Search found 30 matches

by Christopher Anisi 2K
Fri Mar 15, 2019 9:51 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: 5/2R vs 3/2R
Replies: 4
Views: 348

Re: 5/2R vs 3/2R

For a monoatomic gas under a constant pressure the Cp value is equal to 5/2R however if it is under a constant volume the Cv value is equal to 3/2R.
by Christopher Anisi 2K
Fri Mar 15, 2019 9:46 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: residual entropy T=0
Replies: 2
Views: 175

Re: residual entropy T=0

I think the most important aspect of residual entropy is that it does not include the aspect of temperature and is only focused on the number of positions and orientations that the structure can take on.
by Christopher Anisi 2K
Sun Mar 10, 2019 8:45 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Collision Theory
Replies: 5
Views: 246

Re: Collision Theory

I would think the most important concept from collision theory is that when two molecules collide with not enough kinetic energy they bounce apart. If they are met with more than enough kinetic energy, reactant bonds can break and new bonds can form.
by Christopher Anisi 2K
Sun Mar 10, 2019 8:40 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: when exactly do you use the Arrhenius equation?
Replies: 3
Views: 274

Re: when exactly do you use the Arrhenius equation?

The most common instance that I have seen the Arrhenius equation used is when given two rates of reactions at different temperatures, you can use the given information to solve for the activation energy of both of the rate constants but of course whenever given any one of the factors: temperature, a...
by Christopher Anisi 2K
Sun Mar 10, 2019 8:35 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts
Replies: 6
Views: 102

Re: Catalysts

Catalysts lower the activation energy of a reaction by providing an alternative pathway which subsequently increases the speed of the reaction.
by Christopher Anisi 2K
Sun Mar 03, 2019 4:30 pm
Forum: Zero Order Reactions
Topic: zeroth order rate
Replies: 4
Views: 235

Re: zeroth order rate

The rate law (rate=k[A]^0) which would mean that the rate would be equal to k.
by Christopher Anisi 2K
Sun Mar 03, 2019 4:23 pm
Forum: Zero Order Reactions
Topic: Half life
Replies: 7
Views: 578

Re: Half life

Yes, just be sure to include use the proper equation for the corresponding order.
by Christopher Anisi 2K
Sun Mar 03, 2019 4:15 pm
Forum: General Rate Laws
Topic: Units of K
Replies: 4
Views: 68

Re: Units of K

A zero order reaction has units of concentration/s, a first order reaction units are s^-1, and a second order reaction the units are 1/concentration*s.
by Christopher Anisi 2K
Sun Mar 03, 2019 4:12 pm
Forum: General Rate Laws
Topic: Units of K
Replies: 4
Views: 68

Re: Units of K

A zero order reaction has units of concentration/s, a first order reaction units are s^-1, and a second order reaction the units are 1/concentration*s.
by Christopher Anisi 2K
Sun Feb 24, 2019 3:06 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cathode vs. Anode
Replies: 9
Views: 129

Re: Cathode vs. Anode

An anode has the reaction that is being oxidized while the cathode has the reaction that is being reduced.
by Christopher Anisi 2K
Sun Feb 24, 2019 3:03 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: salt bridge
Replies: 3
Views: 60

Re: salt bridge

The salt bridge is used to balance out the charges between the two solutions as the electron transfer occurs.
by Christopher Anisi 2K
Sun Feb 24, 2019 3:02 pm
Forum: Balancing Redox Reactions
Topic: Which Equation to Flip?
Replies: 9
Views: 173

Re: Which Equation to Flip?

Since the table gives the values as the standard reduction potential, the reaction that is being oxidized needs to have the negative of its value.
by Christopher Anisi 2K
Sat Feb 16, 2019 9:19 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: When a system can only be prepared in one way
Replies: 2
Views: 222

Re: When a system can only be prepared in one way

That means that the system can only be oriented in one way meaning that it only has one energy state or degeneracy value of 1. And when utilizing S=KBlnW assuming there is only residual energy involved that would give you an entropy value of 0.
by Christopher Anisi 2K
Sat Feb 16, 2019 9:14 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: Entropy at 0 K
Replies: 6
Views: 266

Re: Entropy at 0 K

It is only possible to have entropy equal to 0 if the temperature is equal to 0K and if the substance in question is perfectly ordered.
by Christopher Anisi 2K
Sat Feb 16, 2019 9:12 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: Degeneracy
Replies: 4
Views: 233

Re: Degeneracy

The residual entropy can be equal to 0 but the lowest the degeneracy value (W) can be is 1 and when using the Boltzmann Equation of Equation for Entropy
S =KblnW, and in this case ln1 is equal to 0 which makes the entire entropy value equal to 0.
by Christopher Anisi 2K
Sat Feb 16, 2019 8:58 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Adding reaction entropies
Replies: 8
Views: 150

Re: Adding reaction entropies

Adding entropies is possible due to the fact that entropy is a state function and therefore is additive.
by Christopher Anisi 2K
Sat Feb 16, 2019 8:41 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy and qp
Replies: 3
Views: 110

Re: Enthalpy and qp

Entalpy is equal to the qp when the reaction takes place at a constant pressure.
by Christopher Anisi 2K
Sat Feb 16, 2019 8:31 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Extensive vs Intensive
Replies: 7
Views: 291

Re: Extensive vs Intensive

Extensive properties are properties of matter that are subject to change like volume, weight, and heat capacity while in contrast intensive properties always remain the constant like density, specific heat, and boiling point.
by Christopher Anisi 2K
Mon Feb 04, 2019 11:38 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Entropy
Replies: 3
Views: 80

Re: Entropy

If there is a constant volume that would mean that the internal energy would be equal to 0 in which q+w = u would actually be q +w = 0 in which heat and the work performed on the system are equal.
by Christopher Anisi 2K
Sun Feb 03, 2019 9:08 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: finding W
Replies: 6
Views: 94

Re: finding W

The equations are the same, Dr. Lavelle wanted to utilize the integral to derive where P (delta V) came from showing that the sum of a small change in volume is equivalent to the integral.
by Christopher Anisi 2K
Sun Feb 03, 2019 8:48 pm
Forum: Phase Changes & Related Calculations
Topic: Compression Work
Replies: 3
Views: 72

Re: Compression Work

If the piston is being pushed up by the gas that means that the gas is performing work on the piston which results in positive work and if the piston being down that means that the piston is performing work onto the gas meaning that work relative to the gas is negative.
by Christopher Anisi 2K
Sun Jan 27, 2019 2:24 pm
Forum: Phase Changes & Related Calculations
Topic: Delta H
Replies: 11
Views: 194

Re: Delta H

A positive delta H indicates that the reaction is endothermic and requires heat to be absorbed while a negative delta H indicates that the reaction is exothermic and releases energy.
by Christopher Anisi 2K
Sun Jan 27, 2019 2:16 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bonds being broken in reaction
Replies: 4
Views: 77

Re: Bonds being broken in reaction

The stronger the bonds the more energy is required to break the bonds apart. For instance, a triple bond would require more energy to break apart than a single bond and would therefore have a higher enthalpy value.
by Christopher Anisi 2K
Sun Jan 27, 2019 11:44 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: State Function?
Replies: 3
Views: 58

Re: State Function?

A state function is independent of the previous process paths to go from state A to B. The amount of energy to get from A to B does not matter when dealing with state functions.
by Christopher Anisi 2K
Sun Jan 20, 2019 2:20 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Pressure
Replies: 8
Views: 128

Re: Pressure

The equilibrium does change when pressure changes due to the fact that when you change pressure you can change the volume in which the reactants/products are kept in which subsequently changes the concentrations of the products/reactants which can then change the Q value and indicate which way the r...
by Christopher Anisi 2K
Sun Jan 20, 2019 2:08 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Water in K
Replies: 3
Views: 80

Re: Water in K

We never include water when expressing the equilibrium equation because it's always in excess with no exceptions that Dr. Lavelle has addressed in his class.
by Christopher Anisi 2K
Sun Jan 20, 2019 1:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Sig figs in pH
Replies: 7
Views: 67

Re: Sig figs in pH

I would say typically when using sig figs in regard to pH having 3 sig figs is standard when presenting your final answer.
by Christopher Anisi 2K
Wed Jan 09, 2019 7:35 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic Reactions
Replies: 9
Views: 145

Re: Exothermic Reactions

They usually provide the delta H of the reaction, which is also known as enthalpy which will described in more detail in lecture. If the delta H, is positive that means that the reaction is endothermic, if the delta H is negative that means that the reaction is exothermic. Depending on whether heat ...
by Christopher Anisi 2K
Wed Jan 09, 2019 7:25 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5G.5 pt.c
Replies: 1
Views: 31

5G.5 pt.c

Why is it when writing the equilibrium constant for the reaction X2 ---> 2X, the answer key included the mol fraction between X and X2? I understand that the equilibrium constant would be written as but I can't understand why they multiplied the mole fraction of the X2 and the mole fraction of X by ...
by Christopher Anisi 2K
Wed Jan 09, 2019 3:20 pm
Forum: Ideal Gases
Topic: Ideal vs Real Gas
Replies: 6
Views: 115

Re: Ideal vs Real Gas

In addition, ideal gases are supposed to have elastic collisions with their respective molecules meaning that no energy is lost when they interact with one another! A real gas acts like an ideal gas during the conditions of high temperature and a low pressure.

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