Search found 51 matches
- Fri Dec 06, 2019 1:12 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: polarizability
- Replies: 4
- Views: 506
Re: polarizability
London Dispersion Forces describe the interactions of temporary induced dipole induced dipole. The ions' or atoms' electron clouds themselves are polarizable, causing the LDF to be stronger or weaker but the LDF itself doesn't have high polarizability.
- Fri Dec 06, 2019 1:10 pm
- Forum: Hybridization
- Topic: hybridization
- Replies: 3
- Views: 229
Re: hybridization
It usually takes place among the outermost electrons, which are the valence electrons. These electrons are used in bonding, and also, hybridization.
- Fri Dec 06, 2019 1:05 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination #
- Replies: 6
- Views: 458
Re: Coordination #
Think of it as how many Ligands are attached to the central metal cation. Each of those bonds added up equals the coordination number.
- Fri Dec 06, 2019 1:03 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligand Definition
- Replies: 4
- Views: 329
Re: Ligand Definition
A ligand is a molecule that donates an electron pair in order to form a coordinate covalent bond with a Transition Metal Cation, which are found in the d-block. It is a Lewis base as it gives away an electron pair.
- Fri Dec 06, 2019 1:00 pm
- Forum: *Molecular Orbital Theory Applied To Transition Metals
- Topic: bond order
- Replies: 7
- Views: 894
Re: bond order
I don't think this would be a topic on the final as we haven't really spent time to cover it but I would study the basics just to be safe.
- Fri Nov 29, 2019 4:26 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2760573
Re: Post All Chemistry Jokes Here
Why shouldn't you trust atoms?
They make up everything.
They make up everything.
- Fri Nov 29, 2019 4:21 pm
- Forum: Bond Lengths & Energies
- Topic: Polarity
- Replies: 5
- Views: 544
Re: Polarity
If a molecule is more polar, it has more intermolecular forces since it has London dispersion forces and dipole-dipole and possibly more. Therefore, since it has more forces acting upon it, polar molecules tend to have higher boiling points.
- Fri Nov 29, 2019 4:17 pm
- Forum: Dipole Moments
- Topic: boiling point
- Replies: 6
- Views: 619
Re: boiling point
HI would have a higher boiling point because it has a greater molar mass and more electrons, causing it to have more London dispersion forces. This means it requires more heat to separate the atoms.
- Fri Nov 29, 2019 4:14 pm
- Forum: Dipole Moments
- Topic: Hydrogen Bonding Sites
- Replies: 9
- Views: 517
Re: Hydrogen Bonding Sites
Hydrogen bonding occurs when there is a covalent bond between a H and F, O, or N, causing a large dipole moment. Then another Hydrogen can bond on the lone pairs of the F, O, or N or another F, O, N can bond to the partially positively charged H.
- Fri Nov 29, 2019 4:09 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: cis platinum
- Replies: 6
- Views: 380
Re: cis platinum
Adding on, it is important to know that due to its structure with the two Cl on the same side, it is more efficient at stopping cell replication.
- Fri Nov 22, 2019 1:25 pm
- Forum: Hybridization
- Topic: sp hybridization
- Replies: 4
- Views: 289
Re: sp hybridization
Since linear molecules have two main regions of electron density, the two hybrid orbitals that will arise are SP orbitals. This is a hybridization between the S and the one of the P orbitals.
- Fri Nov 22, 2019 1:23 pm
- Forum: Coordinate Covalent Bonds
- Topic: Coordinate covalent bonds
- Replies: 9
- Views: 705
Re: Coordinate covalent bonds
Coordinate covalent bonds occur between Lewis acids and bases where the bases donate the electron pair to the Lewis acid, causing it to reach an octet.
- Fri Nov 22, 2019 1:21 pm
- Forum: Sigma & Pi Bonds
- Topic: Why are sigma bonds stronger than pi bonds?
- Replies: 6
- Views: 360
Re: Why are sigma bonds stronger than pi bonds?
In Sigma bonds, the orbitals overlap from end to end, causing it to have a direct and stronger bond while Pi bonds overlap from side to side, causing them to be weaker and not allow the elements bonded to rotate.
- Fri Nov 22, 2019 1:20 pm
- Forum: Lewis Acids & Bases
- Topic: diff b/w lewis acid and base
- Replies: 12
- Views: 636
Re: diff b/w lewis acid and base
Acids are also usually transition metals such as Cobalt which have a positive ionization charge, allowing it to accept lone pairs from other elements.
- Fri Nov 22, 2019 1:18 pm
- Forum: Lewis Acids & Bases
- Topic: lewis acid vs base
- Replies: 2
- Views: 205
Re: lewis acid vs base
Adding on, the base if the one giving the lone pair while the acid is the one accepting the lone pair.
- Sat Nov 16, 2019 12:20 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Does dipole-dipole force only exist among polar molecules?
- Replies: 9
- Views: 1191
Re: Does dipole-dipole force only exist among polar molecules?
Yes, because in order for there to be a nonzero net charge of the molecule, there has to be a dipole moment involved. These variances in dipole moments cause molecules to be polar and therefore they involve themselves in dipole-dipole interactions.
- Sat Nov 16, 2019 12:18 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Polar Vs Nonpolar
- Replies: 7
- Views: 397
Re: Polar Vs Nonpolar
Also, you can draw the vectors of the dipole moments to see if they cancel in each direction. Usually, if more than two elements are used in a molecule that isn't balanced on each side, it is polar.
- Fri Nov 15, 2019 11:59 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: Polarizability and Polar
- Replies: 4
- Views: 284
Re: Polarizability and Polar
Polarizability means how easily that element's electron field gets distorted by a cation while being polar means having a charge.
- Wed Nov 13, 2019 5:48 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Memorization
- Replies: 15
- Views: 900
Re: Memorization
Yes. The questions asked will include what is the geometry and shape of the compound and for that I think you would need to, at bare minimum, memorize their names. Other than that, the names would give some hints as to their angles and other characteristics.
- Wed Nov 13, 2019 5:44 pm
- Forum: Hybridization
- Topic: Hybridization Models
- Replies: 4
- Views: 422
Re: Hybridization Models
I am pretty sure we will need to know how to draw them. But, the best thing is to worry about shape and geometry of the compounds.
- Fri Nov 08, 2019 1:21 pm
- Forum: Dipole Moments
- Topic: Dipole moments
- Replies: 5
- Views: 379
Re: Dipole moments
Also, as the difference in electronegativity increases, the magnitude of the partial charges also increase, affecting the dipole moment.
- Fri Nov 08, 2019 1:19 pm
- Forum: Electronegativity
- Topic: Electronegativity Chart
- Replies: 5
- Views: 463
Re: Electronegativity Chart
Adding on, I think it would also be helpful to just know which elements are generally a lot more electronegative and the electronegativity values of the most electronegative elements like F, N, O, and Cl.
- Fri Nov 08, 2019 1:17 pm
- Forum: Bond Lengths & Energies
- Topic: Bond strengths
- Replies: 9
- Views: 492
Re: Bond strengths
Usually if a bond is shorter, it's because there are more electrons involved and the pull is greater, therefore decreasing the length of the bond. This makes the shorter bonds stronger.
- Fri Nov 08, 2019 1:15 pm
- Forum: Bond Lengths & Energies
- Topic: dissociation energy
- Replies: 6
- Views: 372
Re: dissociation energy
As the number of bonds increases too, like from a single, to double, to triple, the dissociation energy increases as the strength of the bond is more.
- Fri Nov 08, 2019 1:14 pm
- Forum: Bond Lengths & Energies
- Topic: Midterm
- Replies: 9
- Views: 460
Re: Midterm
The midterm will be graded by Wednesday of next week.
- Sun Nov 03, 2019 1:28 pm
- Forum: Resonance Structures
- Topic: Drawing Resonance Structures
- Replies: 4
- Views: 264
Re: Drawing Resonance Structures
Unless they specify to draw all forms of the resonance structure, I don't think that we have to but yes I believe the only way for now is to just redraw the bonds in different locations.
- Sun Nov 03, 2019 1:25 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2760573
Re: Post All Chemistry Jokes Here
How often do I tell chemistry jokes?
Periodically.
Periodically.
- Sun Nov 03, 2019 1:16 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge Purpose
- Replies: 4
- Views: 294
Re: Formal Charge Purpose
Yes. The lower the magnitude of the total formal charge, the more stable that structure is for the compound. Also, allowing the more electronegative atoms to have the lower formal charge makes it more stable.
- Sun Nov 03, 2019 1:15 pm
- Forum: Ionic & Covalent Bonds
- Topic: ionic bonds
- Replies: 4
- Views: 125
Re: ionic bonds
Compounds that have ionic bonds dissolve and dissociate in water. Also, one could look at the charges of each atom based on the periodic table and determine it that way if one atom is negative and the other is positively charged.
- Sun Nov 03, 2019 1:10 pm
- Forum: Lewis Structures
- Topic: Bonds
- Replies: 4
- Views: 128
Re: Bonds
The type of bond depends on the formal charge of each of the elements in the compound. The goal is to get the least magnitude of formal charges.
- Wed Oct 23, 2019 1:07 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Subshell vs. Orbital
- Replies: 9
- Views: 1265
Re: Subshell vs. Orbital
An orbital is a subsection under a subshell. A subshell is recognized based off of the l value: 0=s, 1=p, etc. Then within these, each sub shell has certain orbitals with s having 1, p having 3, d having 5, and f having 7, where each orbital has 2 electrons paired based on their spin state.
- Wed Oct 23, 2019 1:01 am
- Forum: *Particle in a Box
- Topic: Explaining Particle in a Box
- Replies: 4
- Views: 412
Re: Explaining Particle in a Box
The particle in a box is also used to help us visualize how the particle could move and what its limitations are.
- Wed Oct 23, 2019 12:59 am
- Forum: Photoelectric Effect
- Topic: Work Function?
- Replies: 7
- Views: 492
Re: Work Function?
Work function, also symbolized as phi in equations, is the minimum amount of energy needed from a photon to remove an electron from a metal surface. Each metal has a different work function. If the energy of a photon is more, then the electron will have kinetic energy which can be calculated with .5...
- Wed Oct 23, 2019 12:57 am
- Forum: Einstein Equation
- Topic: energy emitted by H electrons
- Replies: 5
- Views: 199
Re: energy emitted by H electrons
Adding on, this difference in energy of a transitioning hydrogen atom could be used to calculate the energy of the emitted photon by the release of energy in the excited hydrogen atom.
- Wed Oct 23, 2019 12:48 am
- Forum: DeBroglie Equation
- Topic: When to combine equations
- Replies: 10
- Views: 508
Re: When to combine equations
If the question is asking for a value that isn't part of an equation, you can combine two of the equations with the help of a common factor to solve for the final variable. Like you said, this was done in the De Broglie's equation.
- Wed Oct 16, 2019 11:39 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2760573
Re: Post All Chemistry Jokes Here
What emotional disorder does a gas chromatograph suffer from?
Separation Anxiety!
Separation Anxiety!
- Wed Oct 16, 2019 11:30 am
- Forum: Properties of Electrons
- Topic: Photons
- Replies: 9
- Views: 282
Re: Photons
In response to Jorge's question, if a photon has enough energy within it, it can interact with an electron which is on its path and then displace its position. It can affect its velocity because if the electron is put on a different trajectory, its distance it travels is changed, causing the velocit...
- Wed Oct 16, 2019 11:25 am
- Forum: Properties of Electrons
- Topic: Equations and confused of when to use what
- Replies: 3
- Views: 220
Re: Equations and confused of when to use what
If some equations have variables in similar, like frequency, they can be substituted into each other to solve for the problem if the other variables in a certain formula aren't provided.
- Wed Oct 16, 2019 11:19 am
- Forum: Properties of Electrons
- Topic: electron mass
- Replies: 8
- Views: 273
Re: electron mass
Just to be safe, I would also memorize it as it saves time while doing calculations on the test.
- Wed Oct 16, 2019 11:17 am
- Forum: Properties of Electrons
- Topic: electrons ejected [ENDORSED]
- Replies: 3
- Views: 231
Re: electrons ejected [ENDORSED]
Adding on, if the energy of the photon is more, that means the electron is ejected has more energy in the form of kinetic energy. This kinetic energy of the displaced electron can be calculated by E(photon) - E(threshold of electron) = kinetic energy.
- Sun Oct 13, 2019 8:51 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2760573
Re: Post All Chemistry Jokes Here
What's the dullest element?
Bohrium
Bohrium
- Sat Oct 12, 2019 1:36 pm
- Forum: Significant Figures
- Topic: Significant Figures and Molar Masses
- Replies: 5
- Views: 386
Re: Significant Figures and Molar Masses
When calculating, the constant values given should not be considered in terms of rounding for significant figures. The given values of a substance in the question with the least significant figures is what should be taken into consideration for rounding. The rest of the calculation should be done wi...
- Sat Oct 12, 2019 1:33 pm
- Forum: Limiting Reactant Calculations
- Topic: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
- Replies: 68
- Views: 6340
Re: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
Showing your work in terms of dimensional analysis also makes it clearer in terms of what factor you need to divide or multiply by.
- Wed Oct 09, 2019 11:15 am
- Forum: Photoelectric Effect
- Topic: Quantum
- Replies: 5
- Views: 258
Re: Quantum
They have to be in integer values like n=1,2,3 and it means that it is the smallest transferrable unit I think.
- Wed Oct 09, 2019 11:09 am
- Forum: Properties of Electrons
- Topic: Kinetic Energy
- Replies: 4
- Views: 145
Re: Kinetic Energy
I would think that as you increase the intensity or frequency, more energy would be given off by the photon, surpassing the threshold energy. Since the energy needs to be conserved, the velocity of the electron would be greater as the energy given by the photon increases since kinetic energy's varia...
- Wed Oct 09, 2019 10:49 am
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 329063
Re: Final Jitters
I would recommend going over problems that have gave you some difficulty and try to understand why those steps are being done. This will let yourself know that you not only know how to solve it, but also why. I would also recommend taking some time off from the books and trying to do something else ...
- Mon Sep 30, 2019 10:34 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2760573
Re: Post All Chemistry Jokes Here
Why do chemists find working with ammonia easy?
It's pretty basic stuff.
It's pretty basic stuff.
- Mon Sep 30, 2019 10:26 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Avogadro's Number
- Replies: 4
- Views: 259
Re: Avogadro's Number
I have even seen it as 6.023X10^23 in other books but I'd say to stick with what Dr. Lavelle is using since it has been working with the class examples and the homework.
- Mon Sep 30, 2019 10:22 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: What does dilution mean in a chemistry problem?
- Replies: 8
- Views: 802
Re: What does dilution mean in a chemistry problem?
I would suggest don't think of dilution as adding or taking out liters in a solution, but rather as decreasing the concentration of a solution while keeping the amount of solute the same.
- Mon Sep 30, 2019 10:16 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Formula Units
- Replies: 4
- Views: 154
Re: Formula Units
In terms of the problems we are solving, I think they are the same since they are considered the same in the textbook questions. One mole is 6.022X10^23 of anything, so in order to calculate, just use Avogadro's number to solve for either atoms or formula units.
- Mon Sep 30, 2019 9:58 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Accuracy vs Precision
- Replies: 10
- Views: 341
Re: Accuracy vs Precision
Precision refers to how close your measurements are to each other while accuracy represents how close to the true value the measurements are. Adding on, although your measurements may be thrown off because of a systematic error (e.g. the weighing scale is not calibrated correctly), they can be accou...