Search found 65 matches
- Sun Jan 17, 2021 6:15 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Pressure Rule
- Replies: 29
- Views: 183
Re: Pressure Rule
Only count moles of gas.
- Sun Jan 17, 2021 2:49 am
- Forum: General Science Questions
- Topic: Conjugate Acids and Bases
- Replies: 4
- Views: 19
Re: Conjugate Acids and Bases
I think it highlights the reversible action of a acid base reaction. In cases where the acid/base aren't strong, the conjugates could potentially play a role in regulating environments (pH), such as bicarbonate in the ocean and our blood.
- Sun Jan 17, 2021 2:46 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Kelvin or Celsius?
- Replies: 55
- Views: 1295
Re: Kelvin or Celsius?
use kelvin.
- Sun Jan 17, 2021 2:39 am
- Forum: General Science Questions
- Topic: Significant Figures and Rounding
- Replies: 9
- Views: 33
Re: Significant Figures and Rounding
The good thing is, there is essentially no homework graded for this class except sapling, and you have infinite attempts per question, so I wouldn't worry about sig figs in that aspect.
- Sun Jan 17, 2021 2:37 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ka vs kb
- Replies: 20
- Views: 55
Re: ka vs kb
Yes, Ka is for acids and Kb is for bases.
- Sun Jan 17, 2021 2:31 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: H2O as a Gas
- Replies: 53
- Views: 372
Re: H2O as a Gas
We include gases, except for inert gases.
- Sun Jan 17, 2021 2:29 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: q vs k
- Replies: 62
- Views: 161
Re: q vs k
Q calculates the same way as K, but Q calculates at concentrations that aren't equilibrium.
- Sun Jan 10, 2021 4:09 am
- Forum: Student Social/Study Group
- Topic: Study Habits
- Replies: 91
- Views: 233
Re: Study Habits
I heard of step up sessions but I don't know what happens there. Could someone fill me in on those? I'm kind of interested in attending one this quarter.
- Sun Jan 10, 2021 4:04 am
- Forum: Ideal Gases
- Topic: Advice on how to navigate Chem Community
- Replies: 17
- Views: 67
Re: Advice on how to navigate Chem Community
It can feel a bit overwhelming, something that has helped me was the active topic section you can find under quick links, it gave me a way to find relevant topics that I can reply to!
- Sun Jan 10, 2021 4:00 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Definition of an Inert Gas
- Replies: 6
- Views: 23
Re: Definition of an Inert Gas
An inert gas is a element that doesn't react to other elements because it's valence shell is filled. Often it is the noble gases because the valence shell is filled.
- Sun Jan 10, 2021 3:48 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Counting Moles
- Replies: 11
- Views: 44
Re: Counting Moles
Only gases are counted!
- Sun Jan 10, 2021 3:40 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Q and K
- Replies: 13
- Views: 31
Re: Q and K
How would you be able to calculate K if you're only given concentrations for Q? They would typically give K to you right?
- Sat Dec 12, 2020 3:34 pm
- Forum: Naming
- Topic: Bis, Tris, Tetrakis
- Replies: 4
- Views: 46
Bis, Tris, Tetrakis
If a molecule has the prefix bis, tris, tetrakis, etc, would that prefix be counted when looking to name the coordination compound? I'm asking because, for question 9c.3, part d named the compound: sodium bisoxalato(diaqua)ferrate(III), when if following the rules, aqua would be first instead of oxa...
- Sat Dec 12, 2020 2:55 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: Textbook Question 6D.11
- Replies: 2
- Views: 33
Re: Textbook Question 6D.11
Me too. Also, does Al3+ make it's surrounding solution acidic because it can give off protons or is it accepting electrons?
- Fri Dec 11, 2020 1:49 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Chelating Ligands
- Replies: 2
- Views: 43
Chelating Ligands
Can trans- orientated ligands be bidentate? More specifically, C2C04?
- Thu Dec 10, 2020 11:39 am
- Forum: Conjugate Acids & Bases
- Topic: Can strong acids become conjugate bases?
- Replies: 3
- Views: 52
Can strong acids become conjugate bases?
If the pH is low enough, can a strong acid become a conjugate base?
- Thu Dec 10, 2020 11:28 am
- Forum: Amphoteric Compounds
- Topic: Strong Acid and Amphoteric?
- Replies: 3
- Views: 39
Strong Acid and Amphoteric?
When learning about Amphoteric molecules, I noticed that the strong acid H2S04, when deprotonated, has a similar structure as other Amphoteric molecules. However, can it be considered a amphoteric molecule if it is a strong acid?
- Sun Dec 06, 2020 10:07 pm
- Forum: Naming
- Topic: Monodentates and Polydentates
- Replies: 8
- Views: 65
Re: Monodentates and Polydentates
So is dentate synonymous with ligand?
- Sun Dec 06, 2020 10:04 pm
- Forum: Naming
- Topic: "(en)" Sapling
- Replies: 19
- Views: 105
Re: "(en)" Sapling
(en) is short for ethylenediamine. I'm pretty sure there are more compounds that have similar naming nature so make sure to read about those ones too as it might be on the test!
- Sat Dec 05, 2020 9:07 pm
- Forum: Biological Examples
- Topic: Hemoglobin vs. Myoglobin
- Replies: 29
- Views: 215
Re: Hemoglobin vs. Myoglobin
Hemoglobin is 4 myoglobin put together. As a result, hemoglobin can carry more oxygen at one time.
- Sat Dec 05, 2020 8:54 pm
- Forum: Amphoteric Compounds
- Topic: How to know if a molecule is amphoteric
- Replies: 9
- Views: 97
Re: How to know if a molecule is amphoteric
I think amphoteric compounds tend to typically have polar bond when containing a H. As a result, there is a H to be donated. If it is donated, there is potential for it to re-accept the H as well.
- Sat Dec 05, 2020 8:44 pm
- Forum: Lewis Acids & Bases
- Topic: Bronsted vs. Lewis bases
- Replies: 11
- Views: 70
Re: Bronsted vs. Lewis bases
Lewis bases donate electrons, Bronstead bases accept protons. Essentially they are the same thing.
- Sun Nov 29, 2020 6:45 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 14B Enrollment [ENDORSED]
- Replies: 26
- Views: 1332
Re: 14B Enrollment [ENDORSED]
I am currently waitlisted for the winter quarter and according to Prof. Lavelle, I'll be able to get in. But I'm wondering how PTE and enrollment works. Could someone explain it? Thanks.
- Sun Nov 29, 2020 6:31 pm
- Forum: Lewis Structures
- Topic: Octet rule
- Replies: 12
- Views: 114
Re: Octet rule
Hydrogen is also an exception to the octet rule!
- Sun Nov 29, 2020 6:28 pm
- Forum: Dipole Moments
- Topic: Tetrahedral Atoms and Dipole Moments
- Replies: 7
- Views: 45
Re: Tetrahedral Atoms and Dipole Moments
Dipole moments can only be cancelled out on a Tetrahedral Atom when it is four of the same elements bonded to a central element. (CCl4)
- Sun Nov 29, 2020 6:25 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: molecule shape polarity
- Replies: 5
- Views: 40
Re: molecule shape polarity
It has to do with dipole moments. A molecule could have all polar covalent bonds and still be nonpolar due to it's shape because the bonds are directly 180 degrees away from each other. H20, because it is bent, not linear, has dipoles that aren't cancelled out. BeCl2, on the other hand, also has pol...
- Sun Nov 29, 2020 6:20 pm
- Forum: Hybridization
- Topic: Sapling #18
- Replies: 10
- Views: 98
Re: Sapling #18
I also was very confused with this problem, is there any way it has to do with the number of double bonds as well?
- Sun Nov 29, 2020 6:16 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Knowing VESPR for final
- Replies: 5
- Views: 40
Re: Knowing VESPR for final
I'm pretty sure we need to memorize all the ones Prof. Lavelle goes over.
- Sun Nov 22, 2020 6:23 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent Character
- Replies: 33
- Views: 200
Re: Covalent Character
To determine covalent character in ionic bonds, you find the DEN of the elements. The lower the DEN, the more covalent it is.
- Sun Nov 22, 2020 6:22 pm
- Forum: Octet Exceptions
- Topic: Expanded Octets
- Replies: 11
- Views: 85
Re: Expanded Octets
Out of curiosity, does anyone know if there is a certain max number of electrons in a expanded octet?
- Sun Nov 22, 2020 6:18 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: London Forces [ENDORSED]
- Replies: 19
- Views: 127
Re: London Forces [ENDORSED]
Yes. It is super weak and only lasts for a brief moment.
- Sun Nov 22, 2020 6:16 pm
- Forum: Lewis Structures
- Topic: Electron Density
- Replies: 14
- Views: 115
Re: Electron Density
Hi. Electron density is basically where a certain electron could be at any given point.
- Tue Nov 17, 2020 6:26 pm
- Forum: Student Social/Study Group
- Topic: Midterm 2
- Replies: 3
- Views: 56
Midterm 2
Prof. Lavelle said in his class website that midterm 2 is up to chemical bonds, does that mean vsper model are not part of the midterm? And if anyone knows, where in the textbook does content go up to? Thanks.
- Sat Nov 14, 2020 9:11 pm
- Forum: Resonance Structures
- Topic: Formal Charge influence on Resonance Structure
- Replies: 4
- Views: 18
Re: Formal Charge influence on Resonance Structure
And if so, does overall formal charge sum also always indicate the overall charge of the molecule?
- Sat Nov 14, 2020 9:10 pm
- Forum: Resonance Structures
- Topic: Formal Charge influence on Resonance Structure
- Replies: 4
- Views: 18
Formal Charge influence on Resonance Structure
Just to clarify, resonance structures are most stable/tend to favor positions where formal charge on each atom is zero right?
- Sat Nov 14, 2020 8:54 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge Formula
- Replies: 4
- Views: 40
Re: Formal Charge Formula
In this equation, the lone stands for all of the free/unbonded electrons. Don't think of it as lone pairs as you might count two electrons as one pair and plug 1 in the equation. Think of it as the individual electrons, so in this example it would be 2 electrons and you would use 2 in the FC equati...
- Sat Nov 14, 2020 8:52 pm
- Forum: Octet Exceptions
- Topic: Radicals
- Replies: 7
- Views: 89
Re: Radicals
Is there a way to predict which element in an atom will have the radical? this came up in textbook problem 2C.5. The radical went with Cl rather than O, and I can't explain why except for that Cl has an odd number of valence electrons to start with. Hi! I believe that the placement of the lone elec...
- Sat Nov 14, 2020 8:46 pm
- Forum: Ionic & Covalent Bonds
- Topic: Electronegativity
- Replies: 18
- Views: 104
Re: Electronegativity
To calculate electronegativity, there is a specific periodic table that shows the electronegativity of every element. However, I think when not asked to detemine the specific DEN, one can base it off of periodic trends (ie far left is more electromotive than far right) and determine an idea of elect...
- Sat Nov 14, 2020 8:44 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge Formula
- Replies: 4
- Views: 40
Formal Charge Formula
In the formal charge formula, F= V- (Lone - Bonds/2), does lone stand for lone pairs and unbonded electrons or just lone pairs.
- Sun Nov 08, 2020 2:13 pm
- Forum: Lewis Structures
- Topic: Lone Pairs Question
- Replies: 22
- Views: 119
Re: Lone Pairs Question
Lone pair electrons are pairs that have not been bonded and naturally belong to said atom.
- Sun Nov 08, 2020 2:08 pm
- Forum: Octet Exceptions
- Topic: Octet rule
- Replies: 9
- Views: 64
Re: Octet rule
The octet rule is the concept that every atom wants to fill it's valence shells to achieve stability and lots of atoms do it by filling their shells, which can contain up to 8, with some special exceptions. As a result, the octet rule is a baseline for creating the structure of compounds by trying t...
- Fri Nov 06, 2020 3:03 pm
- Forum: Lewis Structures
- Topic: Lewis base
- Replies: 3
- Views: 29
Re: Lewis base
Lewis base is just something that donates electrons. I wouldn't necessarily say all negative charges mean it's a lewis base but it's a good way to start off if asked to find a lewis base.
- Fri Nov 06, 2020 2:54 pm
- Forum: Ionic & Covalent Bonds
- Topic: Polarity
- Replies: 9
- Views: 88
Re: Polarity
Polarity means that there is an unequal charge, an unequal distribution of a shared electron. Thus a polar covalent bond has polarity because of an unequally shared electron.
- Fri Nov 06, 2020 2:34 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm grades
- Replies: 19
- Views: 204
Re: Midterm grades
The grades are out!
- Sun Nov 01, 2020 11:27 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: d orbitals
- Replies: 17
- Views: 97
Re: d orbitals
5 d orbitals means that there are 5 orbitals in the d orbital. Each orbital holds 2 electrons.
- Sun Nov 01, 2020 11:24 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Ionization Energy Trend
- Replies: 6
- Views: 54
Re: Ionization Energy Trend
This is because the lower the molecule on a table, the bigger it is, thus it is easier to remove an electron from it's outer shell compared to a smaller molecule because the level of attraction is lower.
- Sun Nov 01, 2020 11:22 pm
- Forum: DeBroglie Equation
- Topic: Avogadro's Number
- Replies: 21
- Views: 129
Re: Avogadro's Number
Avogadro's number represents the number of atoms in one mole. Thus, we should use it whenever a question asks for something regarding atoms.
- Sun Nov 01, 2020 11:21 pm
- Forum: Properties of Light
- Topic: Which model of light is atomic spectroscopy?
- Replies: 8
- Views: 95
Re: Which model of light is atomic spectroscopy?
The particle model is supported by atomic spectroscopy.
- Thu Oct 29, 2020 10:27 am
- Forum: *Particle in a Box
- Topic: Midterm 1
- Replies: 16
- Views: 258
Re: Midterm 1
So we don't need to study 1.D?
- Sun Oct 25, 2020 2:45 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Advice for studying
- Replies: 92
- Views: 2030
Re: Advice for studying
I like to do practice problems and read the textbook. Practice problems is where I mostly retain information from.
- Sun Oct 25, 2020 2:42 am
- Forum: *Shrodinger Equation
- Topic: Schrodinger on MT
- Replies: 7
- Views: 83
Schrodinger on MT
Does anyone know if there will be Schrodinger related questions on MT1?
- Sun Oct 25, 2020 2:41 am
- Forum: Molarity, Solutions, Dilutions
- Topic: What does mmol stand for?
- Replies: 33
- Views: 329
Re: What does mmol stand for?
Hi, mmol is a millimol, which is 1/1000th of a mol.
- Sun Oct 25, 2020 2:40 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Rounding when the last digit is 5
- Replies: 6
- Views: 78
Re: Rounding when the last digit is 5
For general problems, it is round up. But remember that when dealing with mols in empirical formula problems, we multiply to the nearest whole number.
- Sun Oct 25, 2020 2:36 am
- Forum: Properties of Light
- Topic: Constants
- Replies: 21
- Views: 106
Re: Constants
I like to use whatever is on the formula sheet to like 4 decimals.
- Sat Oct 17, 2020 2:21 am
- Forum: Properties of Light
- Topic: Energy Levels
- Replies: 11
- Views: 92
Re: Energy Levels
Hey Chesca, electrons don't technically jump/skip levels, they just have enough energy to go all the way to N=4. That means they'd have to have enough energy to make it through n=2 and n=3 before it could make it to n=4
- Fri Oct 16, 2020 8:15 pm
- Forum: Properties of Electrons
- Topic: Spectral Lines
- Replies: 7
- Views: 90
Re: Spectral Lines
I'm also a bit confused on this topic. Do we just take the difference between n-levels? For example, if an electron starts at the n=6 level and falls to the n=1 level, did it "pass" 5 spectral lines? And if an electron starts at the n=4 level and drops to the n=2 level, did it "pass&...
- Fri Oct 16, 2020 8:11 pm
- Forum: Properties of Light
- Topic: Wave particle duality
- Replies: 4
- Views: 20
Re: Wave particle duality
During Friday's lecture, Dr. Lavelle shows us the experiment where they shine light through an area with openings and light enters and appears where there isn't an opening. If the light was not a wave, the light would just shine straight instead of bending. Because the light was refracted, we are ab...
- Fri Oct 16, 2020 8:07 pm
- Forum: Properties of Light
- Topic: Does light lose energy the farther it travels?
- Replies: 8
- Views: 93
Re: Does light lose energy the farther it travels?
I searched it up and yes light does lose energy the further it travels. But for it to lose energy, it would have to travel super far. That's why we can see stars but aren't super bright.
- Fri Oct 16, 2020 8:05 pm
- Forum: Properties of Light
- Topic: Energy Levels
- Replies: 11
- Views: 92
Energy Levels
In equations such as E=hR/n^2, Dr. Lavelle explains n as energy levels. However, I don't really understand what energy levels are. Could someone explain it?
- Mon Oct 12, 2020 2:49 pm
- Forum: Properties of Light
- Topic: Quanta and Photons
- Replies: 19
- Views: 172
Re: Quanta and Photons
What exactly does it mean that the variables in quantum mechanic equations are "quantized or discrete?" Hi, what this means is that instead of viewing light as one thing, it is viewed as a stream of photons, where each photon is one discrete unit. It is basically looking at every day thin...
- Thu Oct 08, 2020 10:42 pm
- Forum: Empirical & Molecular Formulas
- Topic: Calculation Errors for Empirical Formulas
- Replies: 10
- Views: 67
Re: Calculation Errors for Empirical Formulas
2.8 is close enough to 3 to round up, The only time I wouldn't round up if is it is super close to .75
- Thu Oct 08, 2020 10:37 pm
- Forum: Empirical & Molecular Formulas
- Topic: Empirical and Molecular Formula
- Replies: 17
- Views: 124
Re: Empirical and Molecular Formula
The molecular formula can be the same as the empirical formula.
- Thu Oct 08, 2020 10:29 pm
- Forum: Significant Figures
- Topic: Integers in calculations
- Replies: 6
- Views: 46
Re: Integers in calculations
I'm a little bit confused about integers too. For example, for 300, wouldn't it be like 3 * 10^2 and only have one sig fig? For it to count as 3 sig figs, it has to be written as 300. or 3.00 * 10^2 right? When can we assume that an integer has infinite number of sig figs? Hello! Every question you...
- Thu Oct 08, 2020 10:17 pm
- Forum: Significant Figures
- Topic: Sig Figs for Molar Mass
- Replies: 14
- Views: 115
Re: Sig Figs for Molar Mass
I use 4 sig figs most of the time
- Thu Oct 08, 2020 10:14 pm
- Forum: Significant Figures
- Topic: Molar Mass Sig Figs
- Replies: 9
- Views: 81
Re: Molar Mass Sig Figs
I also use 4 sig figs.