## Search found 47 matches

Sun Mar 18, 2018 8:33 pm
Forum: Calculating Work of Expansion
Topic: Free energy and work
Replies: 3
Views: 263

### Re: Free energy and work

It is the maximum amount of energy that can be used to do work.
Sun Mar 18, 2018 8:33 pm
Forum: Van't Hoff Equation
Topic: Finding K
Replies: 5
Views: 686

### Re: Finding K

ICE tables will not be necessary this quarter.
Sun Mar 18, 2018 8:31 pm
Forum: Balancing Redox Reactions
Topic: Acidic/ basic conditions
Replies: 4
Views: 388

### Re: Acidic/ basic conditions

That is essentially the only difference with regards to balancing the half reactions.
Sun Mar 18, 2018 8:30 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Solids in cell diagrams
Replies: 4
Views: 344

### Re: Solids in cell diagrams

Comas for molecules of the same state, line for different state.
Sun Mar 18, 2018 8:29 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Water and Cell Diagrams
Replies: 3
Views: 355

### Re: Water and Cell Diagrams

Water is assumed because of the aqueous states.
Sun Mar 18, 2018 8:29 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Finding n
Replies: 15
Views: 984

### Re: Finding n

You're going to need to split up the reaction into its half reactions. And then you're going to balance it so the electrons cancel and use that final number of electrons as the n.
Sun Mar 18, 2018 8:28 pm
Forum: Balancing Redox Reactions
Replies: 6
Views: 467

### Re: Adding OH

You will be adding OH- if its under basic conditions and H+ under acidic conditions.
Sun Mar 18, 2018 8:26 pm
Forum: Balancing Redox Reactions
Topic: Basic vs. Acidic Conditions
Replies: 2
Views: 213

### Re: Basic vs. Acidic Conditions

You won't have OH- and H+ in the same reaction for these problems. For acidic you'll add H+ and for Basic you'll add OH-
Sun Mar 18, 2018 8:25 pm
Forum: General Rate Laws
Topic: Finding the rate constant of Reaction
Replies: 2
Views: 324

### Re: Finding the rate constant of Reaction

First solve for concentration, and then if it is second order than square the concentration, then to find k plug in values and solve.
Fri Mar 16, 2018 12:31 pm
Forum: Environment, Ozone, CFCs
Topic: Radical Chain Reactions
Replies: 1
Views: 586

### Radical Chain Reactions

Do we need to know radical chain reactions for the final?
Fri Mar 16, 2018 12:23 pm
Forum: Experimental Details
Topic: Rate Unit Conversion
Replies: 4
Views: 651

### Re: Rate Unit Conversion

Usually conversions will simply involve changing minutes into seconds or hours into seconds.
Fri Mar 16, 2018 12:22 pm
Forum: *Enzyme Kinetics
Topic: Catalysts in a reaction
Replies: 10
Views: 838

### Re: Catalysts in a reaction

At some point in the reaction mechanism, the catalyst would show up on the left side as well because it is important that the enzyme cancels when you add up the elementary steps.
Fri Mar 09, 2018 12:27 pm
Forum: General Rate Laws
Topic: Integrated Rate Laws
Replies: 6
Views: 371

### Re: Integrated Rate Laws

There's never going to be a question that directly asks "derive this equation." But it certainly could be helpful to know the derivations in order to solve problems and simply for the stake of understanding where the equations come from.
Fri Mar 09, 2018 12:23 pm
Forum: Zero Order Reactions
Topic: graph of 0 order
Replies: 10
Views: 788

### Re: graph of 0 order

rate is constant, which means that the graph would be a horizontal line until all the reactants are used up and the rate instantly drops to zero.
Fri Mar 09, 2018 12:18 pm
Forum: Zero Order Reactions
Topic: Half Lives? [ENDORSED]
Replies: 7
Views: 646

### Re: Half Lives?[ENDORSED]

Yes, you would simply calculate the half life and then multiple it by 2 get the time to reach 1/4 of the reactant remaining.
Fri Feb 23, 2018 12:24 pm
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: Reducing Agent/ Oxidizing Agent
Replies: 6
Views: 618

### Re: Reducing Agent/ Oxidizing Agent

The more negative the standard reduction potential for a particular compound, the stronger it will act as a reducing agent.
Fri Feb 23, 2018 12:21 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: n
Replies: 3
Views: 254

### Re: n

Write out the half reactions, and balance them so that the electrons on each side would cancel. Then use the number of electrons that are being transferred as n.
Fri Feb 23, 2018 12:15 pm
Forum: Balancing Redox Reactions
Topic: Cell Diagram [ENDORSED]
Replies: 7
Views: 385

### Re: Cell Diagram[ENDORSED]

The the compounds are in a different state, then you always separate them with bars. Otherwise, if they are in the same state, you would simply separate them with commas.
Fri Feb 16, 2018 12:21 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: reversible system
Replies: 9
Views: 579

### Re: reversible system

Delta S total is zero but delta S of the system is not necessarily equal to zero.
Fri Feb 16, 2018 12:19 pm
Forum: Calculating Work of Expansion
Topic: Isolated System
Replies: 5
Views: 365

### Re: Isolated System

Yes, since no energy or matter would be flowing in or out with all of those values set to 0.
Fri Feb 16, 2018 12:08 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Boiling point at room temperature
Replies: 5
Views: 278

### Re: Boiling point at room temperature

I am also confused about this. The way that we're supposed solve the problem suggests that after boiling, the water cools back down to room temperature. Wouldn't the water just condense again?
Fri Feb 09, 2018 2:31 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Spontaneity
Replies: 9
Views: 691

### Re: Spontaneity

Negative Delta G means spontaneous because energy is leaving the system.
Fri Feb 09, 2018 2:30 am
Forum: Phase Changes & Related Calculations
Topic: Phase changes with entropy?
Replies: 6
Views: 339

### Re: Phase changes with entropy?

Both the entropy and enthalpy change during a phase change, so yes.
Fri Feb 09, 2018 2:28 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: combustion
Replies: 4
Views: 272

### Re: combustion

Yes, state properties are additive!
Fri Feb 02, 2018 12:39 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: bond enthalpies
Replies: 3
Views: 235

### Re: bond enthalpies

The values will always be provided, and it is always bonds broken - bonds formed.
Fri Feb 02, 2018 12:37 pm
Forum: Phase Changes & Related Calculations
Topic: Closed Systems [ENDORSED]
Replies: 8
Views: 640

### Re: Closed Systems[ENDORSED]

You can increase the internal energy of a closed system by adding heat to it or performing work on the system.
Fri Feb 02, 2018 12:33 pm
Forum: Phase Changes & Related Calculations
Topic: The universe
Replies: 9
Views: 503

### Re: The universe

Assuming that the universe contains everything in existence, then the universe would indeed be an isolated system because no energy or matter can leave the system of "everything in existence."
Fri Jan 26, 2018 1:04 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: deltaH Units
Replies: 5
Views: 320

### Re: deltaH Units

You have to write out the units for each step of the reaction so you know what units your final answer should be in.
Fri Jan 26, 2018 1:02 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 5
Views: 348

### Re: Bond Enthalpies

Bond enthalpies represent averages, and do not accurately represent the enthalpies specific to a certain molecule.
Fri Jan 26, 2018 1:00 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Question 8.55
Replies: 1
Views: 121

### Question 8.55

Super confused on this question. In the answer manual they multiply the first equation and its standard reaction enthalpy by 3/2 which makes sense to me. But in the next equation they ONLY multiple O2 by 3/2 so that the O2's cancel and I don't get how you're allowed to do that.
Thu Dec 07, 2017 9:10 pm
Forum: Conjugate Acids & Bases
Topic: Conjugate Base of CH3COOH
Replies: 3
Views: 806

### Re: Conjugate Base of CH3COOH

I think the purpose of writing it as CH3COO- is to indicate that the molecule is a conjugate base to CH3COOH, it shows where the molecule came from.
Thu Dec 07, 2017 9:06 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Percentage Deprotonation
Replies: 4
Views: 1889

### Percentage Deprotonation

What does percentage deprotonation represent?
Wed Nov 29, 2017 11:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Pi and sigma bonds [ENDORSED]
Replies: 7
Views: 441

### Pi and sigma bonds[ENDORSED]

Is the only difference between Pi and Sigma bonds that Pi bonds can rotate?
Wed Nov 29, 2017 11:54 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Square Planar
Replies: 3
Views: 255

### Re: Square Planar

90 degrees between atoms on the side and 180 between atoms if you're going over the lone pairs on the central atom.
Fri Nov 17, 2017 2:23 pm
Forum: Balancing Chemical Reactions
Topic: Combustion Question
Replies: 9
Views: 704

### Re: Combustion Question

A combustion reaction always results in the production of CO2 and H20 in gaseous form.
Fri Nov 17, 2017 2:20 pm
Forum: Hybridization
Topic: Hybridization
Replies: 6
Views: 350

### Hybridization

Wait so is a hybridized orbital basically the addition of two orbitals? So the hybridization of an s orbital and a p would have 8 orbitals? I'm a little confused on what's actually going on here.
Thu Nov 02, 2017 6:20 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Valence Electrons
Replies: 3
Views: 296

### Valence Electrons

Can we tell how many valence electrons an atom has by looking at wavefunctions? Like is are valence electrons the ones that are contained in the outermost sub shell? Im confused how this all works.
Thu Nov 02, 2017 6:04 pm
Forum: *Shrodinger Equation
Topic: Equation Applications
Replies: 1
Views: 237

### Equation Applications

So is all that we really need to know that the orbital numbers are the answers to the Shrodinger Equation? Im a little confused how much we need to understand the equation, do we need how to solve things with it?
Thu Nov 02, 2017 4:27 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Subshells
Replies: 3
Views: 313

### Subshells

I'm confused about how the l quantum number works. I understand that it determines shape in that l = 0 means s-orbital, l = 1 means p-orbital and so on. But if n>4 then can't l be greater than 3? What shape would an l number >3 have? Does it cycle through the shapes?

Thank you!
Fri Oct 27, 2017 11:17 am
Forum: SI Units, Unit Conversions
Topic: SI units [ENDORSED]
Replies: 6
Views: 529

### Re: SI units[ENDORSED]

Mass (kg), length (m), time (s)
Fri Oct 27, 2017 11:14 am
Forum: Properties of Light
Topic: Velocity [ENDORSED]
Replies: 13
Views: 954

### Re: Velocity[ENDORSED]

Yes, the speed of light can be considered a velocity, speed is simply the magnitude of velocity. However, that doesn't mean you can use it has the velocity component in De Broglie's equation. That equation is for particles with mass, not for light waves/photons.
Tue Oct 17, 2017 10:50 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Question 1.15
Replies: 6
Views: 339

### Re: Question 1.15

@Julian Krzysiak 3L No but so that's what's confusing me. I thought it should go exactly as you described, but in the solutions Manual it says that n=1 is initial and n= 3 is the final, which is the opposite of what you said :( and also opposite to what would make sense to me if the electrons are &q...
Tue Oct 17, 2017 5:34 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Question 1.15
Replies: 6
Views: 339

### Question 1.15

Okay so I understand how to get that the two n's are n = 1 and n=3, but how are you supposed to know that it goes from n=1 to n=3 and not the other way around?
Thu Oct 12, 2017 10:18 pm
Forum: *Black Body Radiation
Topic: Black Body Relevance [ENDORSED]
Replies: 1
Views: 446

### Black Body Relevance[ENDORSED]

Okay so I get that that a black body absorbs all of the frequencies of light, but what exactly is the application or relevance to the broader realm of quantum mechanics?
Thu Oct 12, 2017 10:13 pm
Forum: Properties of Light
Topic: Electric Field and Magnetic Field of Light
Replies: 4
Views: 244

### Re: Electric Field and Magnetic Field of Light

Light is made up of both an electrical and a magnetic wave. The waves oscillate in a manner that is perpendicular to each other, so if the electrical field is moving forward than the magnetic field oscillates perpendicular to that direction. In chemistry we only really worry about the electrical wav...
Fri Oct 06, 2017 5:28 pm
Forum: Balancing Chemical Reactions
Topic: Equation Notation [ENDORSED]
Replies: 2
Views: 242

### Re: Equation Notation[ENDORSED]

You are correct. If a subscript follows a group of elements isolated with parenthesis, then the subscript applies to every element in that group. To further clarify your question, the reason that some atoms are paired together in parenthesis is to denote the presence of a polyatomic ion and to show ...
Fri Oct 06, 2017 5:24 pm
Forum: Significant Figures
Topic: Significant Figures of Conversion Factors [ENDORSED]
Replies: 3
Views: 5175

### Re: Significant Figures of Conversion Factors[ENDORSED]

You are correct in assuming that they have infinite significant figures. They are exact values and therefore their precision is not relevant to the problem; only concern yourself with the sig figs from the pieces of data provided by the problem.

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