Search found 47 matches
- Mon Dec 02, 2019 8:45 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Oxalate and CO3 2- as a polydentate
- Replies: 3
- Views: 321
Oxalate and CO3 2- as a polydentate
As I was solving 9C.5, I did not get b) and d). For b, can someone explain how one molecule can either be a mono- or bidentate ligand? For d), since there are four Oxygen molecules with lone pairs, shouldn't it be a tetradentate ligand? Thank you for your help!
- Sat Nov 30, 2019 11:46 pm
- Forum: Student Social/Study Group
- Topic: Preparing for the final
- Replies: 25
- Views: 1317
Re: Preparing for the final
I think in addition to doing the homework, solving out the practice tests really helped me. For example, there was the dino nugget practice test for the first midterm, and it helped me a lot because those were challenging problems that required me to master the concepts. If you think that homework p...
- Sat Nov 30, 2019 11:42 pm
- Forum: Hybridization
- Topic: What to consider for hybridization?
- Replies: 3
- Views: 269
Re: What to consider for hybridization?
For hybridization, I think it is important to take a look at the electron configuration (the up and down arrows) to get a good sense.
- Sat Nov 30, 2019 11:40 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Shapes
- Replies: 3
- Views: 251
Re: Shapes
Tetrahedral occurs when the shape is AX4E0. Square planar occurs when the shape is AX4E2. Fyi, in AXnEn, X is the number of bonds, while E is the number of lone pairs in the central atom.
- Sat Nov 30, 2019 2:55 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: 6B.3
- Replies: 2
- Views: 237
Re: 6B.3
For problems like these, just know that for strong acids, it will dissociate completely. Therefore, you just have to calculate the pH on the premise that all of the HCl has dissociated.
- Sat Nov 30, 2019 2:53 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Weak Acids & Bases
- Replies: 6
- Views: 416
Re: Weak Acids & Bases
Weak acids and bases are the molecules that do not readily give off or accept protons, for example CH3CH3 or NH3 are weak acids, and I- and HSO4 are weak bases.
- Sun Nov 24, 2019 5:50 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2.45
- Replies: 1
- Views: 211
Re: 2.45
For e, the hydrogen atoms would not be in the same plane because they would be the farthest away from each other in order to make the molecule stable, and through being on a different plane they can be at the maximum distance.
- Sun Nov 24, 2019 5:45 pm
- Forum: Bronsted Acids & Bases
- Topic: Weak vs Strong Acids
- Replies: 3
- Views: 273
Re: Weak vs Strong Acids
Acids where the anion is stable when dissolved is a strong acid. In other words, the acids that readily give off their H+ is a strong acid. Therefore, acids such as HBr, HI are strong acids while HF is a weak acid.
- Sun Nov 24, 2019 5:43 pm
- Forum: *Molecular Orbital Theory Applied To Transition Metals
- Topic: Transition Metals
- Replies: 1
- Views: 703
Re: Transition Metals
Transition metal cations can form complexes because they have empty valence shell orbitals which can accept an electron pair from the lewis bases.
- Sun Nov 24, 2019 5:41 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Functional group
- Replies: 2
- Views: 264
Re: Functional group
Those are the major functional groups we need to know, but I think if more functional groups come up during the lecture then we need to know about those as well.
Re: Class
You could try to petition but in all honesty I think it is too late. But trying does not hurt!
- Tue Nov 19, 2019 2:09 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.1
- Replies: 4
- Views: 329
Re: 2E.1
AX2E1 (<120) and AX2E2 (<109.5) is bent, AX2E3 and AX2E4 are linear and ~180.
- Tue Nov 19, 2019 2:07 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: States and Intermolecular forces
- Replies: 4
- Views: 303
Re: States and Intermolecular forces
It isn't really the phases, but the boiling points and the melting points. The general rule is that if intermolecular forces are stronger, the boiling points and melting points are higher.
- Tue Nov 19, 2019 2:06 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Pi and Sigma bonds
- Replies: 5
- Views: 477
Re: Pi and Sigma bonds
The first bond is always sigma bond. The next bonds are pi bonds. For example, triple bond would be sigma bond + 2 pi bonds.
- Tue Nov 19, 2019 1:48 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Thiosulfate Ion
- Replies: 4
- Views: 336
Re: Thiosulfate Ion
You would want to have more charge on the atom with greater electronegativity. If S has formal charge of -2 and O has none, it would not be correct as O needs a negative formal charge (since it has greater electronegativity than S).
- Tue Nov 19, 2019 1:47 am
- Forum: Dipole Moments
- Topic: Dipole Induced- Dipole Induced
- Replies: 13
- Views: 1207
Re: Dipole Induced- Dipole Induced
Induced dipole - induced dipole is the weakest form of intermolecular force. An example of this could be an interaction between O2 molecules. They have a chance of having a weak dipole moment due to random distribution of electrons, which makes part of the molecule partially positive/negative, attra...
- Wed Nov 13, 2019 4:20 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Will we need to know these VSEPR shapes as well?
- Replies: 10
- Views: 654
Re: Will we need to know these VSEPR shapes as well?
I don't think so but I think it is best to know the VESPR shape for conventional molecules just in case, like H2O.
- Wed Nov 13, 2019 4:20 pm
- Forum: Dipole Moments
- Topic: Dipole Moments
- Replies: 4
- Views: 379
Re: Dipole Moments
CH3Cl and CHCl3 are obvious because if you look at the lewis structure since Cl is more electronegative, the molecule will have unequal "pull" of electrons. For CH2Cl2, you have to look at the VESPR model, which will show that they have unequal pull so it will have dipole moment.
- Wed Nov 13, 2019 4:16 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: Dipole-Dipole Moments
- Replies: 3
- Views: 265
Re: Dipole-Dipole Moments
I think IMF for induced-dipole-dipole is proportional to polarizability, which is affected by size and charge. So greater the size, greater the IMF for for induced-dipole-dipole.
- Wed Nov 13, 2019 4:15 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VESPR Model of H2O
- Replies: 12
- Views: 894
VESPR Model of H2O
I was looking up the VESPR model of H2O and it wasn't linear, which I expected it to be. Are there new models we are going to learn?
- Wed Nov 13, 2019 4:13 pm
- Forum: DeBroglie Equation
- Topic: Midterm 2019 Question 3A
- Replies: 2
- Views: 372
Re: Midterm 2019 Question 3A
The solution manual is wrong, I used 9.109383 * 10^-31 and got 7.3 nm, which is the correct answer.
- Sun Nov 03, 2019 1:14 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge
- Replies: 5
- Views: 353
Re: Formal Charge
You should calculate formal charge when you are drawing lewis structures and have more than one possible structure. The one with the lowest formal charge is the most favorable, as it is the most stable structure.
- Sun Nov 03, 2019 1:12 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: When to calculate formal charge
- Replies: 7
- Views: 378
Re: When to calculate formal charge
It would take a lot of time to do formal charge for each lewis structures. It would be best to do them when there are two or more possible structures for one molecule, and you do not know which one is the most favorable one.
- Sun Nov 03, 2019 1:10 am
- Forum: Octet Exceptions
- Topic: 2C.3
- Replies: 3
- Views: 215
Re: 2C.3
Most favorable structure when doing a lewis structure is the one that has the formal charge closest to 0.
- Sun Nov 03, 2019 1:09 am
- Forum: Dipole Moments
- Topic: Definition
- Replies: 5
- Views: 265
Re: Definition
By random chance, the electrons can be concentrated on one side than the other side. If this happens, then the atom will become slightly positive on one side and slightly negative on one side, creating a dipole.
- Sun Nov 03, 2019 1:07 am
- Forum: Ionic & Covalent Bonds
- Topic: 2A.1 Part C
- Replies: 3
- Views: 154
Re: 2A.1 Part C
For transition metals, do you always use that rule? Because Zinc has two valence electrons, but it has 2 in 4s and 10 in 3d.
- Tue Oct 29, 2019 7:03 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A.1 Part C
- Replies: 3
- Views: 154
2A.1 Part C
This question asks you to find the valence electrons of Manganese. How do you find the valence electrons of transition metals such as Mn?
- Tue Oct 29, 2019 6:47 pm
- Forum: Dipole Moments
- Topic: Dimethyl Ether
- Replies: 1
- Views: 108
Re: Dimethyl Ether
It can only accept hydrogen bonds, it cannot make hydrogen bonds with each other.
- Tue Oct 29, 2019 6:43 pm
- Forum: Resonance Structures
- Topic: Expanded octets
- Replies: 2
- Views: 177
Re: Expanded octets
I think SF6 has Sulfur with 12 electrons, 10 electrons is not going to be the max number. I think it is more or equal to 12 electrons.
- Tue Oct 29, 2019 6:41 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 5 HW
- Replies: 4
- Views: 336
Re: Week 5 HW
You have to do chemical bonding as we are finished with the quantum world.
- Tue Oct 29, 2019 6:40 pm
- Forum: Resonance Structures
- Topic: Delocalization
- Replies: 6
- Views: 427
Re: Delocalization
Delocalized electrons are like the ones we saw during resonance. Since these electrons are not strictly associated with a single atom, they move freely. This is why NO3 has distance between single and double bond.
- Sun Oct 20, 2019 4:53 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Matter and wavelike properties
- Replies: 3
- Views: 158
Re: Matter and wavelike properties
Since wavelength and mass is inversely related, calculating the wavelength for large-mass objects (such as baseball in one of our hw problems) result in extremely small wavelength, like 10^-34 m. Since these are basically close to 0, we cannot see these waves.
- Sun Oct 20, 2019 4:48 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Uncertainty value
- Replies: 4
- Views: 127
Re: Uncertainty value
Uncertainty is 10mm, because if the uncertainty is something like 5 5+- mm, then it can range from 0 to 10 mm.
- Sun Oct 20, 2019 4:42 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 1E. 9
- Replies: 1
- Views: 129
Re: 1E. 9
c is not possible. If n = 4, then l can only be 0,1,2,3 or more specifically up to n-1. Therefore, having both n = 4 and l = 4 is not possible.
- Sun Oct 20, 2019 4:40 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Advice for studying
- Replies: 92
- Views: 9245
Re: Advice for studying
I usually read the chapters after Dr. Lavelle goes over them to have a better understanding. Also, doing homework problems can provide additional practice and understanding.
- Sun Oct 20, 2019 4:39 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Uncertainty in Speed
- Replies: 2
- Views: 137
Re: Uncertainty in Speed
When it is +-n, the uncertainty is 2n. Even for 5 +-2, the uncertainty would be 4.
- Wed Oct 16, 2019 12:01 am
- Forum: Properties of Electrons
- Topic: 1B.5
- Replies: 2
- Views: 177
1B.5
Which equation do I use to solve 1B.5? Also, it says that the energy is 140.511 keV. What is this unit and do I have to convert this to Joules?
- Sun Oct 13, 2019 6:37 pm
- Forum: Limiting Reactant Calculations
- Topic: About Finding Limiting Reactant
- Replies: 7
- Views: 443
Re: About Finding Limiting Reactant
I personally found comparing moles much easier, as you have to keep in mind of the coefficients in balanced equation as well.
- Sun Oct 13, 2019 6:36 pm
- Forum: Administrative Questions and Class Announcements
- Topic: How to check how many points I have this week for posting on Chemistry Community?
- Replies: 11
- Views: 427
Re: How to check how many points I have this week for posting on Chemistry Community?
Go to quick links and then go to your posts. I think you should have at least 5 posts by every week to get full credit.
- Sun Oct 13, 2019 6:32 pm
- Forum: Balancing Chemical Reactions
- Topic: Any Easy Way
- Replies: 10
- Views: 617
Re: Any Easy Way
The method I use a lot is to balance the polyatomic ions first, then balance the non-organic elements, and then balance the organic elements.
- Sun Oct 13, 2019 6:31 pm
- Forum: Properties of Light
- Topic: Manipulation of Equations
- Replies: 6
- Views: 354
Re: Manipulation of Equations
They are the same equation, I think when putting them in the calculator you should put parenthesis around the exponent and lambda, see if that makes a difference.
- Sun Oct 13, 2019 6:28 pm
- Forum: Properties of Light
- Topic: Next test
- Replies: 23
- Views: 1117
Re: Next test
Although we get every equation, be sure to memorize what each variable means as it can be confusing sometimes!
- Fri Oct 04, 2019 2:48 pm
- Forum: Balancing Chemical Reactions
- Topic: Strategies for Balancing Chemical Equations
- Replies: 12
- Views: 871
Re: Strategies for Balancing Chemical Equations
I don't know if this is an official efficient way, but I usually balance out the polyatomic ions/non-organic elements and then balance the organic ones.
- Fri Oct 04, 2019 2:44 pm
- Forum: SI Units, Unit Conversions
- Topic: When are the 5 posts due?
- Replies: 6
- Views: 195
Re: When are the 5 posts due?
I think we have to turn them in during the discussion starting from next week!
- Fri Oct 04, 2019 2:42 pm
- Forum: Properties of Light
- Topic: c = fλ
- Replies: 9
- Views: 520
Re: c = fλ
Yea I think the c stays constant, but the f and λ can change.
- Fri Oct 04, 2019 11:52 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Theoretical vs. Actual Yield
- Replies: 38
- Views: 14197
Re: Theoretical vs. Actual Yield
I think it is not plausible for theoretical yield to be less than the actual yield because if you weighed something wrong, that just means you got a wrong theoretical yield.
- Tue Oct 01, 2019 8:38 pm
- Forum: Empirical & Molecular Formulas
- Topic: Typo on L.35
- Replies: 3
- Views: 160
Re: Typo on L.35
This is a lifesaver--I was very confused while reading this problem. Thank you for the clarification!