Search found 53 matches
- Wed Dec 04, 2019 2:33 pm
- Forum: Amphoteric Compounds
- Topic: Amphoteric vs Amphiprotic
- Replies: 9
- Views: 583
Re: Amphoteric vs Amphiprotic
Amphiprotic means that a substance can both accept and donate a proton or H+. Amphoteric means that a substance can act as both an acid and a base. All amphoteric substances are amphiprotic because if a molecule can either donate or accept a proton, that means it can act as both an acid or a base. ...
- Wed Dec 04, 2019 12:00 pm
- Forum: Amphoteric Compounds
- Topic: amphoteric oxides
- Replies: 3
- Views: 288
Re: amphoteric oxides
They have both basic and acidic character, meaning that they can react with bases and acids. The elements around the diagonal line of metalloids typically form amphoteric oxides (such as BeO, Al2O3, Ga2O3)
- Wed Dec 04, 2019 11:55 am
- Forum: Biological Examples
- Topic: Hemoglobin - shape and function
- Replies: 2
- Views: 212
Re: Hemoglobin - shape and function
The central component of hemoglobin, heme, is chelating. This is also called the porphyrin ligand. (We drew a picture of it in lecture)
- Wed Dec 04, 2019 11:51 am
- Forum: Air Pollution & Acid Rain
- Topic: Acid rain eqn
- Replies: 1
- Views: 264
Acid rain eqn
Can someone simply post the equations we need to know for acid rain?
- Wed Dec 04, 2019 11:49 am
- Forum: Polyprotic Acids & Bases
- Topic: Ka value
- Replies: 5
- Views: 459
Ka value
Why does each subsequent Ka value decrease significantly? In class I wrote Ka1 > Ka2 > Ka3 because it is harder to lose H+ from a negatively charges ion but can someone explain this further?
- Wed Dec 04, 2019 11:43 am
- Forum: Amphoteric Compounds
- Topic: H2O
- Replies: 8
- Views: 472
H2O
Is water both amphoteric and amphiprotic?
- Sun Dec 01, 2019 12:21 pm
- Forum: Bronsted Acids & Bases
- Topic: 6A.11
- Replies: 2
- Views: 231
Re: 6A.11
H2O is the best reactant to choose because it is also amphoteric, meaning that it can act as both an acid and a base so it works in both equations.
- Sun Dec 01, 2019 12:19 pm
- Forum: Naming
- Topic: I wanna learn the alphabet
- Replies: 2
- Views: 275
Re: I wanna learn the alphabet
I just read on a different post that you must write anion ligands before neutral ligands so just make sure to do that as well.
- Sun Dec 01, 2019 12:02 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: drawing polydentates [ENDORSED]
- Replies: 1
- Views: 164
drawing polydentates [ENDORSED]
Is the best way to determine if a ligand is polydentate to draw its structure? Or is there some trick to memorize or understand to make this quicker and easier?
- Sun Dec 01, 2019 11:54 am
- Forum: Polyprotic Acids & Bases
- Topic: Polyprotic Acid Reactions- Loss of Proton(s)?
- Replies: 2
- Views: 286
Re: Polyprotic Acid Reactions- Loss of Proton(s)?
In polyphonic reactions protons are lost successively. So several reactions occur one after another and a single proton is removed in each one.
- Sun Dec 01, 2019 11:52 am
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Strong and Weak Acids
- Replies: 7
- Views: 545
Re: Strong and Weak Acids
I think a lot of the time the question will identify if it is strong or weak for you (at least all of the textbook problems do this). But in general stronger acids have a lower pH than weak acids because the bonds in a strong acids are weak which means they can more easily lose H+
- Mon Nov 25, 2019 4:48 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Chelating ligands
- Replies: 1
- Views: 179
Chelating ligands
Are all polydentate ligands chelating ligands? What if a ligand has multiple binding sites but is unable to form a ring? Or is that not a possibility?
- Mon Nov 25, 2019 4:44 pm
- Forum: Naming
- Topic: Chelating Complex
- Replies: 4
- Views: 286
Re: Chelating Complex
A chelating complex contains one or more ligands that forms a ring of atoms that includes the central atom. A common example is edta (which we viewed in class). It can form strong complexes with many different metal ions.
- Mon Nov 25, 2019 4:36 pm
- Forum: Naming
- Topic: Oxidation number
- Replies: 2
- Views: 211
Oxidation number
Can someone simply explain how to calculate the oxidation number? I can't find a clear explanation in the book.
- Mon Nov 25, 2019 4:35 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Naming
- Replies: 3
- Views: 288
Re: Naming
The first thing to remember is that all the ligands are written in alphabetical order, followed by the name of the transition metal cation, and then the Roman numeral which is the oxidation number of the metal. I start by looking at the ligand, determining the Greek prefix and name. For example, in ...
- Mon Nov 25, 2019 4:29 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: determining if polydentate
- Replies: 3
- Views: 225
determining if polydentate
How do you determine if a ligand can be polydentate?
For example, question 9C.5 asks to determine if the following ligand is polydentate, and if so, give the maximum number of places on the ligand that can bind simultaneously to a single metal center.
HN(CH2CH2NH2)2
For example, question 9C.5 asks to determine if the following ligand is polydentate, and if so, give the maximum number of places on the ligand that can bind simultaneously to a single metal center.
HN(CH2CH2NH2)2
- Sat Nov 16, 2019 8:54 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 8
- Views: 644
Re: Bond Angles
The book says it is impossible to predict the extent of distortion of bond angles when lone pairs are present. The only way to determine the value would be to measure it experimentally or calculate it with the Schrodinger eqn (which we don't have to do)
- Sat Nov 16, 2019 8:51 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Test #2
- Replies: 4
- Views: 330
Re: Test #2
This is a list from my TA: -VSEPR (determining shape) -Use dipole moments to determine if polar or non polar -use shame and polar/nonpolar to identify intermolecular interactions -explain why lone pairs are more likely found in certain locations around central atom and how/why they affect bond angle...
- Sat Nov 16, 2019 8:50 pm
- Forum: Bond Lengths & Energies
- Topic: Lone pairs
- Replies: 7
- Views: 642
Lone pairs
Why are lone pairs more likely to be found in certain locations around a central atom? And which locations are these?
- Sat Nov 16, 2019 8:46 pm
- Forum: Hybridization
- Topic: test 2
- Replies: 8
- Views: 505
Re: test 2
I know we have to know the difference between sigma and pi bonds. I'm pretty sure I heard Dr. Lavelle say hybridization will not be on the test but I'm not sure. Here is a list of topics from my TA: -VSEPR (determining shape) -Use dipole moments to determine if polar or non polar -use shame and pola...
- Sat Nov 16, 2019 8:43 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Ions
- Replies: 3
- Views: 334
Re: Ions
Ions have either more electrons (anion) or less electrons (cation) than its original atom. The electron configuration represents this by either adding or removing electrons from the outermost orbital.
- Sun Nov 10, 2019 11:42 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarization of Large Atom
- Replies: 2
- Views: 198
Re: Polarization of Large Atom
Since, as stated above, the atomic radius of a larger atom is so big, its shape can become more easily distorted, meaning it is highly polarizable.
- Sun Nov 10, 2019 11:40 am
- Forum: Dipole Moments
- Topic: Polarity
- Replies: 3
- Views: 247
Re: Polarity
If a molecule is made up of two other same atoms, the molecule is nonpolar because the electronegativities are the same. Also, be sure to note that the bonds within a molecule may be polar even though the overall molecule is nonpolar.
- Sun Nov 10, 2019 11:37 am
- Forum: Dipole Moments
- Topic: Dipole Moments
- Replies: 3
- Views: 208
Re: Dipole Moments
All of the above are great explanations. We denote dipole moments by drawing an arrow from the more positively charged atom pointing to the more negatively charged one.
- Sun Nov 10, 2019 11:31 am
- Forum: Dipole Moments
- Topic: Interactions
- Replies: 4
- Views: 212
Re: Interactions
They are the same. Both names were included under the list of interchangeable names for induced dipole-induced dipole
- Sun Nov 10, 2019 11:28 am
- Forum: Lewis Acids & Bases
- Topic: Why Lewis Acid?
- Replies: 3
- Views: 181
Re: Why Lewis Acid?
In general, bases donate electrons while acids accept electrons
- Sun Nov 10, 2019 11:26 am
- Forum: Bond Lengths & Energies
- Topic: polarizability
- Replies: 9
- Views: 326
Re: polarizability
Polarizability also explains the likelyhood of a certain atom to become distorted. This is why larger atoms have a higher polorizability
- Sun Nov 03, 2019 8:21 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Electromagnetic radiation
- Replies: 1
- Views: 110
Electromagnetic radiation
Why is the energy of an atom not increased when electromagnetic radiation is emitted from it?
- Sun Nov 03, 2019 12:38 am
- Forum: Trends in The Periodic Table
- Topic: Units for energy
- Replies: 1
- Views: 93
Units for energy
Why are the units for kinetic energy and ionization energy different?
- Sun Nov 03, 2019 12:35 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Which equations can be used for what topics
- Replies: 2
- Views: 101
Which equations can be used for what topics
This isn't specific to indeterminancy, but can someone list which equations are allowed to be used for photons and which can be used for electrons?
- Sun Nov 03, 2019 12:31 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: When to calculate formal charge
- Replies: 7
- Views: 365
When to calculate formal charge
Do you always have to compute formal charge when drawing Lewis structures?
- Sun Nov 03, 2019 12:24 am
- Forum: Octet Exceptions
- Topic: Expanded Octets
- Replies: 1
- Views: 108
Expanded Octets
Can someone explain why some elements can bond with others to obtain more than 8 valence electrons? And which elements are these?
- Sun Nov 03, 2019 12:20 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron configurations of ions
- Replies: 4
- Views: 367
Electron configurations of ions
Why is it important to first write the ground state electron configuration of an element before determining the electron configuration of an anion or cation?
- Mon Oct 21, 2019 9:08 pm
- Forum: Trends in The Periodic Table
- Topic: Ionic radii
- Replies: 11
- Views: 369
Re: Ionic radii
I know ionic and atomic radius follow the same trend in the periodic table increasing down the group and decreasing across a period, but does the covalent radius also follow this trend? Lavelle mentioned it in class but I was confused about the trend it follows. I believe covalent radii follow the ...
- Mon Oct 21, 2019 8:53 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: S-, P-, S-, and F- Orbitals
- Replies: 3
- Views: 208
Re: S-, P-, S-, and F- Orbitals
When I try to picture this, it's also helpful to remember that each subshell has an increasing number of orbitals and can therefore hold an increasing amount of electrons. So 3s can only hold 2 electrons since it only has one orbital. But 3p has three orbitals and can therefore hold up to 6 electrons
- Mon Oct 21, 2019 8:46 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration Specifics
- Replies: 3
- Views: 224
Re: Electron Configuration Specifics
From what I could gather, he recommended writing the configuration in this way if not all the orbitals are filled just so we could better visualize how electrons are paired with one another. I think it explains the reasoning behind this in the book a little more if you want more info
- Mon Oct 21, 2019 8:41 pm
- Forum: Trends in The Periodic Table
- Topic: 2nd Ionization Energy
- Replies: 7
- Views: 378
2nd Ionization Energy
What makes the second ionization energy of any given element consistently much higher than the first?
- Mon Oct 21, 2019 8:36 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Cr and Cu Exceptions
- Replies: 2
- Views: 115
Cr and Cu Exceptions
And as a follow-up to my previous question, why are Cr and Cu exceptions to the 4s before 3d rule?
Thanks in advance
Thanks in advance
- Mon Oct 21, 2019 8:33 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 4s before 3d
- Replies: 4
- Views: 234
4s before 3d
Can someone explain exactly why in some instances 4s come before 3d? And in what cases does this occur?
- Mon Oct 14, 2019 10:50 pm
- Forum: *Black Body Radiation
- Topic: What do I really need to know?
- Replies: 6
- Views: 766
What do I really need to know?
I remember Dr. Lavelle saying we won't go into very much depth concerning black body radiation but are there key points I should know and understand?
- Mon Oct 14, 2019 10:47 pm
- Forum: DeBroglie Equation
- Topic: de Broglie vs Heisenberg
- Replies: 2
- Views: 187
de Broglie vs Heisenberg
Can someone explain how you will know when to use which equation? What should I look out for in the context of the problem to determine which equation is most appropriate?
- Mon Oct 14, 2019 10:32 pm
- Forum: Properties of Light
- Topic: HW Question 1.B.19
- Replies: 2
- Views: 100
Re: HW Question 1.B.19
For this problem, you are expected to know the masses of both a proton and a neutron (you can probably find them in the chapter). Then substitute these values into the de Broglie relationship to calculate both wavelengths (they should be equal for 3 sig figs)
- Mon Oct 14, 2019 10:29 pm
- Forum: DeBroglie Equation
- Topic: HW Question 1.B.15
- Replies: 3
- Views: 193
Re: HW Question 1.B.15
You should use the de Broglie relationship to find the wavelength. lambda=h(mv)^-1
- Mon Oct 14, 2019 10:27 pm
- Forum: DeBroglie Equation
- Topic: How to find work function
- Replies: 2
- Views: 135
Re: How to find work function
In order to use the de Broglie relationship, you first need to put m in terms of m.s^-1. Then you can solve for the wavelength by using Plancks constant and the known mass of e-
- Sun Oct 06, 2019 11:44 pm
- Forum: Balancing Chemical Reactions
- Topic: Naming/Polyatomic ions
- Replies: 4
- Views: 228
Re: Naming/Polyatomic ions
I've been told the questions consist of some math questions similar to those in the homework as well as some short conceptual questions that were mostly covered in lecture. So to answer your question, no I don't think we are expected to know that yet.
- Sun Oct 06, 2019 11:40 pm
- Forum: Balancing Chemical Reactions
- Topic: Importance of the State of Molecules
- Replies: 6
- Views: 653
Re: Importance of the State of Molecules
I asked this question in a Step up session today and the UA told me that in most problems where we have to write chemical equations, the state will be explicitly given. But if it is not just try your best to guess because it may be worth a very small amount of points
- Sun Oct 06, 2019 11:36 pm
- Forum: Balancing Chemical Reactions
- Topic: HW problem H11
- Replies: 4
- Views: 164
Re: HW problem H11
Just a quick tip: if the numbers don't seem obvious or you can't seem to make the equation work, try using a system of equations
So (A)Fe3O4 + (B)CO = (C)Fe + (D)CO2
and then proceed to solve for each element
Fe: 3A=C
O: 4A=B+2D
C: B=D
So (A)Fe3O4 + (B)CO = (C)Fe + (D)CO2
and then proceed to solve for each element
Fe: 3A=C
O: 4A=B+2D
C: B=D
- Sun Oct 06, 2019 11:30 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Formula Units
- Replies: 4
- Views: 248
Re: Formula Units
I believe in some cases formula units refers to the number of atoms while in other cases it refers to the number of molecules, just depending on what the specific question is asking
- Sun Oct 06, 2019 11:26 pm
- Forum: SI Units, Unit Conversions
- Topic: SI Units
- Replies: 2
- Views: 188
Re: SI Units
Today in my Step-up session I was told to use the units that logistically make the most sense for the problem (which will usually be g, L, etc) but it is important to have the knowledge of how to convert between the different units in case it is necessary for a specific question.
- Mon Sep 30, 2019 9:25 pm
- Forum: Limiting Reactant Calculations
- Topic: 2 Limiting Reactants
- Replies: 9
- Views: 376
Re: 2 Limiting Reactants
But is it possible if there are at least 3 reactants and 2 of them (the limiting ones) are equal?
- Mon Sep 30, 2019 9:20 pm
- Forum: SI Units, Unit Conversions
- Topic: mol, g.mol and g.mol-1
- Replies: 12
- Views: 1065
Re: mol, g.mol and g.mol-1
These are all different units. I actually don't quite understand the difference between g.mol and g.mol-1 (so far I think we've only used g.mol-1). Mol=moles as in the number of atoms in exactly 12g of carbon-12 (6.022 x 10^23 units of whatever you're measuring). g.mol-1 is the notation for grams pe...
- Mon Sep 30, 2019 9:09 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: What does dilution mean in a chemistry problem?
- Replies: 8
- Views: 882
Re: What does dilution mean in a chemistry problem?
All of the above are true. Just be sure to remember that dilution does NOT change the moles of solute in the solution, only the overall volume
- Mon Sep 30, 2019 9:05 pm
- Forum: Limiting Reactant Calculations
- Topic: Limiting Reactant Calculation post-module question
- Replies: 4
- Views: 165
Limiting Reactant Calculation post-module question
Can someone explain the following problem? According to the following equation, 0.750 g of C6H9Cl3 is mixed with 1.000 kg of AgNO3 in a flask of water. A white solid, AgCl, completely precipitates out. What is the mass of AgCl produced? C6H9Cl3 + 3AgNO3 ---> AgCl + C6H9(NO3)3 I found the molar masse...