Search found 52 matches
- Sun Dec 08, 2019 9:07 am
- Forum: Properties & Structures of Inorganic & Organic Bases
- Topic: Equilibrium sign
- Replies: 9
- Views: 827
Re: Equilibrium sign
No, because for strong acids and bases we assume 100% dissociation, so after the reaction there will be no reactants in solution, only products
- Sun Dec 08, 2019 9:06 am
- Forum: Naming
- Topic: Naming the metal
- Replies: 3
- Views: 362
Re: Naming the metal
You only need to add the -ate ending if the coordination compound has an overall negative charge/is an anion. Otherwise you would leave the transition metal name alone
- Sun Dec 08, 2019 9:02 am
- Forum: Polyprotic Acids & Bases
- Topic: H2S and HCl
- Replies: 2
- Views: 252
Re: H2S and HCl
Cl being more electronegative is the reason HCl is the stronger acid, and as far as I know this is the only explanation we have to be aware of!
- Sun Dec 08, 2019 8:56 am
- Forum: Identifying Acidic & Basic Salts
- Topic: amphoteric salts
- Replies: 1
- Views: 440
Re: amphoteric salts
I would assume we do not have to know how to do this, since the examples for salts as acids and bases in lecture did not cover this
- Sat Dec 07, 2019 1:37 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Novocaine
- Replies: 1
- Views: 270
Novocaine
What specific atoms in the novocaine structure, C13H20N2O2, make it a base and why?
- Thu Dec 05, 2019 1:34 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Weak vs Strong acids and bases
- Replies: 6
- Views: 450
Weak vs Strong acids and bases
How and why would the pH of a solution differ if you use a weak base instead of a strong?
naming
When listing the ligands in alphabetical order, do you go by just the name of the ligand or do you include the prefix? For example, would it be biethylene chloro because b comes before c or chloro biethylene because c comes before e?
- Sun Dec 01, 2019 10:14 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: notes
- Replies: 2
- Views: 251
Re: notes
I think this is saying that oxoacids with other electronegative atoms are stronger because these atoms delocalize the negative charge and make it less likely for a proton to bind/stay bound. For example, in OCl- (hypochlorite ion), the negative charge is largely localized on the single oxygen atom; ...
- Sun Dec 01, 2019 9:50 pm
- Forum: Conjugate Acids & Bases
- Topic: Conjugate/Bronsted/Lewis
- Replies: 2
- Views: 225
Re: Conjugate/Bronsted/Lewis
The lewis definition of a base is the species that donates an electron pair. The bronsted definition is the species that accepts a proton. A conjugate base is, in a reaction, the species formed by the reactant acid after it donates a proton. So to clarify, a conjugate base is defined very similarly ...
- Sun Dec 01, 2019 9:42 pm
- Forum: Bronsted Acids & Bases
- Topic: Final
- Replies: 13
- Views: 784
Re: Final
As far as I know, any topic on the syllabus is fair game for the final. So I would say just go back through that and go over the things you're a little shakier on. Hope this helps!
- Sun Dec 01, 2019 9:37 pm
- Forum: Lewis Acids & Bases
- Topic: Lewis Structures
- Replies: 1
- Views: 160
Re: Lewis Structures
For Lewis acids and bases, the acid and base in a reaction are identified by which donates an e- pair(Lewis base) and which accepts an e- pair (Lewis acid). Lewis structures can be helpful to identify acids and bases because they visually represent the transfer of the e- pair
- Sun Dec 01, 2019 9:28 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: J.9
- Replies: 2
- Views: 167
Re: J.9
As far as I know, it is just a matter of memorizing the strong acids and bases to know which will dissociate completely in water
- Sun Nov 24, 2019 7:46 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: chelating complexes
- Replies: 2
- Views: 240
Re: chelating complexes
A structure can form chelating complexes only if it is polydentate
- Sun Nov 24, 2019 7:35 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Central atom?
- Replies: 5
- Views: 308
Re: Central atom?
Yes, a coordination compound is a transition metal bonded to ligands, specifically by coordinate covalent bonds, in which the ligand donates both e- from a lone pair
- Sun Nov 24, 2019 7:28 pm
- Forum: Naming
- Topic: oxidation state equation
- Replies: 2
- Views: 198
Re: oxidation state equation
If you want to think about it in terms of a formal equation, it would be:
Oxidation state of metal=net charge of compound-(total charge of anions)
it may be easier to just remember the concept though, that the net charge of the compound must be the sum of the charges of all the ions
Oxidation state of metal=net charge of compound-(total charge of anions)
it may be easier to just remember the concept though, that the net charge of the compound must be the sum of the charges of all the ions
- Sun Nov 24, 2019 7:18 pm
- Forum: Naming
- Topic: Oxidation Number
- Replies: 3
- Views: 204
Re: Oxidation Number
How would the calculations differ if the ligand was neutral? If the ligand was neutral, you would still do the calculations the same way. If the compound has a net charge but the ligands are all neutral, then that net charge must come from the metal ion and its oxidation state would equal this net ...
Re: Naming
Yes, it goes ligand names in alphabetical order(with greek prefixes denoting how many are present), the the transition metal cation name(with Roman numeral denoting the oxidation state), then, if there are anions, the anion name plus -hydrate(with Greek prefix denoting how many water molecules prese...
- Tue Nov 19, 2019 10:40 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Figuring Out Bond Angle
- Replies: 3
- Views: 180
Re: Figuring Out Bond Angle
When there is a lone pair, it has stronger repulsion than an atom, so it will force the atoms in the molecule closer together and slightly decrease the angle
This will also happen if one of the atoms is larger than the others
This will also happen if one of the atoms is larger than the others
- Tue Nov 19, 2019 10:25 am
- Forum: Sigma & Pi Bonds
- Topic: Stability of Sigma and Pi Bonds
- Replies: 4
- Views: 316
Re: Stability of Sigma and Pi Bonds
The orbitals in sigma bonds overlap to a greater extent than in pi bonds, so electron density is more concentrated
- Tue Nov 19, 2019 10:16 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: dissociation energy
- Replies: 2
- Views: 143
Re: dissociation energy
Dissociation energy is the energy required to break a bond, so the stronger the bond is the more energy will be required to break it (higher dissociation energy)
- Tue Nov 19, 2019 10:13 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Atomic Size & LDF's
- Replies: 2
- Views: 206
Re: Atomic Size & LDF's
Because there are more electrons
- Tue Nov 19, 2019 10:03 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Magnitude of Molecular Interactions
- Replies: 1
- Views: 147
Re: Magnitude of Molecular Interactions
B=C<E<A<D
Dipole-dipole interactions are weaker in the gas phase because the molecules are farther apart
Dipole-dipole interactions are weaker in the gas phase because the molecules are farther apart
- Mon Nov 11, 2019 12:10 am
- Forum: Ionic & Covalent Bonds
- Topic: Bond Strength
- Replies: 8
- Views: 481
Re: Bond Strength
Ionic bonds are typically stronger than covalent because of the coulombic attraction between ions of different charge
- Mon Nov 11, 2019 12:09 am
- Forum: Resonance Structures
- Topic: Negative Charge
- Replies: 3
- Views: 208
Re: Negative Charge
The most electronegative atom will carry the negative charge
- Mon Nov 11, 2019 12:07 am
- Forum: Resonance Structures
- Topic: how to draw
- Replies: 6
- Views: 408
Re: how to draw
Doctor Lavelle mentioned both ways of drawing resonance structures. I don't know that one is necessarily better, but since in the examples we've been drawing the structures out separately with the double-sided arrows, we should probably stick with that :)
- Mon Nov 11, 2019 12:04 am
- Forum: Coordinate Covalent Bonds
- Topic: Electronegativity
- Replies: 12
- Views: 1681
Re: Electronegativity
Can someone explain how shielding works? I understand the concept as when there are more expanded shells of electrons the electrons are further away and the ones in the furthest shell are not pulled on as much, but is it the idea that the ones closer to the nucleus are "stealing" more of ...
- Sun Nov 10, 2019 10:34 pm
- Forum: Ionic & Covalent Bonds
- Topic: Bond Strength
- Replies: 3
- Views: 171
Re: Bond Strength
Ionic bonds are typically stronger than covalent bonds because of the coulombic attractions between ions of different charges
- Sun Nov 03, 2019 12:00 pm
- Forum: Lewis Structures
- Topic: Atoms that can accept more than 8 Valence E-
- Replies: 3
- Views: 189
Re: Atoms that can accept more than 8 Valence E-
Atoms in period 3 or higher can accommodate more than 8 electrons because they have d-orbitals in their valence shell. The octet guideline comes from the fact that full s- and p-orbitals accommodate 8 e- together (s2 and p6)
- Sun Nov 03, 2019 11:49 am
- Forum: Administrative Questions and Class Announcements
- Topic: Homework before midterm
- Replies: 3
- Views: 156
Homework before midterm
For this week's 5 homework problems, can we turn in problems on any topic as midterm review or do they have to be from the chemical bonds section since that is what we were doing last in lecture?
- Sun Nov 03, 2019 11:41 am
- Forum: Electronegativity
- Topic: Relation between Electronegativity and ionization energy
- Replies: 3
- Views: 143
Re: Relation between Electronegativity and ionization energy
Electronegativity is calculated from the measured ionization energy and electron affinity, which is why they all have similar trends. As ionization energy and electron affinity increase, so will electronegativity because it is a product of these two measurements
- Sun Nov 03, 2019 11:35 am
- Forum: Dipole Moments
- Topic: Interaction between ions and molecules
- Replies: 2
- Views: 166
Re: Interaction between ions and molecules
Interionic and intermolecular attractive forces are attractions caused by opposite charges (in the case of anion/cation attraction) or opposite partial charges, in the case of polar molecules
- Sun Nov 03, 2019 11:32 am
- Forum: Dipole Moments
- Topic: Dipole Moment Clarification
- Replies: 2
- Views: 105
Re: Dipole Moment Clarification
The Electric Dipole Moment in molecules is simply the measure of the charge difference between atoms in a polar covalent bond. It occurs because of a difference in electronegativity between the two atoms.
- Sun Oct 27, 2019 10:41 pm
- Forum: Resonance Structures
- Topic: Arrangement of Atoms
- Replies: 3
- Views: 83
Re: Arrangement of Atoms
A molecule is most stable when all of the atoms have the lowest possible formal charge. If you think you have found the correct structure, check formal charges and if they are mostly 0 or +/-1 to 2, that is an indication that your structure is correct
- Sun Oct 27, 2019 10:24 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Elements having octets
- Replies: 4
- Views: 257
Re: Elements having octets
The octet (8 e-) comes from the full s- and p- subshells; s2p6 totals 8 electrons. Atoms in period 3 or higher have valence shell d-orbitals, so they can accommodate more electrons than the standard 8 for atoms with lower atomic numbers
- Sun Oct 27, 2019 10:18 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionization Energy Unit
- Replies: 6
- Views: 152
Re: Ionization Energy Unit
It's usually given in kilojoules per mole (kJ/M)
- Sun Oct 27, 2019 10:16 pm
- Forum: Ionic & Covalent Bonds
- Topic: electron configuration order
- Replies: 6
- Views: 388
Re: electron configuration order
5s will be filled before 4f
- Sun Oct 27, 2019 10:10 pm
- Forum: Ionic & Covalent Bonds
- Topic: Bond lengths
- Replies: 3
- Views: 133
Re: Bond lengths
These values are experimentally measured bond lengths of an N--O bond in NO3- and a C--C bond in C6H6 specifically. These are important because they show that real-life models of molecules with resonance structures are not any one of these possible structures at a time, but actually an average of al...
- Mon Oct 21, 2019 6:50 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: spins
- Replies: 4
- Views: 155
Re: spins
The quantum number m sub s denotes the spin of the electron: +1/2 is 'spin up' and -1/2 is 'spin down'
- Mon Oct 21, 2019 6:20 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: S-, P-, S-, and F- Orbitals
- Replies: 3
- Views: 183
Re: S-, P-, S-, and F- Orbitals
The way I understand it is that the orbitals are just wave functions modeling where the electrons are most probably located. As the number of electrons increases, the patterns of where they could be located (from the s-subshell, to the p, d ,f) are added to model the atom, which is why the orbitals ...
- Mon Oct 21, 2019 5:54 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Quantum numbers x,y,z
- Replies: 2
- Views: 61
Re: Quantum numbers x,y,z
For the p subshell, x,y, and z are arbitrary because they are all symmetrical
- Mon Oct 21, 2019 5:36 pm
- Forum: Properties of Electrons
- Topic: Angstrom
- Replies: 2
- Views: 165
Re: Angstrom
The easiest way for me to do conversion problems like this is to be able to visualize them using dimensional analysis, so you would set up the problem
110 pm x (1m/10^-12pm) x (1 angstrom/10^-10m) that way the units cancel and you are left with your answer in angstrom
110 pm x (1m/10^-12pm) x (1 angstrom/10^-10m) that way the units cancel and you are left with your answer in angstrom
- Mon Oct 21, 2019 5:09 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: example in class
- Replies: 6
- Views: 180
Re: example in class
As Brian said, the subscripts are arbitrary, but it is helpful to separate the p sub shell into its x-,y-, and z- components to remember Hund's Rule. 1s^22s^22p^3 and 1s^22s^22px^12py^12pz^1 are saying the same thing, but the second makes it clearer that each orbital in this sub shell is filled sing...
- Sun Oct 13, 2019 12:39 pm
- Forum: Properties of Light
- Topic: Problem 1A.9
- Replies: 2
- Views: 162
Re: Problem 1A.9
To calculate the energy of the photon, you can use the equation E=hv (using the frequency that's either been given in the question or that you've calculated using wavelength). Then to match each kind of radiation to the appropriate event, you would look at the electromagnetic radiation spectrum and ...
- Sun Oct 13, 2019 12:29 pm
- Forum: Properties of Light
- Topic: wavelike properties
- Replies: 6
- Views: 171
Re: wavelike properties
DeBroglie's equation suggests that any particle with momentum (in motion) actually has wavelike properties, however these properties can only be observed/detected in particles (like electrons!) with a small enough mass. Electrons can be experimentally proven to have wavelike properties because there...
- Sat Oct 12, 2019 11:03 am
- Forum: Properties of Light
- Topic: Wavelength
- Replies: 4
- Views: 168
Re: Wavelength
Is it possible for interference to be both constructive and destructive (at different times) with the two waves staying the same? I believe that if two waves were not in phase, but also not perfectly 180 degrees out of phase with each other, there would be some points where their interference would...
- Sat Oct 12, 2019 10:58 am
- Forum: Properties of Light
- Topic: Shorter Wavelength
- Replies: 3
- Views: 171
Re: Shorter Wavelength
Yes, because the energy per photon, E=(h)(frequency), so light with lower wavelength/higher frequency has higher energy per photon. Each photon interacts with one electron and must have enough energy to eject one electron, which is why light with higher frequency ejects more electrons.
- Sat Oct 12, 2019 10:26 am
- Forum: Properties of Light
- Topic: Hw Question 1A.9
- Replies: 5
- Views: 630
Re: Hw Question 1A.9
For the line with the frequency listed as 300MHz, I converted to Hz and got 3.00x10^8 Hz, but then using wavelength=c/frequency you would get a wavelength of 1m, which doesn't make sense for the "events" context of this question. Not sure what part I'm doing wrong?
- Thu Oct 03, 2019 10:34 am
- Forum: Limiting Reactant Calculations
- Topic: Ratios between Limiting Reactants and Products
- Replies: 3
- Views: 97
- Thu Oct 03, 2019 10:22 am
- Forum: Molarity, Solutions, Dilutions
- Topic: Wording when answering molarity questions
- Replies: 2
- Views: 93
Re: Wording when answering molarity questions
For the first example, I think the confusion is that when doing dilutions, you are starting with a stock solution with some concentration of a substance already dissolved. So you would use M1V1=M2V2 with the molarity of the original substance given in the question, along with the desired new volume ...
- Thu Oct 03, 2019 10:03 am
- Forum: SI Units, Unit Conversions
- Topic: Homework 2
- Replies: 7
- Views: 309
Re: Homework 2
I'm pretty sure we are allowed to choose some from the review section as well for Homework 2, since we are still covering some of that material for this week and the syllabus just says to turn in 5 hw questions related to class material
- Tue Oct 01, 2019 5:07 pm
- Forum: Empirical & Molecular Formulas
- Topic: HW E17 part C
- Replies: 5
- Views: 237
HW E17 part C
This question asks which contains the greater number of moles of atoms, 7.36x10^27 atoms of Ru or 7.36x10^27 atoms of Fe
I was thinking they should contain the same number of atoms, since a mole of atoms of any element contains 6.0221x10^23 atoms, but I'm not sure if I'm thinking about this wrong
I was thinking they should contain the same number of atoms, since a mole of atoms of any element contains 6.0221x10^23 atoms, but I'm not sure if I'm thinking about this wrong
- Tue Oct 01, 2019 5:02 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: How to access e textbook
- Replies: 4
- Views: 289
Re: How to access e textbook
Your textbook also should have come with a little slip with a code inside that you will need to access the eBook on Sapling Learning