Search found 45 matches

by Mitch Walters
Fri Mar 16, 2018 9:00 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: 9.1
Replies: 5
Views: 230

Re: 9.1

There is a negative because of the fact that the heat is leaving your body and going into the surroundings.
by Mitch Walters
Fri Mar 16, 2018 8:58 pm
Forum: *Nucleophiles
Topic: Functional Groups
Replies: 3
Views: 247

Re: Functional Groups

I think just being able to identify the different functional groups is all that is expected of us.
by Mitch Walters
Fri Mar 16, 2018 8:58 pm
Forum: General Rate Laws
Topic: Negative 1/a
Replies: 8
Views: 264

Re: Negative 1/a

Concentration of reactants decreases.
by Mitch Walters
Fri Mar 09, 2018 4:30 pm
Forum: General Rate Laws
Topic: Rate Constant k
Replies: 6
Views: 202

Re: Rate Constant k

The rate constant is an experimentally determined value for a specific reaction at a specific temperature. It essentially tells you the instantaneous rate of change.
by Mitch Walters
Fri Mar 09, 2018 4:28 pm
Forum: General Rate Laws
Topic: Division in Rate Law
Replies: 3
Views: 123

Re: Division in Rate Law

The answer should be zero, since you would have a negative exponent in the denominator, and a positive exponent in the numerator, so when added together they should equal zero.
by Mitch Walters
Fri Mar 09, 2018 4:24 pm
Forum: First Order Reactions
Topic: k' in Pseudo-First-Order Rate Laws
Replies: 4
Views: 550

Re: k' in Pseudo-First-Order Rate Laws

k' just means a different rate constant. This is because we are treating a second order reaction as if it's a first order reaction, so it must have a different rate constant.
by Mitch Walters
Fri Mar 02, 2018 7:14 pm
Forum: First Order Reactions
Topic: Pseudo First Order Reaction
Replies: 5
Views: 369

Re: Pseudo First Order Reaction

All of the concentrations except for one, of the reactants are super high in a pseudo first order reaction. This is done in order to keep the reactants essentially constants.
by Mitch Walters
Fri Mar 02, 2018 7:13 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Quiz 3
Replies: 6
Views: 223

Re: Quiz 3

Yes.
by Mitch Walters
Fri Mar 02, 2018 7:12 pm
Forum: General Rate Laws
Topic: Determining Order [ENDORSED]
Replies: 8
Views: 207

Re: Determining Order [ENDORSED]

You have to to experiment by looking at how much the rate changes from your initial amount. If it changes by double it is a first order. If it quadruples it is second order. The important thing to note is that it has nothing to do with the coefficients of your chemical equation.
by Mitch Walters
Fri Feb 23, 2018 1:07 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst Equation to find pH
Replies: 6
Views: 1273

Re: Nernst Equation to find pH

Find the concentration of H+ ions, and then take the negative log of that concentration.
by Mitch Walters
Fri Feb 23, 2018 1:06 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Inert Electrodes
Replies: 4
Views: 164

Re: Inert Electrodes

Draw the salt bridge to show that you have finished the oxidation portion of the reaction, and that you are moving onto the reduction portion.
by Mitch Walters
Fri Feb 23, 2018 1:05 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell diagram
Replies: 4
Views: 157

Re: Cell diagram

I prefer to go in the order of what is happening. So with oxidation I start off with some kind of solid and then move to the positive ion. With reduction I start with the positive ion and then move to the solid.
by Mitch Walters
Fri Feb 16, 2018 7:21 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Anode/ Cathode
Replies: 6
Views: 180

Re: Anode/ Cathode

I believe that the template usually has the anode on the left, but I don't think it physically needs this to work.
by Mitch Walters
Fri Feb 16, 2018 7:19 pm
Forum: Balancing Redox Reactions
Topic: Salt Bridges
Replies: 14
Views: 311

Re: Salt Bridges

Salt bridges allow electron transfer between two solutions.
by Mitch Walters
Fri Feb 16, 2018 7:19 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Equilibrium
Replies: 4
Views: 98

Re: Equilibrium

I think that the current keeps going. But there is no change in current.
by Mitch Walters
Wed Feb 07, 2018 11:58 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Calculating Potential Difference between Electrodes
Replies: 3
Views: 107

Re: Calculating Potential Difference between Electrodes

No that makes sense, because you can't actually calculate anything when it's at zero.
by Mitch Walters
Wed Feb 07, 2018 11:57 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Half Reactions
Replies: 6
Views: 182

Re: Half Reactions

It shouldn't matter, because when you add them together you always end up with the original reaction.
by Mitch Walters
Wed Feb 07, 2018 11:54 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Will dissolving a salt in water affect the entropy of the water?
Replies: 3
Views: 145

Re: Will dissolving a salt in water affect the entropy of the water?

Wait new thought, if you're taking a solid and adding it to water, then the entropy would increase, because you now you have an aqueous solution.
by Mitch Walters
Fri Feb 02, 2018 7:13 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Van Hoff Equation
Replies: 3
Views: 115

Re: Van Hoff Equation

It probably can't hurt, but you shouldn't need to know it.
by Mitch Walters
Fri Feb 02, 2018 7:12 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Entropy [ENDORSED]
Replies: 5
Views: 256

Re: Entropy [ENDORSED]

Any reaction that has a negative delta G.
by Mitch Walters
Fri Feb 02, 2018 7:11 pm
Forum: Calculating Work of Expansion
Topic: Free expansion and irreversible expansion
Replies: 2
Views: 110

Re: Free expansion and irreversible expansion

I believe free expansion is when there is no opposing pressure on a system, so it is allowed to expand without doing any work. Irreversible expansion is what allows for the maximum amount of work.
by Mitch Walters
Tue Jan 23, 2018 4:50 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: system of vacuum
Replies: 4
Views: 156

Re: system of vacuum

I think that this question is flawed, because it presupposes that a vacuum is a system. But a vacuum is simply nothing, so it seems wrong to think of it a system.
by Mitch Walters
Tue Jan 23, 2018 4:48 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated system
Replies: 8
Views: 247

Re: Isolated system

No, an isolated system cannot be affected in any way by the surroundings.
by Mitch Walters
Tue Jan 23, 2018 4:47 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Entropy of an Isolated System
Replies: 4
Views: 167

Re: Entropy of an Isolated System

One way of thinking of entropy is simply a measure of energy that becomes unusable. If we know that there is a fixed amount of usable energy in any given system, then it follows that there is also a fixed amount of entropy in a given system as well. If there is a fixed amount it must at some point r...
by Mitch Walters
Thu Jan 18, 2018 6:05 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Reversible, Irreversible
Replies: 4
Views: 183

Re: Reversible, Irreversible

Reversible means that the two pressures are essentially equal and that an infinitesimal change can cause expansion. Irreversible is when no such change can occur.
by Mitch Walters
Thu Jan 18, 2018 6:03 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Adiabatic [ENDORSED]
Replies: 8
Views: 331

Re: Adiabatic [ENDORSED]

It would be a process where q=0 and w=some number.
by Mitch Walters
Thu Jan 18, 2018 6:02 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Most Stable Form
Replies: 3
Views: 109

Re: Most Stable Form

I always think of things in terms of potential energy. Whatever formation has the lowest potential energy should be the most stable.
by Mitch Walters
Sun Jan 14, 2018 2:06 pm
Forum: Phase Changes & Related Calculations
Topic: Why can state properties be added?
Replies: 11
Views: 405

Re: Why can state properties be added?

State properties can be added because only specific points matter when looking at the states. The paths that are taken don't matter, so we can add the relevant points and forget the rest.
by Mitch Walters
Sun Jan 14, 2018 2:05 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Calorimeter
Replies: 10
Views: 393

Re: Calorimeter

It is a way of measuring a specific form of energy.
by Mitch Walters
Sun Jan 14, 2018 2:03 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Systems
Replies: 7
Views: 274

Re: Systems

The ocean.
by Mitch Walters
Thu Dec 07, 2017 7:56 pm
Forum: Lewis Acids & Bases
Topic: 12.13
Replies: 5
Views: 286

Re: 12.13

I would think you should ignore the d orbital. So just write Ag+.
by Mitch Walters
Thu Dec 07, 2017 7:55 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Endothermic v. Exothermic Reactions
Replies: 9
Views: 757

Re: Endothermic v. Exothermic Reactions

In endothermic energy is being consumed, in other words it requires energy in order to function. In an exothermic reaction energy is being released. Often times, exothermic reactions are used to power endothermic reactions.
by Mitch Walters
Fri Nov 24, 2017 12:28 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Expanded octet
Replies: 6
Views: 213

Re: Expanded octet

Just look to see if the atom has access to a d-orbital, that’s the biggest clue you will get!
by Mitch Walters
Fri Nov 24, 2017 12:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Partial Pressure or Concentration
Replies: 3
Views: 142

Re: Partial Pressure or Concentration

I’m curious about this as well!
by Mitch Walters
Wed Nov 08, 2017 8:06 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Unpaired Electrons [ENDORSED]
Replies: 7
Views: 314

Re: Unpaired Electrons [ENDORSED]

When you are adding your electrons to their orbitals, remember to put an electron in each orbital before you fill your orbitals.
by Mitch Walters
Wed Nov 08, 2017 8:02 pm
Forum: Balancing Chemical Reactions
Topic: Net Moles of Gas
Replies: 5
Views: 244

Re: Net Moles of Gas

Why do we assume that the H2O is a liquid?
by Mitch Walters
Tue Oct 31, 2017 8:01 pm
Forum: Trends in The Periodic Table
Topic: Effective Nuclear Charge [ENDORSED]
Replies: 4
Views: 348

Re: Effective Nuclear Charge [ENDORSED]

Effective nuclear charge decreases as you go down a group because you are adding orbitals as you go down, in other words the electron is being added into a new orbital that is farther away from the nucleus. This increases the shielding because there are more electrons in between the nucleus and the ...
by Mitch Walters
Tue Oct 31, 2017 7:50 pm
Forum: Electronegativity
Topic: Electronegativity [ENDORSED]
Replies: 5
Views: 297

Re: Electronegativity [ENDORSED]

Fluorine is in the perfect place to fit that trend. It's in the top corner, so it makes sense that it would be the most electronegative.
by Mitch Walters
Wed Oct 25, 2017 12:19 pm
Forum: Trends in The Periodic Table
Topic: Across a period vs. Down a group
Replies: 3
Views: 215

Re: Across a period vs. Down a group

This might be something that can only be known from experimental values.
by Mitch Walters
Wed Oct 25, 2017 12:18 pm
Forum: *Shrodinger Equation
Topic: Electron Spin
Replies: 6
Views: 394

Re: Electron Spin

A question that I have that is related to this topic is, can an electron change spin? Or will it always have the same spin no matter what?
by Mitch Walters
Wed Oct 18, 2017 8:53 pm
Forum: Properties of Light
Topic: the quantum world [ENDORSED]
Replies: 3
Views: 237

Re: the quantum world [ENDORSED]

I've been wondering about this too. It seems that we have to assume that something is both a particle and a wave until we know which one it is? But perhaps this is wrong. An explanation would be wonderful.
by Mitch Walters
Wed Oct 18, 2017 8:50 pm
Forum: Ideal Gases
Topic: Reading the textbook [ENDORSED]
Replies: 81
Views: 27136

Re: Reading the textbook [ENDORSED]

I find reading the textbook to be invaluable.
by Mitch Walters
Sat Oct 14, 2017 2:16 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Balmer/Lyman Series [ENDORSED]
Replies: 7
Views: 353

Re: Balmer/Lyman Series [ENDORSED]

I don't understand why the balmer series is specific to the visible light portion of the spectrum and the lyman series is specific to the UV portion. Maybe this is a stupid question? Could someone please explain.
by Mitch Walters
Sun Oct 08, 2017 12:41 pm
Forum: Administrative Questions and Class Announcements
Topic: Saying Thank You to Dr. Lavelle
Replies: 200
Views: 45853

Re: Saying Thank You to Dr. Lavelle

Hi Dr. Lavelle,

I just wanted to say thank you for all of the great resources you've provided for us so far. You're a fantastic instructor!

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