Search found 30 matches

by Atul Saha 3D
Sat Dec 08, 2018 2:50 pm
Forum: Lewis Acids & Bases
Topic: Boric acid acidity
Replies: 1
Views: 43

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.
by Atul Saha 3D
Sat Dec 08, 2018 1:59 pm
Forum: Trends in The Periodic Table
Topic: effective nuclear charge
Replies: 2
Views: 118

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...
by Atul Saha 3D
Sat Dec 08, 2018 1:55 pm
Forum: Conjugate Acids & Bases
Topic: strength of conjugate acids & bases
Replies: 1
Views: 105

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.
by Atul Saha 3D
Sat Dec 08, 2018 1:52 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Ligands
Replies: 6
Views: 153

Re: Ligands

Porphyrin is just a tetradentate ligand. When Porphyrin binds with Iron (Fe), the resulting complex is also called a heme group.
by Atul Saha 3D
Mon Dec 03, 2018 10:52 pm
Forum: Lewis Acids & Bases
Topic: Base?
Replies: 2
Views: 66

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.
by Atul Saha 3D
Mon Dec 03, 2018 10:42 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Ka calculations
Replies: 2
Views: 54

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...
by Atul Saha 3D
Mon Dec 03, 2018 10:33 pm
Forum: Bronsted Acids & Bases
Topic: Acid Base Identification
Replies: 1
Views: 69

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.
by Atul Saha 3D
Mon Dec 03, 2018 10:27 pm
Forum: Hybridization
Topic: Coefficients for hybridization
Replies: 2
Views: 104

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.
by Atul Saha 3D
Mon Dec 03, 2018 10:25 pm
Forum: Lewis Acids & Bases
Topic: Lone Pairs only on Central Atoms?
Replies: 2
Views: 65

Re: Lone Pairs only on Central Atoms?

BF3 is a Lewis acid; it can accept an electron pair because Boron has an incomplete octet.
by Atul Saha 3D
Mon Dec 03, 2018 10:05 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate
Replies: 1
Views: 44

Re: Polydentate

A bidentate ligand would form 2 bonds with the central atom.
by Atul Saha 3D
Mon Dec 03, 2018 10:04 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted Acids and Bases vs Conjugate acids and bases
Replies: 1
Views: 50

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...
by Atul Saha 3D
Mon Dec 03, 2018 9:53 pm
Forum: Naming
Topic: Ligand Names
Replies: 3
Views: 80

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
by Atul Saha 3D
Thu Nov 22, 2018 12:03 pm
Forum: Dipole Moments
Topic: London forces and dipole moments
Replies: 4
Views: 106

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.
by Atul Saha 3D
Thu Nov 22, 2018 12:01 pm
Forum: Electronegativity
Topic: electron density
Replies: 4
Views: 91

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
by Atul Saha 3D
Thu Nov 22, 2018 11:53 am
Forum: Determining Molecular Shape (VSEPR)
Topic: I3- molecular shape
Replies: 2
Views: 57

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
by Atul Saha 3D
Sun Nov 11, 2018 8:35 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: tetrahedral
Replies: 3
Views: 49

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 ...
by Atul Saha 3D
Sun Nov 11, 2018 8:29 pm
Forum: Ionic & Covalent Bonds
Topic: Silver Halides
Replies: 3
Views: 90

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
by Atul Saha 3D
Sun Nov 11, 2018 8:26 pm
Forum: Hybridization
Topic: Question 2.43
Replies: 4
Views: 134

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
by Atul Saha 3D
Sun Nov 04, 2018 11:04 pm
Forum: Lewis Structures
Topic: Biradicals
Replies: 1
Views: 36

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
by Atul Saha 3D
Sun Nov 04, 2018 11:03 pm
Forum: Octet Exceptions
Topic: Incomplete Octet
Replies: 5
Views: 99

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
by Atul Saha 3D
Sun Nov 04, 2018 11:00 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 6
Views: 223

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...
by Atul Saha 3D
Sun Oct 28, 2018 6:36 pm
Forum: Quantum Numbers and The H-Atom
Topic: 1D.9 nodes
Replies: 1
Views: 61

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 ...
by Atul Saha 3D
Sun Oct 28, 2018 6:30 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Noble Gases
Replies: 3
Views: 42

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
by Atul Saha 3D
Sun Oct 28, 2018 6:24 pm
Forum: Einstein Equation
Topic: Question 1.27 (Sixth Edition)
Replies: 2
Views: 206

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...
by Atul Saha 3D
Sun Oct 14, 2018 9:09 pm
Forum: Properties of Electrons
Topic: Atomic Spectrum: Lines in a Series
Replies: 2
Views: 83

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...
by Atul Saha 3D
Sun Oct 14, 2018 8:57 pm
Forum: General Science Questions
Topic: White Light
Replies: 2
Views: 172

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...
by Atul Saha 3D
Sun Oct 14, 2018 8:50 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 2.1 6th Edition
Replies: 1
Views: 56

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
by Atul Saha 3D
Fri Oct 05, 2018 12:26 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: 6th Edition Question G5
Replies: 1
Views: 46

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 ...
by Atul Saha 3D
Wed Oct 03, 2018 10:28 pm
Forum: SI Units, Unit Conversions
Topic: Prefixes
Replies: 2
Views: 61

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...
by Atul Saha 3D
Wed Oct 03, 2018 10:23 pm
Forum: Significant Figures
Topic: Rounding off/sig figs during steps of a calculation
Replies: 4
Views: 86

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

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