CHEMISTRY COMMUNITY

princessturner1G

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.

princessturner1G

Does coordination number include double bonds?

princessturner1G

That is correct. For example, [Fe(CN)6]4- has a coordination number of six.

princessturner1G

There have to be two different atoms which have lone pairs for it to be polydentate, correct?

princessturner1G

When do you use hybridization and what is the main point of it?

princessturner1G

VSEPR stands for "Valence-Shell-Electron-Pair-Repulsion". It is used for molecular geometry.

princessturner1G

How do lone pairs affect the bond angles for each shape? Does the bond angle increase or decrease due to lone pairs?

princessturner1G

Yes, a double bond is one sigma plus one pi bond. While a triple bond is a sigma bond plus two pi bonds.

princessturner1G

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...

princessturner1G

Why is the Mg-Cl bond considered to be ionic?

princessturner1G

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.

princessturner1G

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...

princessturner1G

With the double bond between carbon and oxygen, this satisfies the octet rule. Now all the atoms have eight electrons.

princessturner1G

What does the concept "the moles of solute stay the same"?
Can someone give me an example and how I would apply it?

princessturner1G

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...

princessturner1G

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...

princessturner1G

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?"

princessturner1G

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. ...

princessturner1G

It is 1 thousand electrons. 1 electron per one photon.

princessturner1G

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...

princessturner1G

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.

princessturner1G

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.

princessturner1G

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...

princessturner1G

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.

princessturner1G

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.

princessturner1G

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!

princessturner1G

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.

princessturner1G

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+)...

princessturner1G

On exams, we have to prove it so it is definitely best to do the calculations.

princessturner1G

A helpful trick is if the equation is unbalanced and the amount of molecules is odd multiply it to get an even coefficient.

princessturner1G

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!

CHEMISTRY COMMUNITY

Search found 31 matches

Re: Electron densisty

Re: coordination number=polydentate number?

Re: Coordination Number

Re: Polydentate

Re: basics of hybridization

Re: VSEPR

Bond angles [ENDORSED]

Re: Sigma and pi

Re: oxidation

Electronegativity difference

Polar covalent bonds

Re: Central atom

Re: 3.33 b

Moles [ENDORSED]

Re: Test 1. Q 2

Test 1, Q1

2.19

Re: Test 2 #7 [ENDORSED]

Re: Test 2 final question [ENDORSED]

Re: Homework 1.15

Re: Homework number 1.25a [ENDORSED]

Re: Reading the textbook

Photoelectric Post-Module [ENDORSED]

Re: 1.13 (b)

Re: HW 1.15

Re: Expected mastery of Significant Figures

Re: Units - L or mL? [ENDORSED]

Re: Fundamentals G.5 (part a)

Re: M11 HW

Re: Balancing the Equation

Re: possible test question