## Search found 62 matches

Sun Mar 17, 2019 12:39 am
Forum: Administrative Questions and Class Announcements
Replies: 179
Views: 12626

For kinetics ws pt 1 number 5 why isn't C included in the rate law? Is it an intermediate? if so, how can you tell?
Sun Mar 17, 2019 12:29 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: Units k
Replies: 3
Views: 316

### Units k

how do you determine units for rate constant?
Sat Mar 16, 2019 11:23 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: ln k and 1/t
Replies: 3
Views: 323

### Re: ln k and 1/t

yes
Sat Mar 16, 2019 11:21 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Elementary Rxns
Replies: 2
Views: 307

### Elementary Rxns

what would the rate law be for 2A+2B->C be? Do you use the coefficients given for the order or no?
Sat Mar 16, 2019 11:13 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Ea
Replies: 1
Views: 294

### Ea

What is the explicit equation for activation energy?
Sat Mar 16, 2019 10:58 pm
Forum: Experimental Details
Topic: Rate law in multiple step reactions [ENDORSED]
Replies: 3
Views: 650

### Re: Rate law in multiple step reactions[ENDORSED]

You must replace the intermediates with their equal rate law expressions using the molar ratios when needed.
Sat Mar 16, 2019 10:49 pm
Forum: First Order Reactions
Topic: pseudo first order [ENDORSED]
Replies: 5
Views: 532

### Re: pseudo first order[ENDORSED]

So is it technically a second order reaction, but because one of the concentrations is so big its basically constant?
Sat Mar 16, 2019 10:46 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Orientation
Replies: 2
Views: 298

### Orientation

What are the notes referring to when they say the orientations of colliding molecules must be the same?
Sat Mar 16, 2019 10:45 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Units and order
Replies: 3
Views: 293

### Units and order

Can the order of the reaction be determined by the units? I saw something that to solve for n (order) you can use M^1-n ?
Sat Mar 16, 2019 10:37 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: ln k and 1/t
Replies: 3
Views: 323

### ln k and 1/t

When is the profile lnk vs 1/t and when is the profile lnk vs t?
Sat Mar 16, 2019 7:44 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Transition State
Replies: 3
Views: 111

### Transition State

What is the transition state and where does it go on the profile?
Sat Mar 16, 2019 7:39 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Ka and K
Replies: 1
Views: 262

### Ka and K

What are the steps to find Ka after solving for K in the Nernst equation?
Sat Mar 16, 2019 7:34 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Reaction Profiles
Replies: 1
Views: 78

### Reaction Profiles

How does the profile change if it is endergonic vs exergonic?
Sat Mar 16, 2019 7:33 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Approaches to mechanisms
Replies: 2
Views: 127

### Approaches to mechanisms

What is the difference between steady state and pre eq approaches?
Sat Mar 16, 2019 7:29 pm
Forum: General Rate Laws
Topic: Rate Constant
Replies: 1
Views: 257

### Rate Constant

what is the relationship between rate of reaction, rate constant, and half life?
Sat Mar 16, 2019 6:19 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: E* +/-
Replies: 1
Views: 257

### E* +/-

Should the calculated E* value when adding E*s from half reactions always be positive?
Sat Mar 16, 2019 6:18 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Inert Conductor
Replies: 3
Views: 111

### Inert Conductor

How do you know which inert conductor to add Pt vs Hg?
Sat Mar 16, 2019 6:16 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Standard of Formation
Replies: 1
Views: 269

### Standard of Formation

How do you know if you're are given the standard free energy of formation versus just free energy?
Sat Mar 16, 2019 6:13 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Calculating E*
Replies: 1
Views: 233

### Calculating E*

When can you add the E* for each half reaction to get the cell E* and when can you not add them because its not a state function? This came up in Lyndon's review when we had to convert E* to delta G.
Tue Feb 26, 2019 11:03 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Vant Hoff Equation
Replies: 3
Views: 132

### Re: Vant Hoff Equation

It depends on what you are given but most of the time if you are trying to find K but you're given delta H and delta S (or vice versa)
Tue Feb 26, 2019 1:18 am
Forum: Balancing Redox Reactions
Topic: Standard Potential
Replies: 2
Views: 104

### Standard Potential

if the coefficients are proportional but different in the same 2 reactions, do you need to multiply E by the molar proportion or does it stay the same?
Tue Feb 26, 2019 1:00 am
Forum: Administrative Questions and Class Announcements
Replies: 179
Views: 12626

In the Gibbs WS #4 how do you find T? or can you just assume its at 25 C?
Tue Feb 26, 2019 12:45 am
Forum: Administrative Questions and Class Announcements
Replies: 179
Views: 12626

On #1 of the Gibbs to find the standard enthalpy and entropy of formation you have to do the sum of products minus the sum of the reactants using the numbers given right? For some reason I am not getting the same answer.
Mon Feb 04, 2019 12:59 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Thermos
Replies: 4
Views: 151

### Thermos

Why is a thermos considered an isolated system and not a closed system?
Mon Feb 04, 2019 12:58 am
Forum: Calculating Work of Expansion
Topic: Integral calculations
Replies: 4
Views: 200

### Integral calculations

When do you know to take the integral when finding work?
Mon Feb 04, 2019 12:57 am
Forum: Phase Changes & Related Calculations
Topic: Heat and Condensation
Replies: 9
Views: 338

### Heat and Condensation

Is heat absorbed or released during condensation?
Mon Feb 04, 2019 12:57 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: isothermal expansion
Replies: 2
Views: 130

### isothermal expansion

What is isothermal expansion?
Mon Feb 04, 2019 12:56 am
Forum: Phase Changes & Related Calculations
Topic: Reversible changes
Replies: 1
Views: 108

### Reversible changes

What changes to a system are reversible and which are irreversible?
Mon Feb 04, 2019 12:53 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Isothermic definition
Replies: 5
Views: 243

### Isothermic definition

What is the difference between isothermal and isometric?
Fri Jan 11, 2019 4:14 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Inert Gases
Replies: 2
Views: 66

### Inert Gases

Why does adding inert gases only affect the equilibrium constant in a closed system?
Fri Jan 11, 2019 4:11 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Replies: 7
Views: 244

I believe the only variable that affects K is temperature.
Fri Jan 11, 2019 4:07 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids and Liquids in Rxn
Replies: 6
Views: 273

### Solids and Liquids in Rxn

What would K be if the reaction was only made up of solids and liquids, no gases or aq solutions?
Sat Dec 08, 2018 12:32 am
Forum: Calculating the pH of Salt Solutions
Topic: Atoms that don't affect pH
Replies: 3
Views: 316

### Atoms that don't affect pH

How do you know which atoms affect the pH of a solution and which ones do not? For example in NH4Br how do you know not to include Br in the chemical equation?
Fri Dec 07, 2018 9:14 pm
Forum: Amphoteric Compounds
Topic: Amphoteric compounds
Replies: 2
Views: 124

### Amphoteric compounds

How do you know if a compound can be amphoteric?
Fri Dec 07, 2018 9:10 pm
Forum: Amphoteric Compounds
Topic: Amphoteric
Replies: 4
Views: 316

### Amphoteric

Are amphoteric and amphoprotic opposite properties? if not, what is the relationship between the two?
Mon Dec 03, 2018 12:59 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Hydronium
Replies: 4
Views: 187

### Hydronium

Why is hydronium sometimes referred to as H3O+ and sometimes as H+? What is the difference?
Mon Dec 03, 2018 12:42 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Electronegativity and delocalization
Replies: 1
Views: 110

### Electronegativity and delocalization

If an atom has a high electronegativity does it have a strong delocalization power too? Or weak delocal power?
Mon Dec 03, 2018 12:29 pm
Forum: Lewis Acids & Bases
Topic: Lewis v. Bronsted
Replies: 2
Views: 117

### Lewis v. Bronsted

Whats the difference between Lewis acids and bases and bronsted acids and bases?
Mon Dec 03, 2018 12:16 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Calculating pH
Replies: 3
Views: 126

### Calculating pH

When calculating pH do you only ever use the H3O+ concentration or will you ever use OH-?
Tue Nov 27, 2018 1:15 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: I3-
Replies: 1
Views: 97

### I3-

Would I3 ^1- (Iodine) be polar or non polar? its linear with 3 lone pairs on the central atom but is there any net dipole?
Tue Nov 27, 2018 1:04 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: Induced Dipole
Replies: 1
Views: 39

### Induced Dipole

Will nonpolar molecules always have induced dipole forces?
Mon Nov 26, 2018 11:08 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Dipole Forces
Replies: 3
Views: 152

### Dipole Forces

What is the difference between induced dipole and dipole? How do forces between them differ based on what combination you have?
Sun Nov 25, 2018 2:09 pm
Forum: Hybridization
Topic: sp orbitals
Replies: 3
Views: 152

### sp orbitals

what do the 2 and 3 mean in sp2, sp3, sp3d2 etc orbitals?
Sun Nov 25, 2018 10:46 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Naming
Replies: 4
Views: 133

### Naming

Several times in lecture Dr. Lavelle said the shape would be one thing if looking at lone pairs, however it would be named differently. How do we know when to name it correctly based on regions of e- density and when to just give the general shape that considers lone pairs?
Sun Nov 25, 2018 10:41 am
Forum: Determining Molecular Shape (VSEPR)
Topic: pi and sigma bonds
Replies: 9
Views: 383

### pi and sigma bonds

Which bond has more energy pi or sigma?
Sat Nov 24, 2018 2:59 pm
Forum: Hybridization
Topic: Steps to figure out hybridization
Replies: 3
Views: 172

### Steps to figure out hybridization

Do you have to figure the lewis dot and/or VSEPR model to get the right hybridization? What are the steps to figure out if something needs hybridization?
Wed Nov 14, 2018 10:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape
Replies: 4
Views: 155

### Molecular Shape

Why are molecules considered octahedral that only have 6 bonds?
Wed Nov 14, 2018 10:31 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 3
Views: 84

### Bond Angles

Why are some bond angles exactly 120 or 109.5 while others say they are slightly less than that?
Sat Nov 10, 2018 7:19 pm
Forum: Bond Lengths & Energies
Topic: Bond Lengths
Replies: 5
Views: 338

### Bond Lengths

If we are asked to predict bond lengths is it just finding the average based on numbers given to you? How could you determine bond lengths if you weren't given any additional information?
Sat Nov 10, 2018 7:16 pm
Forum: Dipole Moments
Topic: Hydrogen Bonds
Replies: 20
Views: 575

### Hydrogen Bonds

Relative to other types of bonds, how strong are hydrogen bonds?
Sat Nov 10, 2018 7:10 pm
Forum: Electronegativity
Topic: Electronegativity
Replies: 3
Views: 163

### Electronegativity

Whats the difference between electronegativity and ionization energy?
Sat Nov 10, 2018 6:58 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability Trend
Replies: 6
Views: 1193

### Re: Polarizability Trend

Polarizability follows the same trend as atomic radius: increasing right to left and increasing down a group
Sun Nov 04, 2018 10:02 pm
Forum: Lewis Structures
Topic: Expanded Octet Rule
Replies: 4
Views: 180

### Expanded Octet Rule

When a structure includes atoms with expanded octets what the max number of electrons that can be held? Is it 10 because of the d orbital or can it be more?
Sun Nov 04, 2018 10:00 pm
Forum: Lewis Structures
Topic: Expanded Octet Rule
Replies: 1
Views: 44

### Expanded Octet Rule

When a structure includes atoms with expanded octets what the max number of electrons that can be held? Is it 10 because of the d orbital or can it be more?
Sun Nov 04, 2018 9:57 pm
Forum: Lewis Structures
Topic: Resonance structures
Replies: 2
Views: 98

### Resonance structures

When a test question asks for resonance structures should we show all possible ones or only the most logical ones?
Sun Nov 04, 2018 9:53 pm
Forum: Lewis Structures
Replies: 5
Views: 238

How do you determine the number of bonds you should use between Carbon and nitrogen/carbon and carbon/oxygen? Also is there a method to determining where the hydrogens should be placed or can you just do whatever works for the total number of valence e-?
Sun Oct 21, 2018 9:28 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Particle Size
Replies: 3
Views: 145

### Particle Size

As explained in the lecture we can know the momentum and position of a large object such as a baseball going through the detectors but not an electron because it is so small that the detectors interfere with its path. My question is do particles larger than electrons react in the same way? or would ...
Sun Oct 21, 2018 9:17 pm
Forum: Properties of Electrons
Topic: Energy Levels and Electrons
Replies: 1
Views: 124

### Energy Levels and Electrons

When an electron is excited to an n=2 or n=3 etc. state how long does it take to return to the threshold level where it emits a photon?
Sun Oct 21, 2018 9:14 pm
Forum: Properties of Electrons
Topic: Wave Properties
Replies: 4
Views: 168

### Wave Properties

Can other particles (non electrons) have wave-like properties too?
Sun Oct 07, 2018 10:03 pm
Forum: Molarity, Solutions, Dilutions
Topic: Actual/Theoretical Yield
Replies: 8
Views: 2310

### Actual/Theoretical Yield

Should we know why actual yield is lower than theoretical yield in the way specific to the problem or just know the general reasons that actual yield is less than theoretical yield?
Sun Oct 07, 2018 9:56 pm
Forum: Empirical & Molecular Formulas
Topic: Limiting Reactants
Replies: 3
Views: 415

### Limiting Reactants

When finding limiting reagents, how do you know what product to compare moles to if not directly stated in the problem? I noticed several module problems that said what is the limiting reactant for the product created? However, there was more than one product in the reaction.
Sun Oct 07, 2018 9:50 pm
Forum: Empirical & Molecular Formulas
Topic: Converting Units
Replies: 5
Views: 234

### Converting Units

When multiple units are defined in a reaction, is it best to convert to equal units before writing out a reaction? Or will it still be a valid answer if units are converted at the end?