Search found 33 matches
- Sat Dec 08, 2018 7:08 pm
- Forum: Administrative Questions and Class Announcements
- Topic: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
- Replies: 118
- Views: 20160
Re: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
Which HW question is question 17 similar to?
- Sat Dec 08, 2018 6:15 pm
- Forum: Dipole Moments
- Topic: Forces Present in molecules
- Replies: 3
- Views: 568
Forces Present in molecules
How can we know what type of forces are present in different molecules? For example, how can we know if a molecule undergoes dipole dipole, dipole induced dipole, or other types of forces?
- Sat Dec 08, 2018 12:25 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Relative acidity questions
- Replies: 1
- Views: 249
Relative acidity questions
In lectured we learned that weaker A-H bonds will be more acidic because they lose H+ more easily, but isn't HCl a strong base despite its relatively strong H-Cl bond? Can someone help me? I'm pretty confused.
- Fri Dec 07, 2018 11:53 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Chelate geometry
- Replies: 2
- Views: 248
Chelate geometry
Does anyone know what the geometry of a chelate compound would be?
- Fri Dec 07, 2018 11:50 pm
- Forum: Lewis Acids & Bases
- Topic: Simple Question: What are they?
- Replies: 1
- Views: 212
Re: Simple Question: What are they?
Lewis acids are electron pair acceptors in a reaction and Lewis bases are electron pair donors in a reaction.
- Fri Dec 07, 2018 11:46 pm
- Forum: Biological Examples
- Topic: Hemoglobin Myoglobin details for test
- Replies: 1
- Views: 398
Hemoglobin Myoglobin details for test
How much should we know about these compounds for the test?
- Sun Dec 02, 2018 8:55 pm
- Forum: Amphoteric Compounds
- Topic: Amphoteric Compounds
- Replies: 5
- Views: 467
Re: Amphoteric Compounds
Some amphoteric compounds you can also deduce. For example, seeing water, you can deduce that it can lose its H+ ion (proton) to form OH- (acting as Bronsted acid) and you can deduce that it can accept a H+ ion (proton) to form H3O+ (acting as Bronsted base) therefore deducing that it is amphoteric.
- Sun Dec 02, 2018 8:50 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polydentate ligand geometry
- Replies: 1
- Views: 215
Polydentate ligand geometry
Can someone explain to me how the lone pairs on a compound have to be geometrically arranged in order to be a polydentate ligand? Like does the compound have to be a certain shape? or do the lone pairs have to be far part from each other on the compound?
- Sun Dec 02, 2018 8:46 pm
- Forum: Naming
- Topic: Knowing oxidation states
- Replies: 11
- Views: 876
Knowing oxidation states
I was wondering if we have to know the oxidation states of elements in a compound for naming coordinate compounds on the exam. Because in the textbook, there were questions that wanted us to write the oxidation states of the metal when naming the compound, but to get that we will have to know the ox...
- Sun Nov 25, 2018 1:03 am
- Forum: Hybridization
- Topic: Single, Double, and Triple Bonds
- Replies: 1
- Views: 180
Single, Double, and Triple Bonds
I was wondering if knowing whether the central atom has single, double, or triple bonds would help in determining its hybridization.
- Sun Nov 25, 2018 12:56 am
- Forum: Hybridization
- Topic: Hybridization of large molecules
- Replies: 2
- Views: 361
Re: Hybridization of large molecules
I believe you will only have to look at the regions of electron density for the atom asked for. For example, they might ask for the hybridization of a certain carbon in caffeine.
- Sun Nov 25, 2018 12:41 am
- Forum: Hybridization
- Topic: double bonds
- Replies: 14
- Views: 1109
Re: double bonds
the pi bond wraps around the sigma bond in a double bond, and can only form when a sigma bond is present, but no, a pi bond is only a pi bond.
- Sun Nov 25, 2018 12:38 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Linear structure with lone pairs
- Replies: 6
- Views: 585
Linear structure with lone pairs
The only linear structure I can think of is AB2E3 are there any more?
- Sun Nov 25, 2018 12:34 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone pairs determining shape?
- Replies: 5
- Views: 1608
Re: Lone pairs determining shape?
Lone pairs affect the molecular shape, but only atoms are used when naming the shape. For example, a trigonal pyramidal structure is actually a tetrahedral formation of electron densities, but only the atoms are counted towards the shape, thus the shape is trigonal pyramidal.
- Sun Nov 25, 2018 12:30 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: double and triple bonds
- Replies: 10
- Views: 1052
Re: double and triple bonds
They are still referred to one region of electron density, therefore they act the same as single bonds
- Mon Nov 12, 2018 6:46 pm
- Forum: Bond Lengths & Energies
- Topic: bond length such as the midterm question
- Replies: 5
- Views: 561
Re: bond length such as the midterm question
In the midterm it was asking for the resonance bond length, so in this case we can take the average of the single and double bond to make an estimate of the bond length.
- Mon Nov 12, 2018 6:42 pm
- Forum: Dipole Moments
- Topic: Solubility in Water
- Replies: 5
- Views: 1783
Re: Solubility in Water
Polar molecules are more soluble in polar solvents and non polar molecules are more soluble in non polar solvents. In this case, water is polar, so polar compounds are more soluble in water.
- Mon Nov 12, 2018 6:39 pm
- Forum: Dipole Moments
- Topic: Hydrogen Bonds
- Replies: 20
- Views: 1382
Re: Hydrogen Bonds
Hydrogen bonds are the strongest intermolecular forces.
- Sun Nov 04, 2018 1:54 pm
- Forum: Octet Exceptions
- Topic: What are the octet exceptions?
- Replies: 9
- Views: 1016
What are the octet exceptions?
Can some one help me with all the octet exceptions we need to know for the test? Thanks~
- Sun Nov 04, 2018 1:52 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: shortcut for FC
- Replies: 6
- Views: 674
Re: shortcut for FC
What I do is I draw a circle around each atom, so you count one electron for each bond and two electrons for each lone pair. Then you just take the valence electrons of the atom and minus it by how much you count.
- Sun Nov 04, 2018 1:49 pm
- Forum: Resonance Structures
- Topic: Purpose of Resonance Hybrids
- Replies: 4
- Views: 405
Re: Purpose of Resonance Hybrids
The resonance hybrid is whats actually going on in a resonance structure I think. Like the two resonance structures of benzene is just to show what the actual resonance hybrid is an average of.
- Sun Oct 28, 2018 9:27 pm
- Forum: Ionic & Covalent Bonds
- Topic: the Octet rule
- Replies: 21
- Views: 3908
Re: the Octet rule
Most follow the octet rule, but there are exceptions. For example there are the ones Dr. Lavelle mentioned in the lecture, and the expanded octet (I don't know if we will learn about this though).
- Sun Oct 28, 2018 9:22 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: D and P orbital energies
- Replies: 3
- Views: 394
D and P orbital energies
In the lecture it is said that the 3d orbital will be lower in energy than the 4s orbital in all cases where the 4s orbital is filled. But does this mean that there are cases where the 3d orbital has higher energy than the 4s orbital?
- Sun Oct 28, 2018 9:15 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Units
- Replies: 8
- Views: 660
Re: Units
Is it better to always change the units into the standard units used in the equation before calculations are done?
- Fri Oct 19, 2018 5:04 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: orientation of the lobes
- Replies: 2
- Views: 293
Re: orientation of the lobes
I attached an image below that should explain this pretty well. As you can see the px orbital is two lobes that run along the x orbital, and the same goes for the py and pz orbitals.
- Fri Oct 19, 2018 4:48 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Delta x
- Replies: 2
- Views: 112
Delta x
Can anyone explain why the diameter of an atom is typically used for Delta x in the equation? Also, are there any other values that can be used?
- Fri Oct 19, 2018 4:41 pm
- Forum: DeBroglie Equation
- Topic: 6th HW 1.23 What is KeV?
- Replies: 5
- Views: 1391
Re: 6th HW 1.23 What is KeV?
It is an unit of energy called an kilo-electronvolt.
One KeV is 1000 eV, and 1 eV = 1.602 × 10-19 J
Its on the Constants and Equations page that can be found on the class website! :)
One KeV is 1000 eV, and 1 eV = 1.602 × 10-19 J
Its on the Constants and Equations page that can be found on the class website! :)
- Sat Oct 13, 2018 3:54 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Units?
- Replies: 8
- Views: 763
Re: Units?
Just remember that molarity (M) is always 1 mole/Liter or 1 mole/1000 ml. If you keep this in mind you should be good to go no matter what units you are dealing with or end up with.
- Sat Oct 13, 2018 3:51 pm
- Forum: Balancing Chemical Reactions
- Topic: question on "combustion" and "cooking"
- Replies: 3
- Views: 629
Re: question on "combustion" and "cooking"
Yes, a combustion reaction always has oxygen as the reactants and carbon dioxide and water and products.
- Sat Oct 13, 2018 3:50 pm
- Forum: Significant Figures
- Topic: knowing how many sig figs to use
- Replies: 17
- Views: 2052
Re: knowing how many sig figs to use
Its also important that during addition or subtraction, the value with the least amount of decimal spaces should be used instead of sig figs.
- Sat Oct 13, 2018 3:47 pm
- Forum: Properties of Electrons
- Topic: energy transitions
- Replies: 6
- Views: 373
Re: energy transitions
When an electron transfers from a lower energy level to a higher energy level, energy is absorbed and the atom becomes less stable.
- Sat Oct 13, 2018 3:43 pm
- Forum: Properties of Light
- Topic: Measurable wavelengths
- Replies: 5
- Views: 456
Measurable wavelengths
In class, we discussed wavelengths that were so small that they were considered unmeasurable. However, I didn't quite catch the minimum value for which a wavelength is considered "measurable." Does anyone know this?
- Sat Oct 13, 2018 3:39 pm
- Forum: Properties of Light
- Topic: Car Example in Class with De Brogile Equation
- Replies: 8
- Views: 525
Re: Car Example in Class with De Brogile Equation
I think the car has no wavelength properties because something with a mass so large would produce a very small wavelength according to the equation. In the car's case, the wavelength would be so small that would be unmeasurable.