Search found 101 matches
- Sun Mar 08, 2020 11:42 pm
- Forum: Second Order Reactions
- Topic: Final Exam Equations
- Replies: 10
- Views: 791
Re: Final Exam Equations
They'll be given but it's up to you to figure out which is for what order and how to use them exactly.
- Sun Mar 08, 2020 11:37 pm
- Forum: First Order Reactions
- Topic: rate constants
- Replies: 30
- Views: 1537
Re: rate constants
Since rate constants depend on concentration (which is positive), they are always positive.
- Sun Mar 08, 2020 11:16 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Exothermic vs. Endothermic
- Replies: 14
- Views: 980
Re: Exothermic vs. Endothermic
If reactant energy is higher than the product energy, the reaction is exothermic and the opposite for endothermic.
- Sun Mar 08, 2020 10:56 pm
- Forum: General Rate Laws
- Topic: slow step
- Replies: 9
- Views: 652
Re: slow step
I think the slow step is the one that determines the rate law for the overall reaction.
- Sun Mar 08, 2020 10:44 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalysts
- Replies: 8
- Views: 517
Re: Catalysts
PranaviKolla2B wrote:What else are the functions of catalysts, besides lowering the activation energy?
They speed up a reaction by reducing the activation energy or changing the reaction mechanism.
- Sun Mar 08, 2020 10:41 pm
- Forum: General Rate Laws
- Topic: arrhennius question
- Replies: 4
- Views: 307
Re: arrhennius question
Use it to find activation energy or the reaction constant from temperature change.
- Sun Mar 08, 2020 9:34 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: units
- Replies: 11
- Views: 775
Re: units
Mol per liter per time (in seconds).
- Sun Mar 08, 2020 9:31 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: intermediate
- Replies: 26
- Views: 2080
Re: intermediate
It is not in the rate law because it was formed then used and does not appear in the overall reaction.
- Sun Mar 08, 2020 9:28 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: 7.9
- Replies: 2
- Views: 279
Re: 7.9
Google says that "a reaction which is not first-order reaction naturally but made first order by increasing or decreasing the concentration of one or the other reactant is known as pseudo first order reaction."
- Sun Mar 08, 2020 9:17 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Problems
- Replies: 6
- Views: 492
Re: Problems
Are you referencing kinetics vs thermodymanics? If so, I am not sure how that would be formatted.
- Sun Mar 08, 2020 9:09 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Study Advice
- Replies: 73
- Views: 7202
Re: Study Advice
Lyndon's review sessions (especially for the midterm and final) and the textbook problems are the most helpful.
- Sun Mar 01, 2020 11:35 pm
- Forum: Zero Order Reactions
- Topic: overall rate
- Replies: 5
- Views: 868
Re: overall rate
That's right, we don't include zero-order reactions.
- Sun Mar 01, 2020 11:33 pm
- Forum: General Rate Laws
- Topic: tangent lines
- Replies: 5
- Views: 464
Re: tangent lines
The slope of the tangent line is the same as the derivative, so you can just take the derivative.
- Sun Mar 01, 2020 11:31 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Diamond
- Replies: 6
- Views: 468
Re: Diamond
005162520 wrote:What do you mean by large activation energy barrier ? If it has a large activation energy barrier does that mean the reaction takes longer ?
Yes, it takes much longer since it is a lot slower (and usually we don't see diamond rings for example turning to graphite)
- Sun Mar 01, 2020 11:29 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Favorability
- Replies: 4
- Views: 304
Re: Favorability
For favorability, thermodynamics comes in handy; however, kinetics tells you the speed of the reaction not favorability.
- Sun Mar 01, 2020 11:27 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: units
- Replies: 11
- Views: 775
Re: units
Mol/(Liter*second); moles per liter per second
- Sun Feb 23, 2020 7:32 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: F
- Replies: 7
- Views: 456
Re: F
It represents the charge (coulombs) of 1 mole of electrons.
- Sun Feb 23, 2020 7:24 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: n
- Replies: 13
- Views: 785
Re: n
If you are referring to R (since n is the number if moles) then we use 8.134 because it has Joules and moles.
- Sun Feb 23, 2020 7:21 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Half reactions
- Replies: 13
- Views: 771
Re: Half reactions
Half reactions are the reduction and oxidation processes that occur in a redox reaction, which we break up to make easier to solve.
- Sun Feb 23, 2020 7:11 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Le Chatelier’s Principle
- Replies: 11
- Views: 719
Re: Le Chatelier’s Principle
Just like in equilibrium, changing the concentrations will change the direction the rxn is favored, so we apply Le Chatelier's principle.
- Sun Feb 23, 2020 7:07 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: 565
Re: standard conditions
Standard condition is 1M solution at 1 atm, with temperature of 273.15 K.
- Sun Feb 16, 2020 11:50 pm
- Forum: Balancing Redox Reactions
- Topic: Why do we split equations?
- Replies: 12
- Views: 816
Re: Why do we split equations?
I think the whole purpose is that it helps separate the oxidation and reduction.
- Sun Feb 16, 2020 11:41 pm
- Forum: Balancing Redox Reactions
- Topic: Memorizing charges
- Replies: 11
- Views: 745
Re: Memorizing charges
I think we should know the ones in groups 1,2,16,17 and any common ones we talk about.
- Sun Feb 16, 2020 11:39 pm
- Forum: Balancing Redox Reactions
- Topic: Rules for oxidation numbers
- Replies: 6
- Views: 348
Re: Rules for oxidation numbers
Ions are charged particles, so they cannot have a zero charge.
- Sun Feb 16, 2020 11:38 pm
- Forum: Balancing Redox Reactions
- Topic: Reduction vs. oxidation
- Replies: 29
- Views: 1212
Re: Reduction vs. oxidation
Oxidation refers to losing electrons, while reduction means gaining electrons. You can tell by comparing the oxidation numbers of the products and reactants.
- Sun Feb 16, 2020 11:36 pm
- Forum: Balancing Redox Reactions
- Topic: Assuming Oxidation Number
- Replies: 1
- Views: 49
Re: Assuming Oxidation Number
I think it is fine to assume that. Some compounds with oxygen or hydrogen might make it so that the oxygen/hydrogen's oxidation state is different, but I don't think we will discuss it in this course (I'm not 100% sure though).
- Sun Feb 09, 2020 9:06 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Difference between qv and qp
- Replies: 5
- Views: 438
Re: Difference between qv and qp
When you have q[v], it means that volume is constant (v=0), so if you plug that into the deltaU equation, your work will also be 0 since it's based on volume (w=-PdeltaV) and therefore, you get deltaU=q. On the other hand, when you are doing q[p], that means your pressure is constant (p=0) and there...
- Sun Feb 09, 2020 9:00 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Intensive vs. Extensive
- Replies: 15
- Views: 1364
Re: Intensive vs. Extensive
The way I remember the difference is that extensive properties can be divided by the amount of the substance (e.g. heat capacity divided by mass) to become intensive properties (specific heat capacity as a result of heat capacity/mass).
- Sun Feb 09, 2020 8:58 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed system
- Replies: 7
- Views: 385
Re: closed system
Because matter cannot transfer if it is sealed, but heat can (which is what a closed system is).
- Sun Feb 09, 2020 8:57 pm
- Forum: Calculating Work of Expansion
- Topic: Midterm equation sheet
- Replies: 16
- Views: 732
Re: Midterm equation sheet
Yes, it is always the same as on every test/midterm/final.
- Sun Feb 09, 2020 8:47 pm
- Forum: Calculating Work of Expansion
- Topic: reversible expansion
- Replies: 6
- Views: 162
Re: reversible expansion
Natalie Benitez 1E wrote:How would we know on the exam if something is reversible or irreversible ?
I believe it is reversible if the pressure is not constant and if the internal and external pressure are the same.
- Sun Feb 02, 2020 11:53 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: expansion
- Replies: 5
- Views: 329
Re: expansion
It is when the volume increases/expands.
- Sun Feb 02, 2020 11:51 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: First law of thermodynamics
- Replies: 3
- Views: 278
Re: First law of thermodynamics
It's basically conservation of energy (the universe is a closed system, therefore energy transfers but does not get lost).
- Sun Feb 02, 2020 11:48 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Phase change
- Replies: 20
- Views: 874
Re: Phase change
Delta H is positive when ice turns to liquid (applying heat to change from solid to liquid).
- Sun Feb 02, 2020 11:44 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: delta U
- Replies: 9
- Views: 445
Re: delta U
Delta U= q (aka heat) + w (aka work).
- Sun Feb 02, 2020 11:42 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed vs isolated?
- Replies: 7
- Views: 1316
Re: closed vs isolated?
An isolated system is completely closed off from its surroundings and cannot exchange matter or energy with its surroundings. A closed system is closed off from its surroundings and cannot exchange matter, but can exchange energy with its surroundings. Isolated system: a thermos flask. Closed system...
- Sun Jan 26, 2020 9:55 pm
- Forum: Phase Changes & Related Calculations
- Topic: Work (w)
- Replies: 8
- Views: 377
Re: Work (w)
Work (and heat) are not state functions. Work is proportional to the distance an object is moved, which depends on the path used to go from the initial to the final state (therefore not a state function). Usually doing things that require force and distance are considered as doing "work."
- Sun Jan 26, 2020 9:50 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond Enthalpies
- Replies: 6
- Views: 152
Re: Bond Enthalpies
I don't think it's necessary to draw them, but it will probably be helpful; otherwise, the values of the bond enthalpies should be given somewhere.
- Sun Jan 26, 2020 9:47 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess's Law
- Replies: 9
- Views: 455
Re: Hess's Law
Hess' law states that the change of enthalpy in a chemical reaction is independent of the pathway between the initial and final states (enthalpy is a state function and you can add enthalpies to get the total enthalpy).
- Sun Jan 26, 2020 9:44 pm
- Forum: Phase Changes & Related Calculations
- Topic: Physical or Phase Changes
- Replies: 7
- Views: 197
Re: Physical or Phase Changes
I believe those values will probably be given to us based on examples from class.
- Sun Jan 26, 2020 9:41 pm
- Forum: Phase Changes & Related Calculations
- Topic: Enthalpy is said to be additive
- Replies: 10
- Views: 333
Re: Enthalpy is said to be additive
It just means that, since enthalpy is a state property, different enthalpies can be added together.
- Sun Jan 19, 2020 10:56 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle
- Replies: 7
- Views: 204
Re: Le Chatelier's Principle
It predicts what would happen if a parameter changed and how the reaction would adjust to fixing that change in parameter.
- Sun Jan 19, 2020 10:54 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: X was ignored
- Replies: 27
- Views: 1158
Re: X was ignored
X was ignored because 0.10 is less than 10^-3, which means it is so small that it would not make a difference to decrease by X; therefore, you only use the 0.10 (think of Dr.Lavelle's example of the million dollars minus $10).
- Sun Jan 19, 2020 10:50 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q < K
- Replies: 16
- Views: 850
Re: Q < K
Yes, it is the same because when Q is less than K, there are more reactants than products so the reaction needs to form more products to reach equilibrium.
- Sun Jan 19, 2020 10:44 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Quadratic Equation
- Replies: 8
- Views: 385
Re: Quadratic Equation
We use the quadratic equation when equating the values we got from the ICE table (products/reactants) to the given equilibrium constant K, and if X is not smaller than 10^-3.
- Sun Jan 19, 2020 10:41 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ICE Tables
- Replies: 13
- Views: 519
Re: ICE Tables
Because it's a liquid and because it's in excess (as a solvent), it is not included.
- Sun Jan 12, 2020 11:03 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Homogenous Equilibrium
- Replies: 13
- Views: 395
Re: Homogenous Equilibrium
It is when all the reactants and products are in the same phase (e.g. gas).
- Sun Jan 12, 2020 10:57 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Hw for next week
- Replies: 19
- Views: 824
Re: Hw for next week
I think both are fine since they will both be recent topics; I'm saying this because I took Lavelle for 14A and our TAs were OK with it.
- Sun Jan 12, 2020 10:55 pm
- Forum: Ideal Gases
- Topic: Topics on Test 1
- Replies: 37
- Views: 1413
Re: Topics on Test 1
I believe it will be all of "chemical equilibrium" and whatever we get to for "acids and bases" since those are the material for the first two weeks.
- Sun Jan 12, 2020 10:53 pm
- Forum: Ideal Gases
- Topic: PV = nRT
- Replies: 16
- Views: 1984
Re: PV = nRT
The P stands for pressure, the V for volume, the n for number of moles, the R is the gas constant, and T is temperature.
- Sun Jan 12, 2020 10:51 pm
- Forum: Ideal Gases
- Topic: Understanding Q
- Replies: 19
- Views: 756
Re: Understanding Q
Yes, solving for Q is the same thing as solving for K in terms of calculations (just that the reaction might not have reached equilibrium yet).
- Mon Dec 02, 2019 10:40 pm
- Forum: Polyprotic Acids & Bases
- Topic: Polyprotic Question!
- Replies: 12
- Views: 1787
Re: Polyprotic Question!
Polyprotics have more protons to donate.
- Mon Dec 02, 2019 10:37 pm
- Forum: Bronsted Acids & Bases
- Topic: Lecture 12/2
- Replies: 3
- Views: 245
Re: Lecture 12/2
He said that the conjugate base (anion) of a weak acid will raise the pH of a solution by removing protons from the water and generate -OH.
- Mon Dec 02, 2019 10:35 pm
- Forum: Bronsted Acids & Bases
- Topic: Final
- Replies: 13
- Views: 867
Re: Final
It is most likely cumulative, so anything we have learned can be on it.
- Mon Dec 02, 2019 10:32 pm
- Forum: Bronsted Acids & Bases
- Topic: how to identify
- Replies: 2
- Views: 113
Re: how to identify
Bronsted acids have to donate their hydrogen atom/proton; therefore, NH3 can't be a bronsted acid.
- Mon Dec 02, 2019 10:24 pm
- Forum: Lewis Acids & Bases
- Topic: Problem J.9
- Replies: 4
- Views: 190
Re: Problem J.9
Potassium acetate is produced:
CH3CO2H(aq)+K^+(aq)+OH^-(aq)-->K^+(aq)+CH3CO2^-(aq)+H2O(l)
CH3CO2H(aq)+K^+(aq)+OH^-(aq)-->K^+(aq)+CH3CO2^-(aq)+H2O(l)
- Sun Dec 01, 2019 2:15 pm
- Forum: Biological Examples
- Topic: EDTA
- Replies: 8
- Views: 572
Re: EDTA
EDTA is ethylene-diamine-tetra-acetate, and it binds/chelates with cations (metals) in the blood to get rid of them.
- Sun Dec 01, 2019 2:12 pm
- Forum: Biological Examples
- Topic: Chemotherapy
- Replies: 6
- Views: 481
Re: Chemotherapy
Cisplatin is very common for chemotherapy.
- Sun Dec 01, 2019 2:11 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Oxidation number
- Replies: 3
- Views: 272
Re: Oxidation number
You just need to take the sum of all the oxidation numbers and then subtract the overall charge from that to get the charge/oxidation number of the transition metal.
- Sun Dec 01, 2019 2:05 pm
- Forum: Properties & Structures of Inorganic & Organic Bases
- Topic: Nonmental Oxides as Acids
- Replies: 4
- Views: 322
Re: Nonmental Oxides as Acids
Yes, CO2 would be an acid in this case.
- Sat Nov 30, 2019 12:15 pm
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 381862
Re: Final Jitters
There are many times where anxiety plays a huge factor in a students' performance on an exam, but there are solutions such as studying ahead of time and not cramming for a test, as well as getting enough rest.
- Sun Nov 24, 2019 9:10 pm
- Forum: Naming
- Topic: Order in Naming
- Replies: 12
- Views: 745
Re: Order in Naming
It would be the ligand name (alphabetically), then cation.
- Sun Nov 24, 2019 9:02 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligand
- Replies: 10
- Views: 539
Re: Ligand
A ligand is a molecule attached to a metal (in biology, usually attached to protein/enzyme).
- Sun Nov 24, 2019 8:59 pm
- Forum: Naming
- Topic: Meaning of Cis and Trans
- Replies: 11
- Views: 923
Re: Meaning of Cis and Trans
Cis means the electronegative atoms are on the same side (e.g. two chlorines), which trans is when they're on opposite sides. Cisplatin works because Guanine can displace two chlorines from one side, vs. two chlorines on opposite sides (trans).
Re: Oxidation
The oxidation number/state is the charge that cation/anion has. For example, chlorine's oxidation state would be -1 (chloride).
- Sun Nov 24, 2019 8:55 pm
- Forum: Naming
- Topic: Week 9 and Week 10 HW?
- Replies: 21
- Views: 1045
Re: Week 9 and Week 10 HW?
I think we can do it on one sheet of paper and label it week 9 and 10.
- Wed Nov 13, 2019 10:50 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Intermolecular forces
- Replies: 10
- Views: 711
Re: Intermolecular forces
Van der Waals and London interactions are used interchangeably, and refer to induced-dipole induced-dipole interactions. They are the weakest intermolecular force.
- Wed Nov 13, 2019 10:25 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Determining Polarity
- Replies: 5
- Views: 420
Re: Determining Polarity
Yes, the difference in electronegativity should be about 0.5 to be considered polar. Shape also plays a role in terms of the possibility of dipole moments canceling.
- Wed Nov 13, 2019 10:16 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Tetrahedral VSPER model
- Replies: 7
- Views: 566
Re: Tetrahedral VSPER model
I believe it is always tetrahedral when 4 bonds surround the central atom, however, lone pairs could also play a role and change the shape.
- Wed Nov 13, 2019 10:04 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Test 2
- Replies: 15
- Views: 873
Re: Test 2
It should cover material after the midterm (plus the very last slide he did before the midterm about the different interactions). So I believe that would be last Friday's lecture, today's lecture, and probably this Friday's lecture (I'm not sure about next Monday's). Topics would include dipoles, in...
- Wed Nov 13, 2019 9:54 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VESPR Model of H2O
- Replies: 12
- Views: 877
Re: VESPR Model of H2O
H2O would be bent, with oxygen in the center and one hydrogen on the lower left of oxygen and the other on the lower right. This is due to the polarity of water, with the hydrogen atoms having partial positive charge and the dipole arrows being directed toward the oxygen (partial negative charge). O...
- Sat Nov 09, 2019 9:13 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge
- Replies: 9
- Views: 376
Re: Formal Charge
If the compound is neutral, you would need all the formal charges to be zero. However, if it has a net charge then one or more atoms might have a negative or positive charge. You want the most electronegative atoms to have a negative charge (oxygen for example), and typically the central atom needs ...
- Sat Nov 09, 2019 9:09 pm
- Forum: Electronegativity
- Topic: Periodic Trend
- Replies: 13
- Views: 823
Re: Periodic Trend
Electronegativity increases as you go across a period and up a group, with flourine being the most electronegative atom (same trend as ionization energy and electron affinity).
- Sat Nov 09, 2019 9:08 pm
- Forum: Bond Lengths & Energies
- Topic: Hydrogen Bonding melting point
- Replies: 3
- Views: 142
Re: Hydrogen Bonding melting point
Hydrogen bonds are very strong, therefore it is difficult to break them. This means it takes a higher melting point to break the bonds.
- Sat Nov 09, 2019 9:05 pm
- Forum: Bond Lengths & Energies
- Topic: Bonds
- Replies: 2
- Views: 189
Re: Bonds
I agree with the above statement. I'd also like to note that hydrogen bonding occurs with the atoms flourine, nitrogen, and oxygen (electronegative atom that would bond with the hydrogen of a different molecule).
- Sat Nov 09, 2019 9:00 pm
- Forum: Dipole Moments
- Topic: Polar
- Replies: 9
- Views: 588
Re: Polar
Polarity depends on electronegativity. The difference of electronegativty between the two atoms signifies whether they will have a positive or negative partial charge.
- Sun Nov 03, 2019 1:22 pm
- Forum: Electronegativity
- Topic: Electronegativity
- Replies: 9
- Views: 406
Re: Electronegativity
905289082 wrote:What is the pattern on the periodic table that we're supposed to memorize for determining electronegativity?
Electronegativity increases as you move up and across the periodic table.
- Sun Nov 03, 2019 1:19 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge Purpose
- Replies: 4
- Views: 331
Re: Formal Charge Purpose
When the formal charge is 0, that means that the number of bonds of the atom are balanced with its lone pairs. So yes, it does mean that it is more stable.
- Sun Nov 03, 2019 1:03 am
- Forum: Bond Lengths & Energies
- Topic: bond length
- Replies: 6
- Views: 291
Re: bond length
I believe it is possible, but for now all we need to know is that double bonds are shorter and also stronger than single bonds
- Sun Nov 03, 2019 12:56 am
- Forum: Dipole Moments
- Topic: Definition
- Replies: 5
- Views: 263
Re: Definition
It is pretty much the polarity between atoms, indicated with an arrow pointing toward the negative delta direction.
- Sun Nov 03, 2019 12:52 am
- Forum: Dipole Moments
- Topic: Midterm
- Replies: 8
- Views: 366
Re: Midterm
I think we need to know dipole moments for the midterm, but just not the very last slide he was going over with the specifics.
- Sun Oct 27, 2019 1:56 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent bonds
- Replies: 5
- Views: 226
Re: Covalent bonds
As far as we have learned, covalent bonds are only made between nonmetals. However, I did some research and discovered an example of a covalent bond between a metal and nonmetal. Aluminium is a metal but it can bond covalently with chlorine to form aluminium chloride during high temperatures. Alumin...
- Sun Oct 27, 2019 1:35 pm
- Forum: Resonance Structures
- Topic: Bond lengths
- Replies: 5
- Views: 183
Re: Bond lengths
We don't need to know how to find bond lengths; it would be given (in angstroms). Conceptually, we need to know that double bonds are shorter than single bonds.
- Sun Oct 27, 2019 1:08 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A.15
- Replies: 4
- Views: 202
Re: 2A.15
It's easier for Gallium to lose three electrons to become an octet like Argon, than to gain five electrons to become an octet like Krypton.
- Sun Oct 27, 2019 1:05 pm
- Forum: Ionic & Covalent Bonds
- Topic: Cation
- Replies: 23
- Views: 1831
Re: Cation
Cations are positively charged ions since they lose electrons. Anions are negatively charged since they gain electrons. They're important because they help the element form octets.
- Sun Oct 27, 2019 1:03 pm
- Forum: Ionic & Covalent Bonds
- Topic: Midterm Topics Covered
- Replies: 7
- Views: 387
Re: Midterm Topics Covered
I think anything we have covered up until the midterm could possibly be on it. You can also ask Dr. Lavelle just to be sure.
- Tue Oct 15, 2019 7:18 am
- Forum: DeBroglie Equation
- Topic: Three Fundamental Equations
- Replies: 3
- Views: 261
Re: Three Fundamental Equations
It can be a little tricky, but it all depends on what is given. If you are given frequency and need to find wavelength, for example, you can use c=wavelength*frequency and just adjust the equation to what you're trying to solve. Some problems will ask you for an answer after you go through a few dif...
- Tue Oct 15, 2019 1:55 am
- Forum: Einstein Equation
- Topic: Einstein Equation
- Replies: 4
- Views: 254
Re: Einstein Equation
You use E=hv when finding the energy of a photon. In this case, h is Planck's constant and v is frequency.
- Tue Oct 15, 2019 1:46 am
- Forum: Properties of Light
- Topic: Homework
- Replies: 11
- Views: 533
Re: Homework
For this week, the five problems we do have to all come from the "Quantum World." I don't think it matters whether we do more problems from section A or B (etc) than other sections in that unit.
- Tue Oct 15, 2019 1:43 am
- Forum: Properties of Light
- Topic: Quantum Unit length
- Replies: 2
- Views: 104
Re: Quantum Unit length
I'm not positive how much longer we're going to be in this unit, but I have a feeling it might also be next week too, since Professor Lavelle mentioned that this is a lengthy unit. Especially compared to the other topics, this seems more complex.
- Tue Oct 15, 2019 1:37 am
- Forum: Properties of Light
- Topic: MidTerms and Finals
- Replies: 11
- Views: 442
Re: MidTerms and Finals
The midterm and final are going to be outside of class hours. The midterm is scheduled for November 6 from 6-8 pm, and the final is on December 8 from 11:30am-2:30pm. I am not sure where the midterm will be, though.
- Tue Oct 08, 2019 1:29 am
- Forum: Properties of Light
- Topic: Posts Per Week
- Replies: 6
- Views: 257
Re: Posts Per Week
I think that if you post Sunday of week one, it will be counted as week one. The "week" probably starts on Mondays.
- Tue Oct 08, 2019 1:28 am
- Forum: Properties of Light
- Topic: Photons
- Replies: 7
- Views: 333
Re: Photons
Increasing intensity doesn't lead to electrons being emitted, because increasing the intensity only increases the number of photons instead of the energy that each photon has. So in the photoelectric experiment, it's best to see light in terms of photons, since the energy of photons is what helps em...
- Tue Oct 08, 2019 1:17 am
- Forum: Administrative Questions and Class Announcements
- Topic: Study Tips/Schedule
- Replies: 4
- Views: 236
Re: Study Tips/Schedule
I would suggest doing the homework problems so that you get a good range of possible test questions and develop fundamental/conceptual skills to solve problems. You can also look at the lecture notes and online modules, as well as go to peer learning sessions and office hours.
- Tue Oct 08, 2019 1:14 am
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student - Part II [ENDORSED]
- Replies: 298
- Views: 278273
Re: Advice from a Medical Student - Part II [ENDORSED]
HI! Thank you so much for taking time out of your already busy schedule to answer our questions. I'm not sure if someone asked this already, but in terms of medical school, I've always wondered how I'd be able to balance that with family, especially because my ultimate career goal is to become a neu...
- Tue Oct 08, 2019 12:44 am
- Forum: Limiting Reactant Calculations
- Topic: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
- Replies: 68
- Views: 7104
Re: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
Showing work, even if your final answer is incorrect, will always give you partial credit which is important since the tests are 50 points (roughly 7 points/problem if its 7 questions).
- Thu Oct 03, 2019 10:49 pm
- Forum: Balancing Chemical Reactions
- Topic: adding a product
- Replies: 6
- Views: 191
Re: adding a product
When balancing equations, you want to add stoichiometric coefficients to change the number of MOLES of the compound, not the molecules.
- Thu Oct 03, 2019 10:46 pm
- Forum: Balancing Chemical Reactions
- Topic: Combustion
- Replies: 12
- Views: 771
Re: Combustion
Yes, combustion (and oxidation) involve a compound reacting with oxygen (O2) and producing a certain amount of carbon dioxide (CO2) and water (H2O).
- Thu Oct 03, 2019 10:40 pm
- Forum: Empirical & Molecular Formulas
- Topic: Test Materials
- Replies: 13
- Views: 742
Re: Test Materials
I'm sure we will be given the periodic table and the molecular formulas for compounds (if not asked to find the molecular formula). I am not sure about a formula sheet, but I would definitely recommend memorizing Avogadro's constant since I noticed that we had to use it in a lot of questions from se...
- Thu Oct 03, 2019 10:33 pm
- Forum: Empirical & Molecular Formulas
- Topic: Faster way to find molecular formula?
- Replies: 3
- Views: 286
Re: Faster way to find molecular formula?
I don't think there is a faster way, even though that would make things so much easier. Maybe in the future we will learn a simpler way? I wish I could be of more help.