## 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: 137

### 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: 42

### 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: 147

### 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
Mon Mar 09, 2020 9:53 pm
Forum: General Science Questions
Topic: Review Packet
Replies: 14
Views: 467

### 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: 215

### 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: 125

### 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: 50

### 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: 100

### 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: 159

### 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: 134

### 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: 37

### 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: 42

### 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: 52

### 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: 61

### 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: 144

### 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: 384

### 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: 158

### 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: 52

### 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: 43

### 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: 77

### 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: 58

### 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: 168

### 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: 55

### 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: 27

### 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: 54

### 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: 77

### 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: 65

### 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: 43

### 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: 118

### 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: 31

### 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: 61

### 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: 4
Views: 350

### 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: 68

### 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: 175

### 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: 63

### 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: 56

### 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: 118

### 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: 87

### 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: 50

### 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: 17

### 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: 87

### 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: 14

### 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: 101

### 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: 85

### 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: 83

### 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: 28

### 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: 38

### 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: 37

### 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: 70

### 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: 84

### 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: 62

### 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: 107

### 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: 275

### 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: 185

### 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: 81

### 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].
Tue Nov 26, 2019 1:33 am
Forum: Naming
Topic: 9C.1 c)
Replies: 2
Views: 29

### 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: 36

### 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: 88

### 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: 85

### 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: 119

### 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: 54

### 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: 79

### 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: 51

### 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: 55

### 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: 66

### 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: 70

### 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: 51

### 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: 45

### 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: 45

### 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: 141

### 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: 52

### 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: 167

### 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: 167

### 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: 64

### 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: 205

### 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: 65

### 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: 61

### 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: 74

### 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: 83

### 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: 96

### 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: 42

### 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: 29

### 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: 64

### 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: 118

### 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: 142

### 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: 47

### 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: 54

### 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: 1311

### 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: 41

### 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: 58

### 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: 38

### 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: 199

### 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: 95

### 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: 627

### 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: 78

### 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: 100

### 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: 140

### 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: 181

### 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: 46

### 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: 88

### 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.

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