Search found 35 matches

by Francis_Nguyen3D
Tue Dec 04, 2018 1:55 pm
Forum: Naming
Topic: When to use -ate
Replies: 1
Views: 38

Re: When to use -ate

You use the suffix -ate at the end of the metal name when the entire complex has a negative charge. In this problem the complex has a 2- charge which explains the utilization of the suffix -ate.
by Francis_Nguyen3D
Mon Dec 03, 2018 9:50 pm
Forum: Naming
Topic: "(en)" and "(edta)"?
Replies: 3
Views: 74

Re: "(en)" and "(edta)"?

en= ethylenediamine
edta=Ethylenediaminetetraacetic acid
These are the abbreviated forms of these compounds when they are a ligand.
by Francis_Nguyen3D
Mon Dec 03, 2018 4:34 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: 6th Edition 17.37
Replies: 2
Views: 77

Re: 6th Edition 17.37

The coordination number for:
a) 4
b) 2
c) 6
d) 6

The coordination number for c would come from the fact that there are four bonds coming from (en) and two from cl
For d, there are six bonds which is implied through the name of the complex.
by Francis_Nguyen3D
Mon Dec 03, 2018 4:25 pm
Forum: Conjugate Acids & Bases
Topic: Neutral Ligands
Replies: 1
Views: 80

Neutral Ligands

In regards to neutral ligands, are we just expected to memorize which compounds are neutral or is there a way to determine if they are neutral?
by Francis_Nguyen3D
Mon Nov 26, 2018 9:16 pm
Forum: Sigma & Pi Bonds
Topic: 2F.17 7th ed: Pi bond
Replies: 2
Views: 84

Re: 2F.17 7th ed: Pi bond

When there is a single bond there is 1 sigma bond and 0 pi bonds. When there is a double bond, there is 1 sigma bond and 1 pi bond. When there is a triple bond, there is 1 sigma bond and 2 pi bonds. Hope this helps! :)
by Francis_Nguyen3D
Mon Nov 26, 2018 9:12 pm
Forum: Hybridization
Topic: Electron Density and Hybridization
Replies: 1
Views: 54

Re: Electron Density and Hybridization

Yes, regions of electron density do match up with the number of hybridized orbitals. For problem 2F.13, it asks for the hybrid orbitals of each carbon atom. So when you draw the lewis structure of CH2CHCN, there should be three regions of electron density around two of the three carbon atoms and two...
by Francis_Nguyen3D
Mon Nov 26, 2018 4:04 pm
Forum: Bond Lengths & Energies
Topic: Atom Size and Bond Strength
Replies: 2
Views: 103

Re: Atom Size and Bond Strength

A larger atom would result in a weaker bond because the nucleus of the atom doesn't have a strong hold of the outer most electrons. I believe when we refer to the size of the atom, we discuss its molecular mass, atomic number, and atomic radius interchangeably but when discussing bonding, I think at...
by Francis_Nguyen3D
Tue Nov 20, 2018 10:36 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: higher polarizability
Replies: 4
Views: 123

Re: higher polarizability

The smaller cation has higher polarizing power because of its electronegativity. Because of its small size and the fact that it wants electrons, the cation is able to hold onto electrons better. So overall, the smaller the atomic/ionic radius, the more polarizing power the atom/cation has. (charge a...
by Francis_Nguyen3D
Tue Nov 20, 2018 3:45 pm
Forum: Hybridization
Topic: Regions of electron density
Replies: 6
Views: 160

Re: Regions of electron density

I believe that is correct!
regions of electron density around the central atom= number of hybrid orbitals
by Francis_Nguyen3D
Tue Nov 20, 2018 2:16 pm
Forum: Electronegativity
Topic: Electronegativity and Polarity
Replies: 3
Views: 108

Re: Electronegativity and Polarity

As electronegativity decreases, polarizability increases.
by Francis_Nguyen3D
Mon Nov 19, 2018 6:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bold/Dashed Lines in Bonds
Replies: 4
Views: 86

Re: Bold/Dashed Lines in Bonds

Hello, the bold and dashed lines within the lewis structure represent the 3D position of an atom within the molecule. When it is a bold line, that means that the atom is more towards the foreground. When it is a dashed line, that means that the atom is more towards the background. I believe you can ...
by Francis_Nguyen3D
Tue Nov 13, 2018 8:53 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Homework Focus 2A
Replies: 3
Views: 145

Re: Homework Focus 2A

If this problem is from the 7th edition textbook, the correct answer is [Ar]3d^10 because the question asks for the electron configuration of Cu+ not Cu^2+.
by Francis_Nguyen3D
Tue Nov 13, 2018 7:22 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lowest Energy Lewis Structures
Replies: 3
Views: 90

Re: Lowest Energy Lewis Structures

I believe that it would be best to use the Lewis Structure with the lowest energy and with octet exceptions because it would give a more accurate representation of the shape of the molecule. If we were to ignore formal charges and octet exceptions, we might miss a crucial double bond that could help...
by Francis_Nguyen3D
Tue Nov 13, 2018 7:16 pm
Forum: Octet Exceptions
Topic: octet exceptions
Replies: 2
Views: 112

Re: octet exceptions

The first four elements also have octet exceptions where they do not obtain an octet of electrons. This is due to the fact that the first four elements are stable/feel complete with the amount of electrons they currently have. Another exception would consist of elements such as Boron and Aluminum wh...
by Francis_Nguyen3D
Tue Nov 13, 2018 2:19 pm
Forum: Lewis Structures
Topic: VSEPR Model
Replies: 2
Views: 111

Re: VSEPR Model

I believe you can determine whether a molecule is color or nonpolar based on its charge distribution. When you draw the lewis structure, if there is symmetric distribution of charge, then the molecule would be nonpolar. If you draw the lewis structure and there is an uneven distribution of charge, t...
by Francis_Nguyen3D
Thu Nov 08, 2018 3:22 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: 257

Re: Hydrogen Bonds vs. Ion-Dipole Bonds

I believe the reason why Hydrogen Bonds are stronger than ion-dipole interactions is because Hydrogen bonds involve greater differences in electronegativity. This can then create a large electric dipole of positive and negative charges.
by Francis_Nguyen3D
Wed Nov 07, 2018 4:47 pm
Forum: Octet Exceptions
Topic: Resonance Structures
Replies: 7
Views: 261

Re: Resonance Structures

I know this is a pretty simple question but, how do we indicate resonance structures? Can we just draw the structures next to one another or is there a more formal indication? I think one way to indicate resonance structures is to draw out one lewis structure. Then from there see if 1. the structur...
by Francis_Nguyen3D
Wed Nov 07, 2018 4:36 pm
Forum: Octet Exceptions
Topic: List of octect exceptions
Replies: 6
Views: 205

Re: List of octect exceptions

I believe the exceptions we have learned so far consists of: 1. Electron deficiency- which is when there is less than an octet, therefore causing a fourth bond to be made. For example: BF3, since Boron is short one bond to complete its octet, it would seek out another F atom to form BF4-.This would ...
by Francis_Nguyen3D
Wed Nov 07, 2018 10:44 am
Forum: Resonance Structures
Topic: bond length
Replies: 5
Views: 153

Re: bond length

Bond lengths could be the same because of resonance. Resonance molecules do not have one true lewis structure, but rather a variety of structures. Because of this, the resonance lewis structure of a given molecule would be a hybrid of all the possible structures that could be created. This would mak...
by Francis_Nguyen3D
Fri Nov 02, 2018 6:37 pm
Forum: Octet Exceptions
Topic: Number of Unpaired Electrons
Replies: 2
Views: 115

Re: Number of Unpaired Electrons

Hello,
when you do the electron configuration diagram for 3d^8 three orbitals would be filled out of the five orbitals available. Two orbitals would have only one electron in them-making them unpaired.
https://www.adichemistry.com/jee/qb/coordination-chemistry/1/q1-3.png
by Francis_Nguyen3D
Wed Oct 31, 2018 4:06 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Degeneracy
Replies: 4
Views: 357

Re: Degeneracy

Hello,
the S orbital is not degenerate because its l value= 0 therefore making the m1 value=0. This makes the s orbital have 0 degeneracy.
by Francis_Nguyen3D
Tue Oct 30, 2018 9:58 pm
Forum: Lewis Structures
Topic: central atoms
Replies: 8
Views: 184

Re: central atoms

Hello,
the central atom is usually the atom with the lowest ionization energy.
by Francis_Nguyen3D
Mon Oct 29, 2018 11:03 am
Forum: Ionic & Covalent Bonds
Topic: Midterm
Replies: 2
Views: 70

Re: Midterm

Hello,

this was posted on the Chem 14A website under announcements : Midterm covers: Fundamentals, Quantum, Bonding to end of 3.11 (6 Ed.) and to end of 2C (7 Ed.)
by Francis_Nguyen3D
Wed Oct 24, 2018 4:26 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Ground vs Excited State
Replies: 3
Views: 117

Re: Ground vs Excited State

Hello,
this would be considered as an excited state because it does not follow Hund's Rule. The second electron should have filled in the next orbital rather than pairing up in the first one, if it followed this rule.
by Francis_Nguyen3D
Tue Oct 23, 2018 8:30 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Exercise 1.45, 6th Edition
Replies: 1
Views: 75

Re: Exercise 1.45, 6th Edition

It looks like you're correct. Dr. Lavelle has 1.45 on his list of solution manual errors.

Here is the link:https://lavelle.chem.ucla.edu/wp-content/supporting-files/Chem14A/Solution_Manual_Errors_6Ed.pdf

Hope this helps!
by Francis_Nguyen3D
Tue Oct 23, 2018 8:24 pm
Forum: Photoelectric Effect
Topic: Wavelength Calculation
Replies: 2
Views: 168

Re: Wavelength Calculation

Use the equation Energy= hc/(wavelength). Then use the energy of the photon you got from part b, which should be 2.25 x 10^-17J. Rearrange the equation so that you are solving for wavelength so it would be: wavelength= hc/energy Then plug in 6.626 x 10^-34 for h and 3.0 x 10^8 for c and divide by 2....
by Francis_Nguyen3D
Wed Oct 17, 2018 2:18 pm
Forum: Einstein Equation
Topic: 7th Edition 1B.15
Replies: 3
Views: 53

Re: 7th Edition 1B.15

For this problem use the equation: Energy= hc/(wavelength). Then use the energy of the photon you got from part b, which should be 2.25 x 10^-17J. Rearrange the equation so that you are solving for wavelength so it would be: wavelength= hc/energy Then plug in 6.626 x 10^-34 for h and 3.0 x 10^8 for ...
by Francis_Nguyen3D
Tue Oct 16, 2018 8:17 pm
Forum: Properties of Light
Topic: Wave-Like Properties Value
Replies: 2
Views: 55

Re: Wave-Like Properties Value

I believe Dr. Lavelle said that the cut off would be 10^-15 and anything smaller than that is undetectable.
by Francis_Nguyen3D
Tue Oct 16, 2018 5:02 pm
Forum: Properties of Electrons
Topic: electromagnetic radiation
Replies: 3
Views: 85

Re: electromagnetic radiation

The number of photons in a light beam affects the brightness of the whole beam, whereas the frequency of the light controls the energy of each individual photon. In the Photoelectric effect electrons are ejected from a metal surface based on the amount of energy absorbed. So, a certain threshold has...
by Francis_Nguyen3D
Wed Oct 10, 2018 11:03 am
Forum: Photoelectric Effect
Topic: Packets of Energy
Replies: 2
Views: 62

Re: Packets of Energy

Planck proposed the idea that light and other forms of electromagnetic waves were released in certain packets of energy. This became known as "Quanta" because quanta by definition, is a discrete amount of energy proportional between its magnitude and frequency. So, this is known as Planck'...
by Francis_Nguyen3D
Tue Oct 09, 2018 10:24 pm
Forum: Limiting Reactant Calculations
Topic: Percent Yield [ENDORSED]
Replies: 13
Views: 894

Re: Percent Yield [ENDORSED]

So for a theoretical yield, it is the amount(grams) of product that you receive through calculations considering that the conditions of the experiment are perfect. One way to think about theoretical yield is the amount you calculated on paper. As for the actual yield, it is the amount(grams) of prod...
by Francis_Nguyen3D
Sun Oct 07, 2018 3:39 pm
Forum: Significant Figures
Topic: Rounding molar mass on the periodic table
Replies: 3
Views: 93

Re: Rounding molar mass on the periodic table

For calculations, use the given molar mass on the periodic table without rounding. Round based on the amount of sig figs at the end of your calculation.
by Francis_Nguyen3D
Mon Oct 01, 2018 9:09 pm
Forum: General Science Questions
Topic: Periodic Table
Replies: 16
Views: 536

Re: Periodic Table

Typically, it is best not to round the atomic weights of the elements before using it for calculations because your final answer would not be as accurate as it could be. Usually, you would round at the end of your calculation depending on the amount of significant figures there are. You determine th...
by Francis_Nguyen3D
Mon Oct 01, 2018 8:51 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Question E.9: Epsom Salts
Replies: 2
Views: 122

Re: Question E.9: Epsom Salts

When given the name of the compound, I usually like to write out the symbols of the elements. So in the case of this problem, start off with Magnesium. Its symbol would be Mg and then move onto Sulfate. Since Sulfate is not on the periodic table, try utilizing a common ions chart where you will find...
by Francis_Nguyen3D
Sun Sep 30, 2018 1:36 pm
Forum: Balancing Chemical Reactions
Topic: Question H21 (6th Edition)
Replies: 2
Views: 117

Re: Question H21 (6th Edition)

(1) : Balance N first because it appears the less within the equation. 2C10H15N + O2 --> CO2 + H2O + CH4N2O (2): Balance H, there are 30 H on the left side and a total of 6 H on the right, leaving the (4 H) alone, that would be 30-4= 26/2= 13 as your coefficient for H2O 2C10H15N + O2 --> CO2 + 13H2O...

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