Search found 33 matches
- Sat Dec 08, 2018 1:31 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Least to most polarizing power?
- Replies: 1
- Views: 1046
Least to most polarizing power?
On test #3 Q6B, how do we order the cations Li+, Ca2+, Cs+, Ba2+ in order from least to most polarizing power? I'm especially having trouble with putting Cs+ and Ba2+ in the right order.
- Sat Dec 08, 2018 1:28 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Test 3
- Replies: 1
- Views: 485
Re: Test 3
It is the least polarizable because it is the smallest anion in that problem. Chlorine (even without the charge) is the smallest (remember that atomic radius decreases as you go across the periodic table!).
- Wed Dec 05, 2018 2:19 pm
- Forum: Bronsted Acids & Bases
- Topic: Disassociation and stabilization?
- Replies: 2
- Views: 351
Re: Disassociation and stabilization?
Oxoacids, in particular, more readily lose H+ IF the resulting anion (the anion that results when H+ is released) is stabilized by electron withdrawing atoms. These electron withdrawing atoms, a.k.a atoms with greater electronegativities, delocalize and stabilize the negative charge of the anion. J...
- Wed Dec 05, 2018 10:53 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligands
- Replies: 7
- Views: 604
Re: Ligands
(As mentioned in the coordination compounds review session yesterday) The molecular geometry will not allow all three oxygens to be binding sites. If you think about the trigonal planar structure and angles, it is impossible to have more than two oxygens close enough to each other AND have them bond...
- Wed Dec 05, 2018 10:51 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polydentate and Coordination Number?
- Replies: 2
- Views: 769
Re: Polydentate and Coordination Number?
A coordination number is associated with the entire complex -- for example, if the TM has a monodentate ligand as well as a bidentate ligand, the coordination number will be 3.
Polydentates refer to the number of bonding areas (e.g., if there are lone pairs available for bonding) in a ligand.
Polydentates refer to the number of bonding areas (e.g., if there are lone pairs available for bonding) in a ligand.
- Wed Dec 05, 2018 10:42 am
- Forum: Lewis Acids & Bases
- Topic: Resonance Structures
- Replies: 4
- Views: 503
Re: Resonance Structures
I don't believe that resonance structures should matter when determining if it is an acid or a base.
- Wed Dec 05, 2018 10:37 am
- Forum: Bronsted Acids & Bases
- Topic: Disassociation and stabilization?
- Replies: 2
- Views: 351
Disassociation and stabilization?
How are disassociation and stabilization of acids related? I'm just a little confused as I read somewhere that higher electronegativity allows for acids to disassociate more easily, and thus causes them to be stronger acids. However, I also read that higher electronegativity allows for higher stabil...
- Wed Dec 05, 2018 10:35 am
- Forum: Bronsted Acids & Bases
- Topic: Ka Formula
- Replies: 6
- Views: 942
Re: Ka Formula
Just keep in mind that Ka = Kforward rxn/Kreverse rxn When you have a higher Ka, then you have more products (e.g., more H+ ions). This increases the pH (more acidic). Vice versa, when you have a lower Ka, you have more reactants -- there aren't as many H+ ions being produced. This lowers the pH (le...
- Wed Dec 05, 2018 10:23 am
- Forum: Conjugate Acids & Bases
- Topic: Inductive Effect
- Replies: 5
- Views: 587
Re: Inductive Effect
As electronegativity increases, inductive properties increase. This was mentioned in my discussion but I also don't recall the term itself being mentioned too often (if at all) in lecture. In lecture, we did learn that as electronegativity increases, stabilization is stronger, and those acids will b...
- Wed Dec 05, 2018 10:19 am
- Forum: Naming
- Topic: Transition Metal
- Replies: 4
- Views: 463
Re: Transition Metal
From the review session about coordination compounds I attended yesterday, I believe it was mentioned that such cases are unlikely, so don't worry about them for the final.
- Wed Dec 05, 2018 10:15 am
- Forum: Lewis Acids & Bases
- Topic: Lewis Acids and Bronstead Acids
- Replies: 1
- Views: 286
Re: Lewis Acids and Bronstead Acids
Check out Ch 12.1 and 12.2 in the book (6th edition; otherwise, there are likewise chapters in the 7th ed.) To summarize (taken directly from the book): Lewis Acids and Bases A Lewis acid is an electron pair acceptor . A Lewis base is an electron pair donor Bronsted-Lowry Acids and Bases An acid is ...
- Wed Dec 05, 2018 10:05 am
- Forum: Naming
- Topic: Anionic ligands
- Replies: 5
- Views: 609
Re: Anionic ligands
Definitely look at the naming conventions chart on Dr. Lavelle's website: https://lavelle.chem.ucla.edu/wp-conten ... pounds.pdf
Re: Cyanide
They are the same -- just different naming conventions (one is newer, I think). It's on the naming coordination compounds chart from Dr. Lavelle's website.
https://lavelle.chem.ucla.edu/wp-conten ... pounds.pdf
https://lavelle.chem.ucla.edu/wp-conten ... pounds.pdf
- Sat Nov 17, 2018 5:39 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Square Planar Angles
- Replies: 3
- Views: 362
Re: Square Planar Angles
All the angles are 90 degrees even with the two lone pairs! Keep in mind than when there is only one pair but five other atoms bonded to the central atom, the angles do become less than 90 degrees. (square pyramidal)
- Sat Nov 17, 2018 5:36 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: tetrahedral vs trigonal planar
- Replies: 9
- Views: 1117
Re: tetrahedral vs trigonal planar
Danny Elias Dis 1E wrote:How many lone pairs are possible when the molecule is in the trigonal planar shape?
There can be 3 regions for this shape, but I think we've only seen molecules in this shape with one lone pair, e.g. SO2, a bent shape.
- Sat Nov 17, 2018 5:33 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: hybridization for VSEPR
- Replies: 1
- Views: 230
Re: hybridization for VSEPR
I think we should be able to figure out the hybridization of the central atom based on the electron geometry but also, there's a chart in our text book (table 4.2) that has been really helpful for me and might help you out too!
- Fri Nov 16, 2018 6:36 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: Dipole Dipole Forces
- Replies: 3
- Views: 610
Re: Dipole Dipole Forces
Distance and charges!
- Fri Nov 16, 2018 6:30 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Distance from Central Atom
- Replies: 8
- Views: 590
Re: Distance from Central Atom
The direct wedge is coming out of the page and the hatched wedge is going into the page!
- Fri Nov 02, 2018 2:41 pm
- Forum: Octet Exceptions
- Topic: Boron Trifluoride class example
- Replies: 3
- Views: 356
Re: Boron Trifluoride class example
Fluorine needs on electron to fulfill an octet, so taking an electron away from it would be difficult and unlikely. A double bond between B and F would require that positive charge for Fluorine, so in this case, it won't happen.
- Fri Nov 02, 2018 2:33 pm
- Forum: Lewis Structures
- Topic: Formal Charge Tricks
- Replies: 5
- Views: 3617
Re: Formal Charge Tricks
You can think about it as formal charge = "should" - "has".
What your atom should have are the number of valence electrons according to the periodic table.
What your atom, when bonded, actually has are: (lone pair electrons) + (1/2)*(the number of bounded electrons).
What your atom should have are the number of valence electrons according to the periodic table.
What your atom, when bonded, actually has are: (lone pair electrons) + (1/2)*(the number of bounded electrons).
- Fri Nov 02, 2018 2:29 pm
- Forum: Octet Exceptions
- Topic: The center atom
- Replies: 20
- Views: 3340
Re: The center atom
To start finding the structures of this acid, you should first, according to the book, "choose as the central atom the element with the lowest ionization energy." Here, oxygen has the lowest ionization energy (besides Hydrogen, which shouldn't be considered as the central atom). Oxygen as ...
- Sun Oct 28, 2018 9:35 pm
- Forum: Ionic & Covalent Bonds
- Topic: Question regarding ionic bonds
- Replies: 9
- Views: 663
Re: Question regarding ionic bonds
Yup, and remember how iconic bonds are different from covalent bonds (which are between non-metals)
- Sun Oct 28, 2018 9:33 pm
- Forum: Ionic & Covalent Bonds
- Topic: Exceptions
- Replies: 4
- Views: 511
Re: Exceptions
They don't have "space" to fill an octet. They only have room for 2 electrons in the outershell as they have S orbitals only!
- Sun Oct 28, 2018 9:32 pm
- Forum: Ionic & Covalent Bonds
- Topic: bound atoms
- Replies: 8
- Views: 1259
Re: bound atoms
They release energy when they are bound!
- Fri Oct 19, 2018 9:46 pm
- Forum: Photoelectric Effect
- Topic: Equation units
- Replies: 4
- Views: 443
Re: Equation units
I agree, kg is the SI unit for mass.
- Fri Oct 19, 2018 9:44 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Series and Wavelengths
- Replies: 4
- Views: 406
Re: Series and Wavelengths
I believe they are related through the Rydberg equation V = r (1/(n1^2) - (1/(n2^2)). When you calculate frequency, you may plug it into C = wavelength x frequency and solve for the wavelength. These wavelengths would then correspond to the wavelengths you see on figure 1.10. But keep in mind of the...
- Thu Oct 18, 2018 5:54 pm
- Forum: Einstein Equation
- Topic: Number of photons
- Replies: 7
- Views: 1132
Re: Number of photons
You can use dimensional analysis! The total energy multiplied by 1 photon / energy (obtained from E = hv)
- Thu Oct 11, 2018 6:37 pm
- Forum: DeBroglie Equation
- Topic: Homework Question 1.33 (6th Ed)
- Replies: 2
- Views: 164
Re: Homework Question 1.33 (6th Ed)
I agree, you need to use the Debroglie equation because they give you velocity.
- Wed Oct 10, 2018 2:41 pm
- Forum: DeBroglie Equation
- Topic: de Broglie Relationship
- Replies: 3
- Views: 259
Re: de Broglie Relationship
I agree, it's asking for the mass of the electron.
- Wed Oct 10, 2018 2:38 pm
- Forum: Properties of Light
- Topic: Problem 1.9 6th Edition
- Replies: 2
- Views: 162
Re: Problem 1.9 6th Edition
I believe you can try converting MHz to Hz!
1 MHz = 1000000 Hz
1 MHz = 1000000 Hz
- Tue Oct 02, 2018 1:22 pm
- Forum: Balancing Chemical Reactions
- Topic: Audio Visual Focus Topics Balancing Chemical Equations Pre Assessment
- Replies: 2
- Views: 188
Re: Audio Visual Focus Topics Balancing Chemical Equations Pre Assessment
I believe the net amount will be moles of product (gas) - moles of reactant (gas)
- Tue Oct 02, 2018 1:20 pm
- Forum: Significant Figures
- Topic: Mass Percent Composition
- Replies: 4
- Views: 2718
Re: Mass Percent Composition
Use the smallest amount of sig figs you find in the given numbers. For example, if you are given 20.0 grams and 156.6 grams, you'd use three sig figs in your answer (20.0 has three, 156.6 has four.)
- Tue Oct 02, 2018 1:17 pm
- Forum: Empirical & Molecular Formulas
- Topic: Audio Visual Focus Topic Empirical and Molecular Formulas Pre-Assessment
- Replies: 2
- Views: 309
Re: Audio Visual Focus Topic Empirical and Molecular Formulas Pre-Assessment
Yes, exactly. Each percentage is for each individual element of the vitamin.