Search found 50 matches
- Sat Dec 12, 2020 6:58 pm
- Forum: Properties of Light
- Topic: Wavelength
- Replies: 26
- Views: 1145
Re: Wavelength
Usually what I do is see what the equation I'm using is, because I want the units to be able to cancel; this usually helps me make my decision!
- Sat Dec 12, 2020 6:57 pm
- Forum: Industrial Examples
- Topic: Chemotherapy
- Replies: 22
- Views: 1494
Re: Chemotherapy
cisplatin was the one discussed in lecture!
- Sat Dec 12, 2020 6:56 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Denticity
- Replies: 3
- Views: 257
Re: Denticity
Yes this is correct!
- Sat Dec 12, 2020 5:48 pm
- Forum: Conjugate Acids & Bases
- Topic: Fundamentals J.9
- Replies: 2
- Views: 230
Fundamentals J.9
Hi everyone! Could someone explain their thought process for answering a-d on 9 of fundamentals J? Thanks!
- Fri Dec 11, 2020 5:15 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: polydentates
- Replies: 3
- Views: 243
polydentates
How do we tell if a ligand is a polydentate? How would we find the specific amount of bonds the ligand can make? Do we have to memorize them or draw a lewis structure? Thanks in advance
- Sat Dec 05, 2020 11:40 am
- Forum: Naming
- Topic: what does (en) mean?
- Replies: 23
- Views: 9848
Re: what does (en) mean?
I saw this in the sapling homework! (en) is an abbreviation for a compound, commonly called ethylenediamine. It's a bidentate ligand and its formula is NH2CH2CH2NH2! Hope this helps!
- Sat Dec 05, 2020 11:39 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Sapling Homework 9 Problem 2
- Replies: 10
- Views: 554
Re: Sapling Homework 9 Problem 2
Joseph Hsing 3H wrote:If an attached ligand is monodentate then count 1 towards the coordination number for each, and for bidentates count 2 towards the coordination number of the central atom, etc. Hope this helped!
This was super helpful because I kept getting questions with bidentrates wrong! Thank you!!
- Sat Dec 05, 2020 11:38 am
- Forum: Biological Examples
- Topic: chelates
- Replies: 8
- Views: 458
Re: chelates
Based on what Lavelle said in lecture, a chelate is a complex containing a ligand that forms a ring of atoms that includes the central metal atom. Chelating ligands can bind cations tightly.
- Sat Dec 05, 2020 11:36 am
- Forum: *Molecular Orbital Theory Applied To Transition Metals
- Topic: planes
- Replies: 4
- Views: 785
Re: planes
The geometric shape gives a lot of information on the planes! I like to visualize that shapes like how Lavelle used the 3_D models during lecture. What is said above about sigma and pi bonds is also very useful and I didn't know that before!
- Sat Dec 05, 2020 11:35 am
- Forum: Naming
- Topic: Naming Order
- Replies: 16
- Views: 612
Re: Naming Order
As sass above, the transition metal should go first. I'm not as sure whether the rest has a specific order.
- Sat Nov 28, 2020 2:46 pm
- Forum: Coordinate Covalent Bonds
- Topic: Hydrogen bonding
- Replies: 15
- Views: 749
Re: Hydrogen bonding
I think hydrogen bonding is considered distinct because it is an intermolecular force rather than an intramolecular force. I believe that within the molecule, however, there can be covalent character.
- Sat Nov 28, 2020 2:44 pm
- Forum: Dipole Moments
- Topic: What are dipole moments
- Replies: 9
- Views: 612
Re: What are dipole moments
The dipole moment has to do with the polarity of of a molecule and is important in determining bond strength. Like said about the organic chemistry tutor on youtube is a life saver!
- Sat Nov 28, 2020 2:37 pm
- Forum: Bond Lengths & Energies
- Topic: Higher Melting Point
- Replies: 28
- Views: 2439
Re: Higher Melting Point
Iodine's larger amount of electrons make it a bigger atom. This big size creates a high polarizability, making it harder to melt and therefore have a higher melting point.
- Sat Nov 28, 2020 2:35 pm
- Forum: Bond Lengths & Energies
- Topic: Ionic Character
- Replies: 12
- Views: 14854
Re: Ionic Character
Since Br has a higher electronegativity than I, NaBr has higher ionic character due to the electronegativity difference.
- Sat Nov 21, 2020 4:48 pm
- Forum: Lewis Structures
- Topic: Electron Density
- Replies: 14
- Views: 587
Re: Electron Density
Electron density is essentially the probability of finding an electron, and it can change depending on orbital shape. For example, an s orbital may have a higher electron density than a p orbital.
- Sat Nov 21, 2020 4:47 pm
- Forum: Ionic & Covalent Bonds
- Topic: Polar Bonds [ENDORSED]
- Replies: 26
- Views: 1133
Re: Polar Bonds [ENDORSED]
For this, I tend to look at electronegativity and the presence of lone pairs in the lewis structure. Based off of this, we can see which atom wants electrons more and therefore we can see the sharing is not exactly equal, creating a dipole.
- Sat Nov 21, 2020 4:43 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic vs. Covalent Compounds
- Replies: 7
- Views: 398
Re: Ionic vs. Covalent Compounds
I usually go off the fact that ionic compounds involve one metal and one nonmetal, while covalent compounds involve two nonmetals.
- Sat Nov 21, 2020 4:42 pm
- Forum: Ionic & Covalent Bonds
- Topic: Molecule size and ionic character
- Replies: 13
- Views: 1274
Re: Molecule size and ionic character
The main indicator of ionic character is a large electronegativity difference. That being said, usually we can see as trends on the periodic table that atoms/ions with a larger radius tend to be less electronegative.
- Sat Nov 21, 2020 4:41 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent Character
- Replies: 14
- Views: 2178
Re: Covalent Character
The smaller the electronegativity difference, the more covalent character!
- Mon Nov 16, 2020 4:58 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: 1.25 Textbook Problem
- Replies: 1
- Views: 304
1.25 Textbook Problem
Hey guys! Does anyone have a good way of explaining this problem from the textbook? Thanks! 1.25 Suppose that in some other universe a rule corresponding to the Pauli exclusion principle reads “as many as two electrons in the same atom may have the same set of four quantum numbers.” Suppose further ...
- Sun Nov 15, 2020 5:09 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: ground-state
- Replies: 3
- Views: 181
Re: ground-state
Like said above, I think ground-state is often implied!!
- Sun Nov 15, 2020 5:08 pm
- Forum: Trends in The Periodic Table
- Topic: Textbook questions !F
- Replies: 6
- Views: 322
Re: Textbook questions !F
I believe the numbers are for context, and the answer should be just the arrangement.
- Sun Nov 15, 2020 5:07 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic size and trend
- Replies: 5
- Views: 2767
Re: Atomic size and trend
Well in a neutral element the number of protons is equal to the number of electrons. I believe when you go down the table, the size increases faster than across a period since new valence shells are added. What causes large atoms with a high proton count to have large atomic radii is their number o...
- Sun Nov 15, 2020 5:05 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration Exceptions?
- Replies: 5
- Views: 275
Re: Electron Configuration Exceptions?
The 4s subshell has lower energy so it is occupied first!
- Sun Nov 15, 2020 5:02 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Writing Electron Configurations
- Replies: 9
- Views: 797
Re: Writing Electron Configurations
In addition to what others are saying, I will add that I have seen both ways done before and believe they are both correct (but I am not sure which one Lavelle prefers).
- Mon Nov 09, 2020 9:28 am
- Forum: Octet Exceptions
- Topic: expanded octet in d orbital
- Replies: 4
- Views: 199
Re: expanded octet in d orbital
The d-orbtial has extra space (for 10 electrons), so when an element has this orbital, it is more likely to have an expanded octet.
- Mon Nov 09, 2020 9:26 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: H2O ligand vs hydrate
- Replies: 2
- Views: 193
Re: H2O ligand vs hydrate
Like the above answer states, there is no difference.
- Mon Nov 09, 2020 9:25 am
- Forum: Naming
- Topic: type of compound
- Replies: 3
- Views: 257
Re: type of compound
that is amphoteric metal oxide! this means it is a metal oxide that shows basic as well as acidic behavior.
- Mon Nov 09, 2020 9:23 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Avogadro constant
- Replies: 40
- Views: 2145
Re: Avogadro constant
Avogadro's number is used when the question asks for the number of atoms, molecules, or formula units of a specific substance. It is a useful tool for these conversions.
- Mon Nov 09, 2020 9:22 am
- Forum: Significant Figures
- Topic: 0's
- Replies: 32
- Views: 1241
Re: 0's
In response to Lillian, "inner-zeros" are indeed counted for sig figs.
- Sun Nov 01, 2020 6:22 pm
- Forum: Properties of Light
- Topic: Is c always the speed of light?
- Replies: 92
- Views: 4740
Re: Is c always the speed of light?
As stated before, c is the speed of light always!
- Sun Nov 01, 2020 6:21 pm
- Forum: Properties of Light
- Topic: Do we need to know the ranges of waves on the electromagnetic spectrum?
- Replies: 7
- Views: 215
Re: Do we need to know the ranges of waves on the electromagnetic spectrum?
Since it can be hard to memorize all of the boundaries, I tried to mainly memorize the order and a few key wavelengths so that I can use reasoning for problems for now. I feel like this was a good place to start for memorizing and I hope it is helpful!
- Sun Nov 01, 2020 6:20 pm
- Forum: Properties of Light
- Topic: How to remember what v is in equations
- Replies: 46
- Views: 6839
Re: How to remember what v is in equations
In my head, I just think that the "fancy" v is for frequency because they both start with an f. Hope this helps!
- Sun Nov 01, 2020 6:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm grades
- Replies: 19
- Views: 745
Re: Midterm grades
Like said above, I suspect it will be sometime in the next week. Good luck!
- Thu Oct 29, 2020 5:01 pm
- Forum: Photoelectric Effect
- Topic: Post-Module Assessment #28
- Replies: 2
- Views: 123
Post-Module Assessment #28
The following is a question from the photoelectric effect post-module assessment: 28. Light hits a sodium metal surface and the velocity of the ejected electron is 6.61 x 105 m.s-1. The work function for sodium is 150.6 kJ.mol-1. Answer the following three questions. A. What is the kinetic energy of...
- Fri Oct 23, 2020 2:02 pm
- Forum: Biological Examples
- Topic: Hemoglobin
- Replies: 13
- Views: 706
Re: Hemoglobin
They are both hemeproteins. Their main physiological value is their ability to bind to oxygen.
- Fri Oct 23, 2020 2:00 pm
- Forum: Biological Examples
- Topic: Myoglobin
- Replies: 4
- Views: 359
Re: Myoglobin
Myoglobin is found in muscle cells and binds to oxygen. This binding helps provide extra oxygen, which in turn powers muscular contractions.
- Fri Oct 23, 2020 1:56 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: strengths
- Replies: 4
- Views: 326
Re: strengths
What Ethan said about the boiling point is a great point. The higher the boiling point, the more energy required to break apart the bonds. The more energy required to break apart the bonds, the stronger those bonds are.
- Fri Oct 23, 2020 1:54 pm
- Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
- Topic: Viscosity
- Replies: 25
- Views: 3056
Re: Viscosity
For me, when I think of high viscosity I think of things like honey and syrup. The viscosity is like the thickness, and depends on internal frictional force.
- Fri Oct 23, 2020 1:53 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: Hydrogen Bonding and Dipole-Dipole
- Replies: 2
- Views: 301
Re: Hydrogen Bonding and Dipole-Dipole
I believe hydrogen bonds are a specific type of dipole-dipole interaction. I think the idea of a partial positive region and partial negative region is a commonality that occurs in both bonds.
- Sat Oct 17, 2020 10:42 am
- Forum: Trends in The Periodic Table
- Topic: Octet Expansion
- Replies: 5
- Views: 424
Re: Octet Expansion
Adding on the what has been said about period 3 and below, it is important to note that this means period 2 elements, such as C, N, O, and F, cannot expand their octet.
- Sat Oct 17, 2020 10:40 am
- Forum: Trends in The Periodic Table
- Topic: Nitrogen
- Replies: 7
- Views: 533
Re: Nitrogen
As stated before, Nitrogen has a half-filled p shell. Since it is half-full, adding another electron would make it unstable. Therefore, something like Carbon has a greater affinity for electrons than Nitrogen.
- Sat Oct 17, 2020 10:38 am
- Forum: Trends in The Periodic Table
- Topic: Atomic Radii
- Replies: 11
- Views: 671
Re: Atomic Radii
Something interesting that I read that I thought was worth sharing is that the term atomic radius can refer to an ionic radius, covalent radius, metallic radius, or van Der Waals radius!
- Sat Oct 17, 2020 10:34 am
- Forum: Trends in The Periodic Table
- Topic: Exceptions to Electronegativity
- Replies: 6
- Views: 826
Re: Exceptions to Electronegativity
Agreeing with the above posts, noble gases are the only exception. This is because noble gases have a full valence electron shell, so they do not attract more electrons as they don't need them.
- Sat Oct 17, 2020 10:30 am
- Forum: Student Social/Study Group
- Topic: How are you studying?
- Replies: 204
- Views: 16959
Re: How are you studying?
I completely agree with the two posts above. Studying can often times be subjective so I would try to find the method that works best for you personally. For me, watching the lectures while taking notes and using the modules to review concepts I don't understand helps me, along with doing the saplin...
- Wed Oct 07, 2020 12:15 pm
- Forum: Empirical & Molecular Formulas
- Topic: Percent comp calculations
- Replies: 5
- Views: 745
Re: Percent comp calculations
To reiterate what others have posted above, when given the molecular formula your first step is to find the molar mass. Once you have the total more mass, you can find the molar mass of each individual atom and divide that by the total and multiply by 100% to get the mass percent composition!
- Wed Oct 07, 2020 12:11 pm
- Forum: SI Units, Unit Conversions
- Topic: Formula Units
- Replies: 8
- Views: 238
Re: Formula Units
To add to what others are saying, I think it's important to point out that Avogadro's number has multiple units, such as atoms, molecules, formula units, etc, making it an extremely useful conversion factor.
- Wed Oct 07, 2020 12:06 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Mol VS Mole
- Replies: 17
- Views: 680
Re: Mol VS Mole
yes they are the same thing! which is a little funny considering that it is only 1 letter shorter and is still an abbreviation.
- Wed Oct 07, 2020 12:04 pm
- Forum: Significant Figures
- Topic: When are sig figs applied?
- Replies: 12
- Views: 241
Re: When are sig figs applied?
I agree with what others are saying above; I usually do not take sig figs into consideration until the very end of the problem in order to be as accurate as possible!
- Wed Oct 07, 2020 11:59 am
- Forum: Balancing Chemical Reactions
- Topic: Fractions
- Replies: 26
- Views: 698
Re: Fractions
Not sure if anyone mentioned this but I also wanted to add that when you multiply the fraction (and hence multiply all the other reactants and products) the equation is equivalent to what it was previously; as long as you multiply the chemical reaction entirely by the same number, and the ratio is t...