Search found 30 matches
- Sun Dec 09, 2018 7:18 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Why HF is a weaker acid than HCl
- Replies: 17
- Views: 16270
Re: Why HF is a weaker acid than HCl
HCL has a greater bond length making it easier for H+ to disassociate making it a stronger acid.
- Sun Dec 09, 2018 7:17 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: polarizing power
- Replies: 3
- Views: 718
Re: polarizing power
Polarizing power has to do with a cations ability to distort an anions electron cloud. Smaller cations usually have a larger polarizing power.
- Sun Dec 09, 2018 7:15 pm
- Forum: Lewis Acids & Bases
- Topic: Identifying Acids and Bases
- Replies: 5
- Views: 740
Re: Identifying Acids and Bases
F- is a Lewis base. Anions are usually bases.
- Sun Dec 09, 2018 7:12 pm
- Forum: Photoelectric Effect
- Topic: Kinetic energy
- Replies: 11
- Views: 3331
Re: Kinetic energy
It only applies to kinetic energy. For example the energy of a photon is measured by plank's constant times it's frequency.
- Sun Dec 09, 2018 7:07 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: Strength
- Replies: 5
- Views: 924
Re: Strength
an ion-ion interaction is greater than an ion-dipole
- Sun Dec 09, 2018 7:06 pm
- Forum: DeBroglie Equation
- Topic: Momentum
- Replies: 10
- Views: 1462
Re: Momentum
For momentum, either velocity or mass will usually be given. A question might ask you to solve for a missing variable.
- Sun Dec 09, 2018 7:04 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: pH of acids
- Replies: 13
- Views: 3593
Re: pH of acids
The Ph of a strong acid is lower than that of a weak acid, however the concentration of H+ is greater.
- Sun Dec 09, 2018 7:00 pm
- Forum: Electronegativity
- Topic: Trend of Electronegativity
- Replies: 18
- Views: 4205
Re: Trend of Electronegativity
Electronegativity increases across a period and decreases down a group.
- Sun Dec 09, 2018 6:57 pm
- Forum: Bronsted Acids & Bases
- Topic: Lewis vs Bronsted
- Replies: 10
- Views: 1579
Re: Lewis vs Bronsted
Lewis acids and bases are associated with the formation of molecules through electron donation, Lewis acids accept electrons and Lewis bases donate electron pairs. Bronsted Acids have to do with protons. Bronsted acids donate H+ abd Bronsted bases accept them
- Sun Dec 02, 2018 11:33 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Seesaw
- Replies: 13
- Views: 2089
Re: Seesaw
The bond angles of a seesaw would be less than 120 degrees between the equatorial bonds, and less than 90 degrees between the axial and equatorial bonds.
- Sun Dec 02, 2018 11:25 pm
- Forum: Hybridization
- Topic: Hybridization
- Replies: 11
- Views: 1291
Re: Hybridization
The hybridization orbital of a trigonal planar is sp^2 since it has three regions of electron density. A trigonal pyramidal would have a hybridization of sp3 since it has four regions of electron densities.
- Sun Dec 02, 2018 11:14 pm
- Forum: Hybridization
- Topic: Sigma bonds
- Replies: 9
- Views: 934
Re: Sigma bonds
Sigma bonds are always single bonds, or the first bonds in a double or triple bond. The remaining bonds of a double or triple bonds are pi bonds. This is easy to visualize when looking at hybridized orbitals. The hybridized sp orbitals form sigma bonds while the unhybridized p orbitals form pi bonds
- Sun Nov 25, 2018 11:31 pm
- Forum: Hybridization
- Topic: Test 3
- Replies: 7
- Views: 892
Re: Test 3
It says on the website that Bonding from 3.12 to the end of chapter 3 and Molecular shape and structure 4.1-4.7 will be included in the test. As for the number of questions, I'm not sure but I'd say anywhere from 5-8 if it's like the previous tests.
- Sun Nov 25, 2018 11:26 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam
- Replies: 22
- Views: 1659
Re: Final Exam
Pretty sure it'll be cumulative, but with more questions on recently learned topics.
- Sun Nov 25, 2018 11:24 pm
- Forum: Electronegativity
- Topic: The central atom
- Replies: 3
- Views: 715
Re: The central atom
The central atom should be the same as for a Lewis structure, in which we choose the atom with the lowest ionization energy to be the center of the structure. The ionization energy is the minimum energy required to remove an electron from an atom. Electronegativity refers to the pulling power of an ...
- Sun Nov 18, 2018 1:04 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 16
- Views: 1224
Re: Bond Angles
I think it would be helpful to memorize the bond angles respective to the molecular shape.
- Sun Nov 18, 2018 1:01 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polarity
- Replies: 3
- Views: 392
Re: Polarity
A compound that is polar has a greater electronegativity difference (considered ionic) versus one that is nonpolar. These types of compounds form dipoles.
- Sun Nov 18, 2018 12:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Square Planar Angles
- Replies: 3
- Views: 358
Re: Square Planar Angles
The angles are still 90 degrees
- Sun Nov 04, 2018 11:53 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Heisenberg and Wavelength
- Replies: 11
- Views: 1748
Re: Heisenberg and Wavelength
momentum does affect wavelength, since they have a reciprocal relationship. That is the concept behind de Broglie's equation (wavelength= plank's constant/momentum)
- Sun Nov 04, 2018 11:47 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic Radius
- Replies: 6
- Views: 1035
Re: Atomic Radius
The radius increases down a group since the additional shells are further from the nucleus. It decreases down a period because as electrons start filling the same shell the increasing difference in charge causes electrons to be pulled closer to the nucleus.
- Sun Nov 04, 2018 11:41 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge Equation
- Replies: 13
- Views: 3440
Re: Formal Charge Equation
The formal charge equation is as follows
Valence electrons of atom-(number of lone pair electrons+ bonded electrons/2)
it's pretty easy to count the difference by just looking at the structure.
Valence electrons of atom-(number of lone pair electrons+ bonded electrons/2)
it's pretty easy to count the difference by just looking at the structure.
- Sun Oct 28, 2018 11:55 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Heisenberg Indeterminacy Equation
- Replies: 4
- Views: 507
Re: Heisenberg Indeterminacy Equation
The formula shows the there is a limit on the accuracy of our knowledge of an electron's position and momentum at the same time.
- Sun Oct 28, 2018 11:51 pm
- Forum: Lewis Structures
- Topic: Lewis Structures
- Replies: 13
- Views: 1037
Re: Lewis Structures
The atom with the lowest ionization level is at the center of the Lewis structure. These are usually the ones on the left of the periodic table.
- Sun Oct 28, 2018 11:44 pm
- Forum: Photoelectric Effect
- Topic: HW 1.3
- Replies: 4
- Views: 541
Re: HW 1.3
You can eliminate B since the wavelength of the radiation would increase if frequency decreased, for D the energy of the radiation would decrease not increase if the frequency decreased. Since speed is a constant A can be ruled out as well. That leaves us with C.
- Sun Oct 21, 2018 11:16 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Deriving Rydberg's Equation
- Replies: 2
- Views: 325
Re: Deriving Rydberg's Equation
To calculate the differences between two energy levels you take the difference in their frequencies and end up with v=R[1/nf^2-1/ni^2]. Frequency=change in E/ h, is given by the Bohr frequency condition. If we substitute v for E/h, we can multiply the other side of the equation by plank's constant t...
- Sun Oct 21, 2018 11:04 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Energy levels of orbitals?
- Replies: 10
- Views: 769
Re: Energy levels of orbitals?
The energy of the orbitals goes according to their distance from the nucleus. So f would have the highest energy level and d,p, and s would follow.
- Sun Oct 21, 2018 10:58 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: What is the equation used for?
- Replies: 9
- Views: 870
Re: What is the equation used for?
Heisenberg's equation measures the uncertainty in the position and momentum. When conducting an experiment, trying to measure the position of an electron can disrupt the outcome of the velocity, thus affecting momentum.
- Sun Oct 07, 2018 3:44 pm
- Forum: Balancing Chemical Reactions
- Topic: Mole Coefficients in Chemical Equations
- Replies: 6
- Views: 743
Re: Mole Coefficients in Chemical Equations
The moles are not equal but the number of atoms of each element in both the reactant and product side are. The moles indicate the amount of compounds that can be created from the given atoms.
- Sun Oct 07, 2018 3:34 pm
- Forum: Limiting Reactant Calculations
- Topic: Limiting reagents
- Replies: 12
- Views: 860
Re: Limiting reagents
There can only be one limiting reagent in a reaction. Since the limiting reagent determines the amount of product that can be created, once it has been used it would not make sense that another reactant could limit an already determined product.
- Sun Oct 07, 2018 3:26 pm
- Forum: General Science Questions
- Topic: Periodic Table
- Replies: 16
- Views: 1664
Re: Periodic Table
rounding atomic weight/mass can lead to small discrepancies so it's best not to do so until you've reached your answer. Usually I try to include at least three numbers after the decimal for accuracy when rounding to find the number of moles.