## Search found 63 matches

Fri Mar 15, 2019 11:44 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: rules for Delta H
Replies: 1
Views: 252

### rules for Delta H

When does Delta H=q?
Delta H=w?
If ever.
Fri Mar 15, 2019 11:43 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Rules for delta U
Replies: 2
Views: 294

### Rules for delta U

When is delta U=0?
delta U=q?
Fri Mar 15, 2019 11:42 am
Forum: First Order Reactions
Topic: Exponents for rate laws
Replies: 1
Views: 97

### Exponents for rate laws

What determines the exponent for rate laws, the coefficient (like in equilibrium), or the order?
Fri Mar 15, 2019 11:41 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Delta N
Replies: 1
Views: 212

### Delta N

To solve for Delta n is it moles of the product minus moles of the reactant?
Fri Mar 15, 2019 11:40 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy At Constant Volume?
Replies: 2
Views: 240

### Enthalpy At Constant Volume?

Does Enthalpy exist at a constant volume?
Sun Mar 03, 2019 8:51 pm
Forum: First Order Reactions
Topic: homework problems
Replies: 2
Views: 72

### homework problems

Which homework problems are applicable to this chapter? Week 9?
Wed Feb 27, 2019 7:40 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Phases used in a Galvanic Cell
Replies: 3
Views: 142

### Phases used in a Galvanic Cell

Are solids, gases, and aqueous the only phases used on a cell diagram? Are liquids never listed?
Wed Feb 27, 2019 11:39 am
Forum: General Science Questions
Topic: Test 2 7th edition book
Replies: 1
Views: 327

### Test 2 7th edition book

what homework questions does test 2 cover from the seventh edition book?
Sun Feb 24, 2019 5:13 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Determining what is constant
Replies: 1
Views: 94

### Determining what is constant

How do you decide what is at a constant with out it being said. I have run into questions that don't talk about volume then the answer seems to imply that is is constant. How is this determined? Are there any rules informing you on how to decide? What happens if nothing is stated?
Sun Feb 24, 2019 5:10 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Relation to Enthalpy and Entropy
Replies: 4
Views: 1243

### Relation to Enthalpy and Entropy

How are Gibb's Free Energy, Work, Enthalpy and Entropy related?? is this significant?
Sun Feb 24, 2019 5:09 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Spontaneous?
Replies: 6
Views: 262

### Spontaneous?

How do you determine if Gibbs free energy is spontaneous or not?
Fri Feb 22, 2019 2:43 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Porous Disc
Replies: 2
Views: 133

### Porous Disc

I am confused on the porous disk that keeps being referred to in class. What is the difference between a porous disc and a salt bridge?
Fri Feb 22, 2019 2:42 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cathode vs. Anode
Replies: 9
Views: 322

### Cathode vs. Anode

What are the rules for determining which is a cathode and which is an anode?
Fri Feb 22, 2019 2:42 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Homework Questions on Test 2
Replies: 1
Views: 86

### Homework Questions on Test 2

What sections of homework should we be looking at for test 2?
Thu Feb 14, 2019 10:53 am
Forum: General Science Questions
Topic: Midterm Formulas
Replies: 6
Views: 619

### Re: Midterm Formulas

Most of the formulas that are not provided can be derived from the ones given.
Tue Feb 12, 2019 4:23 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: When does delta U equal zero?
Replies: 17
Views: 2155

### When does delta U equal zero?

What are the rules for delta U = 0? When does this happen? Under what circumstances?
Tue Feb 12, 2019 4:22 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Homework Questions
Replies: 2
Views: 180

### Midterm Homework Questions

For the 7th edition of the textbook what is the last section that will be covered on the midterm?
Fri Feb 08, 2019 7:05 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: ideal gas volume
Replies: 1
Views: 72

### Re: ideal gas volume

Is this just having to do with constant volume or would it also be constant temp or pressure?
Fri Feb 08, 2019 7:03 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Study Guides
Replies: 15
Views: 555

### Re: Study Guides

Are there study guides posted for the thermo chem information?
Fri Feb 08, 2019 7:01 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Ideal Gas Laws
Replies: 4
Views: 195

### Ideal Gas Laws

What are the rules and equations that go with ideal gases? Are idea gases noble gases?
Thu Jan 31, 2019 11:04 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Phase changes and enthaplies
Replies: 3
Views: 130

### Phase changes and enthaplies

How are phase changes and enthalpies related? Does it have to do with exothermic and endothermic reactions?
Thu Jan 31, 2019 11:02 am
Forum: Phase Changes & Related Calculations
Topic: What Does U and q stand for?
Replies: 9
Views: 333

### What Does U and q stand for?

In many of the problems in the homework there were equations with U and q. What do these variables stand for?
Thu Jan 31, 2019 11:01 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: closed vs isolated
Replies: 14
Views: 371

### Re: closed vs isolated

I always think of an isolated system like a closed hydroflask compared to a closed water bottle. The hydroflask has layers of steel around it and truly isolates whats inside.
Wed Jan 23, 2019 11:52 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Acids and Bases
Replies: 6
Views: 211

### Re: Acids and Bases

Becky Belisle 1A wrote:It depends on which defintion you use. A Bronsted acid donates a proton, so it must at least have a proton in the formula.

Which definition should we be using to determine if something is an acid or a base?
Wed Jan 23, 2019 11:50 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5% rule and % ionization
Replies: 2
Views: 146

### 5% rule and % ionization

What are the steps for solving for a percent ionized/deprotonized question and how does that relate to the 5% rule?
Wed Jan 23, 2019 11:47 am
Forum: Ideal Gases
Topic: The Difference between Q and Kc [ENDORSED]
Replies: 18
Views: 1909

### Re: The Difference between Q and Kc[ENDORSED]

Q is the same equation as K, but Q is calculated at anytime during the reaction and compared to K. If K and Q match then the system is at equilibrium. If Q<K it moves towards the products, if Q>K it moves towards the reactants.
Wed Jan 16, 2019 8:57 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Test Topics for Week 3 [ENDORSED]
Replies: 1
Views: 132

### Test Topics for Week 3[ENDORSED]

What equations are going to be needed for this upcoming test?
Wed Jan 16, 2019 8:54 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Tricks for ICE tables
Replies: 5
Views: 217

### Tricks for ICE tables

Are there any tricks for knowing when to use an ICE table?
Wed Jan 16, 2019 8:54 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Acid and Base Equilibria
Replies: 7
Views: 283

### Re: Acid and Base Equilibria

If you are saying higher pH in terms of numbers closer to 7 than yes you would be correct. If you think about a strong acid that has completely dissociated, the humber of H+ ions in that solution will be greater than that of a weak acid.
Thu Jan 10, 2019 11:12 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K=1
Replies: 5
Views: 140

### Re: K=1

I think about like a proportion. So if there are 3 particles of reactant there has to be 3 particles of products. Dividing those numbers would equal 1.
Thu Jan 10, 2019 11:08 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K
Replies: 4
Views: 208

### Re: K

I believe each K (other than Keq) has units but when it is placed into the equation the units are no longer needed.
Thu Jan 10, 2019 11:06 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Why Would Equilibrium cause death in humans?
Replies: 3
Views: 809

### Why Would Equilibrium cause death in humans?

I do not understand the concept that a human becoming at equilibrium means they are dead? Why would that be?
Tue Dec 04, 2018 7:53 pm
Forum: Identifying Acidic & Basic Salts
Topic: Identifying the Different Types of Acidic and Bases
Replies: 2
Views: 65

### Identifying the Different Types of Acidic and Bases

I know there are Lewis acids and bases and Bronsted bases and acids, are there anymore we should know? Also, what are the differences between them?
Tue Dec 04, 2018 7:49 pm
Forum: General Science Questions
Topic: Chemistry Community [ENDORSED]
Replies: 7
Views: 418

### Re: Chemistry Community[ENDORSED]

I believe thats how it will work, and I don't think we have to post the week.
Tue Dec 04, 2018 7:34 pm
Forum: Identifying Acidic & Basic Salts
Topic: Rules for acidic & basic salts
Replies: 1
Views: 123

### Rules for acidic & basic salts

Are there any specific rules that apply only to acidic and basic salts? Along with this are there specific calculations for acidic and basic salts?
Fri Nov 30, 2018 10:23 pm
Forum: Sigma & Pi Bonds
Topic: Rotating Bond?
Replies: 4
Views: 452

### Rotating Bond?

I remember Dr. Lavelle talking about either sigma or pi bonds being able to rotate, which one was it? Thank you!
Thu Nov 29, 2018 10:45 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Determining Dipoles
Replies: 2
Views: 138

### Determining Dipoles

How do you determine the dipole direction and sign on a molecule?
Wed Nov 28, 2018 4:09 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Exam topic
Replies: 1
Views: 48

### Exam topic

Is it necessary that we know VSEPR shape formulas for the exam?
Wed Nov 28, 2018 4:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar covalent vs. polar ionic bonds
Replies: 1
Views: 108

### Polar covalent vs. polar ionic bonds

What exactly is the difference between polar ionic bonds and polar covalent bonds?
Wed Nov 28, 2018 4:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarizability
Replies: 2
Views: 148

### Polarizability

I am still a bit confused on how to find the polarizability of and ion and what exactly polarizability is. If anyone could help that would be great! Thank you!
Wed Nov 28, 2018 4:00 pm
Forum: Hybridization
Topic: Polar Power
Replies: 5
Views: 179

### Polar Power Compared to Atomic Radius

Is the polar power only determined by the atomic radius? For this would it be the smaller the radius the larger the polar power?
Tue Nov 13, 2018 4:39 pm
Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
Topic: Shape and Boiling Point
Replies: 12
Views: 1629

### Re: Shape and Boiling Point

Does the distance between the bonds effect the boiling point? Would this cause the bond to be stronger or weaker?
Tue Nov 13, 2018 4:37 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Homework for VSEPR
Replies: 3
Views: 169

### Homework for VSEPR

In terms of homework problems for this week which questions would be the most applicable? Which section would be the best to help learn VSEPR structures?
Tue Nov 13, 2018 4:33 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 3
Replies: 8
Views: 1354

### Re: Test 3

Is anyone aware is test 3 is next week? what happens if our discussion is over break?
Wed Nov 07, 2018 10:16 pm
Forum: Bond Lengths & Energies
Topic: Special Bond Length Rules
Replies: 3
Views: 185

### Special Bond Length Rules

Are there any special bond length rules? Let me know any information is appreciated!!
Wed Nov 07, 2018 10:02 pm
Forum: Ionic & Covalent Bonds
Topic: Ionization Energies
Replies: 13
Views: 474

### Re: Ionization Energies

Remember that Ionization energy is how much energy it takes to create an ion from a stable molecule. This will be very high for noble gases, because they are so stable.
Sun Nov 04, 2018 6:40 pm
Forum: Properties of Electrons
Topic: Frequency of an electron equation
Replies: 2
Views: 345

### Frequency of an electron equation

I know that there are specific equations that you can only use for an electron or something with mass. Which equation would you use to find the frequency of an electron?
Tue Oct 30, 2018 10:14 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Key Words
Replies: 4
Views: 215

### Key Words

Hey!! I'm just wondering if anyone has any keywords and definitions that would help us study for the midterm??
Tue Oct 30, 2018 10:09 pm
Topic: Midterm
Replies: 4
Views: 424

### Re: Midterm

There are study questions posted on here too and they seem to cover most of the main topics so i would use that as a guideline.
Tue Oct 30, 2018 10:06 pm
Forum: Quantum Numbers and The H-Atom
Topic: Electron Spin
Replies: 3
Views: 248

### Re: Electron Spin

In terms of this rule is the up arrow electron positive or negative 1/2?
Tue Oct 23, 2018 10:27 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Is there ever a negative frequency
Replies: 1
Views: 146

### Is there ever a negative frequency

For Rydberg's equation should the answer ever be negative? What if you go from n=4 to n=2 or n=3 to n=5?
Tue Oct 23, 2018 10:25 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation
Replies: 7
Views: 426

### Re: Rydberg Equation

I was running into the same problem. I'm not sure but is the answer ever supposed to be negative?
Tue Oct 23, 2018 10:23 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Relationship Between Equations
Replies: 1
Views: 159

### Relationship Between Equations

What is the relationship between En= -hR/n2 and Rydberg's equation?
Tue Oct 23, 2018 10:09 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation
Replies: 7
Views: 426

### Rydberg Equation

I have been looking around and I can't find a clear answer to tell me if in the Rydberg equation it is R((1/(the original value of n))-(1/(the final value of n)) or the opposite way for the final and initial values. Please let me know if you can! Thank you!
Tue Oct 16, 2018 11:02 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Heisenberg's Indeterminacy Equation
Replies: 3
Views: 127

### Heisenberg's Indeterminacy Equation

For Heisenberg's Indeterminacy Equation we have to find either delta p or delta v. What are the definitions of delta p and delta v so i know which variable a given value falls under? This value would then be placed in the equation and solved.
Tue Oct 16, 2018 10:54 am
Forum: Properties of Light
Topic: Vocab
Replies: 5
Views: 250

### Re: Vocab

When you say "discrete values" does that mean it can only have one value at a time or just a small range of values?
Tue Oct 16, 2018 10:48 am
Forum: Properties of Light
Topic: Week 3 HW
Replies: 5
Views: 295

### Re: Week 3 HW

I believe that it would be helpful to do both Ch 1 and Ch 2, since we have a test next week. The seven problems will be due in your discussion section, too.
Tue Oct 09, 2018 10:20 am
Forum: Significant Figures
Topic: Sig Fig zero rules
Replies: 7
Views: 832

### Sig Fig zero rules

Hello! i am having some trouble remembering how sig figs work with zeros. For example how many sig figs are in 570, 500, 4.0, 40.0, .04, 0.04, .40, .0040? if anyone could help me out with this that would be greatly appreciated. Also if there are any other tricks for knowing how many sig figs there a...
Tue Oct 09, 2018 10:09 am
Forum: Molarity, Solutions, Dilutions
Topic: Finding the volume of stock solution to dilute
Replies: 13
Views: 781

### Re: Finding the volume of stock solution to dilute

Hello! I'm don't think it is completely necessary to convert your answers to mL from Liters, but I usually do since there are sometimes other steps to the problem where you are subtracting a volume from a greater volume and in this case they would both need to have matching units.
Tue Oct 09, 2018 10:02 am
Forum: Properties of Light
Topic: Exam
Replies: 7
Views: 294

### Re: Exam

The way I have been looking at it is first reviewing the problems that we did in our discussions. Those seem to have many important features. Next I am going to watch the audio videos and take notes. The pre and post assessments i am going to use to gauge my understanding of the concepts and then ad...
Tue Oct 02, 2018 3:05 pm
Forum: Administrative Questions and Class Announcements
Topic: Do we have to write out the question for homework?
Replies: 4
Views: 292

### Re: Do we have to write out the question for homework?

I have been writing at least part of the question out on the homework. I find that if helps me review and remember what the question was asking without going all the way back into the book.
Tue Oct 02, 2018 3:01 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity and Mass
Replies: 2
Views: 68

### Re: Molarity and Mass

First you take molarity and multiply it by liters. Then you that the value in mols that you are left with and multiply that by grams/mole. Finally you are left with grams.
Tue Oct 02, 2018 2:59 pm
Forum: SI Units, Unit Conversions
Topic: Textbook Homework Assignment
Replies: 11
Views: 832

### Re: Textbook Homework Assignment

The seventh edition starts with pages like F1. The question that we are supposed to answer are usually at the end of each letter sub section. Once the F pages end the pages are only labeled by numbers.