Search found 30 matches

by Grace Diaz 3F
Sun Dec 09, 2018 7:18 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Why HF is a weaker acid than HCl
Replies: 12
Views: 634

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.
by Grace Diaz 3F
Sun Dec 09, 2018 7:17 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: polarizing power
Replies: 3
Views: 295

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.
by Grace Diaz 3F
Sun Dec 09, 2018 7:15 pm
Forum: Lewis Acids & Bases
Topic: Identifying Acids and Bases
Replies: 5
Views: 333

Re: Identifying Acids and Bases

F- is a Lewis base. Anions are usually bases.
by Grace Diaz 3F
Sun Dec 09, 2018 7:12 pm
Forum: Photoelectric Effect
Topic: Kinetic energy
Replies: 11
Views: 2280

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.
by Grace Diaz 3F
Sun Dec 09, 2018 7:06 pm
Forum: DeBroglie Equation
Topic: Momentum
Replies: 10
Views: 501

Re: Momentum

For momentum, either velocity or mass will usually be given. A question might ask you to solve for a missing variable.
by Grace Diaz 3F
Sun Dec 09, 2018 7:04 pm
Forum: Calculating the pH of Salt Solutions
Topic: pH of acids
Replies: 8
Views: 297

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.
by Grace Diaz 3F
Sun Dec 09, 2018 7:00 pm
Forum: Electronegativity
Topic: Trend of Electronegativity
Replies: 18
Views: 608

Re: Trend of Electronegativity

Electronegativity increases across a period and decreases down a group.
by Grace Diaz 3F
Sun Dec 09, 2018 6:57 pm
Forum: Bronsted Acids & Bases
Topic: Lewis vs Bronsted
Replies: 10
Views: 426

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
by Grace Diaz 3F
Sun Dec 02, 2018 11:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw
Replies: 13
Views: 344

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.
by Grace Diaz 3F
Sun Dec 02, 2018 11:25 pm
Forum: Hybridization
Topic: Hybridization
Replies: 11
Views: 185

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.
by Grace Diaz 3F
Sun Dec 02, 2018 11:14 pm
Forum: Hybridization
Topic: Sigma bonds
Replies: 9
Views: 156

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
by Grace Diaz 3F
Sun Nov 25, 2018 11:31 pm
Forum: Hybridization
Topic: Test 3
Replies: 7
Views: 162

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.
by Grace Diaz 3F
Sun Nov 25, 2018 11:26 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Exam
Replies: 22
Views: 532

Re: Final Exam

Pretty sure it'll be cumulative, but with more questions on recently learned topics.
by Grace Diaz 3F
Sun Nov 25, 2018 11:24 pm
Forum: Electronegativity
Topic: The central atom
Replies: 3
Views: 243

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 ...
by Grace Diaz 3F
Sun Nov 18, 2018 1:04 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 16
Views: 237

Re: Bond Angles

I think it would be helpful to memorize the bond angles respective to the molecular shape.
by Grace Diaz 3F
Sun Nov 18, 2018 1:01 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarity
Replies: 3
Views: 67

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.
by Grace Diaz 3F
Sun Nov 18, 2018 12:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Square Planar Angles
Replies: 3
Views: 77

Re: Square Planar Angles

The angles are still 90 degrees
by Grace Diaz 3F
Sun Nov 04, 2018 11:53 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg and Wavelength
Replies: 11
Views: 532

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)
by Grace Diaz 3F
Sun Nov 04, 2018 11:47 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 6
Views: 355

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.
by Grace Diaz 3F
Sun Nov 04, 2018 11:41 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Equation
Replies: 13
Views: 2593

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.
by Grace Diaz 3F
Sun Oct 28, 2018 11:55 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg Indeterminacy Equation
Replies: 4
Views: 140

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.
by Grace Diaz 3F
Sun Oct 28, 2018 11:51 pm
Forum: Lewis Structures
Topic: Lewis Structures
Replies: 13
Views: 165

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.
by Grace Diaz 3F
Sun Oct 28, 2018 11:44 pm
Forum: Photoelectric Effect
Topic: HW 1.3
Replies: 4
Views: 196

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.
by Grace Diaz 3F
Sun Oct 21, 2018 11:16 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Deriving Rydberg's Equation
Replies: 2
Views: 86

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...
by Grace Diaz 3F
Sun Oct 21, 2018 11:04 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Energy levels of orbitals?
Replies: 10
Views: 147

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.
by Grace Diaz 3F
Sun Oct 21, 2018 10:58 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: What is the equation used for?
Replies: 9
Views: 200

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.
by Grace Diaz 3F
Sun Oct 07, 2018 3:44 pm
Forum: Balancing Chemical Reactions
Topic: Mole Coefficients in Chemical Equations
Replies: 6
Views: 355

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.
by Grace Diaz 3F
Sun Oct 07, 2018 3:34 pm
Forum: Limiting Reactant Calculations
Topic: Limiting reagents
Replies: 12
Views: 202

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.
by Grace Diaz 3F
Sun Oct 07, 2018 3:26 pm
Forum: General Science Questions
Topic: Periodic Table
Replies: 16
Views: 516

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.

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