Search found 55 matches

by Phoebe Chen 4I
Sat Dec 08, 2018 1:26 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Ni3+
Replies: 1
Views: 31

Ni3+

Is the electron configuration for Ni3+ considered an exception in that it would rather have a half filled d-orbital than lose the two s orbital electrons first. Is the correct electron configuration for Ni3+ [Ar]3d^54s^2 or is it [Ar]3d^7? Thank you!
by Phoebe Chen 4I
Sat Dec 08, 2018 8:46 am
Forum: Properties & Structures of Inorganic & Organic Bases
Topic: Oxoacid Strength
Replies: 1
Views: 64

Oxoacid Strength

Why is the number 4 acid weaker than the number 2 compound? That is what it says in the answer key to one of the worksheets.
by Phoebe Chen 4I
Thu Dec 06, 2018 3:12 pm
Forum: Identifying Acidic & Basic Salts
Topic: HW 12.17
Replies: 2
Views: 78

HW 12.17

I am unsure how to do this problem. I am having a hard time imagining how oxides act as acids or bases. Can someone explain this to me? Thank you!
by Phoebe Chen 4I
Thu Dec 06, 2018 2:37 pm
Forum: Naming
Topic: Naming multiple coordination compounds
Replies: 1
Views: 24

Naming multiple coordination compounds

Do we need to know how to name something like this?
by Phoebe Chen 4I
Wed Dec 05, 2018 9:47 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: edta
Replies: 1
Views: 30

edta

Do we need to know ethylenediaminetetraacetato (edta) for the test?
by Phoebe Chen 4I
Tue Dec 04, 2018 2:01 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: HW 17.35 6th Ed
Replies: 1
Views: 30

HW 17.35 6th Ed

I am unsure of how to do this problem and how to tell if something can make a chelate or not. I understand the affect of single bonds and double bonds, but not necessarily the placement. Also, what is the significance or use of chelates? Thanks in advance!
by Phoebe Chen 4I
Tue Dec 04, 2018 1:59 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentates: HW 17.33 6th Ed
Replies: 2
Views: 38

Polydentates: HW 17.33 6th Ed

Hi, I am unsure of how to tell if a ligand is a polydentate and specifically what polydentate. Does it have something to do with the number of lone pairs?
by Phoebe Chen 4I
Fri Nov 30, 2018 10:06 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Square Planar
Replies: 12
Views: 121

Square Planar

Are the bond angles in square planar less than or equal to 90?
by Phoebe Chen 4I
Thu Nov 29, 2018 8:25 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability
Replies: 1
Views: 35

Polarizability

When we talk about polarizability, is that in reference to it making intra or inter molecular bonds? Also, if an anion is more polarizable does it mean the bond it makes, intra or inter depending on the answer above, is more or less stable?
by Phoebe Chen 4I
Thu Nov 29, 2018 12:39 pm
Forum: Bond Lengths & Energies
Topic: 6th edition: 3.87-- bond length vs electronegativity/polarity
Replies: 1
Views: 49

Re: 6th edition: 3.87-- bond length vs electronegativity/polarity

Polarity has more to do with INTERmolecular bonds and LDFs. It seems that this question is asking about INTRAmolecular bonds. When talking about intramolecular bonds it is important to note bond length. We generally do not take electronegativity into account when talking about bond strength between ...
by Phoebe Chen 4I
Thu Nov 29, 2018 12:23 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: CH4O
Replies: 2
Views: 34

Re: CH4O

If that's the case then there would only be the two arrows pointing inwards towards O from the H and the C. Don't those dipole moments cancel? But the compound is polar.
by Phoebe Chen 4I
Thu Nov 29, 2018 11:46 am
Forum: Determining Molecular Shape (VSEPR)
Topic: AX2E2
Replies: 14
Views: 165

AX2E2

Molecules with the VSEPR formula AX2E2 would have bond angles of 109.5 or less than 109.5?
by Phoebe Chen 4I
Thu Nov 29, 2018 11:42 am
Forum: Determining Molecular Shape (VSEPR)
Topic: HW 4.91 6th Ed
Replies: 1
Views: 31

HW 4.91 6th Ed

For this homework question, part b asks why this compound would be highly reactive and attached is the answer to that question, which is that the bond angle between C-C Triple bond C is less than 180 degrees. I do not understand this explanation and feel that it doesn't quite answer the question. Ca...
by Phoebe Chen 4I
Thu Nov 29, 2018 11:38 am
Forum: Determining Molecular Shape (VSEPR)
Topic: CH4O
Replies: 2
Views: 34

CH4O

Is this the correct way to draw out the dipole moments within CH4O?
by Phoebe Chen 4I
Thu Nov 29, 2018 11:11 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar vs Non-Polar
Replies: 2
Views: 22

Polar vs Non-Polar

How do you tell if a compound is polar or non-polar? Do you look at the dipole moments between each atoms and then figure out the net dipole moment? If so, is the dipole moment between atoms dictated by the electronegativity of the different atoms?
by Phoebe Chen 4I
Wed Nov 28, 2018 11:24 pm
Forum: Hybridization
Topic: Bond Strengths
Replies: 4
Views: 64

Bond Strengths

In the 6th Edition textbook section 4.7 it says "a carbon-carbon double bond is stronger than one carbon-carbon single bond but weaker than the sum of two single bonds." I understand why a C-C double bond is stronger than a single bond but I am confused about it being stronger than the sum...
by Phoebe Chen 4I
Wed Nov 28, 2018 10:37 pm
Forum: Hybridization
Topic: s-character
Replies: 1
Views: 24

s-character

In the homework question attached, what is the s-character that they are referring to? Is it the s in the sp^2 or sp^3 orbital? If that is the case, wouldn't the s-character have no effect because it would always only have one orbital to contribute?
by Phoebe Chen 4I
Tue Nov 27, 2018 5:11 pm
Forum: Hybridization
Topic: Regions of Electron Desnity
Replies: 5
Views: 29

Regions of Electron Desnity

Do lone pairs count as regions of electron density for hybridization?
by Phoebe Chen 4I
Mon Nov 19, 2018 3:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Double bonds
Replies: 8
Views: 118

Re: Double bonds

You don't need to depict double bonds in VSEPR diagrams. VSEPR is more concerned with atom arrangement around the central atom.
by Phoebe Chen 4I
Mon Nov 19, 2018 3:40 pm
Forum: Sigma & Pi Bonds
Topic: Rotating Pi bonds
Replies: 3
Views: 29

Re: Rotating Pi bonds

A pi-bond will break when it starts to rotate. I don't think there is a situation where it can rotate.
by Phoebe Chen 4I
Mon Nov 19, 2018 3:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Atom Placement
Replies: 4
Views: 47

Atom Placement

When you have a molecule like SO2CL2, how are you supposed to know how to arrange the oxygen and chlorines around the central atom? Are they placed next to each other or opposite each other? Or does it not matter?
by Phoebe Chen 4I
Sun Nov 18, 2018 6:04 pm
Forum: Administrative Questions and Class Announcements
Topic: Chem Community Posts
Replies: 3
Views: 55

Chem Community Posts

Hi, can we post chem community questions/answers in advance for the next week? Or are our posts only counted for the week they are posted in?
by Phoebe Chen 4I
Thu Nov 15, 2018 3:30 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: HW Q 4.11
Replies: 4
Views: 32

Re: HW Q 4.11

laurenho-4c wrote:SCl4 has a seesaw molecular geometry because you must take into account the effect that the lone pair on S has on shape; if there was no lone pair on SCl4, the shape would be tetrahedral.


If there was no lone pair it would just be SCl4. Would it not be square planar?
by Phoebe Chen 4I
Thu Nov 15, 2018 3:29 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Planar vs Pyramidal
Replies: 3
Views: 34

Planar vs Pyramidal

Trigonal planar and trigonal pyramidal molecules both have three atoms connected to the central atom. How can you tell if a molecule should be planar or pyramidal? I know that if there is a lone pair it will be pyramidal.However, if the three atoms attached to the central atom are all different but ...
by Phoebe Chen 4I
Thu Nov 15, 2018 3:25 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: HW Q 4.13
Replies: 2
Views: 29

HW Q 4.13

For part a to this question, I thought I3- was supposed to be angular but it says the shape is in fact linear. Can someone explain to me why it is linear. I think the three lone pairs are confusing me. I understand that only atoms are considered when naming VSEPR shapes but lone pairs do alter the s...
by Phoebe Chen 4I
Thu Nov 15, 2018 3:23 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: HW Q 4.11
Replies: 4
Views: 32

HW Q 4.11

Initially when I did part a for SCl4, I thought it's shape was supposed to be tetrahedral. But the answer says it is see saw. Can someone explain why its shape is see saw and not tetrahedral and what is a key way of differentiating the two.
by Phoebe Chen 4I
Fri Nov 09, 2018 3:41 pm
Forum: Lewis Structures
Topic: Formal charge question
Replies: 9
Views: 116

Re: Formal charge question

Formal charge is the best way to tell if you have the most stable lewis structure. I don't know of any other way. With the formal charges, you want to get each of them as close to zero as possible and you want to make sure that all of them add up to zero.
by Phoebe Chen 4I
Fri Nov 09, 2018 3:39 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: Hydrogen Bonds vs. Ion-Dipole Bonds
Replies: 5
Views: 83

Re: Hydrogen Bonds vs. Ion-Dipole Bonds

The hydrogen bond is very electronegative which makes it very strong. Hydrogen bonds are a type of dipole-dipole bond but are so prevalent in nature that they get their own classification.
by Phoebe Chen 4I
Thu Nov 08, 2018 12:28 pm
Forum: Lewis Structures
Topic: Octet rule question
Replies: 6
Views: 114

Re: Octet rule question

All the elements with orbitals 3p and up have an expanded octet. Everything before that must adhere to the octet rule. However, elements with only 1s orbitals, and elements with only up to 2s orbitals do not adhere to octet rule and instead only need to have 2 valence or bonded electrons.
by Phoebe Chen 4I
Sun Nov 04, 2018 4:01 pm
Forum: Lewis Structures
Topic: HW 3.39
Replies: 1
Views: 24

HW 3.39

I don't know how to do part c. Could someone please explain it to me?
by Phoebe Chen 4I
Sun Nov 04, 2018 3:59 pm
Forum: Lewis Structures
Topic: Lewis Structure for Ionic Bonds
Replies: 2
Views: 32

Lewis Structure for Ionic Bonds

How do we draw lewis structures for ionic bonds? Also, how do we draw lewis structures that involve a compound, for example ammonium chloride?
by Phoebe Chen 4I
Thu Nov 01, 2018 12:57 am
Forum: Ionic & Covalent Bonds
Topic: Electrostatic Potential Energy
Replies: 2
Views: 72

Electrostatic Potential Energy

Do we need to know this equation or understand it for the midterm?
by Phoebe Chen 4I
Wed Oct 24, 2018 4:27 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: HW 1.15
Replies: 1
Views: 58

HW 1.15

I was able to figure out that the energy levels were n =1 and 3 but I don't know how to figure out which direction it is. Is it n=1 to n=3 or the other way around? How are you able to tell which direction it's supposed to be?
by Phoebe Chen 4I
Wed Oct 24, 2018 4:19 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Balmer, Lyman, Paschen Series
Replies: 3
Views: 133

Balmer, Lyman, Paschen Series

Do we need to explicitly know the Blamer, Lyman, and Paschen series for the test? For example do we need to know which each of their lowest energy levels are?
by Phoebe Chen 4I
Wed Oct 24, 2018 4:16 pm
Forum: Photoelectric Effect
Topic: HW 1.3
Replies: 4
Views: 117

HW 1.3

I know the right answer should be c, but I don't quite understand the explanation given. Can someone explain this please or put it into other words?
by Phoebe Chen 4I
Wed Oct 24, 2018 4:15 pm
Forum: Properties of Electrons
Topic: Electrons and wavelengths?
Replies: 3
Views: 69

Re: Electrons and wavelengths?

How would you find the frequency?
by Phoebe Chen 4I
Wed Oct 24, 2018 3:44 pm
Forum: Properties of Electrons
Topic: Electrons and wavelengths?
Replies: 3
Views: 69

Electrons and wavelengths?

Is it possible for electrons to have wavelengths and frequencies or is that only for photons?
by Phoebe Chen 4I
Wed Oct 24, 2018 3:43 pm
Forum: DeBroglie Equation
Topic: DeBroglie Equation and experiment
Replies: 2
Views: 94

DeBroglie Equation and experiment

Is there an experiment associated with DeBroglie's Equation?
by Phoebe Chen 4I
Mon Oct 22, 2018 6:09 pm
Forum: Photoelectric Effect
Topic: HW Question 1.57
Replies: 4
Views: 154

HW Question 1.57

I am unsure how to solve this problem. First I found the energies of the wavelengths and thought I could use En = -hR/n^2 to find out the energy level number for each energy and see which number would come next. But I don't think that is the right way to solve it. Would appreciate help on this quest...
by Phoebe Chen 4I
Thu Oct 18, 2018 9:31 pm
Forum: Quantum Numbers and The H-Atom
Topic: Orbitals
Replies: 1
Views: 79

Orbitals

p, d, and f orbitals have different shapes and different possible orientations. Are all the possible orientations superimposed over each other or is only one orientations possible but we are not sure which one it is?
by Phoebe Chen 4I
Thu Oct 18, 2018 12:15 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Quantum Number L
Replies: 3
Views: 58

Re: Quantum Number L

What if n=5? Would that mean l could be 0, 1, 2, 3, or 4? I guess I'm also confused about s corresponding to l=0 and p corresponding to l=1, and how that l is separate from the possible values found above. The n value determines l but the orbital shape also determines l? It seems to me as if there a...
by Phoebe Chen 4I
Mon Oct 15, 2018 5:14 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Quantum Number L
Replies: 3
Views: 58

Quantum Number L

According to the textbook the quantum number L can be found by n-1. However, when I was doing the textbook problems I learned that s-orbitals correspond to L=0, p-orbitals L=1 and so on. The L values didn't correspond to the principle quantum number (n) by just subtracting 1 from it. Can someone ple...
by Phoebe Chen 4I
Mon Oct 15, 2018 4:26 pm
Forum: Photoelectric Effect
Topic: HW Question 1.33
Replies: 1
Views: 38

HW Question 1.33

I am unsure how to get the wavelength value for part c of questions 1.33. What I did is take the required frequency of 2.50x10^16 Hz and divided c by that to get wavelength. But my wavelength value did not match the answer.
by Phoebe Chen 4I
Thu Oct 11, 2018 1:12 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Finding Energy Level for H-Atom
Replies: 2
Views: 32

Re: Finding Energy Level for H-Atom

Does n1 mean energy level one, or only in the case for H-Atoms. I thought n1 was just notation for initial energy level.
by Phoebe Chen 4I
Thu Oct 11, 2018 12:40 am
Forum: DeBroglie Equation
Topic: Homework Question 1.37 6th Ed
Replies: 2
Views: 32

Homework Question 1.37 6th Ed

I know that I am supposed to use De Broglie's Equation, however I am not sure how their wavelengths would be different if they have essentially the same values for momentum. With everything else being a constant value, wouldn't their wavelengths be the same? I've attached question 1.37 6th Edition.
by Phoebe Chen 4I
Thu Oct 11, 2018 12:36 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Finding Energy Level for H-Atom
Replies: 2
Views: 32

Finding Energy Level for H-Atom

Hi, I am not sure how to solve this problem. I tried using the wavelength value to find the energy of the photon emitted, but I am not sure where to go from there. Attached is question 1.15 from 6th edition.
by Phoebe Chen 4I
Sun Oct 07, 2018 9:08 pm
Forum: Quantum Numbers and The H-Atom
Topic: The Hydrogen Atom
Replies: 2
Views: 63

Re: The Hydrogen Atom

It does! Thank you!
by Phoebe Chen 4I
Sun Oct 07, 2018 1:49 pm
Forum: Photoelectric Effect
Topic: Photoelectric Equations
Replies: 1
Views: 24

Photoelectric Equations

What is the correct answer supposed to be?
by Phoebe Chen 4I
Sun Oct 07, 2018 1:48 pm
Forum: Properties of Electrons
Topic: Electrons from Sodium Atoms
Replies: 1
Views: 91

Electrons from Sodium Atoms

I don't know how to answer part B and C of this question. The question states that the work function for sodium is 150.6 kJ/mol, I thought that meant 1.506x10^5 J of energy is required to remove an electron from the atom. What does a work function actually mean? For part C I am not sure what the cal...
by Phoebe Chen 4I
Sun Oct 07, 2018 1:44 pm
Forum: Quantum Numbers and The H-Atom
Topic: The Hydrogen Atom
Replies: 2
Views: 63

The Hydrogen Atom

What is supposed to be the right answer?
by Phoebe Chen 4I
Sun Oct 07, 2018 1:43 pm
Forum: Properties of Light
Topic: Calculating amount of photons
Replies: 4
Views: 41

Calculating amount of photons

Does anyone know how to calculate the second part of the question? How many photons of infrared radiation does the lamp generate in 1.0s? Is there a mathematical equation?
by Phoebe Chen 4I
Sun Oct 07, 2018 1:41 pm
Forum: Properties of Electrons
Topic: Energy Levels
Replies: 1
Views: 40

Energy Levels

I am not sure how to solve this question, it is attached as a screenshot in this post. I got the right answer by process of elimination of the multiple choice answers, but I'm wondering if there is a mathematical way to solve it.
by Phoebe Chen 4I
Wed Oct 03, 2018 11:05 pm
Forum: Balancing Chemical Reactions
Topic: Balancing reactions tips
Replies: 29
Views: 551

Re: Balancing reactions tips

You could draw a table of the different atoms and have a column for reactants and products. Then make sure that they equal the same amount. Separate the individual atoms instead of trying to visualize them as molecules.
by Phoebe Chen 4I
Wed Oct 03, 2018 11:03 pm
Forum: Significant Figures
Topic: Sig Figs?
Replies: 3
Views: 55

Re: Sig Figs?

Significant Figures are used to tell us how precise our measurement is. The more digits you have the more precise your measurement will tend to be. All number that are not zero are sig figs. Zeros following a number are sig figs. If there are only zeros before non-zero numbers, those are not sig fig...
by Phoebe Chen 4I
Wed Oct 03, 2018 10:51 am
Forum: Significant Figures
Topic: Calculating Sig Figs
Replies: 3
Views: 57

Re: Calculating Sig Figs

For adding and subtracting, you just do the calculation in the normal fashion. After you get a number, your answer is only allowed to have as many decimal places as one of the numbers you started with with the least amount of decimal places. For example if you did 5.678 + 3.4 = 9.078. 3.4 is one of ...

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