Search found 30 matches

by Jacy Black 1C
Fri Jun 08, 2018 12:13 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.23, confusing LS
Replies: 1
Views: 64

4.23, confusing LS

The question is asking for the lewis structure and to predict the shape of various molecules. Part a) asks to do so for OSbCl3. When I made the LS for OSbCl3, I found that the lowest possible FC was found when there was a double bond between O and Sb, as Sb expands its octet (which it can do, becaus...
by Jacy Black 1C
Fri Jun 08, 2018 11:44 am
Forum: Determining Molecular Shape (VSEPR)
Topic: formal charge and VSEPR
Replies: 8
Views: 262

Re: formal charge and VSEPR

In determining formal charge, I know it is #valence electrons - #bonds and #lp. But, if there is one set of lone pairs (2 electrons, one Lone pair) would I just subtract 1 ? Or because there are two electrons, would I subtract two?
by Jacy Black 1C
Thu Jun 07, 2018 9:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR
Replies: 7
Views: 217

Re: VSEPR

For VSEPR, when you're trying to determine the shape based off of the # of regions of electron density, would you count a double bond as ONE region of electron density or TWO regions of electron density? And would you only count the number of regions of electron densities around the central atom to ...
by Jacy Black 1C
Sat Jun 02, 2018 12:04 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent vs. Angular
Replies: 11
Views: 355

Re: Bent vs. Angular

I'm pretty sure they will take either name for either. Following the pattern on the VSEPR diagram we got, they both are angular/bent.
by Jacy Black 1C
Sat Jun 02, 2018 11:50 am
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.5 Confusion
Replies: 5
Views: 178

Re: 4.5 Confusion

So let me try to reword this so I understand. The overall shape of the molecule is going to be determined by how many regions of electron density, LP and BP. But the overall arrangement of it would be the arrangement as if there were no LPs, and all of the three regions of electron density were BPS?
by Jacy Black 1C
Sat Jun 02, 2018 11:47 am
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.3 Structure and Shape [ENDORSED]
Replies: 4
Views: 119

Re: 4.3 Structure and Shape [ENDORSED]

I am seriously confused on 4.3 from the textbook. The answer key states that HCN is a liner shape, but C forms 4 bonds total, 3 with N and 1 with H. This means there are four regions of electron density, correct? And that means it should be a tetrahedral shape?
by Jacy Black 1C
Fri May 25, 2018 11:45 am
Forum: Determining Molecular Shape (VSEPR)
Topic: shape of water
Replies: 8
Views: 209

Re: shape of water

I do think that Lavelle really emphasized that the lone pairs don't play a role in the naming of shape, although it does affect the overall shape. This is important to know, and is a large part of the reason why the shape isn't pyramidal but bent.
by Jacy Black 1C
Fri May 25, 2018 11:43 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angle
Replies: 10
Views: 266

Re: Bond Angle

When lone pairs are included on the central atom, it makes the bond angle smaller. Is this the only general trend about bond length we need to know, but no specifics?
by Jacy Black 1C
Fri May 25, 2018 11:41 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Resonance
Replies: 7
Views: 264

Re: Resonance

For a resonance structure with one double bond and two single bonds, would the bond length of all of them become a hybrid of all three bonds? I know all the bonds included would have partial double bond character. Affecting the length, would the double bond become a bit longer than normal, and would...
by Jacy Black 1C
Sun May 20, 2018 11:38 pm
Forum: Lewis Structures
Topic: central atom
Replies: 7
Views: 129

Re: central atom

also, this can be tested by calculating formal charges and finding the lowest combination!
by Jacy Black 1C
Sun May 20, 2018 1:57 pm
Forum: DeBroglie Equation
Topic: De Broglie Wavelength on the Midterm
Replies: 4
Views: 234

De Broglie Wavelength on the Midterm

I was wondering about a question on the midterm. It asked for the wavelength of an ejected electron when you're given the velocity of an electron. This is all in the context of the photoelectric effect. Apparently, the information that was given was to be used in the De Broglie wavelength equation t...
by Jacy Black 1C
Sun May 20, 2018 1:51 pm
Forum: Lewis Structures
Topic: 3.41 c [ENDORSED]
Replies: 4
Views: 166

Re: 3.41 c [ENDORSED]

My question for this problem is more related to how to choose which atom is the central atom. At first, I made my structure with NH2 as the center atom, with CH2 and COOH on either side. However, the answer in the textbook has CH2 as the center atom. Why is this? Does it have to do with the formal c...
by Jacy Black 1C
Sun May 13, 2018 9:45 pm
Forum: Properties of Light
Topic: Keywords for Work Function or E_photon?
Replies: 4
Views: 203

Re: Keywords for Work Function or E_photon?

Most times, if it asks for the energy required to eject an electron, this means it is asking for the work function, or the threshold energy. If it’s asking for the wavelength that caused the electron to be ejected, it is most likely asking for you to solve for the E Photon, and then find the wavelen...
by Jacy Black 1C
Sun May 13, 2018 9:43 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: cations vs anions
Replies: 4
Views: 196

Re: cations vs anions

Also, remember that actions are losing electrons. Think of the outermost shell: then imagine losing electrons from that shell until it is empty. For most cations, they lose an electron shell as they lose the electrons inhabiting the shell, and their size is reduced. Gaining electrons, for anions, me...
by Jacy Black 1C
Sun May 13, 2018 9:37 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Calculating energy change (Delta E)
Replies: 4
Views: 245

Calculating energy change (Delta E)

A topic that confused me was the difference in energy after using the equation EN=-hR/ (n^2).
Because the energy of a certain shell (En) will always be negative, how would you calculate the difference between two energy levels, say from n=3 to n= 2?
It would always end up being negative, correct?
by Jacy Black 1C
Mon May 07, 2018 3:38 pm
Forum: *Shrodinger Equation
Topic: Schrodinger Equation [ENDORSED]
Replies: 8
Views: 413

Re: Schrodinger Equation [ENDORSED]

I understand that Schrodinger's equation gives a solution of the wave function which describes orbitals. But how? I'm unsure what the notation itself for the equation means, and how I would describe this system or answer a test question using it.
by Jacy Black 1C
Mon May 07, 2018 3:35 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Significance of - sign
Replies: 2
Views: 171

Re: Significance of - sign

This is also something I am confused about, in using this equation. It is confusing to me how the energy of an electron at a given level of n will always be a negative number, but if it jumps from n=3 to n=4 the change in E will be positive, but wouldn't that just be adding a negative number to a ne...
by Jacy Black 1C
Mon May 07, 2018 3:29 pm
Forum: Properties of Electrons
Topic: Energy Levels and Frequencies
Replies: 3
Views: 340

Re: Energy Levels and Frequencies

Hello! I was looking over the topics mentioned on "The Quantum World" outline, and was confused by one of them. It states what we should be able to "describe the factors affecting the energy of an electron in a many-electron atom." I am unsure what concepts this is referring to r...
by Jacy Black 1C
Mon Apr 30, 2018 1:34 pm
Forum: Quantum Numbers and The H-Atom
Topic: Hw Problem 2.21
Replies: 1
Views: 125

Hw Problem 2.21

SO this question is asking for the principal and orbital angular momentum quantum numbers for each of the following orbitals; a) 6p; b) 3d; c) 2p; d)5f. for a p orbital, the orbital angular momentum quantum number is l= 1, for the f orbital l= 3, and for the d orbital l=2. these are the correct answ...
by Jacy Black 1C
Mon Apr 30, 2018 1:26 pm
Forum: Quantum Numbers and The H-Atom
Topic: Homework problem 2.1 (d) [ENDORSED]
Replies: 2
Views: 99

Re: Homework problem 2.1 (d) [ENDORSED]

The more electrons and the more sub shells inhabited, the larger the atomic radius. If you think of the sub shells as expanding outwards from the nucleus, then the more sub shells that are inhabited, the larger the atom itself. In a very simple example, its like the more electrons orbiting the nucle...
by Jacy Black 1C
Mon Apr 30, 2018 1:22 pm
Forum: Quantum Numbers and The H-Atom
Topic: Four Different Quantum Numbers
Replies: 7
Views: 237

Re: Four Different Quantum Numbers

I think it makes sense to view it as the numbers helping us know where the electrons are located in space. Only two electrons of opposite spin can inhabit the same orbital. This would mean that all of their quantum numbers would be the same except for the spin magnetic quantum number. If all four qu...
by Jacy Black 1C
Mon Apr 30, 2018 1:18 pm
Forum: Quantum Numbers and The H-Atom
Topic: HW 2.19 part D)
Replies: 1
Views: 84

HW 2.19 part D)

The question is asking how many sub shells are there in the shell with n=4. I attempted to solve it in the manner of the other questions, where I found the value of l (n-1; 4-1=3) and then the labels of the different orbitals in the sub shell (3, 2, 1, 0, -1, -2, -3). I thought that the answer would...
by Jacy Black 1C
Sun Apr 22, 2018 11:27 pm
Forum: Molarity, Solutions, Dilutions
Topic: concentration
Replies: 2
Views: 103

Re: concentration

I am assuming that you are asking about the molarity of a solution, and how to find the mass given the molarity. Molarity is a unit of concentration, and the molarity equation is : Molarity= (Moles of solute)/(Volume in LITERS) So, if you're given the concentration, or molarity, you will need to kno...
by Jacy Black 1C
Sun Apr 22, 2018 11:21 pm
Forum: Empirical & Molecular Formulas
Topic: Test 1 Question 7
Replies: 3
Views: 259

Test 1 Question 7

Hello, I was wondering if someone could help explain how to correctly answer the following question from the first test: "Determine the empirical formula for an organic compound that, when burned in the presence of oxygen, formed 8.45g of Carbon Dioxide and 1.73g of Water. What is the mass perc...
by Jacy Black 1C
Sun Apr 22, 2018 11:16 pm
Forum: Molarity, Solutions, Dilutions
Topic: Test 1 Q2
Replies: 2
Views: 166

Re: Test 1 Q2

I also was confused on this question. Essentially the question states that a 50.ml solution of 0.1 M AlCl3 had .015g of aluminum deposited on the surface, asking for the concentration of aluminum ions in the electrolyte. I am confused as to the context of the question, as it mentions electroplating ...
by Jacy Black 1C
Sat Apr 14, 2018 4:15 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Formula, 1.13 HW
Replies: 4
Views: 153

Rydberg Formula, 1.13 HW

Okay so the Rydberg Formula in the book is stated as V= R{(1/(n1)^2)-(1/(n2)^2} This makes sense to me, but in the example of practice problem 1.13, I had trouble understanding which N given would be N1 and which would be N2. 1.13 asks to calculate the wavelength of radiation generated by the transi...
by Jacy Black 1C
Sat Apr 14, 2018 2:24 pm
Forum: Properties of Light
Topic: Help on 1.9 [ENDORSED]
Replies: 4
Views: 183

Re: Help on 1.9 [ENDORSED]

also as a part two, what's the conversion factor from mHz to Hz? That's something that is required to find one of the other answers.
by Jacy Black 1C
Sat Apr 14, 2018 1:57 pm
Forum: Properties of Light
Topic: Help on 1.9 [ENDORSED]
Replies: 4
Views: 183

Help on 1.9 [ENDORSED]

I'm wondering how to solve the second line of the chart for 1.9. The only information given is that the energy of the light photon is 3.3 x 10^-19 J, and it is asking for you to solve for the wavelength and frequency. The answers in the solutions manual only give the example of how to solve the firs...
by Jacy Black 1C
Sat Apr 14, 2018 1:08 pm
Forum: Properties of Light
Topic: HW 1.5 [ENDORSED]
Replies: 7
Views: 289

Re: HW 1.5 [ENDORSED]

I had the same question for 1.5. I think the key is the combination of two things: the table on pg. 4 as someone else noted above, and the table on pg.6 showing the electromagnetic spectrum and the range of wavelengths. While table 1.1 on page 4 differentiates different energy levels for most of the...
by Jacy Black 1C
Thu Apr 12, 2018 1:33 pm
Forum: Balancing Chemical Reactions
Topic: Fastest way to balance chemical equation
Replies: 9
Views: 1259

Fastest way to balance chemical equation

I similarly have trouble not with the simple chemical equations, but balancing the harder chemical equations. The test 1 we just took featured longer, more complicated chemical equations, and I didn't even know where to begin. It seemed like every element I balanced affected another and another, and...

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