Search found 46 matches
- Mon Dec 02, 2019 5:02 pm
- Forum: Bronsted Acids & Bases
- Topic: Using conjugate bases to determine the strength of acids
- Replies: 1
- Views: 179
Using conjugate bases to determine the strength of acids
Can you use the presence of the extra oxygen and its electronegativity to explain why CH3COOH is stronger than CH3CHOH, or does it only have to do with the resonance of the double bonded oxygen?
- Mon Dec 02, 2019 3:14 pm
- Forum: Properties of Light
- Topic: Determining which equation to use
- Replies: 3
- Views: 296
Determining which equation to use
Does anyone have tricks to determine which equation to use for quantum problems (i.e. involving photons, electrons, or other particles)?
- Mon Dec 02, 2019 3:10 pm
- Forum: Significant Figures
- Topic: sig figs from problems
- Replies: 1
- Views: 257
sig figs from problems
Is it a good rule of thumb to go by the number of significant figures in problem?
- Mon Dec 02, 2019 3:08 pm
- Forum: Hybridization
- Topic: Hybridization structures
- Replies: 1
- Views: 201
Hybridization structures
Will we ever be expected to draw hybridization structures (i.e. hybridization orbitals)?
- Mon Dec 02, 2019 3:03 pm
- Forum: Dipole Moments
- Topic: Determining Electronegativity
- Replies: 1
- Views: 257
Determining Electronegativity
Why does O bonded to N constitute a dipole moment, they don't seem to be significantly far away to have a big difference in electronegativity.
- Mon Dec 02, 2019 2:50 pm
- Forum: Lewis Acids & Bases
- Topic: Proton accepting versus donating
- Replies: 2
- Views: 210
Proton accepting versus donating
How do you determine if a molecule is accepting or donating, is this memorization or based on the structure?
- Mon Dec 02, 2019 2:46 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Application of oxidation number
- Replies: 3
- Views: 432
Application of oxidation number
I know that formal charge is used to find the most stable lewis structure, what is the application of the oxidation number, is it at all related to the lewis structure?
- Mon Dec 02, 2019 2:39 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: Determining Hydrogen Bonding Sites
- Replies: 1
- Views: 211
Determining Hydrogen Bonding Sites
Given two molecules, how do you determine where the two molecules will hydrogen bond?
- Mon Dec 02, 2019 2:36 pm
- Forum: Trends in The Periodic Table
- Topic: Isoelectronic
- Replies: 3
- Views: 378
Isoelectronic
What is the trend for isoelectronic properties?
- Mon Dec 02, 2019 2:34 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Subshell Notation
- Replies: 2
- Views: 310
Subshell Notation
Should we know how to determine hybridization based on quantum numbers?
- Mon Dec 02, 2019 2:26 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration
- Replies: 8
- Views: 707
Electron Configuration
When we write electron configurations, do we write 3d, 4s or 4s, 3d?
- Mon Dec 02, 2019 2:24 pm
- Forum: Properties of Light
- Topic: Visible Light Spectrum
- Replies: 3
- Views: 319
Visible Light Spectrum
Do we need to know the range of wavelengths for the visible spectrum from memory?
- Mon Dec 02, 2019 2:22 pm
- Forum: Einstein Equation
- Topic: Work Function
- Replies: 1
- Views: 314
Work Function
How do I calculate the frequency of a photon given the frequency and value for the work function?
- Mon Dec 02, 2019 2:15 pm
- Forum: Properties of Light
- Topic: Average wavelength of an atom
- Replies: 2
- Views: 287
Average wavelength of an atom
What equation should I use to find the average wavelength of an atom given the speed and molar mass?
- Mon Dec 02, 2019 12:32 pm
- Forum: Hybridization
- Topic: Key aspect of hybridization
- Replies: 1
- Views: 186
Key aspect of hybridization
What are the most important aspects of orbital hybridization to know? (i.e. how to determine hybridization from shape or electron configuration, etc.)
- Mon Dec 02, 2019 12:26 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: H-atom energy levels
- Replies: 1
- Views: 228
H-atom energy levels
How should we manipulate the equations on the equation sheet in order to determine what the final energy level of a hydrogen atom? (i.e. how do I derive the equation involving final-initial from the equations on the sheet?)
- Sun Nov 24, 2019 6:19 pm
- Forum: Naming
- Topic: Importance
- Replies: 1
- Views: 166
Importance
What is the relative importance of being able to derive the formula for a compound based on the name?
- Sun Nov 24, 2019 5:57 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Representing larger molecules
- Replies: 4
- Views: 405
Representing larger molecules
How should we draw Lewis structures/determine molecular shape for molecules that have more than one central atom?
- Sun Nov 24, 2019 5:50 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Important aspects of Radicals
- Replies: 6
- Views: 307
Important aspects of Radicals
What are the most important things to know about radicals?
- Sun Nov 24, 2019 5:48 pm
- Forum: Hybridization
- Topic: Describing a molecule using hybridization
- Replies: 4
- Views: 238
Describing a molecule using hybridization
When asked to describe the hybridization of a molecule, how should we format it? By labeling the steric number on the atoms, or listing the hybridization possible?
- Sun Nov 17, 2019 12:54 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar Molecules and Symmetry
- Replies: 3
- Views: 294
Re: Polar Molecules and Symmetry
A molecule is polar when the regions of electron density do not cancel (i.e. if they are not symmetrical).
- Sun Nov 17, 2019 12:50 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Determining Polarity
- Replies: 3
- Views: 224
Re: Determining Polarity
It is important to look at the atoms in the molecule with large differences in electronegativity, in combination with the shape, this will tell you the polarity of the molecule.
- Sun Nov 17, 2019 12:47 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR
- Replies: 6
- Views: 363
Re: VSEPR
In order to determine shape, VSEPR tells us to examine the number of regions with high electron density (double bonds, lone pairs etc.). We then place those regions of high electron density as far as physically possible in three dimensions and this dictates the shape.
- Sun Nov 17, 2019 12:42 pm
- Forum: Lewis Structures
- Topic: Carbon Monoxide
- Replies: 4
- Views: 314
Re: Carbon Monoxide
Remember that for atoms before the 3d block, fulfilling the octet rule is the first priority before checking formal charge and altering for the most stable form.
- Sun Nov 17, 2019 12:38 pm
- Forum: Dipole Moments
- Topic: Dipole moments in trigonal bipyramidal shaped molecules
- Replies: 4
- Views: 553
Re: Dipole moments in trigonal bipyramidal shaped molecules
In addition to shape it is also important to note which atoms compose the molecule and their respective electronegativities.
- Sun Nov 17, 2019 12:31 pm
- Forum: Dipole Moments
- Topic: Dipole-Dipole
- Replies: 2
- Views: 216
Re: Dipole-Dipole
The dipole-dipole moments are weaker because there is less pull between the partially charged molecules.
- Sun Nov 10, 2019 10:17 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic Radius
- Replies: 30
- Views: 2938
Re: Atomic Radius
Atomic radius increases down the row because there are more electron orbitals and shielding leads to less effective nuclear charge, therefore the size of the atom is greater. Atomic radius decreases across the row from left to right because there is a larger number of protons that increases effectiv...
- Sun Nov 10, 2019 10:09 pm
- Forum: Electronegativity
- Topic: Electronegativity
- Replies: 5
- Views: 217
Re: Electronegativity
The closer the number of valence electrons to having a full octet, the more electronegative the atom will be.
- Sun Nov 10, 2019 10:06 pm
- Forum: Resonance Structures
- Topic: Drawing Resonance Structures
- Replies: 3
- Views: 248
Re: Drawing Resonance Structures
When you are asked to draw resonance structures, determine the most stable structure by filling octets, determining the formal charge, then drawing all the possible versions of this particular structure (i.e. if there is a double bond on one atom of which there is multiple, draw that same molecule w...
- Sun Nov 10, 2019 9:43 pm
- Forum: Dipole Moments
- Topic: London Interaction
- Replies: 4
- Views: 132
Re: London Interaction
Most, if not all, molecules have London Dispersion forces because they are caused by momentary interactions from electrons.
- Sun Nov 10, 2019 9:38 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: The exceptions
- Replies: 6
- Views: 378
Re: The exceptions
It's helpful to remember that when dealing with elements that may be exceptions, fill the orbitals according to n instead of according to energy levels. For example, when filling copper, fill the 4s orbital before 3d.
- Sun Nov 03, 2019 4:09 pm
- Forum: Trends in The Periodic Table
- Topic: Ionization Energy of Group 16
- Replies: 3
- Views: 494
Re: Ionization Energy of Group 16
The general trend for ionization energy is that it increases as you move from left to right and decreases as you move from top to bottom. So elements in group 16 will have a higher ionization energy compared to elements on their left.
- Sun Nov 03, 2019 4:04 pm
- Forum: Lewis Structures
- Topic: Steps to Drawing a Lewis Structure
- Replies: 6
- Views: 425
Re: Steps to Drawing a Lewis Structure
First you should count the valence electrons of each atom and sum them together so you have an idea of how many electrons you will be working with in your diagram. Be sure to add or subtract electrons if you are dealing with an ion. Then you should determine which atom can form the most bonds and us...
- Sun Nov 03, 2019 3:58 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 1.E.5 Part D
- Replies: 2
- Views: 92
Re: 1.E.5 Part D
Effective nuclear charge decreases as you move away from the nucleus because the orbitals shield the pull of the nucleus. Therefore the p orbital will have less effective nuclear charge than the s orbital.
- Sun Nov 03, 2019 3:44 pm
- Forum: Ionic & Covalent Bonds
- Topic: middle atom
- Replies: 13
- Views: 498
Re: middle atom
Many times the central atom will be the atom that can form the most bonds based on the number of valence electrons it has.
- Sun Nov 03, 2019 3:42 pm
- Forum: Electronegativity
- Topic: Electronegativity
- Replies: 9
- Views: 348
Re: Electronegativity
It may be helpful to think about the number of bonds that an atom can form and use the atom that forms the most number of bonds at the center of the lewis structure.
- Sun Oct 20, 2019 5:23 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Orbitals
- Replies: 4
- Views: 170
Re: Orbitals
This is somewhat accurate. The farther away the electron is to the nucleus (i.e. in a further/higher energy orbital) the less pull there is on the electron and the easier it is to remove that electron.
- Sun Oct 20, 2019 5:21 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Atomic orbitals
- Replies: 5
- Views: 171
Re: Atomic orbitals
The probability of electron density is simply the probability of finding an electron in a certain location (i.e. a particular orbital). It is described as a probability because we can never be certain of an electrons position at any given time. What you are referring to is the probability of an elec...
- Sun Oct 20, 2019 5:17 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Wave functions
- Replies: 2
- Views: 86
Re: Wave functions
I believe Lavelle said that it we wouldn't be given the wave functions because we will not need to use them in the exam. They were explained in order for us to understand the origin of orbitals.
- Sun Oct 20, 2019 5:15 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg's Constant
- Replies: 3
- Views: 136
Re: Rydberg's Constant
Rydberg's can be derived from the equations given to us. So that we can connect it to what we are learning conceptually, Lavelle wants us to be able to manipulate the given equation rather than memorizing Rydberg's.
- Sun Oct 20, 2019 5:11 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Wave Function
- Replies: 4
- Views: 123
Re: Wave Function
The wave function gives rise to the idea of orbitals. It was given to explain the concept of orbitals but it won't be necessary to know how to solve.
- Sun Oct 13, 2019 6:41 pm
- Forum: Balancing Chemical Reactions
- Topic: Any Easy Way
- Replies: 10
- Views: 548
Re: Any Easy Way
I find it very helpful when balancing chemical equations, especially combustion reactions, to make a list and clearly write out the number of elements on each side, then start with the larger compounds (as opposed to O2) when balancing.
- Sun Oct 13, 2019 6:32 pm
- Forum: Limiting Reactant Calculations
- Topic: About Finding Limiting Reactant
- Replies: 7
- Views: 403
Re: About Finding Limiting Reactant
You should always convert to moles when looking for the limiting reactant because there is no way to tell from looking at the grams of substance what the limiting reactant is. You also need moles in order to use the mole ratios of the balanced equation to determine what the limiting reactant is and ...
- Sun Oct 13, 2019 6:19 pm
- Forum: SI Units, Unit Conversions
- Topic: Unit conversion
- Replies: 15
- Views: 1496
Re: Unit conversion
When doing unit conversions it is helpful to think about setting up your fractions so that you are multiplying the given by what you are looking for divided by the conversion factor (the known that has the same units as the given). In the example of the angstrom, multiply the given amount in meters ...
- Sun Oct 13, 2019 6:04 pm
- Forum: Properties of Light
- Topic: Manipulation of Equations
- Replies: 6
- Views: 318
Manipulation of Equations
What is the difference between the equation: E=hcλ^-1 and E=h(c/λ). From what I remember about negative exponents these two equations should be the same, but my answer does not match the correct answer.
- Sun Oct 13, 2019 5:59 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: M1V1=M2V2
- Replies: 11
- Views: 84846
Re: M1V1=M2V2
You may have to convert to moles in a problem that requires the dilution equation if the question is asking for a particular quantity of moles when given a volume of solution of a certain molarity. It is helpful in these situations to remember that molarity of moles over liters.