Search found 61 matches
- Sun Mar 17, 2019 8:12 pm
- Forum: Balancing Redox Reactions
- Topic: Triprotic
- Replies: 7
- Views: 3720
Re: Triprotic
yes it's H3PO4 with 3 protons
- Sun Mar 17, 2019 8:07 pm
- Forum: *Enzyme Kinetics
- Topic: How do you tell if something is a catalyst vs an intermediate?
- Replies: 16
- Views: 5729
Re: How do you tell if something is a catalyst vs an intermediate?
intermediates are consumed by the reaction, meaning they do not show up in the final rate law.
catalysts are regenerated at the end, and they do show up in the rate law.
catalysts are regenerated at the end, and they do show up in the rate law.
- Sun Mar 17, 2019 8:04 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidizing powers
- Replies: 2
- Views: 489
Re: Oxidizing powers
the more positive reduction potential the higher the oxidizing power.
- Sat Mar 16, 2019 11:34 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: How to know which conducting element to add?
- Replies: 3
- Views: 518
Re: How to know which conducting element to add?
I think for this test, using Pt is the safest bet
- Sat Mar 16, 2019 11:29 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Elementary Rxns
- Replies: 2
- Views: 489
Re: Elementary Rxns
Rate = k[A]^2[B]^2. You can use the coefficients as long as the reaction is an elementary reaction
- Sat Mar 09, 2019 7:36 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: reaction rate
- Replies: 2
- Views: 298
Re: reaction rate
because the faster rate is dependent on the slower one.
- Sat Mar 09, 2019 7:25 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Negligible X
- Replies: 3
- Views: 372
Re: Negligible X
The 5% rule, so if your equilibrium value is smaller than 10^-3, you can ignore that x to make your calculation easier.
- Fri Mar 08, 2019 8:00 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kp
- Replies: 7
- Views: 675
Re: Kp
I'd say use either one it's fine, just make sure all are the units are the same in a problem just to avoid any calculation mistakes.
- Fri Mar 08, 2019 7:24 pm
- Forum: *Enzyme Kinetics
- Topic: Enzymes
- Replies: 8
- Views: 1672
Re: Enzymes
Enzymes lower the activation energy.
- Fri Mar 08, 2019 7:18 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Test 2: Melting Ice
- Replies: 6
- Views: 1038
Re: Test 2: Melting Ice
I was confused about this as well. Sun is melting the ice, so it the ice has to be absorbing heat?
someone help, thanks
someone help, thanks
- Fri Mar 08, 2019 7:09 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Pt
- Replies: 14
- Views: 1243
Re: Pt
Pt is added when no conducting solids are present.
- Tue Feb 19, 2019 1:20 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterms
- Replies: 4
- Views: 535
Re: Midterms
My TA said tomorrow after lecture, so just stay for the lookout afterwards.
- Tue Feb 19, 2019 1:19 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Concentration and free energy
- Replies: 2
- Views: 415
Re: Concentration and free energy
Yes! it's products and reactants concentrations that affect the free energy.
- Tue Feb 19, 2019 12:54 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Negative Delta G
- Replies: 7
- Views: 3926
Re: Negative Delta G
This graph will help better visualize the concept!
- Tue Feb 19, 2019 12:52 am
- Forum: Administrative Questions and Class Announcements
- Topic: 14BL and 14C
- Replies: 5
- Views: 1012
Re: 14BL and 14C
I heard that it's not too bad, just busy work. It depends on what type of person you are!
- Tue Feb 19, 2019 12:49 am
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: entropy and enthalpy
- Replies: 5
- Views: 586
Re: entropy and enthalpy
Yes they are, and it's depending on whether the reaction is exothermic or endothermic.
- Thu Feb 07, 2019 12:04 pm
- Forum: Calculating Work of Expansion
- Topic: Ideal gas expansion
- Replies: 4
- Views: 396
Re: Ideal gas expansion
Maybe because the work energy itself is still an amount, disregarding the fact that it's lost or gained. But I'm not sure though, can someone explain?
- Thu Feb 07, 2019 11:54 am
- Forum: Ideal Gases
- Topic: Ideal gas constant R
- Replies: 10
- Views: 1557
Re: Ideal gas constant R
Depends on the units! L or J
- Thu Feb 07, 2019 11:24 am
- Forum: Administrative Questions and Class Announcements
- Topic: Week 5 Homework
- Replies: 3
- Views: 332
Re: Week 5 Homework
Yes! Anything works because it counts as practice for the midterm.
- Thu Feb 07, 2019 11:10 am
- Forum: Phase Changes & Related Calculations
- Topic: Solids and Liquids
- Replies: 5
- Views: 505
Re: Solids and Liquids
Solids and liquids don't count because their pressure and volume aren't affected
- Sat Feb 02, 2019 6:54 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Open, closed, or isolated systems
- Replies: 10
- Views: 38975
Re: Open, closed, or isolated systems
Open system: matter and energy can exchange with surroundings
beaker of water- water can evaporate
Closed system: only energy can exchange with surroundings
Sealed beaker of water
Isolated system: system where nothing can exchange with surroundings
beaker of water- water can evaporate
Closed system: only energy can exchange with surroundings
Sealed beaker of water
Isolated system: system where nothing can exchange with surroundings
- Sat Feb 02, 2019 6:52 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Capactiy
- Replies: 5
- Views: 464
Re: Heat Capactiy
It depends on the amount of substance/ material so it’s an extensive property.
- Wed Jan 30, 2019 1:07 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Qsystem+Qsurr=0?
- Replies: 6
- Views: 1810
Re: Qsystem+Qsurr=0?
If one loses heat, that heat will be gained by the other. The loss will equal the gain, which makes sense.
- Wed Jan 30, 2019 1:03 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Regular heat capacity: why?
- Replies: 4
- Views: 383
Re: Regular heat capacity: why?
Specific heat capacity is an intensive property. You'll get the specific heat capacity if you divide heat capacity by the amount of substance present (g), so it is a more useful property for calculations.
- Tue Jan 22, 2019 11:22 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: What Happens to a Reaction if Inert Gas is Added?
- Replies: 7
- Views: 2228
Re: What Happens to a Reaction if Inert Gas is Added?
there is no change
- Sun Jan 20, 2019 9:40 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: pressure and volume
- Replies: 5
- Views: 468
Re: pressure and volume
Volume and pressure are inversely related.
- Sun Jan 20, 2019 9:37 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q and K
- Replies: 10
- Views: 771
Re: Q and K
If Q < K, then [R] > [P] and forward reaction is favored
If Q > K, then [R] < [P] and reverse reaction is favored
Q=K then reaction is at equilibrium
If Q > K, then [R] < [P] and reverse reaction is favored
Q=K then reaction is at equilibrium
- Sun Jan 20, 2019 9:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Shortcut method (finding concentration change)
- Replies: 5
- Views: 394
Re: Shortcut method (finding concentration change)
I think you might mean ignoring the -x subtraction in the change. So if Kc=[x][x]/0.5-x, and let's say our kc= 25, to find x you'd set up the equation as [x][x]/0.5-x= 25. In order to avoid the quadratic equation calculations, you can ignore the -x in the denominator, which won't affect the entire v...
- Mon Jan 14, 2019 4:23 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Reaction Quotient Value
- Replies: 5
- Views: 313
Re: Reaction Quotient Value
If Q < K, then [R] > [P] and forward reaction is favored
If Q > K, then [R] < [P] and reverse reaction is favored
Q=K then reaction is at equilibrium
If Q > K, then [R] < [P] and reverse reaction is favored
Q=K then reaction is at equilibrium
- Mon Jan 14, 2019 4:19 pm
- Forum: Ideal Gases
- Topic: Using Kc or Kp
- Replies: 13
- Views: 932
Re: Using Kc or Kp
Kp is used for gases, and Kc for concentrations. Sometimes Kc is used for gases as well, it depends on the question.
- Mon Jan 14, 2019 4:13 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kp
- Replies: 7
- Views: 675
Re: Kp
I think any unit is fine as long as it's consistent throughout the equation.
- Fri Dec 07, 2018 3:38 pm
- Forum: Biological Examples
- Topic: Hemoglobin Question
- Replies: 2
- Views: 362
Re: Hemoglobin Question
Hemoglobin is an oxygen transporting protein in the blood. It's made out of four myoglobin molecules, each binding to one O2 molecule. Myoglobin alone transports one O2 in muscle cells, and hemoglobin transports 4 O2 molecules in the blood stream. Can someone explain the heme structure though? I mis...
- Fri Dec 07, 2018 3:27 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bent molecular geometry
- Replies: 3
- Views: 681
Re: Bent molecular geometry
Yes, they both are bent, it's just that AX2E has an angle <120, and AX2E2 is <109, so the 2 lone pairs are just providing more repulsion than the one lone pair.
- Fri Dec 07, 2018 3:23 pm
- Forum: Conjugate Acids & Bases
- Topic: Conjugate Acids and Bases
- Replies: 1
- Views: 155
Re: Conjugate Acids and Bases
When a base and an acid react, they produce a conjugate base and a conjugate acid. I will attach an image to help explain the concept.
- Sat Dec 01, 2018 7:35 pm
- Forum: Naming
- Topic: Spaces in naming
- Replies: 2
- Views: 275
Re: Spaces in naming
I mean if it helps to keep the spaces and then rewrite it it's fine, I don't think it's minus points either way. I think for your question it's yes, but please someone correct me if I'm wrong.
- Sat Dec 01, 2018 7:23 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Water molecules
- Replies: 9
- Views: 916
Re: Water molecules
The hydrogens in water are partial positive, so they will form hydrogen bonds with any of the NOF atoms charged partial negative.
- Sat Dec 01, 2018 2:13 pm
- Forum: Biological Examples
- Topic: Knowledge of Biological Applications for Final
- Replies: 5
- Views: 382
Re: Knowledge of Biological Applications for Final
I think he focused a lot on the chemo drug, other than that not sure
- Fri Nov 23, 2018 9:14 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: AX2E2
- Replies: 2
- Views: 161
Re: AX2E2
The lone electrons cause the entire molecule to bend. AX2 alone is linear, AX2E2 adds the lone pair which causes strong repulsion.
- Wed Nov 21, 2018 12:29 pm
- Forum: Hybridization
- Topic: bonds
- Replies: 4
- Views: 158
Re: bonds
A sigma bond is a single bond, so every bond is a sigma bond.
Whenever another bond is added, it's called a pi bond.
sigma=single bond
sigma and pi=double bond
1 sigma and 2 pi=triple bond
Whenever another bond is added, it's called a pi bond.
sigma=single bond
sigma and pi=double bond
1 sigma and 2 pi=triple bond
- Tue Nov 20, 2018 12:31 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape Importance
- Replies: 1
- Views: 170
Re: Molecular Shape Importance
Having a lower boiling point means that the bonds of a certain molecule break easier than a molecule that has stronger bonds and attractions. A spherical molecule would have less surface area of bonds and interactions than a rod shaped molecule, which has much more surface area to bond.
- Sat Nov 17, 2018 11:56 pm
- Forum: Dipole Moments
- Topic: How to Identify Dipole Moments
- Replies: 3
- Views: 420
Re: How to Identify Dipole Moments
partial negative and partial positive charges.
- Thu Nov 15, 2018 11:31 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Length
- Replies: 6
- Views: 598
Re: Bond Length
Yes that's right, also I wanted to add that a single bond will be longer than a double bond, and the double bond will be longer than the triple: all because multiple bonds will be shorter. The stronger the bond, the shorter length, and the stronger the attraction.
- Thu Nov 15, 2018 11:25 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: bond angle
- Replies: 4
- Views: 477
Re: bond angle
You have 90° and 180°
- Sun Nov 11, 2018 1:42 pm
- Forum: Electronegativity
- Topic: Electronegativity
- Replies: 4
- Views: 558
Re: Electronegativity
Not sure, but I think it only has to do with the type of bonds not the actual shape. Also the greater the difference in electronegativity the larger the dipole.
Someone correct me if I'm wrong.
Someone correct me if I'm wrong.
- Sat Nov 10, 2018 11:56 pm
- Forum: Electronegativity
- Topic: Electronegativity and Electron Affinity
- Replies: 4
- Views: 477
Re: Electronegativity and Electron Affinity
electron affinity: is the energy released when an electron is added to an atom
electronegativity: ability of an atom to attract an electron
electronegativity: ability of an atom to attract an electron
- Sat Nov 10, 2018 5:53 pm
- Forum: Limiting Reactant Calculations
- Topic: Actual Yield
- Replies: 7
- Views: 1187
Re: Actual Yield
Theoretical yield is calculated from the experiment with any errors that might occur, and actual yield is what's supposed to be the outcome, excluding any small errors. Percent Yield= actual/theoretical x100.
- Sat Nov 03, 2018 10:06 pm
- Forum: Trends in The Periodic Table
- Topic: Cation and Anion Ionic Radius
- Replies: 3
- Views: 148
Re: Cation and Anion Ionic Radius
When an atom loses an electron it's more positively charged, so there will be more attraction between the positive and negative charge of the electrons left there, stronger attraction means smaller radius --> smaller cation. When an atom gains an electron, it causes increased electron-electron repul...
- Sat Nov 03, 2018 9:56 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Radial vs. Angular Nodes
- Replies: 1
- Views: 1584
Re: Radial vs. Angular Nodes
l=n-1. That determines the number of nodes present. if l=0, then it's a radial node (spherical and symmetrical node, s-orbital). When l is greater than 0, angular nodes will also be present in addition to other types of nodes. The angular nodes are the planes that show the p-orbital (the infinity sh...
- Sat Nov 03, 2018 9:35 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: H-Atom Calculation
- Replies: 2
- Views: 467
Re: H-Atom Calculation
I think the second equation is derived from the first. For the exams do the calculation using ΔE= Ef-Ei. Where you find the difference of the energy by doing two calculations (final and initial energy) using the equation En=-hR/n^2.
- Sun Oct 28, 2018 10:54 am
- Forum: Lewis Structures
- Topic: Lewis Structures in Ionic Bonds
- Replies: 2
- Views: 257
Re: Lewis Structures in Ionic Bonds
Yes we do, make sure to know the number of valence electrons of each group, and you can do that by just looking at the periodic table.
- Sat Oct 27, 2018 7:45 pm
- Forum: Ionic & Covalent Bonds
- Topic: Lowest Ionization Energy [ENDORSED]
- Replies: 7
- Views: 703
Re: Lowest Ionization Energy [ENDORSED]
You can know the lowest ionization energy of elements by where they are on the periodic table. Left to right across a period, and upward within group indicate increasing ionization energy.
- Sat Oct 27, 2018 7:36 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Hydrogen’s Energy
- Replies: 1
- Views: 1590
Re: Hydrogen’s Energy
The Balmer and Lyman series equation can be derived from the equation E=-hR/n^2, so yes they both give the same values. For this course, I think Dr. Lavelle and the TAs want us to use the first equation (E=-hR/n^2), just because it practically makes more sense. So when we find the energies, we can d...
- Mon Oct 22, 2018 1:21 pm
- Forum: Properties of Light
- Topic: Visible Light
- Replies: 5
- Views: 452
Re: Visible Light
It's between 400 and 700 nm. Also, I attached an image that shows the ranges for the radiations.
- Sun Oct 21, 2018 1:27 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: 4th quantum number
- Replies: 2
- Views: 300
Re: 4th quantum number
The fourth one gives the orientation of the spin of the electrons, there can be two values +1/2, and -1/2. the positive value indicates a clockwise spin, and the negative indicates an counter clockwise. So what this means in general is that electrons are spinning themselves as they orbit around the ...
- Sun Oct 21, 2018 1:19 pm
- Forum: Significant Figures
- Topic: Sig figs and percentages
- Replies: 3
- Views: 2217
Re: Sig figs and percentages
Percentages do not count as sig figs. In your example, the answer would have the least number of sig figs, which is 2.
- Sat Oct 13, 2018 7:13 pm
- Forum: Photoelectric Effect
- Topic: Example from Class- Photoelectric Effect
- Replies: 2
- Views: 163
Re: Example from Class- Photoelectric Effect
What we did in class, we combined the two equations, E=hv and c=λv. Solving for λ would give you λ=c/v, and solving for v in the first equation will give v=E/h. Substitute the v into the λ equation, which will give λ=hc/E. Once you have this equation, plug in all your given. λ=(6.626*10^-34 Js)(3.00...
- Sat Oct 13, 2018 6:58 pm
- Forum: Properties of Light
- Topic: De Brogile Equation
- Replies: 6
- Views: 312
Re: De Brogile Equation
The concept is that particles exhibit wave-like properties, λ = h/mv; where h is planck's constant, m is mass, v is velocity (use SI units). Also what was mentioned in class is that if the wavelength is less than 10^-13-18 m, it is not considered to be a wavelength property.
- Sat Oct 13, 2018 5:25 pm
- Forum: Properties of Electrons
- Topic: Spectral Lines (Balmer Series & Lyman Series)
- Replies: 3
- Views: 257
Re: Spectral Lines (Balmer Series & Lyman Series)
The lyman series are the ultraviolet region, and the Balmer series are the visible region. The difference is where the electron lands after being excited, for balmer it's n=2, and for lyman it's at n=1. And yes drawing the picture does help to remember.
- Sun Oct 07, 2018 12:24 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: dilutions? [ENDORSED]
- Replies: 5
- Views: 617
Re: dilutions? [ENDORSED]
M1V1=M2V2 is the main equation for dilutions! M=n(mol)/v(l) and you can move the equation around depending on your given in the problem. Also make sure all the units are the same in your equation.
- Tue Oct 02, 2018 11:58 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Units when calculating volume
- Replies: 4
- Views: 3083
Re: Units when calculating volume
Molarity is always given in mol/L. In a problem if you're given a value for molarity, it will be in the units mol/L, so it becomes a problem when you don't convert to liters since now you're using two different units. So, I'd say convert any given volume to Liters if you're given a value for Molarit...
- Tue Oct 02, 2018 11:25 pm
- Forum: Empirical & Molecular Formulas
- Topic: Using the Mass Spectrum in F17(b)
- Replies: 2
- Views: 1314
Re: Using the Mass Spectrum in F17(b)
You're dividing molecular mass by empirical to find the actual number of atoms in the formula (molecular formula). When you get that number (in this problem it's 907/302.24=3), you multiply it by the number of atoms in the empirical formula. So we go from C4O4Os to C12O12Os3.