Search found 46 matches

by Kendall 3H
Sun Dec 01, 2019 3:53 pm
Forum: Sigma & Pi Bonds
Topic: Drawing Sigma and Pi bonds
Replies: 7
Views: 32

Re: Drawing Sigma and Pi bonds

I think you are suppose to individually label the two bonds in the double bond, one as sigma and one as pi, rather than labeling them both at pi +sigma.
by Kendall 3H
Sun Dec 01, 2019 3:48 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Hw problem 9C1.A
Replies: 2
Views: 14

Re: Hw problem 9C1.A

hexacyanoferrate(II) ion

hexa-cyano because cyano is the name of the ligand CN-
ferrate because this is the name of Fe with -ate added to the end to indicate that the entire ion is negative
by Kendall 3H
Sun Dec 01, 2019 3:46 pm
Forum: Student Social/Study Group
Topic: Final topics
Replies: 10
Views: 36

Re: Final topics

I can confirm that the final is cumulative; however, I think it will focus more on the topics we have not been tested on yet.
by Kendall 3H
Sun Dec 01, 2019 3:44 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Hw 9C1. PART C
Replies: 1
Views: 9

Re: Hw 9C1. PART C

aquapentacyanocolbaltate(III) ion

aqua because it is the name of H2O
penta-cyano because cyan is the same of CN- and there are 5 of them
cobaltate (III) because cobalt is the name of Co and it is a negative ion so you must add an -ate to the end of the metal
by Kendall 3H
Sun Dec 01, 2019 3:41 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: meaning of edta and en
Replies: 1
Views: 10

Re: meaning of edta and en

en means bidentate; edta means hexadentate.
by Kendall 3H
Sun Nov 24, 2019 10:16 pm
Forum: Naming
Topic: Di-, Tri-, Tetra- vs Bis-, Tris-, Tetrakis-
Replies: 11
Views: 46

Re: Di-, Tri-, Tetra- vs Bis-, Tris-, Tetrakis-

They are used if the ligand you are naming already has a name with di-, tri-, tetra-, tetra-
by Kendall 3H
Sun Nov 24, 2019 10:10 pm
Forum: General Science Questions
Topic: Week 9 HW
Replies: 6
Views: 35

Re: Week 9 HW

I believe week 9 homework can be done on anything covered after the week 8 test we took.
by Kendall 3H
Sun Nov 24, 2019 10:07 pm
Forum: Sigma & Pi Bonds
Topic: Molecular Shape
Replies: 11
Views: 41

Re: Molecular Shape

sigma and pi bonds do not effect the lewis structure; however, they do effect how the molecule is shaped and how its shape can change because sigma bonds allow for more rotations and movement of the molecules whereas pi bonds do not allow for this full range of motion.
by Kendall 3H
Sun Nov 24, 2019 10:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Hybridization
Replies: 7
Views: 26

Re: Hybridization

hybridization gives an explanation or at least helps to explain a molecules structure when the valance bond theory fails to predict the structure correctly.
by Kendall 3H
Sun Nov 24, 2019 10:00 pm
Forum: Sigma & Pi Bonds
Topic: sigma and pi bonds
Replies: 18
Views: 52

Re: sigma and pi bonds

All single bonds are sigma bonds. All double bonds have one pi bond and one sigma bond. All triple bonds have one sigma bond and two pi bonds and so on. Pi bonds do not allow the molecule to rotate as much as sigma bonds do.
by Kendall 3H
Sun Nov 17, 2019 6:07 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Dispersion
Replies: 5
Views: 34

Re: Dispersion

I believe it is only dipole-dipole, london forces and hydrogen bonding because we have not had a lecture about dispersion and induced dipole yet; but, if lecture this Monday covers these topics and we may have to know it for the test. I would just make sure to know everything covered in lecture up t...
by Kendall 3H
Sun Nov 17, 2019 6:04 pm
Forum: Lewis Structures
Topic: Noble gases
Replies: 3
Views: 35

Re: Noble gases

Xeon and other noble gases with 8 electrons in their valence shells can still form covalent bonds because of their expanded octet.
by Kendall 3H
Sun Nov 17, 2019 5:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: two central atoms
Replies: 3
Views: 14

Re: two central atoms

if there are two central atoms, you treat each central atom as its own thing
by Kendall 3H
Sun Nov 17, 2019 5:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 19
Views: 107

Re: Test 2

When drawing the Lewis Dot structures I think it is important to make sure you have placed the correct amount of double bonds and single bonds and lone pairs around all of the atoms; however, I don't think it is important to make sure your drawing is depicting the correct angles of the bonds because...
by Kendall 3H
Sun Nov 17, 2019 5:45 pm
Forum: Student Social/Study Group
Topic: test 2
Replies: 8
Views: 39

Re: test 2

I think it will be around the same length at test #1 and it is worth 50 points
by Kendall 3H
Sun Nov 10, 2019 11:32 pm
Forum: Student Social/Study Group
Topic: Midterm Grades
Replies: 7
Views: 72

Re: Midterm Grades

Yes, I can confirm hearing that we will get our midterms back on Wednesday but am not sure if this means we just get just the grade of our midterm or if we get our actual midterm. It would make the most sense to me if we just got our grades on Wednesday and then were returned the hard copy of our mi...
by Kendall 3H
Sun Nov 10, 2019 11:30 pm
Forum: Bond Lengths & Energies
Topic: Interaction Potential Energy equation
Replies: 7
Views: 34

Re: Interaction Potential Energy equation

I am also confused on this concept and would love if anyone could help.
by Kendall 3H
Sun Nov 10, 2019 11:25 pm
Forum: Student Social/Study Group
Topic: Final Jitters
Replies: 72
Views: 18981

Re: Final Jitters

I am sure Lavelle and our TA's will cover this in class next week; however, as far as I know, we will get our midterms back before the final and be able to study them without a tutor.
by Kendall 3H
Sun Nov 10, 2019 11:23 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizing Calculations
Replies: 2
Views: 14

Re: Polarizing Calculations

I am not sure if we are going to have to do this for the upcoming test. I think it is best to email your TA and ask them but I also think doing the homework problems is the best way to study so if you have to calculate how polarizing an atom is using electronegativity in any of the homework problems...
by Kendall 3H
Fri Nov 08, 2019 7:21 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: H bonds and Intermolecular Forces
Replies: 4
Views: 21

Re: H bonds and Intermolecular Forces

Its all just based on attraction. They are not actually sharing electrons, it is just that they are attracted to each other because of their partial negative and partial positive charges.
by Kendall 3H
Sat Nov 02, 2019 9:16 pm
Forum: Bond Lengths & Energies
Topic: bond length
Replies: 6
Views: 52

Re: bond length

If it is possible, we have not learned it. However, it is easy to infer the relative strength of the bond through the length of the bond. Short bonds are stronger than long bonds.
by Kendall 3H
Sat Nov 02, 2019 9:14 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Diamagnetic and Paramagnetic
Replies: 1
Views: 13

Re: Diamagnetic and Paramagnetic

If it was never mentioned in lecture and there were no practice problems assigned for it, I am pretty sure we do not need to know it for the midterm.
by Kendall 3H
Sat Nov 02, 2019 9:12 pm
Forum: Ionic & Covalent Bonds
Topic: ionic vs. covalent
Replies: 7
Views: 37

Re: ionic vs. covalent

Covalent molecules share electrons, this is shown by a line in between the atoms. Ionic molecules do not share electrons.
by Kendall 3H
Sat Nov 02, 2019 9:09 pm
Forum: Ionic & Covalent Bonds
Topic: Lewis Structure for Ionic Bonds
Replies: 4
Views: 29

Re: Lewis Structure for Ionic Bonds

I think ions on their own generally are not bracketed, such as Cl-; however, ionic compounds are bracketed. So, when there are multiple atoms that make up a molecule that has a charge all together, there should be a bracket to show that it is the entire molecule that is charged, not just one atom in...
by Kendall 3H
Sat Nov 02, 2019 9:04 pm
Forum: Molarity, Solutions, Dilutions
Topic: initial and final variables
Replies: 4
Views: 45

Re: initial and final variables

Yes, I agree, there is unfortunately no "formula" for knowing which values come first and second in the equation. You must just read the question carefully. Good Luck!
by Kendall 3H
Sun Oct 27, 2019 3:37 pm
Forum: Lewis Structures
Topic: Lewis Structure
Replies: 5
Views: 28

Re: Lewis Structure

I agree with the earlier answers. I believe the main reason and the reason expressed most to us in Lecture was that the structure with 2 double bonds has a formal charger closer to 0 than the structure with 4 single bonds. When drawing Lewis Structures, you always want to option with the formal char...
by Kendall 3H
Sun Oct 27, 2019 3:30 pm
Forum: Ionic & Covalent Bonds
Topic: Resonance
Replies: 10
Views: 66

Re: Resonance

When a molecule has resonance it means its structure is always switching or changing. It doesn't always have to be 3 shapes or bond lengths that it switches between; it can be 2 or 4 ect. And it is not that 3 different structures exist of the molecule, but rather that the molecule is constantly swit...
by Kendall 3H
Sun Oct 27, 2019 3:24 pm
Forum: Lewis Structures
Topic: expanded-octet
Replies: 4
Views: 23

Re: expanded-octet

The d subshell of an atom has 5 orbital and can therefore fit 10 electrons, meaning there can be 10 valence electrons rather than only 8.
by Kendall 3H
Sat Oct 26, 2019 1:17 pm
Forum: Trends in The Periodic Table
Topic: Ionization energy
Replies: 12
Views: 66

Re: Ionization energy

Ionization energy is defined as the minimum amount of energy required to remove the most loosely bound electron from an atom or molecule in gas state. The tighter a molecules radius, the harder to remove an electron from it. Thats how I like to think of it. So as atomic radius increases, ionization ...
by Kendall 3H
Sat Oct 26, 2019 1:14 pm
Forum: Resonance Structures
Topic: Observed Bond Lengths
Replies: 3
Views: 27

Re: Observed Bond Lengths

Yes, that is one way to think about it. Electrons are constantly changing which atoms they are being shared between. It is important to remember that electrons are always moving, they are not stationary.
by Kendall 3H
Sun Oct 20, 2019 8:23 pm
Forum: Administrative Questions and Class Announcements
Topic: Homework week 4
Replies: 4
Views: 31

Re: Homework week 4

I can also confirm that week 4's homework is suppose to be from the quantum world section and therefore you can pick any of the problems from the quantum world section that you have not done for another homework yet.
by Kendall 3H
Sun Oct 20, 2019 8:21 pm
Forum: Photoelectric Effect
Topic: 1B19
Replies: 3
Views: 36

Re: 1B19

All you have to do for this problem is use the equation "wavelength= h/ (mass x velocity)" You are trying to find the wavelength and you already have h and velocity and all you have to do is look up the mass of a proton and a neutron. The masses are very similar. Once you calculate the wav...
by Kendall 3H
Sun Oct 20, 2019 8:18 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: electron configuration exceptions
Replies: 3
Views: 21

Re: electron configuration exceptions

Thank you, this was very helpful!
by Kendall 3H
Sun Oct 20, 2019 8:17 pm
Forum: Properties of Light
Topic: 1B. 5
Replies: 2
Views: 22

Re: 1B. 5

The first step is to convert the energy units from keV to Joules. - 140x10^3 eV x (1.6022 x10^19 joules/ 1 eV) = 2.2513 x 10^-14 Joules Next you can use the formula wavelength= hc/E to find the wavelength - wavelength= (6.626x10^-34 X 2.9x10^8)/ (2.2513x10^-14) which equals 8.82 x 10^-12m or 8.82pm
by Kendall 3H
Sun Oct 20, 2019 8:09 pm
Forum: Properties of Light
Topic: Question 1A.15
Replies: 5
Views: 43

Re: Question 1A.15

First, you must recognize that the ultraviolet spectrum of atomic hydrogen is the lyman series and its n1 = 1. Then you use the equation v=c/lambda to calculate v. (v= 2.998 *10^8/ 102.6 * 10^8) Now, we can use the Rydberg equation to solve for n2. After plugging in all the numbers, you will get n2=3.
by Kendall 3H
Sun Oct 20, 2019 6:25 pm
Forum: Properties of Light
Topic: Question 1A.15
Replies: 5
Views: 43

Re: Question 1A.15

First, you must recognize that the ultraviolet spectrum of atomic hydrogen is the lyman series and its n1 = 1. Then you use the equation v=c/lambda to calculate v. (v= 2.998 *10^8/ 102.6 * 10^8) Now, we can use the Rydberg equation to solve for n2. After plugging in all the numbers, you will get n2=3.
by Kendall 3H
Fri Oct 11, 2019 2:20 pm
Forum: Administrative Questions and Class Announcements
Topic: posting on chemistry community
Replies: 8
Views: 81

Re: posting on chemistry community

I have heard from multiple sources the deadline for posting on chemistry community is Sunday! So you have all weekend to post as well rather than having to post on Friday.
by Kendall 3H
Fri Oct 11, 2019 2:18 pm
Forum: Student Social/Study Group
Topic: Best Sessions
Replies: 12
Views: 58

Re: Best Sessions

I recommend doing all the homework problems and attempting to work them out on your own, then visiting a TA's office hours where you can ask specific questions you had on the homework. I think the more specific your questions are, the better off you are to succeed.
by Kendall 3H
Fri Oct 11, 2019 2:14 pm
Forum: SI Units, Unit Conversions
Topic: Showing work/ rearranging equations
Replies: 8
Views: 69

Re: Showing work/ rearranging equations

I was informed that the better you show your work on homework and test equations, the more points a TA can possibly give you on a problem you didn't get the final correct answer. If your work is very clear, they can see where you made your mistake and hopefully give you credit for the parts you did ...
by Kendall 3H
Fri Oct 11, 2019 2:12 pm
Forum: DeBroglie Equation
Topic: When to use DeBroglie Equation
Replies: 16
Views: 114

Re: When to use DeBroglie Equation

You can use DeBroglie's equation to find the wavelength of anything but light because light does not have mass.
by Kendall 3H
Mon Oct 07, 2019 10:04 pm
Forum: Limiting Reactant Calculations
Topic: Need help on question M.9 for chem 14a
Replies: 4
Views: 2761

Re: Need help on question M.9 for chem 14a

Thank you so much! I was very confused on this question and you explained it so well. I now see that you must first discover which reactant is the limiting reactant and then the problem becomes much more simple.
by Kendall 3H
Thu Oct 03, 2019 3:55 pm
Forum: Significant Figures
Topic: Sig Figs
Replies: 6
Views: 65

Re: Sig Figs

32,000,000 has two sig figs. However, if there were to be a decimal point placed at the end of the number (ex/ 32,000,000.) then there would be 8 sig figs 0.3200 has 4 sig figs because the leading zero is not significant. 3.0200 has 5 sig figs. any time there is a trailing zero of final zero after a...
by Kendall 3H
Thu Oct 03, 2019 3:44 pm
Forum: Balancing Chemical Reactions
Topic: State Symbols
Replies: 5
Views: 78

Re: State Symbols

Yes, when writing chemical formulas you are suppose to include all the states of matter!
by Kendall 3H
Thu Oct 03, 2019 3:43 pm
Forum: SI Units, Unit Conversions
Topic: Formula units vs molecule
Replies: 7
Views: 68

Re: Formula units vs molecule

A formula unit can be thought of as the empirical formula for an ionic compound. For example, NaCL is the formula unit for sodium chloride.
by Kendall 3H
Wed Oct 02, 2019 10:30 pm
Forum: Limiting Reactant Calculations
Topic: Limiting reactant
Replies: 4
Views: 14

Re: Limiting reactant

The limiting reactant is not necessary the reactant with the least amount of moles, but it could be. When thinking about limiting reactant problems, it has always helped me to compare it to baking cookies. For example, to make one batch of cookies, you need 1 cup of butter and 3 cups of flour. Now i...
by Kendall 3H
Wed Oct 02, 2019 10:21 pm
Forum: Significant Figures
Topic: When to apply sig figs?
Replies: 4
Views: 34

Re: When to apply sig figs?

I agree with what everyone else has answered. Sig figs should only be applied to your final answer, this way your final answer can be the most accurate. If you were to apply sig figs to every calculation, you would be doing a lot of unnecessary rounding that could change the final answer pretty sign...

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