Search found 116 matches
- Thu Mar 12, 2020 9:09 am
- Forum: Administrative Questions and Class Announcements
- Topic: FinalReview Sessions
- Replies: 3
- Views: 392
FinalReview Sessions
Does anyone know if Matthew's and Lyndon's final review got posted for us to work on? or was that canceled because of the current situation?
- Thu Mar 12, 2020 9:07 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Steady state
- Replies: 3
- Views: 234
Re: Steady state
no, Lavelle said we would focus on using pre-equilibrium only
- Thu Mar 12, 2020 9:06 am
- Forum: *Enzyme Kinetics
- Topic: How to distinguish the intermediates and catalysts?
- Replies: 9
- Views: 854
Re: How to distinguish the intermediates and catalysts?
Intermediates are produced and then consumed, and catalysts are consumed and then (re)produced
- Thu Mar 12, 2020 9:04 am
- Forum: Administrative Questions and Class Announcements
- Topic: Final exam content
- Replies: 15
- Views: 1179
Re: Final exam content
I assume the final would be similar to the previous exams we have taken, where not every question is from the homework, but the concepts from the hw would be tested and a couple problems would mirror hw problems
- Thu Mar 12, 2020 9:02 am
- Forum: Balancing Redox Reactions
- Topic: Determining the oxidizer and reducer
- Replies: 10
- Views: 735
Re: Determining the oxidizer and reducer
the oxidizing agent is the reactant that gets reduced, whereas the reducing agent is the one that gets oxidized
- Sun Mar 08, 2020 7:36 pm
- Forum: General Rate Laws
- Topic: 7A.3
- Replies: 4
- Views: 413
Re: 7A.3
I feel like the rates would both be positive because I think they are technically the same, just working in the opposite direction. either way, the book says that positive reaction rate is the normal convention in chemical kinetics
- Sun Mar 08, 2020 7:33 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 13
- Views: 838
Re: Cell Diagrams
^ one thing to note though is that you should only add an inert solid if there is not a solid METAL at the cathode or anode side
- Sun Mar 08, 2020 7:29 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing Basic Redox Reactions
- Replies: 6
- Views: 464
Re: Balancing Basic Redox Reactions
^^ for each half reaction, instead of adding H+ to an equation, add water, then add that same amount of OH- to the other side of the reaction
- Sun Mar 08, 2020 7:26 pm
- Forum: Zero Order Reactions
- Topic: examples of zero order reactions?
- Replies: 6
- Views: 510
Re: examples of zero order reactions?
just to add on, one way you can decipher between a 0, 1st, and 2nd order reaction is by looking at what the units of the rate constant, "k", is:
0 order= conc/s
1st= 1/s
2nd= 1/(conc*s)
0 order= conc/s
1st= 1/s
2nd= 1/(conc*s)
- Sun Mar 08, 2020 7:22 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Slow step
- Replies: 2
- Views: 190
Re: Slow step
the elementary step with the rate matching the overall reaction should be the slow step considering 1) the sum of elementary steps=overall rate and 2) the mechanism agrees w the experimentally determined rate law
- Tue Mar 03, 2020 3:40 am
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: hw 6O1
- Replies: 1
- Views: 229
hw 6O1
How would you go about solving the question: A 1.0 m NiSO4(aq) solution was electrolyzed by using inert electrodes. Write (a) the cathode reaction; (b) the anode reaction. (c) With no overpotential at the electrodes, what is the minimum potential that must be supplied to the cell for the onset of el...
- Sun Mar 01, 2020 3:26 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Finding N
- Replies: 6
- Views: 463
Re: Finding N
n refers to the number of moles of electrons transferred, basically it is the total number of electrons you end up cancelling out in your half reaction equations
- Sun Mar 01, 2020 2:17 am
- Forum: Balancing Redox Reactions
- Topic: hw 6l7c
- Replies: 1
- Views: 166
hw 6l7c
how do you balance the reaction:
Cd(s) + 2 Ni(OH)3 (s) --> Cd(OH)2 (s) + 2 Ni(OH)2 (s)?
Cd(s) + 2 Ni(OH)3 (s) --> Cd(OH)2 (s) + 2 Ni(OH)2 (s)?
- Sun Mar 01, 2020 1:57 am
- Forum: Balancing Redox Reactions
- Topic: hw 6l7a
- Replies: 1
- Views: 136
hw 6l7a
when writing the cell diagram for AgBr(s) <--> Ag+(aq) + Br-(aq), where does the AgBr(s) in Ag(s)|AgBr(s)|Br-(aq)||Ag+(aq)|Ag(s) come from?
- Sun Mar 01, 2020 1:52 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Flipping the sign
- Replies: 10
- Views: 614
Re: Flipping the sign
you flip the sign when you are given the reduction potential of a reaction but you have an oxidation reaction you are trying to find the Ecell for
- Sun Mar 01, 2020 1:50 am
- Forum: Balancing Redox Reactions
- Topic: hw 6l7b
- Replies: 2
- Views: 258
hw 6l7b
How would you balance the redox reaction: H+(aq) + OH-(aq) --> H2O(l), the Brønsted neutralization reaction?
In the answer key, they use o2(g) to balance out the oxygens, but how would you know to do that?
In the answer key, they use o2(g) to balance out the oxygens, but how would you know to do that?
- Sun Feb 23, 2020 1:44 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic cell vs battery system
- Replies: 3
- Views: 312
Re: Galvanic cell vs battery system
I think they basically are the same. The textbook states that a battery is a collection of galvanic cells connected in a series
- Sun Feb 23, 2020 1:41 pm
- Forum: Balancing Redox Reactions
- Topic: Acidic vs Basic
- Replies: 4
- Views: 368
Re: Acidic vs Basic
when balancing reactions in a basic solution, you end up having OH- as a product, whereas in acidic solution, you have H+
- Sun Feb 23, 2020 1:40 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: standard conditions
- Replies: 8
- Views: 522
Re: standard conditions
standard conditions refers to a 1M solution at 1 atm and 273.15 K
- Sun Feb 23, 2020 1:36 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Use of Platinum
- Replies: 10
- Views: 583
Re: Use of Platinum
You use platinum whenever you need to carry electrons into or out of the electrode compartment. Platinum is an inert conductor
- Sun Feb 23, 2020 1:31 pm
- Forum: Balancing Redox Reactions
- Topic: balancing acidic vs. basic solutions
- Replies: 3
- Views: 307
Re: balancing acidic vs. basic solutions
as far as i know, it would tell you because whether it is in an acidic or basic solution determines the products
- Sun Feb 16, 2020 10:10 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: endo/exo and temp
- Replies: 12
- Views: 1103
Re: endo/exo and temp
the way i think abt is where heat is placed when it's written in a chemical rxn, when the rxn is endothermic, heat is on the left, and when it's exothermic it's on the left (you can think of this happening bc when heat is released, it is written as -)
- Sun Feb 16, 2020 10:00 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Negative work
- Replies: 14
- Views: 935
Re: Negative work
when a system does work, it is by a negative sign
- Sun Feb 16, 2020 9:59 pm
- Forum: Ideal Gases
- Topic: Equation
- Replies: 4
- Views: 421
Re: Equation
or you could be talking about the boltzmann formula for entropy , "S=klnW" where, S=entropy, k=1.381*10^-23 j/k (the boltzmann constant), and W is the number of ways that the atoms or molecules in the sample can be arranged with the same total energy
- Sun Feb 16, 2020 9:52 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated versus closed
- Replies: 7
- Views: 591
Re: Isolated versus closed
a closed system has a fixed amt of matter but can exchange energy w the surroundings, while an isolated system cannot exchange matter or energy with the surroundings
- Sun Feb 16, 2020 9:28 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2
- Replies: 11
- Views: 710
Re: Test 2
I think the person above is right, in chem 14a, test 2 wasn't cumulative
- Sun Feb 09, 2020 6:48 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Intensive vs Extensive
- Replies: 7
- Views: 345
Re: Intensive vs Extensive
for an intensive property, the value of something will be the same no matter how much of a substance you have (ie, specific heat). for an extensive property, the value of something depends on how much substance you have (ie heat capacity)
- Sun Feb 09, 2020 6:46 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Homework 4C3
- Replies: 2
- Views: 84
Re: Homework 4C3
for parts a and b, you would use similar processes. for part a, you would use the equation q=nCpdeltaT, and for part b, the equation q=nCvdeltaT. These are pretty much the same equations, just one is for constant pressure, whereas the other one is for constant volume. Plug in the values in each equa...
- Sun Feb 09, 2020 6:41 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: System releasing energy
- Replies: 2
- Views: 95
Re: System releasing energy
If I'm reading this correctly, I think you are correct because when energy is released, deltaH is negative, and when delta H is negative, delta G is also negative in most cases
- Sun Feb 09, 2020 6:37 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess's Law
- Replies: 10
- Views: 268
Re: Hess's Law
Enthalpy is a state function, so enthalpy is additive
- Sun Feb 09, 2020 6:37 pm
- Forum: Phase Changes & Related Calculations
- Topic: relationship between heat capacity and heating curve
- Replies: 6
- Views: 255
Re: relationship between heat capacity and heating curve
substances with a lower heat capacity are easier to heat up, so the change in temperature is more extreme after the same period of time taken to heat up a substance with a higher heat capacity. as a result, the heating curve is steeper for a substance with a low heat capacity
- Sun Feb 09, 2020 6:33 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Entropy Question
- Replies: 3
- Views: 167
Re: Entropy Question
i believe so because one of the causes of entropy is change in position (of the molecules in a substance)
- Sun Feb 02, 2020 4:50 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Calorimeter vs. Bomb Calorimeter
- Replies: 4
- Views: 302
Re: Calorimeter vs. Bomb Calorimeter
a calorimeter is "a device in which energy transferred as heat is monitored by recording the change in temperature produced by a process taking place within it" a bomb calorimeter is a more sophisticated version of the calorimeter. it is a sturdy sealed metal vessel of constant volume (the...
- Sun Feb 02, 2020 4:47 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 3 Methods
- Replies: 3
- Views: 144
Re: 3 Methods
1) Hess's Law: use when you know delta H, use addition/subtraction to add up total enthalpy changes 2) using bonding enthalpies to calculate deltaH: add together energy required for the bonds in the reactants to break (positive values) and the energy released when bonds break (the energy of the prod...
- Sun Feb 02, 2020 4:35 pm
- Forum: Calculating Work of Expansion
- Topic: Reversible and Irreversible
- Replies: 5
- Views: 188
Re: Reversible and Irreversible
to add, i think dr. lavelle stated that if a system is at equilibrium, it is a reversible process
- Sun Feb 02, 2020 3:54 pm
- Forum: Phase Changes & Related Calculations
- Topic: phase change from liquid to vapor
- Replies: 8
- Views: 334
Re: phase change from liquid to vapor
^^ the longer line going from liquid to vapor indicates that more heat was released, making the steam burn more than liquid water
- Sun Feb 02, 2020 3:46 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Extra Credit
- Replies: 7
- Views: 420
Re: Extra Credit
I dont think Lavelle ever offers extra credit, but I would just talk to your ta about it, or just do five chemistry community submissions late
- Sun Jan 26, 2020 8:07 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Reversible Reactions
- Replies: 3
- Views: 238
Re: Reversible Reactions
a reaction is reversible when the products of a chemical reaction can convert back to reactants. this is commonly shown in equilibrium reactions in which reactants and products form simultaneously. reversible reactions are written with a double arrow denoting the forward and reverse reactions
- Sun Jan 26, 2020 8:02 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: exo thermic
- Replies: 11
- Views: 355
Re: exo thermic
left because in an exothermic reaction, heat will start on the right side because deltaH is negative, and heating favors reactant formation
- Sun Jan 26, 2020 7:57 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: solvent
- Replies: 10
- Views: 394
Re: solvent
pure substances (solids and liquids) won't be included in the equilibrium constant
- Sun Jan 26, 2020 7:53 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy
- Replies: 3
- Views: 119
Re: Enthalpy
to add, enthalpy is a state property, means that its value is determined only by its current state, and it is not dependent on the path taken to obtain that state
- Sun Jan 26, 2020 7:50 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess's Law
- Replies: 9
- Views: 411
Re: Hess's Law
Hess's Law states that enthalpy changes are additive because enthalpy changes are a state function, which must be additive.
- Fri Jan 17, 2020 2:17 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Tips for Test
- Replies: 23
- Views: 1119
Re: Tips for Test
^^ a lot of homework problems should help because Dr. Lavelle often gets problems from homework and put them on the test
- Fri Jan 17, 2020 2:14 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Determining molar concentration
- Replies: 2
- Views: 219
Re: Determining molar concentration
I feel like you would start by changing grams of PCl5 to moles then finding the molarity of the initial PCl5 by dividing this number by the liters, then continue solving the problem as an ICE box
- Fri Jan 17, 2020 2:08 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Solids and Equilibrium
- Replies: 9
- Views: 282
Re: Solids and Equilibrium
neither affects equilibrium because they are both pure substances
- Fri Jan 17, 2020 2:07 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Solids and Liquids in Le Chatelier
- Replies: 5
- Views: 3233
Re: Solids and Liquids in Le Chatelier
no, solids or liquids (pure substances) would not affect le chatelier because they are not technically included in the equilibrium expression
- Fri Jan 17, 2020 2:05 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ICE and quadratic formula
- Replies: 11
- Views: 561
Re: ICE and quadratic formula
you can only avoid using the quadratic formula when you are given a small k value (<10^-3), otherwise you would have to solve for x normally, which may require you to use the quadratic formula
- Sat Jan 11, 2020 3:46 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Reaction quotient
- Replies: 8
- Views: 412
Re: Reaction quotient
K is calculated at equilibrium , while Q is calculated anytime during the reaction
- Sat Jan 11, 2020 3:45 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Partial Pressure
- Replies: 7
- Views: 325
Re: Partial Pressure
yes, you use partial pressure when all products and reactants are in the gas phase, and you use the equilibrium constant Kp
- Sat Jan 11, 2020 3:42 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: HW 5J.5
- Replies: 8
- Views: 176
Re: HW 5J.5
^^^ the molar concentrations of a pure substance (solid or liquid) does not affect K
- Sat Jan 11, 2020 3:36 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q
- Replies: 10
- Views: 447
Re: Q
Yes! Q or Qc or Qp is calculated the same way as K :)
- Sat Jan 11, 2020 3:35 pm
- Forum: Ideal Gases
- Topic: K vs Q [ENDORSED]
- Replies: 7
- Views: 596
Re: K vs Q [ENDORSED]
K is the equilibrium constant (this tells us where the equilbrium sits), while Q is the reaction quotient (this determines which direction a rxn will proceed)
- Sat Jan 11, 2020 3:32 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5G.1 [ENDORSED]
- Replies: 4
- Views: 190
Re: 5G.1 [ENDORSED]
for this question, the statement, "If one starts with a higher pressure of reactant, the equilibrium constant will be larger" is false because your initial concentration increases, causing the equilibrium constant to be smaller. For example,if you had the equation N2+3H2 <-->2NH3 and an in...
- Sat Dec 07, 2019 1:13 am
- Forum: Administrative Questions and Class Announcements
- Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
- Replies: 115
- Views: 12494
Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
for question 40c, how do you know whether o2 or o3 has the stronger bond and why?
- Sat Dec 07, 2019 1:10 am
- Forum: Dipole Moments
- Topic: Lone pairs
- Replies: 6
- Views: 340
Re: Lone pairs
^^ to add on to that, dipole moments are created by lone pairs if the lone pairs don't cancel each other out, and one factor that can influence whether or not they cancel out is by looking at the bond angles
- Sat Dec 07, 2019 1:01 am
- Forum: Amphoteric Compounds
- Topic: As2O3
- Replies: 2
- Views: 264
Re: As2O3
between the metal oxides (bases) and nonmetal oxides (acids), there is a diagonal band of amphoteric oxides closely matching the diagonal band of metalloids
- Sat Dec 07, 2019 12:59 am
- Forum: Amphoteric Compounds
- Topic: how to identify?
- Replies: 5
- Views: 384
Re: how to identify?
amphiprotic= means that a molecule has the ability to either donate and accept H+
amphoteric= means that a molecule can either act as an acid or a base
amphoteric= means that a molecule can either act as an acid or a base
- Sat Dec 07, 2019 12:55 am
- Forum: Hybridization
- Topic: N-triple bond-N pi bond hybridization
- Replies: 4
- Views: 233
Re: N-triple bond-N pi bond hybridization
AngieGarcia_4F wrote:(N2p, N2p) because pi bonds happen when p orbitals overlap.
does this mean that pi bonds can only be formed in p orbitals only?
- Sat Dec 07, 2019 12:52 am
- Forum: Naming
- Topic: oxidation number
- Replies: 3
- Views: 204
Re: oxidation number
^^ tungsten and molybdenum can get up to +6 I believe, and arsenic can be +5
- Sat Dec 07, 2019 12:50 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbitals
- Replies: 4
- Views: 368
Re: Orbitals
Once you find out what "l" is, you can figure out how many orbitals there are because to find the number of orbitals you can plug "l" into the equation 2*l+1, and that will give you the number of orbitals. Or you can think that ml=-l,...0...,+l, and the number of values you get a...
- Sat Dec 07, 2019 12:36 am
- Forum: Hybridization
- Topic: 2s for Carbon hybridization
- Replies: 3
- Views: 277
Re: 2s for Carbon hybridization
carbon is from the energy level, n=2
- Sun Dec 01, 2019 3:39 am
- Forum: Lewis Acids & Bases
- Topic: Conjugate acid and conjugate base
- Replies: 2
- Views: 148
Re: Conjugate acid and conjugate base
I usually just look at the products of the equation, and the product with an additional H+ is the conjugate acid because bases accept protons based on the Bronsted- Lowry definition. Similarly, since acids donate protons, the product with an H+ taken away from it will be the conjugate base
- Sun Dec 01, 2019 3:34 am
- Forum: Biological Examples
- Topic: How many do we need to know?
- Replies: 1
- Views: 134
Re: How many do we need to know?
On the syllabus, Dr. Lavelle said to know 3: hemoglobin, myoglobin, and vitamin B12
- Sun Dec 01, 2019 3:29 am
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Dimagnetism & Paramagnetism
- Replies: 6
- Views: 377
Re: Dimagnetism & Paramagnetism
I don't think it will be heavily tested either, but just so you know "diamagnetic" means that all electrons are paired, whereas "paramagnetic"means that not all electrons are paired
- Sun Dec 01, 2019 3:20 am
- Forum: Biological Examples
- Topic: Vitamin B12
- Replies: 3
- Views: 165
Vitamin B12
What is the biological function of the naturally occurring coordination compound, vitamin B12?
- Sun Dec 01, 2019 3:17 am
- Forum: Amphoteric Compounds
- Topic: 6A.17
- Replies: 3
- Views: 203
Re: 6A.17
How would you know that Bi2O3 is amphoteric?
- Sun Dec 01, 2019 3:11 am
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Difference between Arrhenius, Bronsted, and Lewis
- Replies: 5
- Views: 8900
Re: Difference between Arrhenius, Bronsted, and Lewis
An arrhenius:
- acid: gives off H+
- base: gives off OH-
Bronsted-Lowry
- acid: is a proton donor
- base: is a proton acceptor
Lewis
- acid: is an electron acceptor
-base: is an electron donor
- acid: gives off H+
- base: gives off OH-
Bronsted-Lowry
- acid: is a proton donor
- base: is a proton acceptor
Lewis
- acid: is an electron acceptor
-base: is an electron donor
- Sun Dec 01, 2019 2:48 am
- Forum: Administrative Questions and Class Announcements
- Topic: Difficulty
- Replies: 14
- Views: 888
Re: Difficulty
I agree with Kayley and Megan, I took AP chem in high school, and I think it definitely helped, but I also am not having an easy time in the class either. There's a lot of concepts like they were saying that go more in depth here in college
- Sat Nov 23, 2019 7:37 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Forming Chelating Complexes: HW 9C.7
- Replies: 1
- Views: 127
Forming Chelating Complexes: HW 9C.7
In reference to HW 9C.7 (Which of the following isomers of diaminobenzene can form chelating complexes? Explain your reasoning.) and/or 9C.8 (Which of the following ligands do you expect to form chelating complexes? Explain your reasoning.) How do you know what isomers or ligands can form chelating ...
- Sat Nov 23, 2019 7:27 pm
- Forum: Naming
- Topic: Latin Names of Atoms
- Replies: 4
- Views: 285
Re: Latin Names of Atoms
^^ in Lavelle's lectures I feel like he uses the English name, plus the book uses the English name from what I've seen
- Sat Nov 23, 2019 7:25 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligand
- Replies: 4
- Views: 306
Re: Ligand
In the book, a ligand refers to "A group attached to the central metal ion in a complex"
- Sat Nov 23, 2019 7:22 pm
- Forum: Biological Examples
- Topic: Cisplatin
- Replies: 15
- Views: 645
Re: Cisplatin
^^ just to add on, Lavelle was saying how transplatin is only able to form one bond in DNA (which is weak, so it can't stop cell division), whereas cis platin is able to form 2 bonds in the DNA, causing for the DNA to be interfered with enough to the point of stopping cell division & ultimately,...
- Sat Nov 23, 2019 7:03 pm
- Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
- Topic: Hydrogen Bonding/Pi bonds
- Replies: 11
- Views: 1592
Re: Hydrogen Bonding/Pi bonds
805097738 wrote:Zoya Mulji 1F wrote:Intermolecular forces:
ionic bonding --> H-bonding --> dipole-dipole bonding --> induced dipole/London dispersion
is this ascending or descending in strength?
this is in decreasing strength. hydrogen bonds are the strongest and LDF /induced dipole forces are the weakest
- Sun Nov 17, 2019 8:27 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR
- Replies: 7
- Views: 355
Re: VSEPR
^^ i think we would also need to know the bond angles and were not necessarily graded on the lewis structure, but in order to determine the shape, we'd have to know how to draw the lewis structure
- Sun Nov 17, 2019 8:25 pm
- Forum: Sigma & Pi Bonds
- Topic: sigma and pi bonds
- Replies: 4
- Views: 283
Re: sigma and pi bonds
sigma bonds are just single bonds, pi bonds occur when you have a double bond or triple bond. if you have a double bond, you would have one sigma and one pi bond, and if you had a triple bond, youd have one sigma and two pi bonds
- Sun Nov 17, 2019 8:21 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar vs non polar
- Replies: 5
- Views: 277
Re: Polar vs non polar
no, some of the lone pairs will create dipole moments that cancel each other out, resulting in a molecule not necessarily becoming polar
- Sun Nov 17, 2019 8:17 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 3
- Views: 206
Re: Bond Angles
They'll always be smaller because the lone pairs repel shared electrons, reducing bond angles. In general, atoms/electrons want to be as far away as possible due to electron repulsion. Molecules w/ lone pairs lower bond angles because lone pairs repel shared electrons, leading shared electrons to be...
- Sun Nov 17, 2019 5:05 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: geometric angles
- Replies: 4
- Views: 257
Re: geometric angles
^^^ the geometric angles correspond with the VSEPR chart which depends on how many bonding pairs and lone pairs you have. for example a structure with 2 bonding pairs and 2 lone pairs would be bent and would have bond angles of less than 109.5 because of the lone pairs “pushing” on the angles in the...
- Sun Nov 17, 2019 5:01 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Cis-Dichloroethene vs Trans-Dichloroethene
- Replies: 3
- Views: 287
Re: Cis-Dichloroethene vs Trans-Dichloroethene
just to add on, cis structures will have the same elements on one side of a structure, making it polar, whereas trans structures will have the same elements on opposite sides of the structure, making it nonpolar
- Wed Nov 06, 2019 4:18 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: HW 2D.3
- Replies: 5
- Views: 592
HW 2D.3
Can someone explain to me why BaBr2 has bonds primarily ionic?
(in reference to HW question 2D.3:
"Which of these compounds has bonds that are primarily ionic? (a) BBr3; (b) BaBr2; (c) BeBr2."
(in reference to HW question 2D.3:
"Which of these compounds has bonds that are primarily ionic? (a) BBr3; (b) BaBr2; (c) BeBr2."
- Wed Nov 06, 2019 4:15 am
- Forum: Photoelectric Effect
- Topic: HW Question Focus 1, 1.3
- Replies: 1
- Views: 231
HW Question Focus 1, 1.3
How would you solve the problem Focus 1.3 in the textbook: "In each second, a certain lamp produces 2.4 x 10^21 photons with a wavelength of 633 nm. How much power (in watts) is produced as radiation at this wavelength (1W = 1 J x s^-1)?" I tried using E=hv and c=wavelength(frequency) and ...
- Mon Nov 04, 2019 1:07 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Heisenberg Uncertainty Quantum World Worksheet
- Replies: 3
- Views: 269
Heisenberg Uncertainty Quantum World Worksheet
The question: "Your bowling ball of mass 4.02kg rolls down a lane with a speed of 2.35+/-0.1m/s. What is the minimum indeterminancy of its position? Can you blame the Heisenberg Uncertainty Principle when your ball misses the pins" appeared in Karen's Quantum World WS. How do you know when...
- Mon Nov 04, 2019 1:00 pm
- Forum: SI Units, Unit Conversions
- Topic: Memorizing Conversions
- Replies: 25
- Views: 1338
Re: Memorizing Conversions
There's a few conversions on the sheet, such as 1nm=10^-9m, but I would look at the conversion sheet to see what conversions you should become more familiar with
- Sun Nov 03, 2019 6:54 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge and Energy
- Replies: 4
- Views: 328
Re: Formal Charge and Energy
the lowest energy lewis structure has an overall formal charge of 0/close to 0
- Sun Nov 03, 2019 6:42 pm
- Forum: Octet Exceptions
- Topic: Expanded Valence Shells
- Replies: 6
- Views: 194
Expanded Valence Shells
Why can only some elements in the 3rd period have an expanded valence shell?
- Sun Nov 03, 2019 6:38 pm
- Forum: Trends in The Periodic Table
- Topic: Drawing Structures
- Replies: 3
- Views: 171
Re: Drawing Structures
You can draw a molecule in different ways/ a molecule has resonance when you can draw a structure with multiple bonds in different positions (ie move one bond to another to create a double bond)
- Sun Nov 03, 2019 6:36 pm
- Forum: Resonance Structures
- Topic: Resonance structures
- Replies: 6
- Views: 499
Re: Resonance structures
a resonance structure is a blending of lewis structures with the same arrangements of atoms but different arrangement of electrons. it spreads multiple bond character over a molecule and also can lower its energy
- Sun Nov 03, 2019 6:31 pm
- Forum: Lewis Structures
- Topic: lowest energy
- Replies: 5
- Views: 253
Re: lowest energy
^^ the central atom/all atoms would have a formal charge of 0; basically the lowest energy lewis structure will be the lewis structure with the overall formal charge closest to zero
- Sun Oct 27, 2019 9:43 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal charge
- Replies: 3
- Views: 119
Re: Formal charge
Find the formal charge of each bound atom then add up all the individual formal charges to find the overall formal charge. The most stable atoms have a formal charge of 0.
- Sun Oct 27, 2019 9:39 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Finding Most Stable Structure
- Replies: 9
- Views: 276
Re: Finding Most Stable Structure
The most stable compounds typically have an overall total charge of zero (the exception would be if the compound or element is an anion or cation, that is, if they have an overall charge other than zero). And just a quick note, formal charge = # of valence electrons an atom has - (# bonds + lone pai...
- Sun Oct 27, 2019 9:26 pm
- Forum: Lewis Structures
- Topic: Choosing the central atom
- Replies: 16
- Views: 762
Re: Choosing the central atom
The central atom is the element with the lowest ionization energy. Usually, it is the first element in a compound, and when it is placed in the middle, you are able to draw atoms symmetrically around it.
- Sun Oct 27, 2019 9:23 pm
- Forum: Octet Exceptions
- Topic: octet exceptions
- Replies: 5
- Views: 277
Re: octet exceptions
^^ atoms in period 3 or higher have d-orbitals in valence shell that can accommodate additional electrons.
- Sun Oct 27, 2019 9:17 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 1E.23 (unpaired electrons)
- Replies: 2
- Views: 1472
Re: 1E.23 (unpaired electrons)
For me, the easiest way to determine how many atoms are unpaired or paired is just to draw out an energy diagram and fill up the orbitals until all electrons are accounted for. Just a note, when all electrons are paired, the compound is known to be diamagnetic, and when they're not al paired, it is ...
- Sun Oct 27, 2019 9:11 pm
- Forum: Trends in The Periodic Table
- Topic: Electron affinity.
- Replies: 8
- Views: 266
Re: Electron affinity.
Electron affinity is the energy released when an electron is added to a neutral atom to become an anion.
- Sun Oct 27, 2019 9:09 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic VS. Covalent Bond
- Replies: 8
- Views: 433
Re: Ionic VS. Covalent Bond
Ionic bonds form when a metal transfers its electrons with a nonmetal (this involves cation and anion interactions), and covalent bonds form when nonmetals share electrons. Nonmetals do not form cations because their ionization energies are too high.
- Sun Oct 27, 2019 9:02 pm
- Forum: Electronegativity
- Topic: Electronegativity
- Replies: 6
- Views: 546
Electronegativity
If electronegativity increases from left to right and bottom to top of the periodic table, why is fluorine the most electronegative element?
- Sun Oct 20, 2019 11:57 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Writing Electron Configurations
- Replies: 7
- Views: 350
Re: Writing Electron Configurations
yup just to add on, you could either write nitrogen is 1s^2, 2s^2, 2px^1, 2py^1, 2pz^1, or nitrogen is 1s^2, 2s^2, 2p^3 and both would be correct
- Sun Oct 20, 2019 11:55 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Exceptions for Electron Configuration
- Replies: 6
- Views: 212
Re: Exceptions for Electron Configuration
He said the two exceptions were for the elements copper (Cu) and chromium (Cr)
- Wed Oct 16, 2019 12:36 am
- Forum: Quantum Numbers and The H-Atom
- Topic: hw help
- Replies: 1
- Views: 109
hw help
In reference to question 1.E.1, "Which of the following increase when an electron in a lithium atom undergoes a transition from the 1s-orbital to a 2p-orbital? (a) Energy of the electron. (b) Value of n. (c) Value of l. (d) Radius of the atom. Which answers would be different for a hydrogen ato...
- Wed Oct 16, 2019 12:21 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: HW Help
- Replies: 3
- Views: 126
HW Help
For HW problem 1.D.23: "How many orbitals can have the following quantum numbers in an atom:(a)n=2,l=1;(b)n=4,l=2,m1=-2; (c)n=2;(d)n=3,l=2,m1 =+1?" Would it be better to state the max number of orbitals, or all the different possibilities? For example, for part c, you can assume l = -1,0,1...