Search found 32 matches
- Sun Jun 10, 2018 11:35 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: H+ Acidic and OH- Basic
- Replies: 4
- Views: 622
Re: H+ Acidic and OH- Basic
I think the main part we should know is that Lewis acids and bases are involved with electron lone pairs( whether you gain it for an acid or loose it for a base) whereas Bronsted acid and bases have to do with protons (which include H+ atoms) and whether you gain them for a base or donate them for a...
- Sun Jun 10, 2018 11:32 pm
- Forum: Hybridization
- Topic: pi bonds and sigma bonds [ENDORSED]
- Replies: 4
- Views: 827
Re: pi bonds and sigma bonds [ENDORSED]
Hi, I found a good link that might help
https://www.youtube.com/watch?v=YcSPPKESpwc
But i like to think of it as a sigma bond is a single bond, whereas a pi bond is the second or third bond of the ligand. This video goes more in depth about it. Hope that helps!
https://www.youtube.com/watch?v=YcSPPKESpwc
But i like to think of it as a sigma bond is a single bond, whereas a pi bond is the second or third bond of the ligand. This video goes more in depth about it. Hope that helps!
- Sun Jun 10, 2018 11:29 pm
- Forum: SI Units, Unit Conversions
- Topic: Sig Figs for Final
- Replies: 8
- Views: 1220
Re: Sig Figs for Final
Sig figs will be taken into consideration on the final as it was on the midterm
- Sun Jun 10, 2018 11:27 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Valence Electron Configurations [ENDORSED]
- Replies: 1
- Views: 286
Valence Electron Configurations [ENDORSED]
Will we be expected on the final to know how to make the valence shell electron configurations? The ones with sigma bonds and such
- Sat Jun 09, 2018 9:47 pm
- Forum: Ionic & Covalent Bonds
- Topic: Finding Bond order
- Replies: 2
- Views: 452
Finding Bond order
How do we calculate the bond order ? And if possible can someone give an example?
- Wed Jun 06, 2018 1:17 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: How does size affect polarizing power/ polarizability
- Replies: 3
- Views: 3544
Re: How does size affect polarizing power/ polarizability
The larger the size, the more polarizability it has because larger atoms are usually easier to remove electrons from. However, the larger the size, the less polarizing power it has I believe.
- Wed Jun 06, 2018 1:11 pm
- Forum: Trends in The Periodic Table
- Topic: Isoelectronic elements and their characteristics
- Replies: 2
- Views: 1101
Re: Isoelectronic elements and their characteristics
Two elements being isoelectronic just mean that they have the same number of electrons and the same electron configurations. They can still have different characteristics. For example, K+ and Cl- are isoelectronic with Argon, however, Cl- is larger than K+ because K+ has more protons so it'll pull i...
- Mon Jun 04, 2018 10:32 pm
- Forum: Dipole Moments
- Topic: determining dipole moment
- Replies: 3
- Views: 622
Re: determining dipole moment
I like to look at the electronegativities of the atoms in the molecule to help. For example, with HCL, Cl is more negative than H so the covalent bond makes electrons to be pulled closer to the CL, making it more partial negative, and H as a result, a partial positive.
- Sun Jun 03, 2018 11:06 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: MO Theory
- Replies: 1
- Views: 356
MO Theory
Will this be a topic addressed on the final?
- Tue May 22, 2018 6:17 pm
- Forum: Electronegativity
- Topic: Electronegativity Caluclations
- Replies: 4
- Views: 626
Electronegativity Caluclations
Will we be given the electronegativity of elements of compounds to calculate their electronegative difference or will we be expected to estimate/memorize them?
- Sun May 20, 2018 5:22 pm
- Forum: Ionic & Covalent Bonds
- Topic: Which is more Ionic
- Replies: 2
- Views: 336
Which is more Ionic
I was doing a practice problem and it was asking which compound is more ionic, LiH or HCl, and I thought the correct answer would be HCl since H and Cl have a greater electronegative distance on the periodic table from each other than Li and H, however, according to the answer key, the correct answe...
- Sun May 20, 2018 2:39 pm
- Forum: Lewis Structures
- Topic: Lewis Structure of XeO2F2
- Replies: 2
- Views: 516
Re: Lewis Structure of XeO2F2
I believe because Xe is one of the exceptions to the rule that it must have an octet( any element that is after the second period / has an atomic number > 10), it can have as many bonds/electrons as it needs to satisfy the number of electrons in the compound. Both O and F have an atomic number less ...
- Sun May 20, 2018 2:28 pm
- Forum: Octet Exceptions
- Topic: 3.55
- Replies: 1
- Views: 289
Re: 3.55
You did 3.56 by accident I think. The BRO and BF4- are from the next problem
- Sat May 19, 2018 8:58 pm
- Forum: Lewis Structures
- Topic: Exception to Lewis Structure?
- Replies: 4
- Views: 574
Exception to Lewis Structure?
Can someone explain why Chlorine in this Lewis structure is allowed to break the octet rule and have more? Are there any other elements like Chlorine that might have this exception as well?
- Mon May 14, 2018 8:35 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: formal charge
- Replies: 11
- Views: 1674
Re: formal charge
I like to think of it as the number of valence electrons minus the sum of how many electrons there are around it on the lewis sturcture (a bond=1 electron, a lone pair of electrons =2). The charge would be more negative if there are more electrons required to fill the octet than the number of valenc...
- Mon May 14, 2018 8:31 pm
- Forum: Lewis Structures
- Topic: HW 3.49.C
- Replies: 1
- Views: 322
Re: HW 3.49.C
The net overall charge is 0. The -1 from the C, and the +1 from the O cancel out to give you the overall net charge of the entire compound (-1+1=0). Hope that helps!
- Mon May 14, 2018 8:27 pm
- Forum: Lewis Structures
- Topic: BF3
- Replies: 2
- Views: 420
BF3
After todays's lecture where we learned that the element B doesnt need a full octet, does this rule apply to all the group 13 elements or just some specific ones, and if so, what are they?
- Sat May 12, 2018 2:03 pm
- Forum: Ionic & Covalent Bonds
- Topic: "1.20A or 1.40A"
- Replies: 2
- Views: 315
Re: "1.20A or 1.40A"
I dont think we've covered this yet so we dont have to worry about it now
- Sat May 12, 2018 1:29 pm
- Forum: Resonance Structures
- Topic: Resonance structure of benzene
- Replies: 4
- Views: 663
Re: Resonance structure of benzene
I attached an image of it, hope this helps!
- Sat May 12, 2018 1:20 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Calculating formal charges
- Replies: 5
- Views: 1120
Calculating formal charges
Can someone explain how to calculate formal charges again? Or if there's another way aside from the equation we learned in class? And if we're trying to ionic element's lewis structure, do we had the charge to the number of electrons to the element/compound?
- Sat May 05, 2018 11:17 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Exceptions for Electron Configuartions
- Replies: 5
- Views: 939
Exceptions for Electron Configuartions
Can someone explain why specifically Chromium and Copper are exceptions? I know what their electron configurations are, but I was wondering why those two elements had different configurations?
- Sat May 05, 2018 11:09 pm
- Forum: Photoelectric Effect
- Topic: In class problem 5/4
- Replies: 3
- Views: 559
Re: In class problem 5/4
How would we know when to use the lamda=H*c/E or when to solve for the energy first?
- Sun Apr 22, 2018 11:39 pm
- Forum: Properties of Light
- Topic: Test 2 Material
- Replies: 12
- Views: 1203
Re: Test 2 Material
Its everything up from chapter 1.1-1.5. None of the material covered on Friday's class will be on Test 2
- Sun Apr 22, 2018 11:03 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Memorizing spectrum
- Replies: 5
- Views: 766
Re: Memorizing spectrum
I remember in class he said we should have a basic knowledge of the the spectrum and the ranges. I dont think we'll have to go into too much depth such as knowing the different colors that coordinate to the ranges, but at least know what the ranges are for gamma rays, microwaves, uv rays, etc.
- Sun Apr 22, 2018 2:19 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: The Negative Sign in En = -hR/n^2
- Replies: 5
- Views: 622
Re: The Negative Sign in En = -hR/n^2
Why is it when we solve for the E in the Rydberg equation, we have to switch the sign from a negative to a positive when solving for another variable such as wavelength?
- Sun Apr 15, 2018 10:06 pm
- Forum: Properties of Light
- Topic: Wavelength and frequency proportions [ENDORSED]
- Replies: 5
- Views: 686
Wavelength and frequency proportions [ENDORSED]
Can someone clarify what Professor Lavelle was talking about in lecture about the wavelength and frequency relationships. For example, why is it when the frequency doubles, the wavelength halves? I'm still a little confused on this concept.
- Sun Apr 15, 2018 9:54 pm
- Forum: Photoelectric Effect
- Topic: When to use Planck's Constant [ENDORSED]
- Replies: 5
- Views: 671
Re: When to use Planck's Constant [ENDORSED]
Plank's constant is the amount of energy a photon carries with the frequency of its electromagnetic wave. We use it whenever we solve for the energy per photon (E= frequency x plank's constant)
- Sun Apr 15, 2018 9:38 pm
- Forum: Empirical & Molecular Formulas
- Topic: Finding Molecular X
- Replies: 9
- Views: 1005
Re: Finding Molecular X
First I would solve for the number of moles produced for each product but break it down to C,H,O. Then divide each of the moles you got by the lowest number of moles produced. Then you would use those values for the empirical. To find the molecular formula, just divide the given molecular mass by th...
- Sun Apr 15, 2018 9:22 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing Chemical Reactions
- Replies: 5
- Views: 476
Re: Balancing Chemical Reactions
Whenever one of the stoichiometric coefficients is a fraction, multiply the entire equation by the denominator. That would get rid of the fraction and multiply all the coefficients by a factor of the denominator.
- Sun Apr 15, 2018 8:48 pm
- Forum: Empirical & Molecular Formulas
- Topic: Finding Molecular X
- Replies: 9
- Views: 1005
Re: Finding Molecular X
What do you mean by molecular compound? Are you talking about when they give us the name and not the compound? Because if thats the case, we havent learned how to form molecular compounds from names yet
- Sat Apr 07, 2018 4:04 pm
- Forum: SI Units, Unit Conversions
- Topic: Chemical Formulas [ENDORSED]
- Replies: 11
- Views: 1019
Re: Chemical Formulas [ENDORSED]
Dr. Lavelle did say that he was going to provide us with the chemical formulas for now, however it probably wouldnt hurt brushing up on how to write chemical formulas for future references.
- Sat Apr 07, 2018 4:01 pm
- Forum: Limiting Reactant Calculations
- Topic: In-Class Limiting Reactant and Theoretical Yield Problem [ENDORSED]
- Replies: 3
- Views: 367
Re: In-Class Limiting Reactant and Theoretical Yield Problem [ENDORSED]
I believe that it would still be the same because essentially, the limiting reactant determines the maximum amount of how much a product would be produced. However, someone should reassert this.