Search found 30 matches
- Sat Dec 08, 2018 2:50 pm
- Forum: Lewis Acids & Bases
- Topic: Boric acid acidity
- Replies: 1
- Views: 297
Re: Boric acid acidity
So lewis acids do not dissociate protons (hence the distinction with dissociation). The boron has an incomplete octet, which is why it can accept the lone pairs to fill the 2p orbital. This is not a reference to its strength as an acid.
- Sat Dec 08, 2018 1:59 pm
- Forum: Trends in The Periodic Table
- Topic: effective nuclear charge
- Replies: 2
- Views: 619
Re: effective nuclear charge
Effective nuclear charge is the amount of attraction the nucleus exerts on an electron; alternatively it is how strong of a positive force the electron experiences. The trends are that it increases across a period because there is a larger number of protons with no increase in electron shielding, an...
- Sat Dec 08, 2018 1:55 pm
- Forum: Conjugate Acids & Bases
- Topic: strength of conjugate acids & bases
- Replies: 1
- Views: 484
Re: strength of conjugate acids & bases
Generally, the rule is that the stronger a Bronsted acid or base is, the weaker its conjugate is.
For example with HCl, the strong acid creates the weak conjugate base Cl-. Cl- is already fairly stable and has an octet,meaning it wouldnt' need a proton.
For example with HCl, the strong acid creates the weak conjugate base Cl-. Cl- is already fairly stable and has an octet,meaning it wouldnt' need a proton.
- Sat Dec 08, 2018 1:52 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Ligands
- Replies: 6
- Views: 1041
Re: Ligands
Porphyrin is just a tetradentate ligand. When Porphyrin binds with Iron (Fe), the resulting complex is also called a heme group.
- Mon Dec 03, 2018 10:52 pm
- Forum: Lewis Acids & Bases
- Topic: Base?
- Replies: 2
- Views: 326
Re: Base?
Strong Bases fully dissociate while weak bases will only partially dissociate. This is also true for strong acids vs weak acids. The strength of an acid or base , especially weak acids and bases, can be given by the equilibrium Ka for acids and Kb for bases.
- Mon Dec 03, 2018 10:42 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Ka calculations
- Replies: 2
- Views: 349
Re: Ka calculations
[x] = molarity of x Ka = [Anion (A)] [H+] / [HA] Take HCl. The more HCl dissociates into H+ and Cl- (the anion), the more acidic it is. Because it dissociates almost completely, the numerator of the Ka, which is [A]*[H+] will be much higher than the denominator ( the concentration of the acid that d...
- Mon Dec 03, 2018 10:33 pm
- Forum: Bronsted Acids & Bases
- Topic: Acid Base Identification
- Replies: 1
- Views: 381
Re: Acid Base Identification
The molecule NH4I dissociates into 2 species NH4+ and I- . Bronsted acids donate protons (H+) and bronsted bases accept protons (H+). I- + H+ --> HI means that I accepts that proton and acts as a base. NH4+ --> NH3 + H+ means that the ammonium ion donates the H+ and is an acid.
- Mon Dec 03, 2018 10:27 pm
- Forum: Hybridization
- Topic: Coefficients for hybridization
- Replies: 2
- Views: 372
Re: Coefficients for hybridization
That coefficient juts gives the primary quantum number. But the hybridized orbital type is sp2 or sp3 and just like a "normal" s or p orbital can theoretically be found at any principal quantum number.
- Mon Dec 03, 2018 10:25 pm
- Forum: Lewis Acids & Bases
- Topic: Lone Pairs only on Central Atoms?
- Replies: 2
- Views: 344
Re: Lone Pairs only on Central Atoms?
BF3 is a Lewis acid; it can accept an electron pair because Boron has an incomplete octet.
- Mon Dec 03, 2018 10:05 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polydentate
- Replies: 1
- Views: 234
Re: Polydentate
A bidentate ligand would form 2 bonds with the central atom.
- Mon Dec 03, 2018 10:04 pm
- Forum: Bronsted Acids & Bases
- Topic: Bronsted Acids and Bases vs Conjugate acids and bases
- Replies: 1
- Views: 356
Re: Bronsted Acids and Bases vs Conjugate acids and bases
Conjugate Acids and bases describe the relationships between bronsted acids and bases. Bronsted acids donate protons and Bronsted bases act as proton acceptors. Protons are equivalent to H+, so think of the conjugate base to every bronsted acid as the molecule minus one H+ ion. HCl is an acid and Cl...
- Mon Dec 03, 2018 9:53 pm
- Forum: Naming
- Topic: Ligand Names
- Replies: 3
- Views: 429
Re: Ligand Names
More important than specific ligands are the rules you need to know. However some common exceptions to the rule you might include the NH3 group which becomes ammine, CO becomes Carbonyl, and NO becomes nitrosyl.
Hope this helps,
Atul
Hope this helps,
Atul
- Thu Nov 22, 2018 12:03 pm
- Forum: Dipole Moments
- Topic: London forces and dipole moments
- Replies: 4
- Views: 465
Re: London forces and dipole moments
Temporary dipole dipole moments happen more frequently when the size of the molecule increases. If a given amount of substance experiences more of these dipole dipole moments that would mean that the london forces are stronger in that molecule.
- Thu Nov 22, 2018 12:01 pm
- Forum: Electronegativity
- Topic: electron density
- Replies: 4
- Views: 569
Re: electron density
The first step is to draw the lewis structure. Electron densities include areas where you are most likely to find electrons. This includes all lone pairs and bonding regions. It's important to note that a double or triple bond would still count as one electron density.
Much Joy,
Atul
Much Joy,
Atul
- Thu Nov 22, 2018 11:53 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: I3- molecular shape
- Replies: 2
- Views: 383
Re: I3- molecular shape
In this instance, the lone pairs on the central atom would create a bent shape. Essentially, the lone pairs would repel the bonds to create an angle that would approximate to around 120˚.
Much Joy,
Atul
Much Joy,
Atul
- Sun Nov 11, 2018 8:35 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: tetrahedral
- Replies: 3
- Views: 389
Re: tetrahedral
The bonds want to create the max amount of distance between them. With only two or three bonds, the bonds can be exist in a plane. With 4, the bonds have the angle of 109.5 degrees. VSEPR states that the lone pairs / bonds will repel each other, and hence the tetrahedral structure makes sense since ...
- Sun Nov 11, 2018 8:29 pm
- Forum: Ionic & Covalent Bonds
- Topic: Silver Halides
- Replies: 3
- Views: 568
Re: Silver Halides
Silver Halides (except for AgF) have a very high lattice energy. We didn't cover this in class, but basically the energy of the bonds holding the structure of the silver halides together is too much to overcome, hence they are insoluble.
Much Joy,
Atul
Much Joy,
Atul
- Sun Nov 11, 2018 8:26 pm
- Forum: Hybridization
- Topic: Question 2.43
- Replies: 4
- Views: 512
Re: Question 2.43
Technically, when the 4d orbital is occupied, it exists at a lower energy state than 5s orbital. However, the 5s orbital is technically filled out before the 4d orbital.
Much Joy,
Atul Saha
Much Joy,
Atul Saha
- Sun Nov 04, 2018 11:04 pm
- Forum: Lewis Structures
- Topic: Biradicals
- Replies: 1
- Views: 257
Re: Biradicals
Hund's rule states that electrons will go to the lowest energy level by first filling out all degenerate orbitals once before forming pairs.
Much Joy,
Atul
Much Joy,
Atul
- Sun Nov 04, 2018 11:03 pm
- Forum: Octet Exceptions
- Topic: Incomplete Octet
- Replies: 5
- Views: 1345
Re: Incomplete Octet
This mostly requires memorization, as that specific group has these unique properties. Boron and Aluminum are the two most common elements that might show up on examinations.
Much Joy,
Atul
Much Joy,
Atul
- Sun Nov 04, 2018 11:00 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic Radius
- Replies: 6
- Views: 1039
Re: Atomic Radius
The atomic radius decreases across the period because the effective nuclear charge increases. For every electron added, a proton is added as well. However, because the electrons are added to the same shell, they are more spread out as they fill out the probability field. This means there is less ele...
- Sun Oct 28, 2018 6:36 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: 1D.9 nodes
- Replies: 1
- Views: 314
Re: 1D.9 nodes
Angular nodes are planar areas where there is 0 probability of finding electrons, kind of like a flat sheet. Radial nodes are spherical shells where there is 0 probability of finding electrons, like a peel. The second quantum number ℓ gives the number of angular nodes. The number of radial nodes is ...
- Sun Oct 28, 2018 6:30 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Noble Gases
- Replies: 3
- Views: 352
Re: Noble Gases
Put the atomic symbol of the previous noble gas and then fill out the rest of the remaining electron shells e.g. Neon = [He] 2s^2 2p^6
Much Joy,
Atul
Much Joy,
Atul
- Sun Oct 28, 2018 6:24 pm
- Forum: Einstein Equation
- Topic: Question 1.27 (Sixth Edition)
- Replies: 3
- Views: 889
Re: Question 1.27 (Sixth Edition)
Hey Steve, First calculate the energy from the lamp, which is Wattage (32 J/s) * time (2s) = 64 J. You can next calculate the energy corresponding to the given wavelength 420 nm (utilize the formula E=hc/wavelength), which provides the energy per ONE photon. From here, use dimensional analysis total...
- Sun Oct 14, 2018 9:09 pm
- Forum: Properties of Electrons
- Topic: Atomic Spectrum: Lines in a Series
- Replies: 2
- Views: 300
Re: Atomic Spectrum: Lines in a Series
Hey Alli, The different series have different base energy levels. So only the Lyman series has the base energy level with quantum level n1. The Balmer series is at base energy level 2, etc. The series are probably important to know also in the context of their location on the EM spectrum differentia...
- Sun Oct 14, 2018 8:57 pm
- Forum: General Science Questions
- Topic: White Light
- Replies: 2
- Views: 362
Re: White Light
Hi Isabelle, White light is the combination of all the different wavelengths of light. It's similar to how mixing all the colors of paint creates black. The prism splits up white light into its component parts which our eyes visualize as a continuous spectrum (the rainbow). Black is not a color of l...
- Sun Oct 14, 2018 8:50 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 2.1 6th Edition
- Replies: 1
- Views: 291
Re: 2.1 6th Edition
Hey Claudia,
Lower energy levels (ie 1 as compared to 2) translate to a smaller radius. Higher energy levels have electron probability fields that are further from the nucleus.
Much Joy,
Atul
Lower energy levels (ie 1 as compared to 2) translate to a smaller radius. Higher energy levels have electron probability fields that are further from the nucleus.
Much Joy,
Atul
- Fri Oct 05, 2018 12:26 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: 6th Edition Question G5
- Replies: 1
- Views: 229
Re: 6th Edition Question G5
Hey Netpheel, Keep in mind that Na2CO2 would dissociate into its individual ions in an aqueous solution. That specific equivalence in the dimension factor is meant to demonstrate that for every mole of Na2CO2, there are 2 moles of Na+ ions. You can figure this out by looking at the subscript on the ...
- Wed Oct 03, 2018 10:28 pm
- Forum: SI Units, Unit Conversions
- Topic: Prefixes
- Replies: 6
- Views: 347
Re: Prefixes
Dr. Lavelle mentioned that some of those prefixes, specifically the larger ones (e.g. Giga- , Mega-) would not be as relevant for 14A. He conversely highlighted the importance of the Ångström (10^-10) for the use of calculations for the reason that it is the distance for hydrogen bonds. There are no...
- Wed Oct 03, 2018 10:23 pm
- Forum: Significant Figures
- Topic: Rounding off/sig figs during steps of a calculation
- Replies: 4
- Views: 415
Re: Rounding off/sig figs during steps of a calculation
Hey Shirley,
I believe that it would be better to simply use the fraction in your calculation to represent the repeating decimal. This would eliminate the rounding in the calculation.
Much Joy,
Atul
I believe that it would be better to simply use the fraction in your calculation to represent the repeating decimal. This would eliminate the rounding in the calculation.
Much Joy,
Atul