Search found 47 matches
- Sun Mar 10, 2019 11:55 pm
- Forum: Biological Examples
- Topic: Enzymes, Lecture example.
- Replies: 3
- Views: 1182
Enzymes, Lecture example.
In lecture, it was brought up that enzymes are a zero order reaction. I was wondering why that is true because to be it would make more sense for them to be a first-order reaction since the amount you have would matter? So wouldn't it be dependent on concentration?
- Sun Mar 10, 2019 11:50 pm
- Forum: Zero Order Reactions
- Topic: Integration/Derivation
- Replies: 3
- Views: 542
Integration/Derivation
Will we need to know how to derive/integrate all of the orders?
- Sun Mar 10, 2019 11:49 pm
- Forum: Zero Order Reactions
- Topic: Zero Order Units
- Replies: 3
- Views: 439
Zero Order Units
What is a good way of memorizing the units for zero, 1 and 2nd order reactions, like in a way that you understand the concepts?
- Wed Feb 27, 2019 9:18 pm
- Forum: Balancing Redox Reactions
- Topic: 14.15 Tips?
- Replies: 1
- Views: 291
14.15 Tips?
Does anyone have any tips on how to do 14.15 a), b) and C)? Is there a particular way to break the problem down? Does anyone have a preferred first step? Or a chart? I understand how to balance redox reactions, but I am a little thrown off by these problems. Any tip would be nice. Just want to try n...
- Wed Feb 27, 2019 9:12 pm
- Forum: Balancing Redox Reactions
- Topic: d from 14.13
- Replies: 2
- Views: 375
d from 14.13
Why is it that Au+ -----> Au and Au3+ --------> Au?
When the original equation is: Au+-----> Au + Au3+
How can Au3+ and Au be on opposite sides???
When the original equation is: Au+-----> Au + Au3+
How can Au3+ and Au be on opposite sides???
- Wed Feb 27, 2019 8:53 pm
- Forum: Balancing Redox Reactions
- Topic: 14.13
- Replies: 1
- Views: 339
14.13
In 14.3, why do we split H and Cl and then combine them again? I am really confused on how some balancing problems we can or cannot split elements up such as HCl.
- Wed Feb 27, 2019 8:51 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Which Molar Ratio?
- Replies: 2
- Views: 332
Which Molar Ratio?
Which molar ratio is to be used when calculating the Gibbs Free energy of a cell reaction? For example in 14.9 it has Ce and I in the equation, but how do I know which molar ratio to use? And on which side of the equation??? Thank you!
- Wed Feb 27, 2019 8:21 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 14.11
- Replies: 2
- Views: 352
14.11
I am confused as to why we can use the reverse of the anode equation. When are we allowed to flip the half equations?
- Wed Feb 27, 2019 8:09 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: BASIC VS ACIDIC METHODOLOGY
- Replies: 1
- Views: 276
BASIC VS ACIDIC METHODOLOGY
When calculating the half-reactions and the final balanced reactions, there are two methodologies to use. The one for the bases requires to use H20 and H to balance the equations, and the acidic one requires using H2O and Oh. How do I know which methodology to use without the question explicitly men...
- Sun Feb 24, 2019 9:37 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Wmax and -W
- Replies: 2
- Views: 286
Wmax and -W
I understand that potential difference is (-w)/charge and is written in units J/C
Cell potential is E = (-w)/charge
However, I am confused on why wmax=-charge * E
Why is it not -w, but wmax?
Cell potential is E = (-w)/charge
However, I am confused on why wmax=-charge * E
Why is it not -w, but wmax?
- Sun Feb 24, 2019 9:29 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram Lines
- Replies: 3
- Views: 349
Re: Cell Diagram Lines
I'm not 100% sure, but one line represents the interface between phases in contact with each other which includes a porous disk. Two lines represent the salt bridge.
- Sun Feb 24, 2019 8:58 pm
- Forum: Balancing Redox Reactions
- Topic: Problem 14.1, 6th ed.
- Replies: 3
- Views: 391
Problem 14.1, 6th ed.
In problem 14.1, we have to balance the equation in regards to hydrogen and oxygen, but I thought we only needed to balance the elements being oxidized or reduced as well as the electrons. Why do we also need to balance the hydrogens with oxygens? Thank you, the chemical equation is below. H(+) (aq)...
- Sun Feb 17, 2019 11:11 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy and Molar Ratios
- Replies: 2
- Views: 808
Gibbs Free Energy and Molar Ratios
For the Gibbs problems, sometimes we are given the equation which has different molar ratios. Does that mean we just use the information provided of entropies and multiply them by the number of moles per product? Or do we have to set such chemical equation so that the products equal one and convert ...
- Sun Feb 17, 2019 11:08 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy Problems
- Replies: 3
- Views: 355
Gibbs Free Energy Problems
For problems pertaining to Gibbs Free Energy, will we be given the standard enthalpies and the entropies? I am wondering because we have them in the textbook. Will we be given another sheet for the test with the information or will it be provided in the problem? Thank you!
- Sun Feb 17, 2019 11:06 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: HW for W7
- Replies: 7
- Views: 700
HW for W7
Hello, I was wondering if the homework from this week can have Gibbs Energy problems or only Electrochemistry? Thank you!
- Sun Feb 10, 2019 9:36 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Midterm 2019
- Replies: 9
- Views: 906
Re: Midterm 2019
Basically, study chapters 11, 12, 8, and Chapter 9 up to section 9.8 in the 6th edition.
- Sun Feb 10, 2019 9:09 pm
- Forum: Ideal Gases
- Topic: How do I know what is an Ideal Gas
- Replies: 11
- Views: 993
How do I know what is an Ideal Gas
People keep mentioning ideal gasses, and I have no idea what is considered an ideal gas? How do you know the difference?
- Sun Feb 10, 2019 9:04 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Entropy and Enthalpy
- Replies: 3
- Views: 430
Entropy and Enthalpy
Hello, what is a good way not to mix up entropy and enthalpy problems, with all these equations, it gets a bit confusing? Thank you.
- Sun Feb 03, 2019 9:43 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Thermochemistry // Thermodynamics
- Replies: 2
- Views: 401
Thermochemistry // Thermodynamics
I understand that we are entering a new unit, but I am confused. What is the difference between thermochemistry and thermodynamics? Does thermodynamics have more to do with calculations? I find it useful to make links and distinguishes between units/topics. Thermochemistry Hess' Law Thermodynamics D...
- Sun Feb 03, 2019 9:36 pm
- Forum: Phase Changes & Related Calculations
- Topic: Phase Changes
- Replies: 2
- Views: 348
Phase Changes
For clarification. When something goes through a phase change, it does not change temperature but it does take time? If so, won't it eventually change in temperature after the phase change though?
- Sun Feb 03, 2019 9:28 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess's Law
- Replies: 2
- Views: 332
Hess's Law
I understand that delta H is equal to the summation of all the changes in enthalpy when a reaction occurs. However, I am unclear how to do this on a problem that involves reactions. I'm unsure which textbook has this problem, but how would you solve the equation below: 3C(s)+S8(s) ----> C3S8(l) I kn...
- Sun Jan 27, 2019 10:02 pm
- Forum: Phase Changes & Related Calculations
- Topic: Enthalpy H(r)
- Replies: 1
- Views: 262
Enthalpy H(r)
Phase transitions have a slope of zero in regards to temperature over time. Why does phase transition length, though at a zero slope have such large effects such as causing a greater burn?
- Sun Jan 27, 2019 9:45 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy
- Replies: 1
- Views: 304
Enthalpy
Mentioned in class it was said that we should not always expect the same enthalpy for reactions since pressure and because products and reactions can be in different states. For clarification, does this apply to both the forward and reverse reaction?
- Sun Jan 27, 2019 9:40 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess's Law
- Replies: 3
- Views: 350
Hess's Law
Will we need to calculate the kJN when working with Hess's law? Or will it always be given?
- Sun Jan 13, 2019 8:54 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Catalysts [ENDORSED]
- Replies: 3
- Views: 317
Re: Catalysts [ENDORSED]
This is a really good question. I was wondering the same thing as well since a catalyst does add more reactants, guess it would change it. However, I am uncertain. I would assume that it could influence it. I am. however, interested in seeing what others say. Great question.
- Sun Jan 13, 2019 8:42 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q
- Replies: 2
- Views: 213
Q
In class it has been mentioned that Q tells us if a reaction goes forward or not in regards if it is greater or less than K. However, I am unsure if that also relates to determining an endothermic and exothermic reaction. Is it connected or are these separate concepts? Thank you!
- Sun Jan 13, 2019 8:33 pm
- Forum: Ideal Gases
- Topic: R [ENDORSED]
- Replies: 5
- Views: 566
R [ENDORSED]
Hello, I am confused by what units we are to use when using the Pv=nRT equation, specifically in regards to R. There are various units you can have it in. However, it is unclear to me which ones are the correct ones when regarding to concentration.
- Sun Jun 10, 2018 11:38 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Final [ENDORSED]
- Replies: 5
- Views: 629
Final [ENDORSED]
In regards to the final will we need to distinguish the difference between the different types of "Bent" and "linear"? For example, can we just write bent or linear or do we need to specify by saying the number of areas of electron density and the number of lone pair densities? F...
- Sun Jun 10, 2018 11:32 pm
- Forum: Air Pollution & Acid Rain
- Topic: ACID RAIN
- Replies: 5
- Views: 847
ACID RAIN
In regards to acid rain, I understand that all rain is acidic, but that "acid rain" is more harmful. Is that because it is more concentrated in terms of morality or because it more acidic?
- Sun Jun 10, 2018 11:29 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: H+ Acidic and OH- Basic
- Replies: 4
- Views: 627
H+ Acidic and OH- Basic
From what I understand from lecture, the more H+ ions the more acidic something is and the more OH- ions the more basic something is or becomes. What I am confused about it, the relationship between Lewis and Bronsted acids and bases. Like what relationship do they hold?
- Sun May 27, 2018 10:23 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: oxidation
- Replies: 7
- Views: 861
Re: oxidation
So when you are dealing with oxidation states, you will generally have a + or -, because almost any element can have e- added or taken away in order to get to the nearest noble gas configuration. The goal is to get an octet. An example from chapter 3 HW is 3.23, Cl can have -1 or +7. This is becaus...
- Sun May 27, 2018 10:19 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: oxidation
- Replies: 7
- Views: 861
Re: oxidation
105012653 1F wrote:Sorry, I'm kind of confused; what exactly is an oxidation state?
Oxidation state is the same as the charge given to an element when it is by itself.
- Sun May 27, 2018 10:15 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Drawing
- Replies: 7
- Views: 836
VSEPR Drawing
Will we need to know how to draw the VSEPR geometric shape in the official way or do we just need to know the bond angles?
- Sun May 27, 2018 10:07 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular shape
- Replies: 1
- Views: 127
Molecular shape
By following the general rules that we have learned about the geometric shape, is that enough information that you need to know? For example, trigonal planar are all at a 120 degree angle. Is there any exceptions we need to be aware of?
- Sun May 20, 2018 12:41 pm
- Forum: Lewis Structures
- Topic: Chemical Formula Name
- Replies: 3
- Views: 532
Chemical Formula Name
So the other day I was doing a HW problem, specifically 3.39, part C. I noticed that the name of the compound was sodium hypochloride. My first instinct was to write out Na for sodium and then H and Cl for hypochloride. However after checking my answer I discovered that hypochloride is composed of O...
- Sun May 13, 2018 10:47 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: oxidation
- Replies: 7
- Views: 861
Re: oxidation
So when you are dealing with oxidation states, you will generally have a + or -, because almost any element can have e- added or taken away in order to get to the nearest noble gas configuration. The goal is to get an octet. An example from chapter 3 HW is 3.23, Cl can have -1 or +7. This is because...
- Sun May 13, 2018 10:27 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge Equation
- Replies: 2
- Views: 286
Formal Charge Equation
The formal charge equation: Valence electrons (-) Lone pair electrons (-) .5(Bond electrons) I just want to clarify, but if there is no charge in the compound equation, then when you add up the charge it should be zero. With that logic, then when a compound is charged, then you should have that char...
- Sun May 13, 2018 10:07 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: In Class Example, Re: radicals, NO
- Replies: 2
- Views: 417
In Class Example, Re: radicals, NO
In class we were given the example of NO and the Lewis structure given the formal charge. Although we were not given the formal charge, we end up with N+ and O-, and because of that we know to fill O and leave N with only five e- dots. However, we are given the counterexample where the reverse is do...
- Sun Apr 29, 2018 10:03 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Atomic Radius
- Replies: 4
- Views: 530
Re: Atomic Radius
The radius is half of the diameter. According to what I recall in lecture, most atoms are about one Ångström in length which is 1x10^-10, smaller than a nanometer (1x10^-9). I'm sure it differs between atoms. However, if you are searching the for the radius of an atom, I assume you add the length(s)...
- Sun Apr 29, 2018 9:47 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Using shorthand [Ar] [ENDORSED]
- Replies: 5
- Views: 599
Using shorthand [Ar] [ENDORSED]
In regards to using short hand, for example, Ca: [Ar] 4s^2 and Br: 3d^10 4s^2 4p^5, are we allowed to use Neon or Helium, or is it only after Argon that we are allowed to use this shorthand? Like can we do this regarding shorthand, Na: [Ne] 3s^1
Thank you!
Thank you!
- Sun Apr 29, 2018 7:34 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: In regards to ml
- Replies: 2
- Views: 304
In regards to ml
So I know that the first three quantum numbers are n,l, and ml, and part of my confusion arises with ml. Is ml like a sub-number of l or is it independent. From where this confusion arises is from whether or not m has the subscript l. Sorry if this is confusing, and thanks for the help!
- Sun Apr 15, 2018 11:36 pm
- Forum: Properties of Light
- Topic: Amplitude
- Replies: 3
- Views: 158
Amplitude
I know that amplitude is not that often mentioned, nor is there an equation regarding amplitude, that we have encountered. However, I was wondering what the relevance was regarding the photoelectric effect and the first experiment. I know that increasing wavelength and amplitude, will do nothing if ...
- Sun Apr 15, 2018 11:26 pm
- Forum: Einstein Equation
- Topic: Different equations
- Replies: 4
- Views: 540
Re: Different equations
For far for quantum, I would say that you be familiar with the following equations: c=wavelength * frequency E= h (constant, *6.63x10^-34) * frequency Ephoton(hv) - Ethreshhold(phi) = Eexcess (1/2me-ve-^2)<---- heads up that is mass and velocity, mass is constant How I am memorizing or just understa...
- Sun Apr 15, 2018 11:11 pm
- Forum: Properties of Light
- Topic: Equations in Quantum
- Replies: 2
- Views: 270
Re: Equations in Quantum
What I believe Dr. Lavelle meant by discrete is that there are only whole numbers and that is because of how small the particles, such as electrons are. This is evident in the energy levels, like you can't be at level 1.12443262, it has to be 1 or 2, thus you are constrained to those numbers. Which ...
- Sun Apr 15, 2018 11:05 pm
- Forum: Properties of Light
- Topic: Frequency 1/s or s^-1 [ENDORSED]
- Replies: 3
- Views: 541
Frequency 1/s or s^-1 [ENDORSED]
Hello, in class and on some questions I've noticed that when you solve for frequency which is in Hz, that sometimes it is given in either 1/s or s^-1. Is the way you give Hz relevant to the problem or is it just preference?
- Tue Apr 10, 2018 6:37 pm
- Forum: SI Units, Unit Conversions
- Topic: Units for Answer
- Replies: 10
- Views: 1202
Units for Answer
How do we know what units to give the answer in? If what I am solving for was previously stated in kg, does that mean that my answer must be in kg? Some questions give you initial value in kg and then they give you the value of something else (which you are not solving for, but use in order to get a...
- Tue Apr 10, 2018 5:54 pm
- Forum: SI Units, Unit Conversions
- Topic: L35, What is t? (Conversion)
- Replies: 3
- Views: 483
L35, What is t? (Conversion)
So for this problem we are asked to convert from kilograms to t, but I am unsure what t is. I searched it up, but found nothing convincing. On the test, will we be given units that are not SI?