Search found 75 matches
- Sun Mar 17, 2019 10:35 am
- Forum: Second Order Reactions
- Topic: units of K
- Replies: 3
- Views: 690
Re: units of K
The units for k in a second order reaction is M^-1s^-1
- Sun Mar 17, 2019 10:18 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalysts
- Replies: 28
- Views: 1845
Re: Catalysts
Catalysts lower the curve of the reaction.
- Sun Mar 17, 2019 10:16 am
- Forum: Zero Order Reactions
- Topic: overall rate
- Replies: 5
- Views: 873
Re: overall rate
You're correct. You don't add the zero order.
- Sun Mar 10, 2019 8:30 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Order
- Replies: 2
- Views: 348
Re: Order
^I agree. When solving for one experiment, you determine the numbers you are doing the calculations with by seeing which other variables are constant. So for example, if you are trying to find the rate of A, you look at the chart to see when B and C are constant in an experiment and then divide thos...
- Sun Mar 10, 2019 8:26 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Activation Energy
- Replies: 3
- Views: 350
Re: Activation Energy
Increasing activation energy means that the reaction rate is increasing because you are making the reaction slower and causes more energy to be needed.
- Sat Mar 09, 2019 11:37 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Fast Step vs Slow Step
- Replies: 3
- Views: 388
Fast Step vs Slow Step
What's the main difference between fast and slow steps and how can you tell them apart if they aren't mentioned? Also, why is the slow step the one that determines the reaction?
- Sun Mar 03, 2019 3:35 pm
- Forum: Zero Order Reactions
- Topic: Units of k in Zero Order Reactions
- Replies: 4
- Views: 502
Units of k in Zero Order Reactions
Are the units for zero order reactions M/s or mol/(L*s)?
- Sun Mar 03, 2019 3:31 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Value of “k” in Kinetics
- Replies: 5
- Views: 811
Re: Value of “k” in Kinetics
k is products over reactants, so if k > 1, then the products are favored and the forward rate is faster; however, if k < 1, then the reactants are favored and the reverse rate is faster.
- Sun Mar 03, 2019 3:29 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Stoichiometric coefficients
- Replies: 4
- Views: 916
Re: Stoichiometric coefficients
Yes, they are used for elementary step rate laws, but always keep in mind you cannot use it when you're trying to solve for the rate law of the overall reaction because the coefficients may not always line up.
- Sun Mar 03, 2019 3:25 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Purpose of Kinetics
- Replies: 6
- Views: 1731
Re: Purpose of Kinetics
The purpose of kinetics is to see what various substances affects the rate of the reaction and how fast the reactants are turned into products. So basically what you pretty much got it.
- Sun Mar 03, 2019 3:22 pm
- Forum: First Order Reactions
- Topic: Negative Orders
- Replies: 5
- Views: 968
Re: Negative Orders
Yes, negative orders are possible and just means that whatever the substance is, it decreases and cases the reaction rate to increase. I had the same confusion, but a TA told me to get familiar with negative orders and fractions.
- Fri Feb 22, 2019 9:30 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: salt bridge
- Replies: 5
- Views: 570
Re: salt bridge
Ultimately, a salt bridge is what helps maintain a battery and allows it to work. When adding a salt bridge, it the elements K+ favors the cathode and CL- favors the anion, and helps the stabilize the flow of electrons between the two.
- Fri Feb 22, 2019 9:24 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Finding K or Q with Nernst's Equation
- Replies: 2
- Views: 622
Finding K or Q with Nernst's Equation
If a problem were to ask you to find the value of K or Q, how would you do this when using Nernst's equation?
- Fri Feb 22, 2019 9:23 am
- Forum: Balancing Redox Reactions
- Topic: Redox and Oxidation
- Replies: 3
- Views: 416
Re: Redox and Oxidation
First, you should always see if the equation is balanced out or not. From there, you go to each compound/ion and find the charge of each one. From there, you compare the reactants with the products to see which are being reduced and which are being oxidized. The reducing agent is the one that gets o...
- Tue Feb 12, 2019 10:56 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Isothermal vs. Non-Isothermal
- Replies: 1
- Views: 287
Isothermal vs. Non-Isothermal
Just for clarification, why do isothermal systems use the constant R and why don't non-isothermal systems use R?
- Tue Feb 12, 2019 10:54 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Higher Molar Entropy
- Replies: 3
- Views: 423
Re: Higher Molar Entropy
Molecules that are more complex (larger in size) are the ones with higher entropy. Also, residual entropy is the difference in entropy (left over in the system) when it is at absolute 0 Kelvin.
- Tue Feb 12, 2019 10:51 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Standard Molar Entropies
- Replies: 2
- Views: 342
Re: Standard Molar Entropies
Larger compounds/atoms are more complex and larger in weight, allowing it to have accessible vibrational energy levels. This is what causes it to have higher entropy.
- Fri Feb 08, 2019 8:00 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Standard Molar Entropy
- Replies: 1
- Views: 536
Standard Molar Entropy
Why aren't there any delta symbols for the standard molar entropy formula? Also, why are the components always positive?
- Fri Feb 08, 2019 7:58 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Relationship Between Temperature and Entropy
- Replies: 1
- Views: 221
Relationship Between Temperature and Entropy
Just to be clear, does low temperature mean there's an increase in entropy? Or is it the opposite?
- Fri Feb 08, 2019 7:54 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Steam vs. Boiled Water
- Replies: 2
- Views: 332
Steam vs. Boiled Water
Why is steam hotter than boiled water? It was discussed in lecture, but I still am confused with the concept.
- Sun Feb 03, 2019 9:30 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Adiabatic
- Replies: 4
- Views: 507
Re: Adiabatic
Adiabatic means q=0, which means delta U=w
- Sun Feb 03, 2019 9:29 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Isochoric
- Replies: 4
- Views: 503
Re: Isochoric
Isochoric means delta V=0, which means w=0 and delta U=q
- Sun Feb 03, 2019 9:28 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Isobaric
- Replies: 2
- Views: 315
Re: Isobaric
Isobaric means that delta P=0 or qp=delta H, which means that delta U=delta H—P*delta V
- Sun Feb 03, 2019 9:23 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Negative or Positive Work
- Replies: 3
- Views: 367
Negative or Positive Work
When do you know when work is negative or positive?
- Sun Feb 03, 2019 9:20 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Specific Heat (Csp)
- Replies: 3
- Views: 977
Specific Heat (Csp)
On an exam, when conducting a problem using the equation, q=g*Csp*deltaT, are we supposed to memorize the specific heat (Csp) even if the problem doesn't give it to you, or will it be given?
- Sun Feb 03, 2019 9:09 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated System Example
- Replies: 4
- Views: 1028
Isolated System Example
I understand the concepts of systems, but what's a good example of an isolated system?
- Thu Jan 24, 2019 1:05 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: q vs. qp
- Replies: 2
- Views: 179
q vs. qp
What is the difference between q and qp?
- Thu Jan 24, 2019 1:04 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Heat and Work Not State Properties
- Replies: 1
- Views: 96
Heat and Work Not State Properties
Why aren't heat and work considered a state property?
- Thu Jan 24, 2019 1:03 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: p in qp
- Replies: 1
- Views: 90
p in qp
What does the p represent in the expression "qp"?
- Mon Jan 14, 2019 11:06 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE table
- Replies: 3
- Views: 445
ICE table
When conducting the ICE table, are aqueous and gas compounds allowed only?
- Mon Jan 14, 2019 11:05 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Q vs. K
- Replies: 5
- Views: 516
Q vs. K
What's the difference between Q and K??
- Mon Jan 14, 2019 11:02 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Change in temperature and K
- Replies: 2
- Views: 296
Change in temperature and K
Why does a change in temperature affect K and not a change in pressure or concentration?
- Mon Jan 07, 2019 11:20 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Partial Pressure Problems
- Replies: 1
- Views: 207
Partial Pressure Problems
When working on problems dealing with partial pressure, should we always write a "P" before the constant? (e.g. Kp= PCO2) Because it was shown to do it in lecture?
- Mon Jan 07, 2019 11:17 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Large/Small Equilibrium Constant
- Replies: 2
- Views: 203
Large/Small Equilibrium Constant
In lecture we went over how if there is a large equilibrium constant, it is a result from it having less product because it is stable; however, if the product is more than the reaction, will it make it a smaller equilibrium constant? And would it count as a reverse reaction?
- Mon Jan 07, 2019 11:13 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Concentration vs Pressure
- Replies: 6
- Views: 446
Re: Equilibrium Concentration vs Pressure
It depends on the information given in the problem. It will most likely ask for you to find either or.
- Mon Jan 07, 2019 11:10 pm
- Forum: Ideal Gases
- Topic: R in PV=nRT
- Replies: 34
- Views: 7135
R in PV=nRT
What does the R represent in the equation PV=nRT? and what are the units?
- Wed Dec 05, 2018 5:08 pm
- Forum: Properties & Structures of Inorganic & Organic Bases
- Topic: HF ion
- Replies: 3
- Views: 553
HF ion
Why is HF not considered a strong acid??
- Wed Dec 05, 2018 5:02 pm
- Forum: Conjugate Acids & Bases
- Topic: Strong acids/bases and Weak conjugate acids/bases
- Replies: 1
- Views: 164
Strong acids/bases and Weak conjugate acids/bases
Just to be clear, strong acids usually have weak conjugate bases and strong bases usually have weak conjugate acids right?
- Wed Dec 05, 2018 4:59 pm
- Forum: Lewis Acids & Bases
- Topic: Resonance Structures and Acids/Bases
- Replies: 1
- Views: 125
Resonance Structures and Acids/Bases
If a compound consists of resonance structures, can that help distinguish if it's a weak or strong acid or base?
- Wed Dec 05, 2018 4:56 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pOH from pH
- Replies: 2
- Views: 345
Re: pOH from pH
Yup! When given pH and want to find pOH, you simply subtract the pH by 14, due to the fact that pH and pOH together equal 14.
- Wed Dec 05, 2018 4:53 pm
- Forum: Conjugate Acids & Bases
- Topic: OH- vs -OH
- Replies: 3
- Views: 431
OH- vs -OH
I noticed in lecture, Professor Lavelle wrote hydroxide ion as [-OH], instead of [OH-]. BY moving the charge, does it alter the compound? Are they both the same or are they different?
- Wed Dec 05, 2018 4:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
- Replies: 118
- Views: 21868
- Sun Dec 02, 2018 10:07 am
- Forum: Naming
- Topic: Oxidation State
- Replies: 4
- Views: 365
Re: Oxidation State
You first find the oxidative number of the compound (given) and are usually given another oxidative number of one of the atoms or you must know (e.g. (NH3) is 0). From there, you find the difference between the oxidative states to find the oxidative number of the missing one(s).
- Sun Dec 02, 2018 10:00 am
- Forum: Conjugate Acids & Bases
- Topic: Strong and Weak Acids and Bases in Relations with H2O
- Replies: 3
- Views: 347
Strong and Weak Acids and Bases in Relations with H2O
What are the relationships between strong and weak acids and bases with water? Do they dissociate or not? Does one dissociate faster than the other?
- Sun Dec 02, 2018 9:51 am
- Forum: Bronsted Acids & Bases
- Topic: Bronsted and Lewis Acids/Bases
- Replies: 1
- Views: 397
Bronsted and Lewis Acids/Bases
Do the definitions of Bronsted acids and bases and Lewis acids and bases relate to oxidation and reduction reactions? Just thought I saw a connection with a bio topic and chem topic.
- Sat Nov 24, 2018 10:13 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: vsepr shape
- Replies: 6
- Views: 697
- Sat Nov 24, 2018 10:12 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: vsepr shape
- Replies: 6
- Views: 697
Re: vsepr shape
The two models are pretty similar, but I first start by drawing out the lewis structure in the most linear shape as possible. Then I add the dotted and darkened lines as much needed. I also circle in the lone pairs. From there, I find it easier to the the VSEPR shape. Hope this helps.
- Sat Nov 24, 2018 10:01 am
- Forum: Electronegativity
- Topic: Largest Electronegativity
- Replies: 4
- Views: 468
Re: Largest Electronegativity
Fluorine is the element with the highest electronegativity
- Sat Nov 24, 2018 9:57 am
- Forum: Resonance Structures
- Topic: Resonance in VSEPR Theory
- Replies: 1
- Views: 1165
Resonance in VSEPR Theory
Do resonance structures also occur in VSEPR models? Like when you are drawing them with the dotted lines?
- Sat Nov 24, 2018 9:55 am
- Forum: Sigma & Pi Bonds
- Topic: Delta Bonds
- Replies: 4
- Views: 410
Re: Delta Bonds
When all four lobes of the d orbitals interact with each other making it a covalent bond.
- Sat Nov 24, 2018 9:53 am
- Forum: Sigma & Pi Bonds
- Topic: Amount of sigma bonds
- Replies: 6
- Views: 968
Re: Amount of sigma bonds
Single bond = one sigma bond, double bond = one sigma bond and one pi bond, and triple = one sigma bond and two pi bonds
- Sat Nov 24, 2018 9:49 am
- Forum: Sigma & Pi Bonds
- Topic: Sigma and Pi Bonds
- Replies: 2
- Views: 174
Sigma and Pi Bonds
Is there a difference in length/distance for sigma and pi bonds?
- Sat Nov 24, 2018 9:42 am
- Forum: Hybridization
- Topic: Writing out Hybridization
- Replies: 8
- Views: 614
Writing out Hybridization
If a d-block does appear, would writing the hybridization out like sp^3d be correct or do we have to put the d in the beginning first like dsp^3?
- Sat Nov 24, 2018 9:34 am
- Forum: Lewis Structures
- Topic: Lewis Structure to 3D
- Replies: 3
- Views: 486
Re: Lewis Structure to 3D
I don't believe so, but it's always good to know how to draw the 3D model
- Sat Nov 24, 2018 9:32 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape
- Replies: 5
- Views: 478
Re: Molecular Shape
I think you have to memorize those as well. Or you can look at the shape and determine it from there, but you would have to draw the shape correctly if you are looking doing it that way
- Tue Nov 06, 2018 10:25 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizing Power vs Polarisabiltiy
- Replies: 2
- Views: 298
Polarizing Power vs Polarisabiltiy
What's the difference between polarizing power and polarisability?
- Sun Nov 04, 2018 9:55 pm
- Forum: Resonance Structures
- Topic: Resonance Structures
- Replies: 3
- Views: 422
Resonance Structures
Are we supposed to draw all of the resonance structures even if the problem does not ask?
- Sun Nov 04, 2018 9:52 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge and Lewis Structures
- Replies: 5
- Views: 647
Formal Charge and Lewis Structures
When drawing out the Lewis Structures, are we supposed to add the charges on the atoms even when it's not asked in the problem?
- Sun Nov 04, 2018 9:48 pm
- Forum: Electronegativity
- Topic: Electronegativity
- Replies: 5
- Views: 578
Electronegativity
I understand the trend of electronegativity, but what is the purpose of electronegativity?
- Fri Oct 26, 2018 10:06 pm
- Forum: Lewis Structures
- Topic: Periodic Table Trends
- Replies: 3
- Views: 327
Re: Periodic Table Trends
There shouldn't be any exceptions in regards to periodic trends and drawing Lewis structures
- Fri Oct 26, 2018 10:03 pm
- Forum: Lewis Structures
- Topic: Drawing Lewis Structures with Charges
- Replies: 6
- Views: 879
Drawing Lewis Structures with Charges
When drawing Lewis Structures for polyatomic molecules, what are the rules if charges exist?
- Fri Oct 26, 2018 10:02 pm
- Forum: Octet Exceptions
- Topic: Octet Exceptions
- Replies: 3
- Views: 541
Octet Exceptions
Why are H, He, Li, and Be exceptions to the octet rule?
- Thu Oct 18, 2018 11:41 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: How to Find the Number of Orbitals
- Replies: 3
- Views: 301
How to Find the Number of Orbitals
We haven't mentioned in Lecture 1 yet, but how do you find the number orbital of in a sub shell??
- Thu Oct 18, 2018 11:33 pm
- Forum: Einstein Equation
- Topic: Values of Each Symbol
- Replies: 3
- Views: 453
Values of Each Symbol
Will the values of the symbols be given on the exam or should we just memorize them? (e.g. Planck's constant or speed of light)
- Fri Oct 12, 2018 3:04 pm
- Forum: DeBroglie Equation
- Topic: Week 3 Textbook Assignment
- Replies: 2
- Views: 133
Week 3 Textbook Assignment
For week 3, are we choosing another set of 7 questions from the Quantum World chapter or do we move on to the Chemical Bonds chapter?
- Fri Oct 12, 2018 9:28 am
- Forum: Einstein Equation
- Topic: Symbol for frequency
- Replies: 12
- Views: 2302
Re: Symbol for frequency
I would just stick with v because that's what Lavelle has been giving us.
- Thu Oct 11, 2018 4:04 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: En=-hR/n^2
- Replies: 3
- Views: 244
En=-hR/n^2
Why is this equation negative again? I know Professor Lavelle mentioned this in class, but can someone please refresh it to me?
- Mon Oct 08, 2018 9:36 pm
- Forum: Photoelectric Effect
- Topic: Significance of Photoelectric Effect
- Replies: 3
- Views: 321
Significance of Photoelectric Effect
Can someone please narrow down the significance of photoelectric effect? I still don't get it.
- Mon Oct 08, 2018 9:34 pm
- Forum: Einstein Equation
- Topic: Einstein's Equation: E=hv
- Replies: 11
- Views: 1593
Einstein's Equation: E=hv
What does the h in E=hv represent again??
- Wed Oct 03, 2018 7:39 pm
- Forum: SI Units, Unit Conversions
- Topic: Textbook Homework Assignment
- Replies: 11
- Views: 1394
Re: Textbook Homework Assignment
Quick Question: Are we supposed to write down the questions for the textbook problems when doing the homework??
- Tue Oct 02, 2018 12:30 pm
- Forum: SI Units, Unit Conversions
- Topic: Textbook Homework Assignment
- Replies: 11
- Views: 1394
Re: Textbook Homework Assignment
You complete any 7 problems that you want to do
- Mon Oct 01, 2018 6:46 pm
- Forum: SI Units, Unit Conversions
- Topic: Textbook Homework Assignment
- Replies: 11
- Views: 1394
Re: Textbook Homework Assignment
False alarm. I figured it out (:
- Mon Oct 01, 2018 6:12 pm
- Forum: Balancing Chemical Reactions
- Topic: States of Atoms
- Replies: 7
- Views: 507
States of Atoms
If I don't know the states of atoms when writing a chemical equation, what should I do? Leave it blank or just do an educated guess?
- Mon Oct 01, 2018 6:08 pm
- Forum: Balancing Chemical Reactions
- Topic: Law of Conservation of Mass [ENDORSED]
- Replies: 7
- Views: 1085
Law of Conservation of Mass [ENDORSED]
Anyone willing to give a simpler definition of the Law of Conservation of Mass?
- Mon Oct 01, 2018 6:02 pm
- Forum: SI Units, Unit Conversions
- Topic: Textbook Homework Assignment
- Replies: 11
- Views: 1394
Textbook Homework Assignment
Hey guys. Am I the only one that is confused about where the problems are located in the textbook? What pages are the textbooks problems in, for the 6th and 7th edition??