Search found 34 matches

by Zuri Smith 1A
Sun Jun 10, 2018 10:46 pm
Forum: Bronsted Acids & Bases
Topic: Writing the chemical equation for proton transfers
Replies: 2
Views: 218

Writing the chemical equation for proton transfers

When writing the chemical equation for a proton transfer reaction, is the general rule just to disregard atoms that aren't involved in the transfer of protons? For ex: J.15 (a) NaC6H5O reacts with water. Correct answer: C6H5O + H2O --> OH- + C6H5OH Why not NaC6H5O + H2O --> OH- + NaC6H5OH? Should we...
by Zuri Smith 1A
Mon Jun 04, 2018 8:44 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: 4.79 (diamagnetism)
Replies: 1
Views: 175

4.79 (diamagnetism)

4.79 asks, "(a) Order the following molecules according to increasing C-F bond length: CF+, CF, CF- . (b) Which of these molecules will be diamagnetic, if any? Explain your reasoning." What does diamagnetic even mean? Does it have something to do with radicals? My approach to this problem ...
by Zuri Smith 1A
Mon Jun 04, 2018 8:09 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Outlining Steps for Determining Shape
Replies: 1
Views: 83

Re: Outlining Steps for Determining Shape

This is the process I use, hope it helps! I used CH4 in exercise 4.73 as an example. 1. Count the # of valence electrons for each atom. For example, CH4: Carbon has 4 valence e-, H, has 4 x 1 e- = 8 e- total 2. Draw the correct Lewis structure -- check using the formal charge equation. For example, ...
by Zuri Smith 1A
Mon Jun 04, 2018 1:58 pm
Forum: Hybridization
Topic: Meaning of hybridization
Replies: 2
Views: 138

Meaning of hybridization

What is the point of hybridization? Aren't there still the same amount of unpaired electrons, even with a hybrid orbital? For example, Carbon can form 4 bonds in the 2p orbital (each of the 2 unpaired electrons can receive a pair, and there can be 2 new electrons added for a total of 4) and so can t...
by Zuri Smith 1A
Sun Jun 03, 2018 10:15 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Pi bonds
Replies: 4
Views: 135

Re: Pi bonds

From what I understood in lecture, if there is a single bond, it will always be a sigma bond. A double bond will be one sigma bond and one pi bond. A triple bond will be one sigma bond and two pi bonds.

However, I do not know which of the bonds are which. Could someone explain further?
by Zuri Smith 1A
Sun Jun 03, 2018 10:13 pm
Forum: Sigma & Pi Bonds
Topic: sigma and Pi bonds
Replies: 2
Views: 206

Re: sigma and Pi bonds

From my understanding, sigma bonds have atoms that interact end-to-end, and sigma bonds allow the bound atoms to ROTATE on an axes, due to the bond's cylindrical symmetry. Pi ponds, on the other hand, overlap side-by-side, and Pi bonds do NOT allow atoms to rotate, because pi ponds have electron den...
by Zuri Smith 1A
Sun Jun 03, 2018 10:10 pm
Forum: Dipole Moments
Topic: dipole moments
Replies: 9
Views: 375

Re: dipole moments

Maybe they were talking about the strength of a vector? I'm curious about this too. Also, dipole moments are just created when two atoms have a difference in electronegativities, right?
by Zuri Smith 1A
Sat Jun 02, 2018 8:21 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Define Ligands?
Replies: 10
Views: 316

Re: Define Ligands?

So are all ligands Lewis bases?
by Zuri Smith 1A
Sat Jun 02, 2018 8:20 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: formal charge and VSEPR
Replies: 8
Views: 262

Re: formal charge and VSEPR

This is somewhat unrelated, but does VSEPR just refer to the notation? Like AXE4?
by Zuri Smith 1A
Tue May 29, 2018 8:46 pm
Forum: Resonance Structures
Topic: How to determine resonance
Replies: 2
Views: 165

How to determine resonance

Do molecules have "resonance" if the bonds between atoms can simply be moved around? Or do entirely new bonds have to be made in order for a molecule to be said to have resonance? (Can you just move an atom with a double bond from the top, to the right, to the bottom, and then to the left?...
by Zuri Smith 1A
Mon May 28, 2018 8:49 pm
Forum: Hybridization
Topic: hybridization example
Replies: 3
Views: 117

Re: hybridization example

Yes, I believe he is referring only to the valence electrons (the electrons that will form bonds with other atoms).

Also what exam are you referring to –- the final?
by Zuri Smith 1A
Mon May 21, 2018 9:35 pm
Forum: Lewis Structures
Topic: 3.33 and ionization energy
Replies: 3
Views: 147

Re: 3.33 and ionization energy

According to pg. 78 in the textbook, "In simple chemical formulas, the central atom is often written first, follow by the atoms attached to it." Perhaps this is the reason why the correct answer is what it was.
by Zuri Smith 1A
Sun May 20, 2018 2:57 pm
Forum: Lewis Structures
Topic: 3.33 and ionization energy
Replies: 3
Views: 147

3.33 and ionization energy

I thought that: a) ionization energy increases across a period and up a group, and b) The element with the highest ionization energy is chosen as the central atom when creating a lewis structure. Question 3.33 part b asks us to write the lewis structure of COCl2. I thought that O or even Cl had high...
by Zuri Smith 1A
Sun May 20, 2018 12:11 pm
Forum: Dipole Moments
Topic: Meaning of an induced dipole
Replies: 3
Views: 230

Re: Meaning of an induced dipole

Ohh ok. So in the cases you mentioned, how is energy involved with dipole interactions? I ask only because of the lecture in class, which discussed different values of energy for different interactions
by Zuri Smith 1A
Sat May 19, 2018 10:00 pm
Forum: Dipole Moments
Topic: Meaning of an induced dipole
Replies: 3
Views: 230

Meaning of an induced dipole

Can someone please explain the meaning of an induced dipole, and what the given energy represents (as it was presented in class -- is this the energy of the attraction? The energy needed to break the bond?)
by Zuri Smith 1A
Tue May 15, 2018 2:58 pm
Forum: Ionic & Covalent Bonds
Topic: 3.23 (meaning of oxidation)
Replies: 7
Views: 283

Re: 3.23 (meaning of oxidation)

Ohh okay. So basically +7 means that Cl can give up, at most, 7 negatively charged electrons (which is why it is +7 and not -7). Thank you!
by Zuri Smith 1A
Mon May 14, 2018 7:09 pm
Forum: Ionic & Covalent Bonds
Topic: 3.23 (meaning of oxidation)
Replies: 7
Views: 283

3.23 (meaning of oxidation)

Question 3.23 states: Chlorine can exist in both positive and negative oxidation states. What is the maximum (a) positive and (b) negative oxidation number that chlorine can have? My question is, what exactly does oxidation mean? Chlorine (Cl) has 7 valence electrons, meaning it needs only one to fo...
by Zuri Smith 1A
Tue May 08, 2018 9:52 pm
Forum: Properties of Electrons
Topic: Wave-like properties
Replies: 1
Views: 145

Wave-like properties

Do neutrons and protons have wave-like properties similar to those of electrons?
by Zuri Smith 1A
Sun May 06, 2018 12:30 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: What is Zeff (prob 2.37) [ENDORSED]
Replies: 2
Views: 125

What is Zeff (prob 2.37) [ENDORSED]

2.37: Which of the following statements are true for many e- atoms? If false, explain. (A) the effective nuclear charge of Zeff is independent of the number of electrons present in an atom.

What is "Zeff" and how can it be used to solve problems about quanta?
by Zuri Smith 1A
Mon Apr 30, 2018 6:37 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: HW 2.19
Replies: 2
Views: 138

Re: HW 2.19

For part b, If 6=n, why would l=2? I thought that l could be, at max, n-1.
by Zuri Smith 1A
Mon Apr 30, 2018 4:48 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 2.1 help [ENDORSED]
Replies: 3
Views: 127

Re: 2.1 help [ENDORSED]

It was my understanding that each shell has at least 1 subshell: s,p,d, or f. Therefore, if an electron changes subshells, is it possible for it to remain in the same shell? If so, then wouldn't electrons in the same shell have the same value for "n"?
by Zuri Smith 1A
Mon Apr 23, 2018 10:02 pm
Forum: Photoelectric Effect
Topic: equation for the photoelectric effect
Replies: 1
Views: 82

equation for the photoelectric effect

In class, I remember Dr. Lavelle describing the equation for the Photoelectric Effect as being: E(photon) = hv = Work - 1/2mv^2. However, as I am trying to complete some of the problems in the book, the equation that is often used says "Work PLUS KE", rather than "Work MINUS KE"....
by Zuri Smith 1A
Sun Apr 22, 2018 11:17 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Balmer and Lyman Series
Replies: 9
Views: 603

Balmer and Lyman Series

For Test 2, should we memorize what series correspond to different spectra? For ex, in problem 1.15, the question states "In the ultraviolet spectrum of atomic hydrogen, a line is observed at 102.6 nm. Determine the values of n for the initial and final energy levels of the electron during the ...
by Zuri Smith 1A
Sat Apr 21, 2018 10:42 pm
Forum: Limiting Reactant Calculations
Topic: Question from test 1 [ENDORSED]
Replies: 4
Views: 317

Re: Question from test 1 [ENDORSED]

Okay thank you! And just to reconfirm, the limiting reagent is basically just the reactant that has the smallest # of moles (and thus runs out the quickest)?
by Zuri Smith 1A
Sat Apr 21, 2018 5:02 pm
Forum: Limiting Reactant Calculations
Topic: Question from test 1 [ENDORSED]
Replies: 4
Views: 317

Question from test 1 [ENDORSED]

I don't know if we're allowed to ask questions from test 1, and so I sincerely apologize if I am breaking a rule by posting this question. I was wondering how to do the following, which involves finding the limiting reaction and then determining how much unreacted fuel is left over. The equation is ...
by Zuri Smith 1A
Wed Apr 18, 2018 9:06 pm
Forum: Properties of Electrons
Topic: Diffraction meaning
Replies: 6
Views: 242

Re: Diffraction meaning

I think of constructive diffraction as adding the magnitudes of 2 overlapping wavelengths of different sizes, and destructive diffraction would then be a subtraction of 2 overlapping, alternating wavelengths of different sizes (I don't know if this is actually true but I hope that it is!)
by Zuri Smith 1A
Wed Apr 18, 2018 9:03 pm
Forum: Administrative Questions and Class Announcements
Topic: Test Number 1
Replies: 10
Views: 458

Re: Test Number 1

My T.A. said that the average was about 22/40 for all of her discussion sections.
by Zuri Smith 1A
Mon Apr 16, 2018 9:32 pm
Forum: Properties of Light
Topic: Rydberg equation
Replies: 2
Views: 104

Rydberg equation

I understand this was explained briefly in class, but what is the Rydberg equation and how is it derived? It would be useful to use that equation for problem 1.17, which states: "The energy levels of hydrogen like one-electron ions of atomic number Z differ from those of hydrogen by a factor of...
by Zuri Smith 1A
Mon Apr 16, 2018 8:19 pm
Forum: Properties of Light
Topic: HW 1.3 [ENDORSED]
Replies: 12
Views: 457

Re: HW 1.3 [ENDORSED]

I also could understand why A,B, and D were incorrect, but still have trouble understanding the logic behind why C is correct. Is there an equation that could be used that allows us to know that the extent of the change in the electrical field decreases, such as the one covered in class today?
by Zuri Smith 1A
Mon Apr 16, 2018 8:08 pm
Forum: Empirical & Molecular Formulas
Topic: Creating a molecular/empirical formula
Replies: 3
Views: 192

Creating a molecular/empirical formula

When given the actual physical structure of a molecule, how do we construct the molecular/empirical formulas? I.e., if we are given a structure in which there are five Carbon and Hydrogen atoms paired together, and connected by bonds, would the equation be 5(CH)? Or (CH) subscript 5?
by Zuri Smith 1A
Mon Apr 16, 2018 8:01 pm
Forum: Properties of Light
Topic: The speed of light
Replies: 4
Views: 143

The speed of light

I apologize if this question is elementary, but do all forms of energy on the electromagnetic spectrum (gamma rays, x rays, infrared, etc) travel at the speed of light?
by Zuri Smith 1A
Mon Apr 09, 2018 7:28 pm
Forum: Administrative Questions and Class Announcements
Topic: Test #1 [ENDORSED]
Replies: 4
Views: 202

Re: Test #1 [ENDORSED]

Hi, I also have a question about test#1. Will we be expected to know things that weren't covered in class, but are listed in Outline 1? This includes problems from sections G, L and M. For example: reaction stoichiometry, mass to mass calculations, volumetric analysis.
by Zuri Smith 1A
Mon Apr 09, 2018 6:59 pm
Forum: Empirical & Molecular Formulas
Topic: Converting from empirical to molecular to formula units [ENDORSED]
Replies: 1
Views: 122

Converting from empirical to molecular to formula units [ENDORSED]

Hi, In class we learned how to find both the molecular and empirical formulas. How do we use this information to find formula units, and what exactly are formula units? For example, in E21.: "Calculate the amount (in moles) and the number of molecules and formula units (or atoms if indicated) i...
by Zuri Smith 1A
Sat Apr 07, 2018 4:36 pm
Forum: SI Units, Unit Conversions
Topic: Units + their meanings
Replies: 3
Views: 154

Units + their meanings

Sorry if this is a dumb question, but what are the units for moles? Simply "mol"? Furthermore, what do the units of g/mol signify? Are those related to atomic mass, molar mass, or something else entirely?

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