Search found 30 matches
- Sat Dec 08, 2018 1:37 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Least to most polarizing power?
- Replies: 1
- Views: 991
Re: Least to most polarizing power?
Atoms that are smaller and with higher charges have more polarizing power. Li is the smallest so it has the most polarizing power. Ca2+ is the next smallest. Between Cs and Ba2+, Cs is bigger and therefore has a lower polarizing power. So, the final order from least polarizing power to most would Cs...
- Sat Dec 08, 2018 1:31 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Ni3+
- Replies: 1
- Views: 545
Re: Ni3+
Ni3+ would just be [Ar] 3d7
- Sat Dec 08, 2018 1:27 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polarity
- Replies: 7
- Views: 677
Re: Polarity
A polar bond will also result in a dipole (which can be both within a molecule, and between molecules). This dipole means one of the atoms has a partial negative charge and the other has a partial positive charge, making it polar.
- Thu Dec 06, 2018 2:50 pm
- Forum: Naming
- Topic: 17.31D (6th edition)
- Replies: 2
- Views: 264
Re: 17.31D (6th edition)
THe diaqua part is written first because this is the cation. The bisoxalato is negatively charged, and is an anion that should be written second in the formula.
- Thu Dec 06, 2018 2:43 pm
- Forum: Naming
- Topic: Naming multiple coordination compounds
- Replies: 1
- Views: 233
Re: Naming multiple coordination compounds
Yes I would think so.. You would have to remember that in naming, the cation always comes first (the NH3 compound). After that you add the ligand and then the metal with its oxidation number.
- Mon Dec 03, 2018 11:56 pm
- Forum: Conjugate Acids & Bases
- Topic: Weak Acid, Strong Base
- Replies: 1
- Views: 298
Re: Weak Acid, Strong Base
The weaker that an acid is, the stronger the conjugate base is because: a strong Bronsted acid wants to give up its protons. If it gives the proton away, it wouldn't make sense for the resulting compound to want it back (which would be the case for a strong conjugate base). This would basically mean...
- Mon Dec 03, 2018 11:48 pm
- Forum: Naming
- Topic: Roman Numerals
- Replies: 2
- Views: 254
Re: Roman Numerals
roman numerals just need to be included when indicating the oxidation state of the transition metal cation. This oxidation is found last, and it's found by recognizing that all oxidation states have to add to the overall compound charge.
- Wed Nov 28, 2018 10:33 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: Energy of Intermolecular Force
- Replies: 2
- Views: 317
Re: Energy of Intermolecular Force
Intermolecular energy is really just talking about the forces between molecules. These forces can be those of attraction or repulsion between the molecules, and it's important to remember that intermolecular forces are much weaker than intramolecular forces (that hold the atoms together),
- Wed Nov 28, 2018 10:27 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Labeling
- Replies: 1
- Views: 190
Re: Bond Labeling
I think for most molecules they will just be looking for the overall types of bond angles (such as 90 degrees, or 120 degrees, or a little less than 120 degress - just as some examples) and not require you to illustrate which specific atoms are bonded in which angles.
- Sun Nov 25, 2018 11:58 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape
- Replies: 4
- Views: 402
Re: Molecular Shape
When looking at molecular shape, we are mainly looking at regions of electron density and atoms in lone pairs. The charges are used primarily in drawing lewis structures (which we do before looking at shape) so we can then figure out the regions of electron density and what the shape of the structur...
- Sun Nov 25, 2018 11:54 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Ionic Character
- Replies: 3
- Views: 352
Re: Ionic Character
I think we are just supposed to use our knowledge of the electronegativity values of elements in the table (and knowing that typically metals are less EN and nonmetals are more EN) to see the difference, which would help us recognize if a compound is ionic or covalent (and then polar v. nonpolar)
- Fri Nov 16, 2018 1:15 pm
- Forum: Sigma & Pi Bonds
- Topic: Strength
- Replies: 1
- Views: 234
Re: Strength
A sigma bond has increased overlapping, and similarly greater strength, than a pi bond. But, the combination of a pi and sigma bond is stronger than either of the bonds by themselves. Since the pi bond is weaker though, a double bond doesn't necessarily mean the bond is twice as strong...
- Fri Nov 16, 2018 1:12 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 4
- Views: 482
Re: Bond Angles
We don't have to know the exact bond angles, just that when a lone pair is added, the other atoms will repel from the lone pair a little more, causing distortions in the bond angles. For example, if we atoms in the plane and then add a lone pair of electrons ABOVE the plane, the atoms will tilt more...
- Wed Nov 14, 2018 1:36 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Electron density
- Replies: 6
- Views: 615
Re: Electron density
yes, the electron density only refers to the central atom and that is what we used to determine the shape of the molecule. If there are lone pairs, this will change the shape name and bond angles between the atoms.
- Sun Nov 11, 2018 8:42 pm
- Forum: Bond Lengths & Energies
- Topic: Determine bond length
- Replies: 3
- Views: 451
Re: Determine bond length
We wouldn't be able to know the exact bond length if it wasn't given to us, but we could give the general answer that atoms that are larger in size (by looking at periodic trends) will also have larger bond length. The bond length is essentially the length of the bond from the nucleus of the atom to...
- Sun Nov 11, 2018 8:38 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 4.3 Draw the structures and name the shapes of the following molecules: (a) HCN; (b) CH2F2.
- Replies: 4
- Views: 1573
Re: 4.3 Draw the structures and name the shapes of the following molecules: (a) HCN; (b) CH2F2.
Adding on to this, for part A, the VSEPR formula for a.) would be AX2 (with 2 bonds to the central atom) and for b.) would be AX4 (with 4 bonds to the central atom)
- Sun Nov 11, 2018 8:33 pm
- Forum: Ionic & Covalent Bonds
- Topic: Silver Halides
- Replies: 3
- Views: 547
Re: Silver Halides
Per what I understand, the bigger the anion is, the more polarizable it is. This happens because larger anions have larger electron clouds that are easier to distort, giving them higher polarizability. This trait also means the larger anion will have more covalent character, because there is greater...
- Thu Nov 08, 2018 2:53 am
- Forum: Dipole Moments
- Topic: Dipole-Dipole vs Induced Dipole
- Replies: 5
- Views: 1028
Re: Dipole-Dipole vs Induced Dipole
I know that the dipole-induced dipole interactions cause the atoms to develop either slightly positive or slightly negative charges, but can anyone explain why exactly this happens?
- Thu Nov 08, 2018 2:51 am
- Forum: Bond Lengths & Energies
- Topic: MIDTERM Bond Length Question
- Replies: 15
- Views: 1532
Re: MIDTERM Bond Length Question
For the question that came this one, did people say that the bond length was the same for all the structures since they are resonance structures? (the bond lengths for the most stable structure of the compound?)
- Thu Nov 08, 2018 2:38 am
- Forum: Resonance Structures
- Topic: Resonance Lewis Structures
- Replies: 3
- Views: 405
Re: Resonance Lewis Structures
Resonance structures are a blending of structures with the same arrangement of atoms but different arrangement of electrons. We have only discussed it really in relation to bonding pairs.
- Sun Oct 28, 2018 5:36 pm
- Forum: Ionic & Covalent Bonds
- Topic: the Octet rule
- Replies: 21
- Views: 4018
Re: the Octet rule
Hydrogen only holds 1 electron in the outermost shell (only 1 valence electron), so if drawing a lewis dot structure, it will only have a single bond to another atom and no more dots around it.
- Sun Oct 28, 2018 5:29 pm
- Forum: Resonance Structures
- Topic: Hw problem 3.43 6th edition
- Replies: 1
- Views: 255
Re: Hw problem 3.43 6th edition
Resonance structures are just different ways of showing the Lewis Dot structure for a molecule. Except for the few exceptions, resonance structures still need to satisfy the octet rule, they are just used differently to show possibilities in how the bonds can be expressed between the atoms.
- Sat Oct 20, 2018 2:54 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: energy difference vs. E subscript n
- Replies: 2
- Views: 1246
Re: energy difference vs. E subscript n
Delta E is just the overall change in energy, but E subscript n is for the energy levels at a specific energy LEVEL (like when it's n=1,2,3...4)
- Sat Oct 20, 2018 2:51 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: What is "parity"
- Replies: 1
- Views: 1267
Re: What is "parity"
since particles' wave functions can change depending on which system of coordinates you use (like what plane you are drawing them on), parity basically means you are changing the sign of the coordinate system. So basically, if on one coordinate system we have the axis x, y and z, then the parity tra...
- Sat Oct 20, 2018 2:47 pm
- Forum: Properties of Light
- Topic: Grades
- Replies: 7
- Views: 638
Re: Grades
grades should be on the ccle site somewhere ! That's where they are for other classes at least
- Thu Oct 11, 2018 5:39 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect
- Replies: 3
- Views: 166
Re: Photoelectric Effect
I believe the electron jumps back down immediately to its resting state, but either way, does that change anything when making calculations?
- Thu Oct 11, 2018 5:36 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chemistry Community Questions Due Date
- Replies: 7
- Views: 540
Re: Chemistry Community Questions Due Date
I believe it's by the end of the week (Friday) each week
- Thu Oct 11, 2018 5:35 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Heisenberg
- Replies: 5
- Views: 425
Re: Heisenberg
I read that the indeterminacy principle is the idea that we can never be 100% of the velocity or position of an object, when measuring at the same time. So if you were to find one while disregarding the other (such as just velocity or just position), the results would be more accurate.
- Wed Oct 03, 2018 1:47 pm
- Forum: Empirical & Molecular Formulas
- Topic: F5 (6TH EDITION)
- Replies: 5
- Views: 501
Re: F5 (6TH EDITION)
you would find the mass composition of EACH element written as a fraction of the TOTAL MASS of the compound!
- Wed Oct 03, 2018 1:29 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student [ENDORSED]
- Replies: 297
- Views: 383042
Re: Advice from a Medical Student [ENDORSED]
what science path would you recommend taking for a student trying to go to med school? For example, what courses would you suggest for after chem 14A and B?