a reaction, while kinetics deals with the speed of a reaction.
by Jacob Bershatski 4C
Sun Mar 03, 2019 11:23 pm
Forum: General Rate Laws
Topic: Unique vs instantaneous rate
Replies: 6
Views: 129

Re: Unique vs instantaneous rate

The instantaneous rate is equal to the limit of the average rate as delta(t) approaches 0.
by Jacob Bershatski 4C
Sun Feb 24, 2019 10:34 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Wmax and -W
Replies: 2
Views: 49

Re: Wmax and -W

I am also confused on this question.
by Jacob Bershatski 4C
Sun Feb 24, 2019 10:33 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Spontaneous?
Replies: 13
Views: 185

Re: Spontaneous?

Enthalpy cannot be used to determine spontaneity. By definition, a negative deltaG means a reaction is spontaneous. A positive deltaS I assume would also be considered spontaneous in most cases according to the Second Law of Thermodynamics.
by Jacob Bershatski 4C
Sun Feb 24, 2019 10:31 pm
Forum: Balancing Redox Reactions
Topic: platinum
Replies: 7
Views: 93

Re: platinum

No. Platinum simply catalyzes the transfer of electrons. It is not chemically involved in the reaction.
by Jacob Bershatski 4C
Tue Feb 19, 2019 1:05 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Delta G
Replies: 4
Views: 78

Re: Delta G

Gibbs free energy itself is a state function. Because it is a state function, we only ever need to consider the change in G from its initial state to its final state because state functions are independent of the path taken by the system.
by Jacob Bershatski 4C
Tue Feb 19, 2019 1:03 am
Forum: Van't Hoff Equation
Topic: Derivation
Replies: 9
Views: 423

Re: Derivation

I think the equations that we need to know are given to us on the formula sheet.
by Jacob Bershatski 4C
Tue Feb 19, 2019 1:02 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy
Replies: 5
Views: 79

Re: Gibbs Free Energy

Gibbs free energy is the energy available to do work. I think it means that this energy is able to be used up in a reaction and is not wasted as heat.
by Jacob Bershatski 4C
Sun Feb 10, 2019 8:20 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Spontaneity
Replies: 2
Views: 51

Re: Spontaneity

Using the equation given to calculate Gibbs Free Energy, you can predict the spontaneity of a system. If deltaG>0, the change is non-spontaneous. If deltaG<0, the change is spontaneous.
by Jacob Bershatski 4C
Sun Feb 10, 2019 8:17 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Delta U
Replies: 8
Views: 150

Re: Delta U

Based on the equation, deltaU=(3/2)nR(deltaT), deltaU is 0 when deltaT is 0. I am still a little confused about this myself. However, whenever you have an isolated system, deltaU always equals 0 because heat and work cannot be transferred into or out of the system.
by Jacob Bershatski 4C
Sun Feb 10, 2019 8:14 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Counting Moles to Find Entropy
Replies: 2
Views: 213

Re: Counting Moles to Find Entropy

I think you just count the moles of gas, but I am not 100% certain
by Jacob Bershatski 4C
Sun Feb 03, 2019 2:00 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: 3 methods for enthalpy calculation
Replies: 10
Views: 179

Re: 3 methods for enthalpy calculation

I think on the test he will tell us which method to use. However, he did mention in class that using bond enthalpy is the least accurate means of calculation the enthalpy of the reaction. This is because, aside from diatomic molecules like Cl2, the bond enthalpies given are averages rather than exac...
by Jacob Bershatski 4C
Sun Feb 03, 2019 1:52 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Calorimeter
Replies: 6
Views: 112

Calorimeter

During lecture, Professor Lavelle spent a significant amount of time discussing calorimetry (i.e. bomb calorimeter). Should we be able to describe calorimetry for exams?
by Jacob Bershatski 4C
Sun Feb 03, 2019 1:49 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: kJ v. kJ/mol
Replies: 3
Views: 57

kJ v. kJ/mol

I am a little confused when we should be calculating enthalpy in terms of kJ and kJ/mol. Can someone please explain?
by Jacob Bershatski 4C
Sun Jan 27, 2019 8:29 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard Enthalpy
Replies: 1
Views: 32

Standard Enthalpy

Will we need to memorize the standard state of certain molecules when calculating the standard enthalpy or the standard enthalpy of formation? If so, which ones?
by Jacob Bershatski 4C
Sun Jan 27, 2019 8:25 pm
Forum: Phase Changes & Related Calculations
Topic: Steam v. Boiling Water
Replies: 4
Views: 79

Steam v. Boiling Water

What is the explanation for why steam at 100*C causes a worse burn than boiling water at 100*C? I know he explained this in class but I am still a little confused.
by Jacob Bershatski 4C
Sun Jan 27, 2019 8:20 pm
Forum: Phase Changes & Related Calculations
Topic: State Properties
Replies: 5
Views: 75

Re: State Properties

State functions only depend on their current state. For example, if you wanted to calculate the change in enthalpy, you would have to subtract the initial enthalpy from the final enthalpy. You can have different inputs of work but still attain the same change in enthalpy. It is similar to the work p...
by Jacob Bershatski 4C
Sun Jan 20, 2019 11:01 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Conjugate?
Replies: 5
Views: 273

Re: Conjugate?

CH3COOH + H20 = H3O^+ + CH3COO^-

In this reaction, CH3COOH is the acid because it is donating a proton. Its conjugate base is CH3COO-. Water in this reaction acts as a base since it is receiving a proton, making its conjugate base to be H3O+.
by Jacob Bershatski 4C
Sun Jan 20, 2019 10:57 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Ka Kb significance
Replies: 3
Views: 393

Re: Ka Kb significance

Ka and Kb are the equilibrium constants for the hydrolysis of acids and basis in water. The higher the Ka, the stronger the acid and the weaker its conjugate base. The higher the Kb, the stronger the base and the weaker its conjugate acid. pKa and pKb are just a simplified way to represent this.
by Jacob Bershatski 4C
Sun Jan 20, 2019 10:39 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Conjugate Base versus an Acid
Replies: 2
Views: 256

Re: Conjugate Base versus an Acid

A conjugate base will have a lower Ka and a higher Kb versus an acid.
by Jacob Bershatski 4C
Sun Jan 13, 2019 9:33 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Changing Temperature
Replies: 4
Views: 108

Changing Temperature

Does changing the temperature in a reaction affect both the K value and concentration?
by Jacob Bershatski 4C
Sun Jan 13, 2019 9:31 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Example in Class
Replies: 7
Views: 153

Re: Example in Class

Decreasing the amount of NH3 would make Q<K, which would cause the reaction to shift right and more NH3 to form so that Q=K.
by Jacob Bershatski 4C
Sun Jan 13, 2019 9:29 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Volume increasing
Replies: 4
Views: 77

Re: Volume increasing

Yes. If the volume of the container increases then the reaction will favor the side of the reaction with more moles. I think the reason for this is that when you increase the volume, you decrease the concentrations of gases since concentration = moles/volume.

Go to advanced search