Search found 35 matches

by Eunnie_Lee_3H
Sat Mar 18, 2017 9:17 pm
Forum: *Alcohols
Topic: Phenols
Replies: 1
Views: 432

Re: Phenols

I would highly doubt it. I believe that functional groups that are listed in the course reader pages 97-98 (and how to name them on page 99) are all that we'd need to know, even if the Intro to Organic Chemistry book might talk about other functional groups.

If I'm wrong, please correct me!
by Eunnie_Lee_3H
Sun Mar 12, 2017 8:20 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Arrhenius Equation
Replies: 1
Views: 255

Re: Arrhenius Equation

Usually no. You can probably determine it if they give you everything else in the equation (rate constant k, activation energy, temperature), but usually it's not necessary to know A to solve a problem (if ever).
by Eunnie_Lee_3H
Tue Feb 28, 2017 4:31 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 3 & Extra Credit
Replies: 2
Views: 332

Re: Quiz 3 & Extra Credit

The way I understood it, the extra credit is so that your lowest quiz score will be replaced with your highest quiz score, so yes in a way, your highest score will be recorded twice, and the lowest score will be dropped. I can only speculate, but I would think it will include the rest of kinetics an...
by Eunnie_Lee_3H
Sun Feb 26, 2017 11:02 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Activation Energy
Replies: 3
Views: 422

Re: Activation Energy

I don't believe you can tell based on (solely) activation energy if a reaction is exothermic or endothermic. Looking at whether the reactants have more energy than the products should be a better way of figuring out whether or not a reaction is exothermic or endothermic. If the reaction is endotherm...
by Eunnie_Lee_3H
Tue Feb 21, 2017 5:04 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 890225

Re: Post All Chemistry Jokes Here

I'm feeling STOICHED for chem.
by Eunnie_Lee_3H
Sun Feb 12, 2017 11:56 am
Forum: Balancing Redox Reactions
Topic: Balancing Reactions
Replies: 1
Views: 184

Re: Balancing Reactions

Yes, this would generally be the correct procedure. https://chem.libretexts.org/Core/Analytical_Chemistry/Electrochemistry/Redox_Chemistry/Balancing_Redox_reactions This page goes step by step with neutral, acidic, and basic solutions. You'll probably have to be careful with adding the OH- at the en...
by Eunnie_Lee_3H
Thu Feb 02, 2017 7:36 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Trouton's rule
Replies: 4
Views: 535

Re: Trouton's rule

No, it shouldn't be required. I didn't see a problem on my quiz that was about Trouton's Rule.
by Eunnie_Lee_3H
Wed Feb 01, 2017 7:41 pm
Forum: Calculating Work of Expansion
Topic: P delta(V) =delta(n)RT
Replies: 2
Views: 318

Re: P delta(V) =delta(n)RT

I suppose you could use it any time you think you need to use P \Delta V but you don't have P and/or V. Some homework problems have it so that you would have to solve for work, but they don't give you P or \Delta V. Oftentimes, these homework problems will give you the mols of the element/compound i...
by Eunnie_Lee_3H
Sun Jan 29, 2017 4:10 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy
Replies: 2
Views: 285

Re: Gibbs Free Energy

Also, Gibbs free energy isn't something that we can directly measure. It's defined by other measurements that happen to be state functions (if you take a look at the equation, it uses things like enthalpy and entropy, which are state functions). So, I suppose it just ends up being a state function.
by Eunnie_Lee_3H
Sun Jan 22, 2017 3:21 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Example 8.13 in Textbook
Replies: 2
Views: 251

Re: Example 8.13 in Textbook

I believe what they're trying to say is that by breaking the Br-Br bonds, the Br molecules were free to bond with the C's, and thus there are 2 C-Br bonds that were created in the products. CH3CH=CH2 has 1 C-C bond and 1 C=C bond, and in order for the C-Br bonds to be formed, the C=C bond was broken...
by Eunnie_Lee_3H
Mon Jan 16, 2017 11:10 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Enthalpy [ENDORSED]
Replies: 3
Views: 365

Re: Enthalpy [ENDORSED]

Enthalpy is the amount of heat released or absorbed at a constant pressure. For a single bond in a compound to become a double bond would require the compound's single bond to be broken, and then a double bond to be formed. Breaking bonds require energy, while forming bonds would release energy. Bre...
by Eunnie_Lee_3H
Fri Dec 02, 2016 10:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: ax2e2 question [ENDORSED]
Replies: 1
Views: 267

Re: ax2e2 question [ENDORSED]

It would be bent. An example of AX2E2 would be H2O; O is the central atom A and has 2 lone pairs (E2), and the two H's are X2.
by Eunnie_Lee_3H
Thu Nov 17, 2016 12:50 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: polydentate ligands [ENDORSED]
Replies: 2
Views: 334

Re: polydentate ligands [ENDORSED]

Basically if that ligand has multiple places it can bond. Ligands like NH 3 (ammine) and (OH) - (hydroxo) can only bond in one place (for ammine, it bonds by the N, and hydroxo can bond by O). So, those ligands would be monodentates. Ethylenediamine (en) can bond in two places (there are 2 N's that ...
by Eunnie_Lee_3H
Mon Nov 07, 2016 7:47 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: MO theory
Replies: 3
Views: 345

Re: MO theory

Higher bond orders generally mean more stability, yes, and whatever you calculate to be your bond order generally seems to correspond to a type of bond (meaning, 0=no bond, 1=single bond, 2=double bond, 3=triple bond, though you can have bond orders of 1.5, 2.5, etc, so you can see why higher bond o...
by Eunnie_Lee_3H
Mon Oct 24, 2016 2:06 pm
Forum: Ionic & Covalent Bonds
Topic: Stronger bonds
Replies: 3
Views: 340

Re: Stronger bonds

There are covalent bonds and ionic bonds. Covalent bonds "share" their electrons between them, while in ionic bonds, one of the atoms "takes" the electrons of the other atom to complete its electron shell. The greater the difference is between the two atom's electronegativity val...
by Eunnie_Lee_3H
Mon Oct 17, 2016 3:21 pm
Forum: Lewis Structures
Topic: Best Way to Determine Central Atom [ENDORSED]
Replies: 1
Views: 549

Re: Best Way to Determine Central Atom [ENDORSED]

The trend for electronegativity, electron affinity, and ionization energy is the same on the periodic table. As you go up and to the right, electronegativity, electron affinity, and ionization energy increases. So saying least electronegative is similar to saying lowest ionization energy or lower e...
by Eunnie_Lee_3H
Mon Oct 17, 2016 2:52 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals [ENDORSED]
Replies: 9
Views: 905

Re: Orbitals [ENDORSED]

There's no just "m" quantum number, there is m l and m s . The m l describes the different orbitals in the subshell (There's the subshell p, and m l would show differentiate between p x , p y , and p z orientations). m s on the other hand tells you if one of the electrons (in one orientati...
by Eunnie_Lee_3H
Mon Oct 17, 2016 2:32 pm
Forum: General Science Questions
Topic: Determining reactants given the products [ENDORSED]
Replies: 1
Views: 589

Re: Determining reactants given the products [ENDORSED]

I suppose it depends. There are different types of reactions, such as synthesis, decomposition, single replacement, double replacement, etc. Synthesis: If you're only given a compound, like NaCl, you can guess that the reactants were probably Na and Cl 2 . Decomposition: If you're given two elements...
by Eunnie_Lee_3H
Tue Oct 11, 2016 10:17 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Questions on the two exceptions, Chromium and Copper. [ENDORSED]
Replies: 3
Views: 391

Re: Questions on the two exceptions, Chromium and Copper. [ENDORSED]

If you look closely, when it jumps from 3d 3 (V) to 3d 5 (Cr), the 4s 2 changes to 4s 1 . So it seems that as you go from Vanadium to Chromium, one of the electrons from 4s moves to 3d (since 3d 5 and 3d 10 subshells have lower energy) and another electron is added, turning it from 3d 3 4s 2 to 3d 5...
by Eunnie_Lee_3H
Sun Oct 09, 2016 12:42 am
Forum: Properties of Light
Topic: Properties of Light [ENDORSED]
Replies: 1
Views: 211

Re: Properties of Light [ENDORSED]

Many of light's behaviours can be explained by the wave model (such as diffraction with the diffraction patterns), but it is the photoelectric effect in which we can only explain light's behaviour with the particle model (photons). I'm not sure if it would be exactly correct to think of it as light ...
by Eunnie_Lee_3H
Sun Oct 09, 2016 12:01 am
Forum: Balancing Chemical Reactions
Topic: Whole Numbers [ENDORSED]
Replies: 1
Views: 283

Re: Whole Numbers [ENDORSED]

I've seen equations being written with numbers like 3.5 or 0.5, but it's probably best to have them all in whole numbers. So yeah, you'd multiply by 2 to get whole numbers.
by Eunnie_Lee_3H
Fri Oct 07, 2016 11:27 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Post Module Heisenberg #11 [ENDORSED]
Replies: 4
Views: 556

Re: Post Module Heisenberg #11 [ENDORSED]

For per mole, all you have to do is multiply the value of Joules per electron by Avogadro's number, 6.022*10 23 atoms(in this case, electrons)/mol. Since this atom is Hydrogen, 1 atom has 1 electron, so getting to electrons/mol using dimensional analysis: 6.022*10 23 atoms/mol * 1 electron/1 atom (o...
by Eunnie_Lee_3H
Fri Oct 07, 2016 11:17 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg's Indeterminacy Equation Clarification [ENDORSED]
Replies: 3
Views: 614

Re: Heisenberg's Indeterminacy Equation Clarification [ENDORSED]

Schrodinger's equation basically combined the concepts of De Broglie's equation and the Heisenberg's indeterminancy equation into one formula. Schrodinger wanted an equation that would allow people to find the energy of an electron by describing the electron as a wave function without having to use ...
by Eunnie_Lee_3H
Fri Oct 07, 2016 6:49 pm
Forum: Photoelectric Effect
Topic: Stern and Gerlach Experiment [ENDORSED]
Replies: 2
Views: 381

Re: Stern and Gerlach Experiment [ENDORSED]

As seen in the course reader page 62, the set up was to have an atom beam of silver atoms going through a magnetic field, which would hit a collection plate on the other side. What happened was that the atoms (which were in their ground state with their 1 unpaired electron) were accumulating on two ...
by Eunnie_Lee_3H
Fri Oct 07, 2016 4:58 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Pauli Exclusion Principle [ENDORSED]
Replies: 1
Views: 251

Re: Pauli Exclusion Principle [ENDORSED]

Yes, 2 electrons can both be in 1 orbital (m l ) only as long as they are paired (have different spins, AKA different m s values). They cannot have the same spin (both +1/2 or both -1/2), if they're to inhabit the same orbital. Pauli's exclusion principle also states that each orbital can only have ...
by Eunnie_Lee_3H
Fri Oct 07, 2016 4:38 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg's Indeterminacy Equation Clarification [ENDORSED]
Replies: 3
Views: 614

Re: Heisenberg's Indeterminacy Equation Clarification [ENDORSED]

\Delta p = uncertainty in momentum, \Delta x = uncertainty in position The worked examples actually don't ask for position; they actually give us the uncertainty in position \Delta x (1st example gives us 1.7*10 -15 m, and the 2nd example gives us 2.5*10 -10 m). The examples don't actually directly...
by Eunnie_Lee_3H
Fri Oct 07, 2016 3:01 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Hund's Rule confusion [ENDORSED]
Replies: 1
Views: 348

Re: Hund's Rule confusion [ENDORSED]

So it means that the orbitals (m l ) of the subshells (l) need to have the same spin (m s ). For example, in the 2p subshell, there are the orbitals 2p x , 2p y , and 2p z . According to Hund's Rule, you need to have the same m s number for each of these orbitals, which would be either +1/2 or -1/2....
by Eunnie_Lee_3H
Fri Oct 07, 2016 2:55 pm
Forum: Properties of Electrons
Topic: Electron Configurations of Atoms [ENDORSED]
Replies: 1
Views: 261

Re: Electron Configurations of Atoms [ENDORSED]

Electrons in the same orbital (m l ) cannot have the same spin (m s ). So m s for the two electrons can't be both +1/2 or -1/2. So for example, the 2 electrons that occupy the orbital (m l ) 2p x cannot both have m s value +1/2. There has to be one of each +1/2 and -1/2. This is what it means to be ...
by Eunnie_Lee_3H
Thu Oct 06, 2016 8:34 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Uncertainty in Velocity? [ENDORSED]
Replies: 1
Views: 255

Re: Uncertainty in Velocity? [ENDORSED]

I believe when you're using the value in the indeterminancy equation, you use double [whatever the number is], if it's given in this format. Like you said, yea you'd double the amount and use that value, and it would be the spread.

So, = [whatever number]
by Eunnie_Lee_3H
Thu Oct 06, 2016 8:00 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: wave functions and the heisenburg uncertainty [ENDORSED]
Replies: 1
Views: 213

Re: wave functions and the heisenburg uncertainty [ENDORSED]

The Heisenberg indeterminancy equation shows us that there is no way for us to know both the exact position and momentum of an electron at a certain point in time, and that we can only know the "range" of the possible positions and momentum the electron could be at. \psi 2 shows the probab...
by Eunnie_Lee_3H
Thu Oct 06, 2016 6:15 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Indeterminacy Equation
Replies: 1
Views: 231

Re: Indeterminacy Equation

It wouldn't be the electron with the diameter of 10 -15 but rather the atom's diameter (AKA in this case the "range" of the possible positions the electrons could be in). If the atom's diameter is less than 10 -15 , then yes it would be unrealistic. I'm not entirely too sure on the "u...
by Eunnie_Lee_3H
Thu Oct 06, 2016 5:58 pm
Forum: *Shrodinger Equation
Topic: Wave function [ENDORSED]
Replies: 1
Views: 328

Re: Wave function [ENDORSED]

A wave function ( \psi ), the way I understand it, is a function that models a wave. You can model waves with the sin and cos functions (sin and cos really only differ by their phases, and derivative of sin(x) -> cos(x), and derivative of cos(x) -> -sin(x)). Schrodinger, in a way, combined the De Br...
by Eunnie_Lee_3H
Thu Oct 06, 2016 11:40 am
Forum: *Shrodinger Equation
Topic: Relation to sin and cos [ENDORSED]
Replies: 1
Views: 412

Re: Relation to sin and cos [ENDORSED]

Schrodinger basically used a wave function to describe an electron so he could come up with a general equation for finding the energy of an electron instead of having just an empirical equation like the Rydberg equation. Wave functions are basically talking about the sin/cos functions. And, the deri...
by Eunnie_Lee_3H
Fri Sep 30, 2016 4:27 pm
Forum: Student Social/Study Group
Topic: Sunset Village Study Group
Replies: 17
Views: 1439

Re: Sunset Village Study Group

Hey! I'm also in B1, so I'd be interested as well!
by Eunnie_Lee_3H
Thu Sep 29, 2016 2:39 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: The Number of Moles in 2Na+2H2O--> 2NaOH+H2?
Replies: 3
Views: 10175

Re: The Number of Moles in 2Na+2H2O--> 2NaOH+H2?

Hey, Coefficients in chemical equations do not strictly refer to moles. More generally, it tells us the ratio of reactants needed to produce products. It could both mean the number of individual atoms/molecules of product and reactants, and the number of moles of product and reactants. Most of the t...

Go to advanced search