Search found 30 matches
- Sun Dec 09, 2018 9:21 am
- Forum: Amphoteric Compounds
- Topic: Amphiprotic vs Amphoteric
- Replies: 5
- Views: 432
Re: Amphiprotic vs Amphoteric
amphiprotic and amphoteric refer to the Bronsted and Lewis defintions of acids and bases, respectively. Therefore look to see if it gives/receives a proton and is an electron pair donor/acceptor.
Re: Naming
e.g. diethylenediamine would be written bisethylenediamine because DI is already in the name
- Wed Dec 05, 2018 11:26 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Terminology
- Replies: 2
- Views: 127
Re: Terminology
chelating agents remove metal cations, but are characterized by the RING that they form around these cations, which serves to "trap" them. https://www.google.com/url?sa=i&source=images&cd=&ved=2ahUKEwi20MG91orfAhWFLnwKHVnBBAsQjRx6BAgBEAU&url=https%3A%2F%2Fwww.slideshare.net...
- Wed Dec 05, 2018 11:22 pm
- Forum: Identifying Acidic & Basic Salts
- Topic: HF
- Replies: 4
- Views: 442
Re: HF
electronegativity is NOT a factor in determining bond strength. The only factors are atomic radius and bond multiplicity (i.e. is it a single, double or triple bond). Cl is a larger atom, so the bond length between it and H will be longer than that of F and H, making it a weaker bond, easier to brea...
- Wed Nov 28, 2018 10:41 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: diamagnetism and paramagnetism
- Replies: 2
- Views: 181
Re: diamagnetism and paramagnetism
Another note is that paramagnetic compounds are radicals because they possess an unpaired electron.
- Wed Nov 28, 2018 10:38 pm
- Forum: Hybridization
- Topic: hybridized orbitals
- Replies: 2
- Views: 149
Re: hybridized orbitals
Hybridized orbitals form when atoms are bonding, and they create a new (i.e. lower) energy level for electrons to occupy. This is favorable because electrons always want to occupy the lowest energy level possible.
- Wed Nov 28, 2018 10:31 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Square Pyramidal
- Replies: 2
- Views: 184
Re: Square Pyramidal
https://www.google.com/url?sa=i&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjvn4mC_fjeAhUT0lQKHeHrCqwQjRx6BAgBEAU&url=http%3A%2F%2Facademic.pgcc.edu%2F~rgross%2FGeometry%2520Predictor%2FSquare%2520pyramidal%2520sp3d2%2FExamples%2520of%2520square%2520pyramidal%2520structures_...
- Wed Nov 28, 2018 8:13 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Shape and Lewis Structure
- Replies: 1
- Views: 93
Re: Shape and Lewis Structure
If the question specifically asks for Lewis structure, I think it would be best to draw it out. However, it is usually helpful to draw or name the shape as well, as doing so helps you determine the polarity of the molecule.
- Tue Nov 13, 2018 1:23 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar vs. NonPolar
- Replies: 5
- Views: 302
Re: Polar vs. NonPolar
It is also important to note that molecular structure plays an important role in polarity. For example, C02 would be expected to be a polar molecule, since the difference in electronegativity of C and O is large. However, the two O's are on either side of the C, giving it a linear shape. Due to this...
- Tue Nov 13, 2018 1:19 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: Hydrogen Bonding Question
- Replies: 3
- Views: 187
Re: Hydrogen Bonding Question
Hydrogen bonds are less transient than other VDW, making them stronger. A fluctuating dipole is instantaneous and unpredictable, whereas the partial negative/positive charges found in hydrogen bonds are more constant, and can be thought of as being 'always present'. It is easier to break a temporary...
- Tue Nov 13, 2018 1:16 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: Boiling point
- Replies: 12
- Views: 807
Re: Boiling point
A rod or oval shaped molecule has more surface area with which it can interact with another oval molecule, increasing the VDW interactions between the two, making the bond stronger, harder to break, and resulting in a higher melting point. A circular molecule has less surface area with which it can ...
- Tue Nov 06, 2018 5:47 pm
- Forum: Octet Exceptions
- Topic: Lewis acids and bases
- Replies: 3
- Views: 219
Re: Lewis acids and bases
https://opentextbc.ca/chemistry/wp-content/uploads/sites/150/2016/05/CNX_Chem_15_02_BF3-LA_img.jpg Lewis acids are electron acceptors , so they will not have a complete octet/ be in need of electrons to be more stable Lewis bases are electron donors, and will have a pair of electrons to share with ...
- Tue Nov 06, 2018 5:41 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: formal charge on most electronegative atom
- Replies: 3
- Views: 295
Re: formal charge on most electronegative atom
If the Lewis structure cannot or should not be drawn where all atoms have FC=0, then any resulting negative charges should be on the most electronegative atom in the molecule. The more electronegative an atom is, the stronger the pull it has on electrons, so it would make sense that an element like ...
- Tue Nov 06, 2018 5:37 pm
- Forum: Bond Lengths & Energies
- Topic: Resonance Structures
- Replies: 4
- Views: 219
Re: Resonance Structures
https://chem.libretexts.org/@api/deki/files/43158/IMG00012.GIF?revision=1 Resonance structures are characterized by the difference in location of a bond (in this picture, the double bond in the molecule NO3-). Since there is a double bond, the bond length of the N-O bonds will be shorter than that ...
- Tue Oct 30, 2018 10:16 pm
- Forum: Ionic & Covalent Bonds
- Topic: ionization energy
- Replies: 7
- Views: 414
Re: ionization energy
The outermost electron occupies the highest energy level, and is the furthest from the nucleus and therefore experiences the weakest attraction from the nucleus. Therefore, it takes the least amount of energy to remove this electron. An atom that has lost an electron is now a cation and now the amou...
- Tue Oct 30, 2018 10:08 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Energy and Stability of an Atom
- Replies: 2
- Views: 169
Re: Energy and Stability of an Atom
It's a kind of counter intuitive concept that is really important in biology/chemistry. Atoms and electrons are always going to favor configurations with lower energy. In the same way that electrons want to fill the lower orbitals (i.e. lower energy states) first, atoms themselves also want to have ...
- Tue Oct 30, 2018 10:02 pm
- Forum: Ionic & Covalent Bonds
- Topic: Number of Unpaired Electrons
- Replies: 3
- Views: 261
Re: Number of Unpaired Electrons
https://upload.wikimedia.org/wikipedia/commons/thumb/6/6b/Electron_configuration_potassium.svg/1000px-Electron_configuration_potassium.svg.png Only count the valence electrons when determining whether they are unpaired or not, as the subshells below the valence will be full and therefore every elec...
- Mon Oct 22, 2018 5:14 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Test Two: Electron Configuration
- Replies: 6
- Views: 342
Re: Test Two: Electron Configuration
Response to Lily Smith on electron spin Electron spin is the 4th quantum number denoted by ms, and it affects the magnetic field. There are only two possibilities for the 'spin' an electron can have, which are spin up and spin down. If the electron is spin up, its ms value is +1/2, and if it is spin...
- Mon Oct 22, 2018 5:06 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 4s and 3d Orbitals [ENDORSED]
- Replies: 3
- Views: 134
Re: 4s and 3d Orbitals [ENDORSED]
https://www.google.com/url?sa=i&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwiLq4OdopveAhVsIDQIHVW2DLkQjRx6BAgBEAU&url=http%3A%2F%2Flazysupply.co%2Fdefn-orbital-diagrams.html&psig=AOvVaw1WKL3Z67CbgIj7-r6_AdGL&ust=1540339420627441 In some cases, the 4s orbital actually...
- Mon Oct 22, 2018 5:01 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Px. Py, Pz
- Replies: 6
- Views: 615
Re: Px. Py, Pz
In lecture we were determining electron configurations, and I believe he used carbon as an example. The configuration is 1s2 2s2 2px1 2py1. However, this can be written in a less specific form, which is 1s2 2s2 2p2. In this second form, it shows that there are 2 electrons in the 2p orbital, but does...
- Tue Oct 16, 2018 9:56 pm
- Forum: Einstein Equation
- Topic: Question 9; 6th edition
- Replies: 3
- Views: 183
Re: Question 9; 6th edition
When doing calculations that involves wavelength, e.g.
, the units for
should be in meters, but in conversions/final answers it usually makes more sense to represent this value in nanometers, which is why Lavelle/the solutions manual usually does so.
- Tue Oct 16, 2018 9:52 pm
- Forum: Einstein Equation
- Topic: Kinetic energy and e = hv
- Replies: 3
- Views: 226
Re: Kinetic energy and e = hv
You are correct in assuming that if the kinetic energy is zero, that means that the work function is equal to (E=hv), as the energy of the photon was the exact amount needed for the particular threshold. Therefore, the electron is released but has no 'leftover' energy for kinetic energy, so it has n...
- Tue Oct 16, 2018 9:46 pm
- Forum: DeBroglie Equation
- Topic: Mass of electrons
- Replies: 4
- Views: 255
Re: Mass of electrons
The SI unit for mass is always kg, which can be confusing for measuring objects with very small mass (like electrons). Just know that in equations, like 1/2mv^2 for kinetic energy, the mass must always be represented in kg.
- Fri Oct 12, 2018 4:22 pm
- Forum: DeBroglie Equation
- Topic: Question about diffraction patterns
- Replies: 2
- Views: 181
Re: Question about diffraction patterns
http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/imgsou/int5.gif In constructive interference, the crests and troughs of two waves line up, and their respective amplitudes are added, making the amplitude of the new wave bigger. In destructive interference, the crests and troughs are opposite to one...
- Fri Oct 12, 2018 4:17 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Wavelength Worked Example from Lecture
- Replies: 3
- Views: 50
Re: Wavelength Worked Example from Lecture
This wavelength is not detectable because it is so small (10^-34). This is logical because when you observe a car in real life, it does not display wavelike properties. Extremely small particles, like electrons, do exhibit wavelike properties, and therefore their wavelength tends to be larger.
- Fri Oct 12, 2018 4:14 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Explain an example in Lecture
- Replies: 3
- Views: 73
Re: Explain an example in Lecture
This is because the change in energy is negative, as the electron went from a higher energy level (n=4) to a lower energy level (n=2), and therefore the difference is negative. Echange=Efinal-Einitial. The energy becomes positive in the next step however, because photons cannot have negative energy....
- Fri Oct 12, 2018 4:14 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Explain an example in Lecture
- Replies: 3
- Views: 73
Re: Explain an example in Lecture
This is because the change in energy is negative, as the electron went from a higher energy level (n=4) to a lower energy level (n=2), and therefore the difference is negative. Echange=Efinal-Einitial. The energy becomes positive in the next step however, because photons cannot have negative energy....
- Thu Oct 04, 2018 2:05 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing equations (Problem H21 6th edition)
- Replies: 3
- Views: 200
Re: Balancing equations (Problem H21 6th edition)
Unfortunately, there is no shortcut for balancing equations. It is important to make sure the numbers of atoms of each respective element are equal on either side. However, with practice it becomes a lot easier to recognize patterns/familiar equations and it should take you less time to do so!
- Thu Oct 04, 2018 2:00 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Atomic Weight, Molecular Weight, Formula Weight [ENDORSED]
- Replies: 2
- Views: 123
Re: Atomic Weight, Molecular Weight, Formula Weight [ENDORSED]
Atomic and molecular weight apply to atoms and molecules, but formula units are slightly different . They all apply to the same concept, they only differ in that atomic weight only applies to atoms (e.g. Ag) molecular weight applies to molecules (e.g. H20). Formula units are the same thing as empiri...
- Thu Oct 04, 2018 1:39 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Dilutions
- Replies: 3
- Views: 179
Re: Dilutions
You would need to calculate the molar masses separately as they are different compounds with different molar masses.