Search found 31 matches
- Sun Jun 10, 2018 1:05 pm
- Forum: Hybridization
- Topic: Electron densisty
- Replies: 5
- Views: 794
Re: Electron densisty
Electron density is the number of bonds and unpaired electrons around an atom. Bonds, whether single, double or triple and unpaired electrons count as one region of electron density. If there are 3 bonds attached to an atom and one pair of unpaired electrons, it has 4 regions of electron density.
- Sat Jun 09, 2018 1:44 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: coordination number=polydentate number?
- Replies: 5
- Views: 568
Re: coordination number=polydentate number?
Does coordination number include double bonds?
- Sat Jun 09, 2018 1:07 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Number
- Replies: 2
- Views: 349
Re: Coordination Number
That is correct. For example, [Fe(CN)6]4- has a coordination number of six.
- Sat Jun 09, 2018 1:05 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polydentate
- Replies: 5
- Views: 850
Re: Polydentate
There have to be two different atoms which have lone pairs for it to be polydentate, correct?
- Sun Jun 03, 2018 10:02 pm
- Forum: Hybridization
- Topic: basics of hybridization
- Replies: 18
- Views: 2418
Re: basics of hybridization
When do you use hybridization and what is the main point of it?
- Sun Jun 03, 2018 10:01 pm
- Forum: Hybridization
- Topic: VSEPR
- Replies: 11
- Views: 1493
Re: VSEPR
VSEPR stands for "Valence-Shell-Electron-Pair-Repulsion". It is used for molecular geometry.
- Sun Jun 03, 2018 1:20 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond angles [ENDORSED]
- Replies: 3
- Views: 487
Bond angles [ENDORSED]
How do lone pairs affect the bond angles for each shape? Does the bond angle increase or decrease due to lone pairs?
- Sun May 27, 2018 8:31 pm
- Forum: Sigma & Pi Bonds
- Topic: Sigma and pi
- Replies: 12
- Views: 1556
Re: Sigma and pi
Yes, a double bond is one sigma plus one pi bond. While a triple bond is a sigma bond plus two pi bonds.
- Sun May 20, 2018 11:09 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: oxidation
- Replies: 7
- Views: 802
Re: oxidation
So when you are dealing with oxidation states, you will generally have a + or -, because almost any element can have e- added or taken away in order to get to the nearest noble gas configuration. The goal is to get an octet. An example from chapter 3 HW is 3.23, Cl can have -1 or +7. This is becaus...
- Sun May 20, 2018 5:12 pm
- Forum: Electronegativity
- Topic: Electronegativity difference
- Replies: 3
- Views: 542
Electronegativity difference
Why is the Mg-Cl bond considered to be ionic?
- Sun May 20, 2018 4:05 pm
- Forum: Ionic & Covalent Bonds
- Topic: Polar covalent bonds
- Replies: 2
- Views: 345
Polar covalent bonds
Can someone explain what a polar covalent bond is? The book states "A bond in which ionic contributions to the resonance result in partial charges", but I am not entirely sure what that means.
- Thu May 17, 2018 8:55 am
- Forum: Lewis Structures
- Topic: Central atom
- Replies: 7
- Views: 849
Re: Central atom
Wait, where are you guys getting ionization energy from? I thought the central atom has to be the element that was the least electronegative, which is why C is the central atom since it has the electronegativity Ionization energy follows the same trend as electronegativity, so you can think of it a...
- Mon May 14, 2018 9:10 pm
- Forum: Ionic & Covalent Bonds
- Topic: 3.33 b
- Replies: 2
- Views: 377
Re: 3.33 b
With the double bond between carbon and oxygen, this satisfies the octet rule. Now all the atoms have eight electrons.
- Sun May 06, 2018 4:52 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Moles [ENDORSED]
- Replies: 2
- Views: 443
Moles [ENDORSED]
What does the concept "the moles of solute stay the same"?
Can someone give me an example and how I would apply it?
Can someone give me an example and how I would apply it?
- Sun May 06, 2018 3:55 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Test 1. Q 2
- Replies: 3
- Views: 798
Re: Test 1. Q 2
I did not have the same version of the test, but here is what I think are the correct steps: So, it says that 50.0 mL of .200M of NiCl2 aqueous solution is prepared (called electrolyte). An electrode surface is placed into the solution, and after the electrodeposition process, some of the Ni is dep...
- Sat May 05, 2018 11:50 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Test 1, Q1
- Replies: 2
- Views: 466
Test 1, Q1
a)A solution of anhydrous iron chloride, FeCl3, is prepared by dissolving 10g of salt to 1L water. What is the concentration of chloride ions of the above solution? b) The above solution is diluted with 1L of 0.100 M potassium chloride, KCL, solution. What is the concentration of chloride ions after...
- Wed May 02, 2018 10:44 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 2.19
- Replies: 3
- Views: 444
2.19
How do we know how many subshells there are when we are given an n value?
For example, "How many subshells are there in the shell with n=4?"
For example, "How many subshells are there in the shell with n=4?"
- Fri Apr 27, 2018 4:50 pm
- Forum: Photoelectric Effect
- Topic: Test 2 #7 [ENDORSED]
- Replies: 3
- Views: 458
Re: Test 2 #7 [ENDORSED]
Could someone explain how to do #7 from test 2 Thanks You use the equation Energy of a photon-work function=Kinetic Energy. Since it is asking for the maximum wavelength kinetic energy equals 0. The energy of the photon is then equal to the work function. The energy of the photon= 9.02 x 10^-19 J. ...
- Fri Apr 27, 2018 3:11 pm
- Forum: Photoelectric Effect
- Topic: Test 2 final question [ENDORSED]
- Replies: 15
- Views: 1818
Re: Test 2 final question [ENDORSED]
It is 1 thousand electrons. 1 electron per one photon.
- Tue Apr 24, 2018 5:27 pm
- Forum: Properties of Electrons
- Topic: Homework 1.15
- Replies: 1
- Views: 457
Re: Homework 1.15
First, you would start by finding the velocity using v=c/lambda. You are given the wavelength in the problem, which is 102.6 nm (102.6x10^-9 m). Once you solve for the velocity you can use the equation v=R((1/(n final)^2)-(1/(n initial^2)). You know that n1=1 because it is in the ultraviolet spectru...
- Tue Apr 24, 2018 5:12 pm
- Forum: Einstein Equation
- Topic: Homework number 1.25a [ENDORSED]
- Replies: 3
- Views: 571
Re: Homework number 1.25a [ENDORSED]
Yadira Flores 1G wrote:What units would the final answer be in?
The final answer would be in Joules, since it is asking for the energy.
- Sun Apr 22, 2018 6:39 pm
- Forum: Ideal Gases
- Topic: Reading the textbook
- Replies: 262
- Views: 146992
Re: Reading the textbook
yazminedesan1F wrote:what's the best way to learn the material for someone who's not so familiar with chemistry concepts?
Completing the pre-assessment and the post-assessment are extremely helpful. I recommended doing these and watching the videos as well.
- Sat Apr 21, 2018 3:04 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric Post-Module [ENDORSED]
- Replies: 3
- Views: 348
Photoelectric Post-Module [ENDORSED]
Hello, I am having trouble answering the following question on the photoelectric post-module assessment. Light hits a sodium metal surface and the velocity of the ejected electron is 6.61 x 105 m.s-1. The work function for sodium is 150.6 kJ.mol-1. Answer the following three questions. A. What is th...
- Mon Apr 16, 2018 10:10 pm
- Forum: Properties of Light
- Topic: 1.13 (b)
- Replies: 6
- Views: 673
Re: 1.13 (b)
You know it is the Balmer series because the wavelength is 486 nm. When you look at Table 1.1, 486 nm is closest to the wavelength of blue light. Since blue light is a type of visible light, you know that it is the Balmer Series.
- Mon Apr 16, 2018 10:05 pm
- Forum: Properties of Light
- Topic: HW 1.15
- Replies: 4
- Views: 378
Re: HW 1.15
I think n=1 because in the problem it states that it is in the ultraviolet spectrum. We learned that for the ultraviolet region that corresponds to the Lyman series. The Lyman series is from higher energy levels to the n=1 level. This is how we would know n is one.
- Sat Apr 14, 2018 4:13 pm
- Forum: Significant Figures
- Topic: Expected mastery of Significant Figures
- Replies: 6
- Views: 536
Re: Expected mastery of Significant Figures
I think by the next test we should be able to use the correct amount of sig figs. Remember always use the lowest number of sig figs and don't round until the end!
- Thu Apr 12, 2018 12:59 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Units - L or mL? [ENDORSED]
- Replies: 15
- Views: 4594
Re: Units - L or mL? [ENDORSED]
The answer usually should be in L. If it is given to you in mL, it is usually easier to multiply it by 10^-3.
- Tue Apr 10, 2018 10:54 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Fundamentals G.5 (part a)
- Replies: 1
- Views: 295
Re: Fundamentals G.5 (part a)
Remember that M= mol/liters or Liters= mol/M so to calculate the volume we would have to find M first. You can find this by 2.111g/(105.99gmol^-1)(.2500L) = 0.07967 M Now that you have M you can solve for volume by plugging into in V= mol/M V= (2.15*10^-3 mol Na+)/ (0.07967 molL^-1 Na2CO3)(2mol Na+)...
- Sun Apr 08, 2018 9:10 pm
- Forum: Limiting Reactant Calculations
- Topic: M11 HW
- Replies: 4
- Views: 486
Re: M11 HW
On exams, we have to prove it so it is definitely best to do the calculations.
- Sun Apr 08, 2018 9:02 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing the Equation
- Replies: 9
- Views: 1172
Re: Balancing the Equation
A helpful trick is if the equation is unbalanced and the amount of molecules is odd multiply it to get an even coefficient.
- Sun Apr 08, 2018 1:47 pm
- Forum: Balancing Chemical Reactions
- Topic: possible test question
- Replies: 1
- Views: 259
Re: possible test question
My TA said we should memorize the common names of compounds because there is a chance we can be tested on it in the future.
Hope that helps!
Hope that helps!