Search found 101 matches
- Mon Mar 09, 2020 10:19 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: endothermic reaction
- Replies: 5
- Views: 436
Re: endothermic reaction
If a reaction is endothermic, you can treat heat as a reactant, but you wouldn't actually write it out.
- Mon Mar 09, 2020 9:58 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: ln(A) Arrhenius Equation
- Replies: 3
- Views: 273
Re: ln(A) Arrhenius Equation
As long as you understand the Arrhenius Equation and why it's used, you should be fine. You would be given A or asked to solve for it given the other values.
- Mon Mar 09, 2020 9:55 pm
- Forum: Ideal Gases
- Topic: Liter to meter cubed?
- Replies: 4
- Views: 468
Re: Liter to meter cubed?
I like to use this acronym to help me remember the order of prefixes:
King Henry Died By Drinking Chocolate Milk
Kilo Hecto Deka Base Deci Centi Milli
King Henry Died By Drinking Chocolate Milk
Kilo Hecto Deka Base Deci Centi Milli
- Mon Mar 09, 2020 9:53 pm
- Forum: General Science Questions
- Topic: Review Packet
- Replies: 14
- Views: 1288
Re: Review Packet
Lyndon just posted practice problems for Electrochemistry and Kinetics that can be found if you search up ENDGAME.
- Mon Mar 09, 2020 9:52 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Going from pKa to pH
- Replies: 10
- Views: 733
Re: Going from pKa to pH
Also, don't forget that pKa and pKb are related to one another. So if you are given the pKb and asked for pH you can convert to pKa and go from there.
- Fri Mar 06, 2020 12:28 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Concentration Cells
- Replies: 5
- Views: 439
Re: Concentration Cells
The concentration difference is what gives the cell a current. At equilibrium, the concentrations are the same on both sides, so there would be no current.
- Fri Mar 06, 2020 12:26 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: same solutions in cell diagram
- Replies: 2
- Views: 215
Re: same solutions in cell diagram
Something to note is that a straight line between to different species can indicate a porous disk while double lines indicate the presence of a salt bridge.
- Fri Mar 06, 2020 12:25 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Equilibrium Constants
- Replies: 3
- Views: 268
Re: Equilibrium Constants
You could use the Nernst equation depending on what else is given.
- Fri Mar 06, 2020 12:23 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Favoring reactions
- Replies: 7
- Views: 620
Re: Favoring reactions
Looking at the Nernst Equation and how the variables related to one another can help you understand the effect of anode/cathode differences.
- Fri Mar 06, 2020 12:22 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: E° vs E
- Replies: 7
- Views: 537
Re: E° vs E
Standard conditions are at 25 degrees Celsius and 1M or 1 bar/atm.
- Sat Feb 29, 2020 3:36 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Difference in concentration
- Replies: 2
- Views: 226
Re: Difference in concentration
For a concentration cell, the same type of solution is used for both compartments. The only difference is the concentration.
- Sat Feb 29, 2020 3:34 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: hydrogen electrodes
- Replies: 3
- Views: 225
Re: hydrogen electrodes
Electrodes can transport electrons from one half-cell to another.
- Wed Feb 26, 2020 1:27 am
- Forum: Balancing Redox Reactions
- Topic: Acidic vs basic solution
- Replies: 2
- Views: 186
Re: Acidic vs basic solution
The homework problems from section 6K specified whether it was in an acidic or basic solution, so it will be provided.
- Wed Feb 26, 2020 1:26 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Platinum on one side of galvanic diagram
- Replies: 3
- Views: 230
Re: Platinum on one side of galvanic diagram
You can generally disregard the plutonium when it comes to cell potential calculations.
- Wed Feb 26, 2020 1:23 am
- Forum: Balancing Redox Reactions
- Topic: Homework 6M1
- Replies: 5
- Views: 474
Re: Homework 6M1
Copper is actually the anode, so you would subtract it's cell potential from the cathode's cell potential and set that to the provided cell potential.
- Thu Feb 20, 2020 6:18 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Anode and Cathode
- Replies: 14
- Views: 1051
Re: Anode and Cathode
To remember what's being oxidized and what's being reduced, it's helpful to think of the mnemonic LEO says GER. (Lose Electrons Oxidation. Gain Electrons Reduction.)
- Thu Feb 20, 2020 6:15 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation number of Ozone
- Replies: 10
- Views: 754
Re: Oxidation number of Ozone
It is 0 because no electrons are transferred.
- Thu Feb 20, 2020 6:13 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: salt bridge
- Replies: 5
- Views: 334
Re: salt bridge
It's also helpful to know where the salt bridge would be in a typical diagram of a galvanic cell.
- Thu Feb 20, 2020 6:10 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: standard hydrogen electrode
- Replies: 3
- Views: 250
Re: standard hydrogen electrode
The standard hydrogen electrode is the standard measurement of electrode potential for the thermodynamic scale of redox potentials.
- Thu Feb 20, 2020 6:07 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing Redox Reactions
- Replies: 5
- Views: 327
Re: Balancing Redox Reactions
It does not matter where they are placed in the reaction because the overall reaction stays the same.
- Tue Feb 11, 2020 10:25 pm
- Forum: Calculating Work of Expansion
- Topic: A system doing no work
- Replies: 4
- Views: 271
Re: A system doing no work
In a closed system, energy cannot be transferred to the surroundings.
- Tue Feb 11, 2020 10:24 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Delta U
- Replies: 8
- Views: 602
Re: Delta U
When solving for internal energy, it is helpful to keep track of the terms given in relation to the system and not the surroundings.
- Tue Feb 11, 2020 10:22 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Entropy in different phases
- Replies: 3
- Views: 209
Re: Entropy in different phases
Entropy in increasing order goes solid, liquid, and then gas.
- Tue Feb 11, 2020 10:21 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Eq and Ksp
- Replies: 1
- Views: 89
Re: Eq and Ksp
We do not need to know Ksp, it was not covered in lecture.
- Tue Feb 11, 2020 10:21 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: different formulas of w
- Replies: 3
- Views: 181
Re: different formulas of w
-P delta V is used to calculate work when there is a constant external pressure.
- Thu Feb 06, 2020 10:54 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Positive ∆S
- Replies: 5
- Views: 320
Re: Positive ∆S
Based off the second law of thermodynamics I feel like you can make the assumption that it is spontaneous because the total entropy of the universe is always increasing.
- Thu Feb 06, 2020 10:50 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Heat vs Temp
- Replies: 3
- Views: 225
Re: Heat vs Temp
Temperature is measured in Kelvin or Celsius while heat is typically measured in kilojoules or joules.
- Thu Feb 06, 2020 10:44 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Explaining Le Chatelier’s principle
- Replies: 2
- Views: 238
Re: Explaining Le Chatelier’s principle
Something to remember is that for endothermic reactions, heat can be thought of as a reactant and for exothermic reactions it can be thought of as a product.
- Thu Feb 06, 2020 10:37 pm
- Forum: Phase Changes & Related Calculations
- Topic: Heating Curve Phase Changes
- Replies: 11
- Views: 630
Re: Heating Curve Phase Changes
It is where the state is changing. It can be either the solid/liquid in between phase or the liquid/gas in between phase.
- Tue Feb 04, 2020 9:55 pm
- Forum: Calculating Work of Expansion
- Topic: Isobaric Processes
- Replies: 1
- Views: 90
Re: Isobaric Processes
By looking at the ideal gas equation PV=nRT we can see that volume can change if pressure stays constant because the number of moles and temperature can still affect the volume.
- Fri Jan 31, 2020 4:34 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: Calculating microstates
- Replies: 3
- Views: 255
Re: Calculating microstates
Yes, that'd be correct.
- Fri Jan 31, 2020 4:33 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: KbNa
- Replies: 5
- Views: 770
Re: KbNa
The Boltzmann constant is only used for gases because it relates the average KE of particles in a gas with the gas's temperature.
- Tue Jan 28, 2020 11:03 pm
- Forum: Phase Changes & Related Calculations
- Topic: Calculating Work
- Replies: 6
- Views: 223
Re: Calculating Work
W=-P(DeltaV) is the equation we should be using for problems. It's also found on the equation sheet.
- Tue Jan 28, 2020 11:02 pm
- Forum: Phase Changes & Related Calculations
- Topic: Units
- Replies: 16
- Views: 886
Re: Units
The change in temperature remains a constant regardless of what temperature unit is used. It's important to keep temperature units the same for each problem.
- Tue Jan 28, 2020 11:00 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Delta U
- Replies: 6
- Views: 291
Re: Delta U
Another popular unit the book uses for delta U or internal energy is kilojoules (kJ).
- Thu Jan 23, 2020 7:09 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Value of X
- Replies: 7
- Views: 235
Re: Value of X
You would use the Ka or Kb value and use an ice table to solve for x. If you're given the final concentration of any of the products you can work backwards, since the change in product concentration is equal to the final concentration.
- Thu Jan 23, 2020 7:08 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Chemical equation
- Replies: 5
- Views: 258
Re: Chemical equation
The chemical equations will be given to us.
- Tue Jan 21, 2020 8:42 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Discussion
- Replies: 8
- Views: 311
Re: Discussion
Attendance is not taken at discussion, however homework is returned and turned in during discussion sections. If you were planning on missing, someone in the class can turn it in for you.
- Tue Jan 21, 2020 8:40 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: salt and water reactions
- Replies: 2
- Views: 142
Re: salt and water reactions
Polyprotic acids typically have multiple Hydrogens allowing the Hydrogen to donate its proton in each reaction. The conjugate base resulting will contain one less Hydrogen and therefore, an additional negative charge.
- Tue Jan 21, 2020 8:39 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: pKa, Ka, and strength of acid
- Replies: 3
- Views: 112
Re: pKa, Ka, and strength of acid
Since strong acids dissociate completely, there will be a greater amount of products versus reactants. Since the Ka is the ratio of products to reactants, the Ka will be high for strong acids.
- Thu Jan 16, 2020 10:00 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Exothermic
- Replies: 5
- Views: 272
Re: Exothermic
Energy is required to break a bond.
- Thu Jan 16, 2020 9:58 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Percentage Ionization
- Replies: 2
- Views: 76
Re: Percentage Ionization
Percent ionization is the amount dissociated (concentration) over the initial concentration multiplied by 100.
- Wed Jan 15, 2020 6:08 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: When to use K and Kp
- Replies: 12
- Views: 438
Re: When to use K and Kp
Typically, if the problem gives concentration, then Kc is used. In most cases, it will be easy to know what you are asked for, if not specified.
- Tue Jan 14, 2020 12:09 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6A.19
- Replies: 6
- Views: 205
Re: 6A.19
Yeah, when I did this problem, I got 3.2x10^-15.
- Mon Jan 13, 2020 4:25 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Excess Reactant in Le Chatelier's Principle
- Replies: 6
- Views: 232
Re: Excess Reactant in Le Chatelier's Principle
When given problems regarding Le Chatelier's Principle, we are to assume that the products and reactants are in excess.
- Thu Jan 09, 2020 8:28 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ksp?
- Replies: 2
- Views: 106
Re: Ksp?
Ksp is not on the outline for chemical equilibrium found on Dr. Lavelle's website, only Kc and Kp.
- Thu Jan 09, 2020 8:26 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Clarification on equilibrium
- Replies: 3
- Views: 149
Re: Clarification on equilibrium
Whatever side is favored has a greater number of moles and a higher concentration than the other side.
- Thu Jan 09, 2020 8:23 pm
- Forum: Ideal Gases
- Topic: Rate of reaction
- Replies: 2
- Views: 131
Re: Rate of reaction
When the concentration of the reactants increase, the reaction rate increases and vice versa when the concentration of the reactants decrease.
- Thu Jan 09, 2020 8:21 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Catalysts
- Replies: 7
- Views: 199
Re: Catalysts
A catalyst is a substance that speeds up a chemical reaction by lowering the activation energy.
- Tue Jan 07, 2020 11:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5G11
- Replies: 5
- Views: 389
Re: 5G11
For part b, the reactant concentrations are excluded because they are in the solid and liquid forms.
- Tue Dec 03, 2019 6:21 pm
- Forum: Bronsted Acids & Bases
- Topic: Memorization
- Replies: 1
- Views: 149
Re: Memorization
At Lyndon's workshop on Monday, he gave us a worksheet called Acids and Bases Fundamentals. On it the list of common strong acids and bases included HCl, HBr, HI, HNO3, H2SO4, HCLO4, LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2, Sr(OH)2, and Ba(OH)2.
- Tue Dec 03, 2019 11:18 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: TEST 2 POLAR molecule
- Replies: 6
- Views: 454
Re: TEST 2 POLAR molecule
The lewis structure can actually be drawn with the Chlorine atoms across from each other. Although symmetrical, because not all atoms surrounding the central atom are the same, it is a polar molecule.
- Tue Dec 03, 2019 11:15 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Periodic Trends
- Replies: 8
- Views: 703
Re: Periodic Trends
The melting and boiling points rise across the three metals because of the increasing strength of their metallic bonds.
- Tue Dec 03, 2019 11:13 am
- Forum: Bond Lengths & Energies
- Topic: Boiling Point and bonds
- Replies: 5
- Views: 509
Re: Boiling Point and bonds
Drawing the lewis structure of the molecule can help you figure out the intramolecular forces. From there, the stronger the forces/bonds, the higher the boiling point.
- Mon Dec 02, 2019 4:38 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: how to find pH
- Replies: 4
- Views: 302
Re: how to find pH
If the pH of the acid and conjugate base are known, you can use the equation pH = pKa + log [A-]/[HA].
Re: 9C.1 c)
The "ate" suffix is typically used to denote the compound's net negative charge.
- Tue Nov 26, 2019 1:31 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: abbreviations
- Replies: 2
- Views: 90
Re: abbreviations
These can be found in the handout Dr. Lavelle shared with us through email a few days ago.
- Mon Nov 25, 2019 10:34 pm
- Forum: Student Social/Study Group
- Topic: Final Exam Review Session Topics
- Replies: 2
- Views: 233
Re: Final Exam Review Session Topics
I think there would be a heavy emphasis on the newer content, but we should be given a practice final that includes all the content from the course.
- Mon Nov 25, 2019 10:32 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Larger molecules
- Replies: 3
- Views: 269
Re: Larger molecules
We should know how to get the molecular formula from the name and then draw the lewis structure based off of the molecular formula.
- Mon Nov 25, 2019 10:28 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: OH2 vs H2O
- Replies: 4
- Views: 309
Re: OH2 vs H2O
You would not be marked down because they're interchangeable.
- Wed Nov 20, 2019 2:35 pm
- Forum: Dipole Moments
- Topic: Hydrogen Bonds
- Replies: 3
- Views: 132
Re: Hydrogen Bonds
Yes, the partial positive of the Hydrogen atom is attracted to the partial negative or the Oxygen, Fluorine, or Nitrogen atom, creating a Hydrogen bond.
- Tue Nov 19, 2019 10:19 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Sigma & Pi bonds
- Replies: 5
- Views: 345
Re: Sigma & Pi bonds
It's much lower energy to combine a single sigma bond and a single pi bond than trying to force two sigma bonds between two atoms.
- Tue Nov 19, 2019 10:16 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: See-Saw Shape
- Replies: 3
- Views: 267
Re: See-Saw Shape
The lone pair causes the angle to be slightly less than 90 degrees.
- Tue Nov 19, 2019 10:14 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polarity
- Replies: 5
- Views: 327
Re: Polarity
A single bond indicates sigma bond while a double bond means one sigma bond and one pi bond. The electron of the pi bond is loosely bound and therefore weak . The pi bond is easily shifted to any one of the two atoms. Due to the shifting of the pi electron, polarity comes up in the molecule with les...
- Tue Nov 19, 2019 10:06 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: polarizability of anions
- Replies: 3
- Views: 158
Re: polarizability of anions
Larger anions are more polarizable because they have more electrons over protons. The outer electrons are more loosely held together and can be easily distorted by the cation.
- Thu Nov 14, 2019 11:55 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Formula
- Replies: 3
- Views: 198
Re: VSEPR Formula
A helpful way I found to learning how to come up with the VSEPR formula for a molecule was by looking at different examples of lewis structures and their corresponding formulas.
- Thu Nov 14, 2019 11:53 am
- Forum: Administrative Questions and Class Announcements
- Topic: Test #2
- Replies: 4
- Views: 220
Re: Test #2
No, the test covers topics covered after midterm content to Friday's lecture.
- Tue Nov 12, 2019 10:00 pm
- Forum: Dipole Moments
- Topic: Why doesn't CH3CHO form a hydrogen bond?
- Replies: 3
- Views: 598
Re: Why doesn't CH3CHO form a hydrogen bond?
The Hydrogen attaches to the Carbon with a single bond and the Oxygen attaches to the Carbon with a double bond.
- Tue Nov 12, 2019 11:09 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Forces
- Replies: 3
- Views: 113
Re: Forces
Lone pairs weaken the bond because of electron repulsion. And, the weaker the bond, the longer the bond.
- Tue Nov 12, 2019 11:05 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizing Power
- Replies: 6
- Views: 1276
Re: Polarizing Power
Small cations have a high polarizing power while large anions have high polarizability.
- Wed Nov 06, 2019 10:23 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge
- Replies: 2
- Views: 144
Re: Formal Charge
Another helpful tip when it comes to figuring out which elements should have the extra electron is not only the more electronegative one, but also the extra element is found on the elements that are at the ends of the lewis structure.
- Tue Nov 05, 2019 7:18 pm
- Forum: SI Units, Unit Conversions
- Topic: When to use scientific notation
- Replies: 4
- Views: 317
Re: When to use scientific notation
Scientific notation is most commonly used with numbers that have powers greater than or equal to +/-3
- Tue Nov 05, 2019 7:17 pm
- Forum: SI Units, Unit Conversions
- Topic: When to use scientific notation
- Replies: 4
- Views: 317
Re: When to use scientific notation
Scientific notation is most commonly used with numbers that have powers greater that or equal to +/-3
- Tue Nov 05, 2019 7:11 pm
- Forum: Octet Exceptions
- Topic: Naming molecules
- Replies: 2
- Views: 181
Re: Naming molecules
For this midterm, I believe that we don't need to know how to name molecules and that the chemical formula will be provided unless it's something like CO2 or H2O.
- Tue Nov 05, 2019 12:23 am
- Forum: *Black Body Radiation
- Topic: Ludwig Boltzmann law midterm question
- Replies: 3
- Views: 378
Re: Ludwig Boltzmann law midterm question
I think you should have a general idea of what black body radiation is, however I don't think we will be tested on the law.
- Mon Nov 04, 2019 1:03 pm
- Forum: Ionic & Covalent Bonds
- Topic: Midterm
- Replies: 2
- Views: 195
Re: Midterm
Yes, we'll be given the same equation sheet that was given to us for test 1.
- Wed Oct 30, 2019 10:58 pm
- Forum: Resonance Structures
- Topic: Delocalized Electrons
- Replies: 4
- Views: 213
Re: Delocalized Electrons
Delocalized electrons are electrons in a molecule, ion or solid metal that are not associated with an atom or covalent bond.
- Wed Oct 30, 2019 10:57 pm
- Forum: Coordinate Covalent Bonds
- Topic: coordinate covalent bonds
- Replies: 3
- Views: 197
Re: coordinate covalent bonds
Coordinate covalent bonds occur when one atom provides a lone pair of electrons to the bond.
- Wed Oct 30, 2019 10:55 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A.21
- Replies: 4
- Views: 179
Re: 2A.21
If the last orbital has an odd number of electrons in the configuration, then this is an indication that there is an unpaired electron.
- Wed Oct 30, 2019 10:52 pm
- Forum: Octet Exceptions
- Topic: Radicals
- Replies: 5
- Views: 270
Re: Radicals
A radical is an atom, molecule, or ion that has an unpaired valence electron.
- Tue Oct 29, 2019 7:54 pm
- Forum: Electronegativity
- Topic: Is there a relationship between ionization energy and electronegativity?
- Replies: 2
- Views: 140
Re: Is there a relationship between ionization energy and electronegativity?
They generally have an inverse relationship.
- Wed Oct 23, 2019 4:01 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Ion
- Replies: 3
- Views: 136
Re: Ion
In a ground-state of an atom, all electrons are in the lowest possible energy levels.
- Wed Oct 23, 2019 3:58 pm
- Forum: Octet Exceptions
- Topic: Octet Rule
- Replies: 6
- Views: 280
Re: Octet Rule
Yes! The octet rule is applicable to most elements, including the ones past the second period.
- Wed Oct 23, 2019 3:55 pm
- Forum: Lewis Structures
- Topic: Finding Valence Electrons
- Replies: 8
- Views: 436
Re: Finding Valence Electrons
Another way to remember this is that the noble gases are very stable therefore they have 8 valence electrons, the most stable configuration.
- Wed Oct 23, 2019 3:54 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Week 4 HW questions
- Replies: 4
- Views: 342
Re: Week 4 HW questions
It should be from either the Quantum World or Chemical Bonds section.
- Wed Oct 23, 2019 3:50 pm
- Forum: Trends in The Periodic Table
- Topic: Trend in periodic table
- Replies: 6
- Views: 251
Re: Trend in periodic table
Typically when moving down the periodic table and towards the left corner, the atomic radius gets bigger.
- Wed Oct 16, 2019 3:10 pm
- Forum: Properties of Light
- Topic: Midterm- Electromagnetic spectrum
- Replies: 3
- Views: 184
Re: Midterm- Electromagnetic spectrum
It'd be helpful to know the spectrum because questions we've had include knowing if the wavelength is visible or what type of electromagnetic radiation our answer deals with (like is it gamma or x-ray...). You should also know the wavelength range for the visible light spectrum and the order of the ...
- Tue Oct 15, 2019 11:56 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Best Way To Study?
- Replies: 56
- Views: 3667
Re: Best Way To Study?
I attended a step-up session and it really helped reinforce important topics that will appear on tests and midterms. I highly recommend it!
- Tue Oct 15, 2019 11:52 am
- Forum: Properties of Light
- Topic: 1.A.3
- Replies: 2
- Views: 112
Re: 1.A.3
Amplitude and frequency are independent of one another. Larger amplitude means higher energy and lower amplitude means lower energy. Higher frequency means more energy and lower frequency means lower energy using the E=h(frequency) equation.
- Mon Oct 14, 2019 2:02 pm
- Forum: Properties of Electrons
- Topic: 1B.15 Question
- Replies: 2
- Views: 230
Re: 1B.15 Question
Part C is asking for the wavelength of the electromagnetic radiation that hits the metallic surface. The energy of the incoming photon, E, is the work function and kinetic energy of the electron added together because the energy going into the surface is a part of the work function and the excess in...
- Mon Oct 14, 2019 1:54 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Homework 3 due during discussion in week 4
- Replies: 1
- Views: 110
Re: Homework 3 due during discussion in week 4
In an email Dr. Lavelle sent on October 5th he mentions that Homework #3 is only on quantum topics.
- Fri Oct 11, 2019 4:30 pm
- Forum: Student Social/Study Group
- Topic: Best Sessions
- Replies: 12
- Views: 490
Re: Best Sessions
If you're an AAP member you can attend peer learning sessions that are weekly that are really helpful. If you don't know if you are eligible or if you are not and still want to apply, Campbell Hall has resources that can help you join the program and gain access to the sessions.
- Thu Oct 10, 2019 11:59 am
- Forum: Einstein Equation
- Topic: 1B.9 HW
- Replies: 2
- Views: 320
Re: 1B.9 HW
First convert the given wavelength of 420 nm to m (420 x 10^-9) and multiply the given 32 W to joules (32 J/s). Since the problem tell us it's in 2 seconds, multiply the time with the Joules/sec to give 64 total Joules. Now, use the E=hc/lambda equation and substitute 420 x 10^-9 m for lambda. You s...
- Thu Oct 10, 2019 10:04 am
- Forum: Balancing Chemical Reactions
- Topic: Combustion
- Replies: 17
- Views: 1077
Re: Combustion
The most important thing to know for a combustion reaction is that O2(gas) is always a reactant and the products are always H2O and CO2.
- Tue Oct 08, 2019 10:40 am
- Forum: Properties of Light
- Topic: Planck's Law
- Replies: 4
- Views: 166
Re: Planck's Law
Another way to think of it is that electromagnetic radiation isn't a single flow. It is made up of quanta of energy, the size of which involves Planck's constant.
- Mon Oct 07, 2019 10:33 pm
- Forum: Properties of Light
- Topic: Posts Per Week
- Replies: 6
- Views: 265
Re: Posts Per Week
Posts for the week count from Monday at 12:00am to Sunday at 11:59pm.
- Thu Oct 03, 2019 2:09 pm
- Forum: Limiting Reactant Calculations
- Topic: Percentage Yields
- Replies: 8
- Views: 595
Re: Percentage Yields
I believe the closest to 100% is preferred but from 70% and up is acceptable.
- Thu Oct 03, 2019 2:07 pm
- Forum: Significant Figures
- Topic: Powers of 10
- Replies: 10
- Views: 640
Re: Powers of 10
You generally use sig figs when dealing with number with 2 or more powers of 10.
- Thu Oct 03, 2019 2:05 pm
- Forum: Empirical & Molecular Formulas
- Topic: How to properly order moles of a compound
- Replies: 2
- Views: 165
Re: How to properly order moles of a compound
I'm pretty sure the positively charged elements are placed first and then the negatively charged ones.
- Thu Oct 03, 2019 2:01 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Where do we turn in the homework?
- Replies: 5
- Views: 218
Re: Where do we turn in the homework?
This Friday, you'll probably turn in homework at the beginning of lecture in the front. There are usually separate piles based on your discussion section so make sure you know what section you're in.