Search found 59 matches
- Sun Dec 08, 2019 5:18 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Shortcut for Formal Charge
- Replies: 19
- Views: 1668
Re: Shortcut for Formal Charge
Lyndon showed us that you can draw a circle around one of the atoms and count everything within the circle, any loan pair electrons and the bonded electrons (the circle breaks any bond in half so just count like 2 instead of 4 if there is a double bond), and subtract that from the number of valence ...
- Sun Dec 08, 2019 5:11 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pH sig figs
- Replies: 11
- Views: 664
Re: pH sig figs
Yes
- Sun Dec 08, 2019 5:11 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: enthalpy?
- Replies: 3
- Views: 260
Re: enthalpy?
No, I do not believe so
Re: cobalt
You only add -ate to the end when the complex is negatively charged.
- Sun Dec 08, 2019 5:06 pm
- Forum: Lewis Acids & Bases
- Topic: all acids and bases
- Replies: 4
- Views: 392
Re: all acids and bases
A lewis acid is an electron acceptor and a Bronsted acid is a proton donor. A Bronsted acid or base is always either a lewis acid or base, but some Lewis acids and bases are not considered to be Bronsted.
- Sun Dec 08, 2019 5:03 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3611777
Re: Post All Chemistry Jokes Here
Q: What do chemists call a benzene ring with iron atoms replacing the carbon atoms?
A: A ferrous wheel.
A: A ferrous wheel.
- Sun Dec 08, 2019 5:02 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3611777
Re: Post All Chemistry Jokes Here
Q: What did the scientist say when he found 2 isotopes of helium?
A: HeHe
A: HeHe
- Sun Dec 08, 2019 5:02 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3611777
Re: Post All Chemistry Jokes Here
Q: Anyone know any jokes about sodium?
A: Na
A: Na
- Sun Dec 08, 2019 5:02 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3611777
Re: Post All Chemistry Jokes Here
Q: What do you do with a sick chemist?
A: If you can't helium, and you can't curium, then you might as well barium.
A: If you can't helium, and you can't curium, then you might as well barium.
- Sun Dec 08, 2019 5:01 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3611777
Re: Post All Chemistry Jokes Here
Q: Why do chemists like nitrates so much?
A: They're cheaper than day rates.
A: They're cheaper than day rates.
- Sun Dec 01, 2019 9:33 pm
- Forum: Bronsted Acids & Bases
- Topic: Definition Bronsted Acids
- Replies: 3
- Views: 265
Re: Definition Bronsted Acids
A Bronsted acid is a proton donor and the base is a proton acceptor
- Sun Dec 01, 2019 9:27 pm
- Forum: *Molecular Orbital Theory Applied To Transition Metals
- Topic: Transition metals
- Replies: 11
- Views: 1096
Re: Transition metals
Transition metals also always have valence electrons in at least two shells instead of just one
- Sun Dec 01, 2019 9:18 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polydentate
- Replies: 2
- Views: 216
Re: Polydentate
A polydentate ligand can be recognized if it has more than 2 lewis base sites.
- Sun Dec 01, 2019 6:59 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Calculating pH of bases
- Replies: 3
- Views: 268
Re: Calculating pH of bases
I think you can just find the pOH, which just uses the same equation as finding the pH, and then subtract that value from 14.
- Sun Dec 01, 2019 6:48 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Calculating pH
- Replies: 4
- Views: 296
Re: Calculating pH
To find the pH you take the negative log of the hydrogen ion concentration of a solution.
- Sun Nov 24, 2019 6:30 pm
- Forum: Naming
- Topic: polydentate?
- Replies: 7
- Views: 481
Re: polydentate?
A polydentate ligand can be recognized by having more than 2 lewis base sites, such as multiple lone pair donating sites used to bond to a central atom or ion.
- Sun Nov 24, 2019 6:16 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: diamagnetism
- Replies: 5
- Views: 391
Re: diamagnetism
In addition, a compound is diamagnetic if it only contains paired electrons and is not attracted to a magnetic field.
- Sun Nov 24, 2019 6:08 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: bond order
- Replies: 4
- Views: 389
Re: bond order
Bond order is the difference between the number of bonds and anti-bonds.
- Sun Nov 24, 2019 5:32 pm
- Forum: Biological Examples
- Topic: TMs' biological functions
- Replies: 3
- Views: 250
Re: TMs' biological functions
I believe that this was a reference to Chromium(III) picolinate, which is a coordination compound.
- Sun Nov 24, 2019 5:27 pm
- Forum: Hybridization
- Topic: Clarification
- Replies: 2
- Views: 235
Re: Clarification
Electron geometry describes the arrangement of electron groups whereas molecular geometry describes the arrangement of atoms, excluding lone pairs.
- Sun Nov 17, 2019 10:03 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Drawing molecules
- Replies: 12
- Views: 735
Re: Drawing molecules
I think we'll be asked to draw the lowest energy Lewis structure and then name the shape and what the bond angles are.
- Sun Nov 17, 2019 10:00 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSPER
- Replies: 7
- Views: 558
Re: VSPER
VESPR is a model used to predict the geometry of molecules based on minimizing the electrostatic repulsion of a molecule's valence electrons around the central atom.
- Sun Nov 17, 2019 9:59 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 8 HW
- Replies: 4
- Views: 311
Re: Week 8 HW
It'd probably be best to focus on problems from Outline 4 for this week, especially because the content from there will make up the majority of this weeks test.
- Sun Nov 17, 2019 9:52 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: vsepr angles
- Replies: 10
- Views: 492
Re: vsepr angles
Yes, I think that we are supposed to have the bond angles memorized for this test.
- Sun Nov 17, 2019 9:45 pm
- Forum: Student Social/Study Group
- Topic: Test 2
- Replies: 5
- Views: 350
Re: Test 2
The test should be in your discussion section this week.
- Mon Nov 11, 2019 11:03 am
- Forum: Bond Lengths & Energies
- Topic: Van Der Waals BP
- Replies: 6
- Views: 315
Re: Van Der Waals BP
Ionic forces have the greatest impact on boiling point.
- Mon Nov 11, 2019 10:56 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: The Strength of Hydrogen Bonding
- Replies: 4
- Views: 147
Re: The Strength of Hydrogen Bonding
Although hydrogen bonds are one of the strongest intermolecular forces, ionic and covalent bonds are still stronger.
- Mon Nov 11, 2019 10:53 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: Hydrogen Bonding in Biology
- Replies: 2
- Views: 161
Re: Hydrogen Bonding in Biology
This is because hydrogen bonding allow proteins to bend, fold, and fit into various shapes as necessary which determines the protein's biological activity.
- Mon Nov 11, 2019 10:51 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: London Forces??
- Replies: 3
- Views: 193
Re: London Forces??
Dispersion forces are present between all molecules, whether they are polar or nonpolar. All molecules have dispersion forces because to have a dispersion force a molecule needs electrons, and since all molecules have electrons all molecules have dispersion forces.
- Mon Nov 11, 2019 10:48 am
- Forum: Resonance Structures
- Topic: What is a Resonance "Structure"
- Replies: 12
- Views: 1027
Re: What is a Resonance "Structure"
Resonance structures are two forms of a molecule where the chemical connectivity is the same but the electrons are distributed differently around the structure.
- Sun Nov 03, 2019 11:25 pm
- Forum: Trends in The Periodic Table
- Topic: ionization energy vs electronegativity
- Replies: 4
- Views: 191
Re: ionization energy vs electronegativity
The main difference is that electron affinity gives the amount of energy released when an atom gains an electron while ionization energy is the amount of energy required to remove an electron from an atom.
- Sun Nov 03, 2019 11:19 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: magnetic quantum number
- Replies: 5
- Views: 208
Re: magnetic quantum number
The magnetic quantum number describes the orbitals available within a subshell.
- Sun Nov 03, 2019 10:36 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: formal charge
- Replies: 7
- Views: 443
Re: formal charge
I believe that you only need to solve for formal charge if the question asks you to find the lowest energy lewis structure. I believe you wouldn't need to find the formal charge for compounds such as methane, ethane, and some of the other alkanes because they consist of single bonds and there aren't...
- Sun Nov 03, 2019 10:27 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Shortcut for Formal Charge
- Replies: 19
- Views: 1668
Re: Shortcut for Formal Charge
From the chemistry review session on Friday one of the UA's showed us that you can draw a circle around one of the atoms and count everything within the circle, any loan pair electrons and the bonded electrons (the circle breaks any bond in half so just count like 2 instead of 4 if there is a double...
- Sun Nov 03, 2019 10:24 pm
- Forum: Lewis Structures
- Topic: Chloric acid
- Replies: 1
- Views: 139
Re: Chloric acid
From the youtube video that I watched on this it seems that the hydrogen atom bonds with the outermost oxygen atom because H is bonding with the polyatomic ion ClO3 to form an acid.
- Sun Nov 03, 2019 10:18 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge Work on Test
- Replies: 2
- Views: 101
Re: Formal Charge Work on Test
I think that if the question specifically asks to find the Formal Charge it would be better to write out the full formula. If the question just asks to draw the lowest energy Lewis structure it'd probably fine to do Lyndon's method.
- Sun Oct 27, 2019 11:19 pm
- Forum: Trends in The Periodic Table
- Topic: Ionizatiom Energy
- Replies: 1
- Views: 117
Re: Ionizatiom Energy
This is because as shells fill up, more shells are added and the outermost electron becomes even more distant from the nucleus, which lowers the ionization energy because it is easier to remove that electron.
- Sun Oct 27, 2019 11:03 pm
- Forum: Lewis Structures
- Topic: Lewis symbols
- Replies: 5
- Views: 304
Re: Lewis symbols
I believe that each atom would have a maximum of 6 dots as the single bond that connects the atom to the central atom would make up for the other 2 valence electrons.
- Sun Oct 27, 2019 10:32 pm
- Forum: Lewis Structures
- Topic: Formal Charge [ENDORSED]
- Replies: 6
- Views: 176
Re: Formal Charge [ENDORSED]
Formal charge is the charge which is assigned to an atom in a molecule. To calculate formal charge you add the number of lone pair electrons to half of the number of bound electrons, and subtract the sum from the number of valence electrons.
- Sun Oct 27, 2019 10:28 pm
- Forum: Resonance Structures
- Topic: Kekule Structure
- Replies: 2
- Views: 96
Re: Kekule Structure
A kekule structure is a Lewis structure in which bonded electron pairs in covalent bonds are represented with lines.
- Sun Oct 27, 2019 10:26 pm
- Forum: Trends in The Periodic Table
- Topic: Inert-Pair Effect
- Replies: 1
- Views: 117
Re: Inert-Pair Effect
The inert-pair effect is the tendency to form ions two units lower in charge than expected from the group number; it is most pronounced for heavy elements in the p-block. An example of the inert-pair effect is Helium.
- Sun Oct 27, 2019 10:17 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionization Energy Unit
- Replies: 6
- Views: 206
Re: Ionization Energy Unit
The units for ionization energy are kilojoules per mole.
- Sun Oct 27, 2019 10:11 pm
- Forum: Ionic & Covalent Bonds
- Topic: electron configuration order
- Replies: 6
- Views: 416
Re: electron configuration order
I believe that 5s is filled before 4f.
- Sun Oct 20, 2019 10:24 pm
- Forum: DeBroglie Equation
- Topic: Conversion Units for 1B.21
- Replies: 3
- Views: 116
Re: Conversion Units for 1B.21
When converting from ounces to grams: 1). Convert into pounds (1 lbs = 16 oz) 2). Convert from pounds to kilograms (2.2 lbs = 1 kg) 3). Convert from kilograms to grams. When converting from miles per hour into meters per second: 1). Convert from miles to meters (1mi = 1609.34m) 2). Convert from hour...
- Sun Oct 20, 2019 10:11 pm
- Forum: Properties of Light
- Topic: 1F.19
- Replies: 5
- Views: 228
Re: 1F.19
This is because s-block metals usually have lower ionization energies when compared to p-block metals. With this low ionization energy, s-block metals tend to form cations, because they are more willing to give their electrons away, are are thus more reactive.
- Sun Oct 20, 2019 10:04 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Test 1- Q5b
- Replies: 4
- Views: 304
Re: Test 1- Q5b
I don't know how you get 2.99mL based off of the values that you provided, but I was able to get 3.06mL. I believe that your mistake was that you divided by 1000 instead of multiplying by 1000 when converting from L to mL.
- Sun Oct 20, 2019 9:55 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Test 1- Q5a
- Replies: 2
- Views: 218
Re: Test 1- Q5a
The steps for solving 5a were: 1). Convert the grams of aspirin provided, in my case it was 12.0g but I think the tests were different for each discussion, to moles by dividing by the molar mass. 2). Convert the mL of of ethanol provided to L by dividing by 1000. 3). Finding the molarity by diving t...
- Sun Oct 20, 2019 9:48 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic Radius
- Replies: 7
- Views: 483
Re: Atomic Radius
The atomic radius of an atom is found by measuring the distance between the nuclei of two touching atoms. I believe that the atomic radius increases from right to left and from top to bottom on the periodic table.
- Sun Oct 20, 2019 9:38 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Test 1- Q5b
- Replies: 4
- Views: 304
Re: Test 1- Q5b
Did you remember to convert your final answer from Liters to Milliliters?
- Fri Oct 11, 2019 10:15 pm
- Forum: DeBroglie Equation
- Topic: Crossing out units
- Replies: 3
- Views: 194
Re: Crossing out units
Because you are multiplying s^-2 by s in the numerator you need to add their exponents, in this case -2 and 1, which leaves you with s^-1. This is also canceled out because you are dividing by s^-1, which means you need to subtract -1 from -1, which ultimately leaves you with 0 and cancels out secon...
- Fri Oct 11, 2019 9:43 pm
- Forum: DeBroglie Equation
- Topic: The Constant, h
- Replies: 2
- Views: 162
Re: The Constant, h
The constant h is Planck's constant. Planck's constant is equal to 6.626*10^-34 J*s, and it is also used when finding the energy of light in the equation E=hv.
- Fri Oct 11, 2019 9:15 pm
- Forum: DeBroglie Equation
- Topic: P
- Replies: 3
- Views: 167
Re: P
P is the variable assigned to Momentum. To find P, you need to multiply mass and velocity together. The units for P are kilogram meter per second, kg*m/s.
- Fri Oct 11, 2019 9:09 pm
- Forum: Properties of Light
- Topic: Adding formulas
- Replies: 5
- Views: 176
Re: Adding formulas
I believe that E=(hc)/lambda is the equation used to find the energy of a Photon. Dr. Lavelle probably added the equations to show us how the final equation was initially derived.
- Fri Oct 11, 2019 9:06 pm
- Forum: Einstein Equation
- Topic: Variables in equations
- Replies: 4
- Views: 207
Re: Variables in equations
I think the easiest way to differentiate between nu and velocity would to just memorize all of the ways that one of the two can be applied in chemistry. So far, I think we've only seen velocity used to calculate momentum for De Broglie's Wave Equation. As we move through the quarter it might be a go...
- Sat Oct 05, 2019 12:01 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron configuration order
- Replies: 4
- Views: 265
Re: Electron configuration order
Notation is written by increasing energy, so maybe because the d-orbital is not completely filled it actually has a lower energy level than the s-orbital.
- Fri Oct 04, 2019 11:53 pm
- Forum: Empirical & Molecular Formulas
- Topic: Empirical and Molecular Formulas
- Replies: 2
- Views: 147
Re: M. 19
I believe that Nitrogen is found in caffeine so when burned it is released as a gas.
- Fri Oct 04, 2019 11:24 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Showing work in detail
- Replies: 7
- Views: 634
Re: Showing work in detail
I don't think they have to be too detailed as long as your work is clear and easy to follow. However, I feel like it's better to have a more detailed dimensional analysis so that you can check your own work.
- Fri Oct 04, 2019 11:16 pm
- Forum: Limiting Reactant Calculations
- Topic: Textbook M15-Calculation?
- Replies: 3
- Views: 188
Re: Textbook M15-Calculation?
What did you calculate as the mass of AlCl3 produced based on the 535 grams of Cl2? For percent yield you would need to divide the actual yield, 300grams of AlCl3, by the theoretical yield, your calculation, and multiply that by 100.
- Fri Oct 04, 2019 6:16 pm
- Forum: Einstein Equation
- Topic: Planack's constant
- Replies: 8
- Views: 580
Re: Planack's constant
I believe that Planck's constant is used when calculating the energy of a photon. It is represented by the variable h in the equation E=hv.