## Search found 61 matches

Sat Mar 16, 2019 6:50 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Intermediates in Rate Law
Replies: 4
Views: 161

### Re: Intermediates in Rate Law

intermediates never are included in the rate law. however, catalysts are always included when present.
Fri Mar 15, 2019 4:57 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: using q=n(deltaH) vs q=mc(deltaT)
Replies: 4
Views: 2570

### using q=n(deltaH) vs q=mc(deltaT)

I am confused about when to use q=n(deltaH) vs q=mc(deltaT). I am doing problem 4C.11 in the 7th edition textbook and it asks how much heat is needed to convert 80 g ice at 0 degrees C into liquid water at 20 degrees C, and I don't understand why q=n(deltaH) is used for the ice calculation and why q...
Tue Mar 12, 2019 5:17 pm
Forum: General Rate Laws
Topic: Equations
Replies: 2
Views: 111

### Equations

Will the rate law equations (the integrated rate laws)/half-life equations be given on the equation sheet? I don't remember ever seeing them on there before.
Sat Mar 09, 2019 8:57 pm
Forum: General Rate Laws
Topic: Reaction Orders for multiple reactants
Replies: 1
Views: 74

### Re: Reaction Orders for multiple reactants

That would be first order I believe because a second order reaction would have one of the values (A or B) squared. How many reactants there are doesn't determine the order of the reaction but instead to determine the order of the reaction you have to compare how affecting the concentration of the re...
Sat Mar 09, 2019 8:55 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Bimolecular
Replies: 13
Views: 652

### Re: Bimolecular

it basically just means that there are two reactants as in A+B yields C or 2A yields B
Sat Mar 09, 2019 8:53 pm
Forum: Student Social/Study Group
Topic: Note Taking
Replies: 32
Views: 2488

### Re: Note Taking

I handwrite everything because I find it hard to remember stuff that I type down and its a lot easier for me to organize my thoughts on paper than it is on a google doc or something like that
Thu Feb 28, 2019 8:47 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy and Entropy
Replies: 6
Views: 484

### Gibbs Free Energy and Entropy

Does a negative deltaG mean that the entropy is always lower? Just wondering because the textbook says that a solid has a lower G value than a liquid or gas.
Thu Feb 28, 2019 3:59 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 7th Edition Problem 6M 1
Replies: 1
Views: 93

### 7th Edition Problem 6M 1

In problem 6M 1 (7th edition) the problem states the standard Cu(s)|Cu2+(aq) cell and another half cell containing unknown metal "M" forms the cell M(s)|M+(aq)||Cu2+(aq)|Cu(s) and the Ecell value is -0.689. I really do not understand this problem because looking at the answer/the fact that...
Thu Feb 28, 2019 3:25 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Adding inert electrode to cell diagram
Replies: 1
Views: 77

### Adding inert electrode to cell diagram

So I know when you add inert electrodes to the cell diagram but what exactly is their purpose?
Thu Feb 21, 2019 8:42 pm
Forum: Balancing Redox Reactions
Topic: redox reactions
Replies: 3
Views: 131

### Re: redox reactions

I follow the acronym OIL RIG which means oxidation is the loss (of electrons), reduction is the gain (of electrons). So whichever molecule/atom in the reaction is losing electrons (becoming more positive) is being oxidized and whichever molecule/atom is gaining electrons (becoming more negative) is ...
Thu Feb 21, 2019 8:41 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: how does gibbs free energy relate to redox
Replies: 1
Views: 72

### Re: how does gibbs free energy relate to redox

They are related by the equation G=-n*F*(Ecell) in which G is Gibbs Free energy, n is number of mols, F is Faraday's constant, and E is cell potential.
Thu Feb 21, 2019 8:39 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: salt bridge
Replies: 5
Views: 169

### Re: salt bridge

The salt bridge allows ions to flow so that the electrical circuit is completed but it's a salt so the cell reaction isn't affected.
Fri Feb 15, 2019 9:59 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Replies: 35
Views: 1146

my ta said today that they should be graded by friday of week 7
Fri Feb 15, 2019 9:57 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: delta G knot
Replies: 4
Views: 247

### Re: delta G knot

g knot is the g value under standard conditions
Tue Feb 12, 2019 10:04 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Work done vs work on system
Replies: 18
Views: 1393

### Work done vs work on system

I know that there can either be work done on the system or work done by the system but I can't remember which one is positive and which one is negative when being calculated?
Thu Feb 07, 2019 12:54 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: 7th edition 4F.7
Replies: 3
Views: 158

### Re: 7th edition 4F.7

When there is a constant pressure you multiply 5/2 by R and when there is constant volume you multiply 3/2 by R. Not sure why though I just know you do.
Wed Feb 06, 2019 9:37 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Temp affecting K
Replies: 4
Views: 192

### Temp affecting K

In the textbook it states that K does not change due to the fact that it is a characteristic of the reaction and says that instead Q is changing, which makes complete sense and that's how I thought it was. However, it also states that K changes depending on the temperature (ex: increasing temp in ex...
Wed Feb 06, 2019 8:25 pm
Forum: Calculating Work of Expansion
Topic: Isothermal processes
Replies: 2
Views: 131

### Isothermal processes

What does isothermal expansion exactly mean? And just wanting to make sure I'm correct but for isothermal expansion the equation S=nRln(v1/v2) is used, right?
Sat Feb 02, 2019 1:02 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: pressure
Replies: 3
Views: 180

### Re: pressure

The pressure under standard conditions is always 1 atm. Unless it is stated that the system is not under STP, then you can assume its 1 atm.
Sat Feb 02, 2019 1:01 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Homework sections
Replies: 2
Views: 109

### Re: Homework sections

On the website you can see what sections in the textbook each section covers under the "Learning Outcomes" section!
Fri Jan 25, 2019 11:01 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Increasing Pressure
Replies: 3
Views: 154

### Increasing Pressure

For the homework question 5J.5 (7th edition), part E asks "if there is a change in overall pressure, what is the change in equilibria?" for the reaction Cl2 (g) ⇄ 2Cl (g). The answer book says that reactants are favored but why is that?
Thu Jan 24, 2019 3:06 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: delta H and pressure
Replies: 2
Views: 101

### Re: delta H and pressure

I believe it's because changing the pressure can possible change the reaction rate.
Thu Jan 24, 2019 3:05 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: State Properties
Replies: 6
Views: 147

### Re: State Properties

Because calculating those units requires you to look at the path that was taken to get to that state; not just the final state of the system.
Thu Jan 24, 2019 9:59 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: pKa and pKb
Replies: 2
Views: 106

### Re: pKa and pKb

No they are not interchangeable. The pOH is the -log(concentration) and pKb is the -log of Kb which is equal to [products]/[reactants].
Sun Jan 20, 2019 12:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Sig figs in pH
Replies: 7
Views: 155

### Sig figs in pH

How do you figure out how many sig figs you are supposed to have in your final answer if being asked to calculate pH?
Sun Jan 20, 2019 11:59 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Assuming X value
Replies: 3
Views: 101

### Assuming X value

How small does the Kb/Ka value have to be in order to assume the value of X and not have to use the quadratic formula?
Mon Jan 14, 2019 8:07 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc, Kw, and pKw
Replies: 4
Views: 2027

### Kc, Kw, and pKw

What do Kc, Kw, and pKw stand for exactly?
Fri Jan 11, 2019 10:30 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: defining Q
Replies: 6
Views: 257

### Re: defining Q

The equation is not at equilibrium unless Q=K.
Fri Jan 11, 2019 10:28 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: vant Hoff factor and equation
Replies: 3
Views: 45

### Re: vant Hoff factor and equation

If Lavelle or your TA ever goes over it, then it's probably important but I wouldn't worry about it if they don't mention it at all.
Wed Jan 09, 2019 10:20 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: "Shifting"
Replies: 15
Views: 1051

### Re: "Shifting"

If you refer to a system "shifting" it is implying that it is no longer at equilibrium.
Thu Dec 06, 2018 10:41 pm
Forum: Amphoteric Compounds
Topic: Determining Amphoteric Compounds
Replies: 3
Views: 129

### Re: Determining Amphoteric Compounds

Yes I believe you just have to know those specific atoms are amphoteric compounds.
Thu Dec 06, 2018 10:39 pm
Forum: Naming
Replies: 2
Views: 108

### Re: Adding "o" to Anion

I would go with chloro because that is how Lavelle taught it.
Thu Dec 06, 2018 10:37 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Overall Polarity of the Molecule/Net Dipole
Replies: 1
Views: 119

### Re: Overall Polarity of the Molecule/Net Dipole

Lone pairs will make the atom with the lone pairs more negative than those that don't so there will be a dipole moment. Looking at VSEPR formula you can see how many lone pairs there are for example in a AX3E2 model there are 2 lone pairs. Looking at Lewis structures, you can determine the polarity ...
Thu Nov 29, 2018 5:55 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 3
Views: 80

### Re: Bond Angles

There are as many bond angles are there are bonds between S, O, and Cl. Drawing a lewis diagram will help visualize it and help you count. Then depending on the shape of the molecule you can determine the actual bond angle degree.
Wed Nov 28, 2018 11:52 am
Forum: Hybridization
Topic: Sigma and Pi bonds and hybridization
Replies: 1
Views: 68

### Sigma and Pi bonds and hybridization

Why are sigma bonds hybridized while pi bonds are unhybridized?
Wed Nov 28, 2018 11:31 am
Forum: Hybridization
Topic: pi vs sigma
Replies: 12
Views: 524

### Re: pi vs sigma

because if a pi bond rotates then the bond immediately breaks
Wed Nov 28, 2018 11:30 am
Forum: Determining Molecular Shape (VSEPR)
Topic: VESPR Theory
Replies: 1
Views: 88

### Re: VESPR Theory

The position of the lone pairs are typically on top of the atom with the lone pairs and they push the other atoms bonded to it down/as far away from the lone pairs as possible.
Mon Nov 26, 2018 10:20 pm
Forum: Bond Lengths & Energies
Topic: Bond Length
Replies: 2
Views: 106

### Bond Length

How can we tell between a group of molecules which ones have longer/shorter bond lengths?
Mon Nov 26, 2018 10:15 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability
Replies: 3
Views: 210

### Polarizability

What exactly is polarizability?
Thu Nov 15, 2018 5:23 pm
Forum: Dipole Moments
Topic: Dipole Moments
Replies: 6
Views: 207

### Dipole Moments

I'm still a little unclear about what exactly dipole moments are could someone explain it to me?
Thu Nov 15, 2018 5:18 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AX2E3 shape
Replies: 2
Views: 168

### Re: AX2E3 shape

Because that is the furthest the molecules can get from each other.
Thu Nov 15, 2018 5:17 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Hydrogen Bonding
Replies: 5
Views: 230

### Re: Hydrogen Bonding

Hydrogen bonding is used when hydrogen is bonded to an H,N,O, or F atom and it's a dipole-dipole attraction
Thu Nov 08, 2018 11:31 pm
Forum: Ionic & Covalent Bonds
Topic: Electronegativity values
Replies: 4
Views: 176

### Electronegativity values

Will we be given values of electronegativities when asked, for example, to say which compound would have bonds that are primarily ionic?
Sun Nov 04, 2018 3:40 pm
Forum: Student Social/Study Group
Replies: 3
Views: 179

Does anyone know if we need to know about radicals for the midterm?
Sun Nov 04, 2018 12:37 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: # of Electrons for Sb
Replies: 1
Views: 86

### # of Electrons for Sb

Question 2A.1 in the 7th edition textbook says that Sb has 5 valence electrons when including the d-block but shouldn't it be 15? Why is it 5 e-?
Sun Nov 04, 2018 12:07 pm
Forum: Lewis Structures
Topic: Lewis Structures
Replies: 11
Views: 343

### Re: Lewis Structures

It is the atom with the lowest ionization energy in the middle
Thu Nov 01, 2018 10:19 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: X,Y,and Z in reference to 3p orbital
Replies: 5
Views: 151

### Re: X,Y,and Z in reference to 3p orbital

Athena L 1B wrote:What does the p actually refer to?

The p refers the the p orbital
Thu Nov 01, 2018 10:18 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical Formulas with Masses
Replies: 3
Views: 213

### Empirical Formulas with Masses

If you are asked to find the empirical formula of a compound and you are given the mass of the compound and the masses of its products how would you go about solving the problem?
Thu Oct 25, 2018 12:14 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Bohr Frequency Condition
Replies: 1
Views: 177

### Bohr Frequency Condition

What does the Bohr frequency condition have to do with explaining the lines in the spectrum of an element?
Wed Oct 24, 2018 11:18 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: X,Y,and Z in reference to 3p orbital
Replies: 5
Views: 151

### X,Y,and Z in reference to 3p orbital

How do you know when to use 3x, y, or z in reference to quantum numbers? Dr. Lavelle said that the state for the quantum numbers (3,1,0) was 3py but I don't understand why it is y.
Wed Oct 24, 2018 11:14 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Electron Configurations
Replies: 3
Views: 114

### Re: Electron Configurations

d-block always comes before s-block when the electron configuration is written because it has a lower energy level than the s-block
Wed Oct 24, 2018 11:11 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Ordering of electrons in d-shell
Replies: 2
Views: 100

### Re: Ordering of electrons in d-shell

You always put the d-block before the s-block there are no exceptions (at least from what I learned/got out of what was said in lecture)
Thu Oct 18, 2018 2:46 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodal Plane and Symmetic
Replies: 1
Views: 97

### Re: Nodal Plane and Symmetic

The 2s orbital has no nodes because it is just a sphere. The p orbital is symmetric but also has nodes in the center of the two nodes. So only the 2s orbital is symmetric and has no nodes
Thu Oct 18, 2018 2:38 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron configuration
Replies: 2
Views: 88

### Re: Electron configuration

Silver's electron configuration is like that because in some transition metals the electron from the s orbital transfers to complete the d orbital
Thu Oct 18, 2018 2:32 pm
Forum: *Shrodinger Equation
Topic: Schrodinger Equation
Replies: 2
Views: 54

### Re: Schrodinger Equation

I believe we just need to know that it shows the probability of finding an electron at a certain position and that it relates to wavefunctions
Thu Oct 11, 2018 11:44 am
Forum: Properties of Light
Topic: Electromagnetic Spectrum
Replies: 2
Views: 133

### Re: Electromagnetic Spectrum

You should at least have a good idea of what the ranges are for each spectrum (visible light, uv, ir)
Thu Oct 11, 2018 11:41 am
Forum: Student Social/Study Group
Topic: Studying techniques
Replies: 12
Views: 387

### Re: Studying techniques

Do the extra homework problems that are listed on the syllabus and watch bozeman youtube videos and take notes theyre super helpful
Wed Oct 10, 2018 6:50 pm
Forum: Einstein Equation
Topic: Work Function
Replies: 4
Views: 184

### Work Function

I am confused about what exactly the work function is. Can someone explain to me the basics of it?
Tue Oct 02, 2018 2:58 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity and Mass
Replies: 2
Views: 67

### Molarity and Mass

How would you find the mass of a compound that is needed to get a certain molarity (when given the molarity and volume)?
Tue Oct 02, 2018 2:55 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Moles!
Replies: 7
Views: 250

### Re: Moles!

Bozeman AP chem videos are very helpful!
Tue Oct 02, 2018 2:53 pm
Forum: Balancing Chemical Reactions
Topic: Short cuts/methods for balancing equations
Replies: 15
Views: 380

### Re: Short cuts/methods for balancing equations

Personally I think the easiest way to balance chemical equations is to start with the atoms that occur the least in the reaction and continue to progress from there.