## Search found 107 matches

Fri Mar 13, 2020 5:26 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Reduction Potential
Replies: 4
Views: 64

### Re: Reduction Potential

The cathode is the cell reduction potential that is most positive. So if they are both negative, then it would be the smallest negative number at the cathode.
Fri Mar 13, 2020 4:27 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 7D.1 Formula
Replies: 1
Views: 57

### Re: 7D.1 Formula

The textbook used the Arrhenius equation for two temperatures, denoted T1 and T2, when the rate constants have the value K1 and K2. At temperature T1: lnk_{1}=lnA-\frac{E_{a}}{RT_{1}} At temperature T2: lnk_{2}=lnA-\frac{E_{a}}{RT_{2}} lnA is eliminated by subtracting the first equation from the sec...
Thu Mar 12, 2020 7:05 am
Forum: Administrative Questions and Class Announcements
Topic: Worksheet for Review Session?
Replies: 3
Views: 138

### Re: Worksheet for Review Session?

Wed Mar 11, 2020 6:39 pm
Forum: Zero Order Reactions
Topic: 7A.15A
Replies: 3
Views: 39

### Re: 7A.15A

Yes, that is correct.
Mon Mar 09, 2020 4:10 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 7D.5 Solution
Replies: 1
Views: 34

### Re: 7D.5 Solution

The value of R is 8.314 J/mol x K so it should be 0.008314 if you are converting to KJ/mol x K. The solutions manual seems to have missed one decimal place.
Mon Mar 09, 2020 3:48 pm
Forum: General Rate Laws
Topic: overall order
Replies: 5
Views: 50

### Re: overall order

The overall order is just the sum of all the powers of the reactants in the rate law. Such as Rate=k[A]^2[B]^1 has an overall order of 3
Mon Mar 09, 2020 3:33 pm
Forum: First Order Reactions
Topic: Textbook question 7B.3
Replies: 5
Views: 132

### Re: Textbook question 7B.3

[A]_{t} represents the concentration of reactant A that remains at time t. The problem states that the concentration of product B rises to 0.034 M. This means that the concentration of reactant A decreased by 0.068 M. You would need to subtract this number from the initial concentration given to fi...
Sun Mar 08, 2020 6:42 pm
Forum: General Science Questions
Topic: Review Packet
Replies: 14
Views: 326

### Re: Review Packet

The review sessions are up on the Chem 14B page and Lyndon usually announces that the review packets are up in lecture. So, it will probably announced some time during the week.
Sun Mar 08, 2020 6:33 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Molecularity
Replies: 12
Views: 151

### Re: Molecularity

molecularity is the number of reactant molecules, atoms, or ions taking part in a specified elementary reaction.
Sun Mar 08, 2020 6:25 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: 7A.15
Replies: 5
Views: 66

### Re: 7A.15

C is zero order reaction which can be seen from experiments 1 and 4 where A and B are constant while C changes but the rate stays the same. Knowing this, C doesn't need to be taken into account since its concentration has no effect on the rate
Sat Mar 07, 2020 3:20 pm
Forum: General Rate Laws
Topic: 7A.17 part C
Replies: 3
Views: 76

### Re: 5A.17 part C

The table gives the initial concentration in (mmol/L) as well as the initial rate (mmol/LxS). The textbook solution converts the mmol to mol in their calculations which results in the final answer being 2.85x10^12 L^4/mol^4xS
Fri Mar 06, 2020 8:31 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Units G=-nFE
Replies: 6
Views: 176

### Re: Units G=-nFE

F is also Coulombs/mol and Volts is Joules/Coulomb. When multiplied together, the units cancel out leaving Joules for deltaG
$-nFE^{\circ}cell=-n(\frac{C}{mol})(\frac{J}{C})$
Sat Feb 29, 2020 6:28 pm
Forum: Balancing Redox Reactions
Topic: 6K5a Oxygen Oxidation Numbers
Replies: 1
Views: 65

### Re: 6K5a Oxygen Oxidation Numbers

Wed Feb 26, 2020 8:09 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6M.1
Replies: 5
Views: 110

### Re: 6M.1

We know that the cell diagram is reversed when the cell potential is negative. The cell potential was given as -0.689 which means that the cathode is the left of the cell diagram and the anode is the right side of the cell diagram. This makes the unknown metal the cathode and the copper the anode.
Wed Feb 26, 2020 7:58 pm
Forum: Balancing Redox Reactions
Topic: Homework 6M1
Replies: 5
Views: 135

### Re: Homework 6M1

A positive cell potential means that the cathode is the electrode on the right of the cell diagram. A negative cell potential means that the cathode is the electrode on the left side of the cell diagram. Since the problem states that the cell potential was found to be negative, then this means that ...
Tue Feb 25, 2020 8:16 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Platinum electrode
Replies: 4
Views: 69

### Re: Platinum electrode

A chemically inert metallic conductor is needed to carry the electrons into or out of the electrode compartment. Therefore, Platinum solid is included when there are no metallic conductors on either the anode or the cathode. Both sides have to have a metallic conductor. In some cases, there may be a...
Tue Feb 25, 2020 8:08 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Where to find Ecell values
Replies: 15
Views: 194

### Re: Where to find Ecell values

The Ecell values can be found in the back of the textbook in Appendix 2B.
Sat Feb 22, 2020 12:46 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: n in -nFE
Replies: 12
Views: 124

### Re: n in -nFE

n is the number of electrons in moles. This can be found by writing the two half-reactions and seeing how many electrons are transferred.
Sat Feb 22, 2020 12:08 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Pt
Replies: 7
Views: 67

### Re: Pt

But some problems in the textbook have Pt(s) on the anode side or both sides (6L.3 (d) and (e)). Why do some have it only on the cathode or anode side and others on both? Each side of the cell diagram needs to have a conducting solid. In the problems that have Platinum on only one side, there alrea...
Fri Feb 21, 2020 7:44 pm
Forum: Balancing Redox Reactions
Topic: Homework 6K5
Replies: 1
Views: 42

### Re: Homework 6K5

In the step where it balances the H, it results in this equation: 2H_{2}O(l)+O_{3}(g)\rightarrow O_{2}(g)+H_{2}O(l)+2OH^{-}(aq) Since there are two H20 in the reactants side and one H2O on the products side, the H2O on the products side cancels out with one of...
Fri Feb 21, 2020 7:15 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.5
Replies: 4
Views: 85

### Re: 6L.5

Oxidation occurs in the anode and Reduction occurs in the cathode. In this problem, Au is both the oxidizing and reducing agent. Au+ is being oxidized when it goes to Au3+ since it goes from having an oxidation state of +1 to +3. It is being reduced when Au+ goes to Au(s) since it goes from having a...
Fri Feb 21, 2020 6:42 pm
Forum: Balancing Redox Reactions
Topic: Charge of oxygen
Replies: 15
Views: 151

### Re: Charge of oxygen

The oxidation state of O2 will be -2 even if it stands alone. For O3, the oxidation state will be 0. Oxygen is sometimes -1 such as peroxides, H2O2, since hydrogen has an oxidation state of +1
Sun Feb 16, 2020 5:25 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Meaning of q=-w
Replies: 14
Views: 314

### Re: Meaning of q=-w

q=-w can help you figure out that the reaction is isothermal reversible which means that it has a constant temperature and that the internal energy equals zero.
Sun Feb 16, 2020 5:15 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: q of ice and q of water
Replies: 8
Views: 164

### Re: q of ice and q of water

The heat lost by the system is the heat gained by the surroundings. In this case, since the heat is lost by the water it is negative and the heat of the ice is positive since it gained the heat.
Sun Feb 16, 2020 4:59 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Delta s = 0
Replies: 8
Views: 195

### Re: Delta s = 0

When a reaction is reversible, the delta S (total) equals 0, because the delta S of the surrounding is the same as the delta S of the system with opposite sign.
Sun Feb 16, 2020 4:48 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Delta E
Replies: 11
Views: 235

### Re: Delta E

Delta E is the change in energy and it can be used interchangeably for the change in internal energy.
Sun Feb 16, 2020 2:50 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Constant Pressure and Volume
Replies: 6
Views: 136

### Re: Constant Pressure and Volume

Calculations vary for monoatomic gases since Cv is 3R/2 under constant volume and Cp is 5R/2 under constant pressure.
Sun Feb 16, 2020 2:02 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: relationship between delta G and K
Replies: 2
Views: 34

### Re: relationship between delta G and K

If the equilibrium constant and the temperature is given, then you can find delta G
Sat Feb 08, 2020 12:56 pm
Forum: Calculating Work of Expansion
Topic: units
Replies: 3
Views: 57

### Re: units

You would just use the conversion of 101.325 J/ 1 L* atm.
Sat Feb 08, 2020 12:40 pm
Forum: Calculating Work of Expansion
Topic: Midterm equation sheet
Replies: 16
Views: 214

### Re: Midterm equation sheet

Yes, the same constants and equation sheet will be be provided on the midterm.
Sat Feb 08, 2020 12:09 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: open system
Replies: 5
Views: 69

### Re: open system

A car is an open system because it exchanges both heat and matter. Matter in the form of gasoline to start the engine and heat is released when the car is running.
Sat Feb 08, 2020 12:01 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Calorimeters
Replies: 17
Views: 384

### Re: Calorimeters

A bomb calorimeter is constant volume which means that since there is no change in volume then there is no work done.
Fri Feb 07, 2020 11:47 pm
Forum: Phase Changes & Related Calculations
Topic: Environment
Replies: 4
Views: 82

### Re: Environment

The combustion of fossil fuels releases carbon dioxide into the atmosphere which contributes to global warming. Some alternatives for fossil fuels are ethanol, methane, and biodiesel. One way that this could be asked on the midterm is calculating the heat of combustion.
Fri Jan 31, 2020 12:26 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 5
Views: 53

### Re: Bond Enthalpies

Bond enthalpies are the least accurate method to calculate enthalpy changes because they are an average of many bonds.
Fri Jan 31, 2020 12:04 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: hess's law
Replies: 13
Views: 90

### Re: hess's law

Yes, they must be on the opposite sides of the reaction equation in order to cancel out.
Thu Jan 30, 2020 10:12 pm
Forum: Phase Changes & Related Calculations
Topic: 4B.1
Replies: 6
Views: 82

### Re: 4B.1

It would be positive since work is being done on the system.
Thu Jan 30, 2020 9:54 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: State Functions
Replies: 6
Views: 64

### Re: State Functions

Heat and work are not state functions because they depend on the paths they take.
Thu Jan 30, 2020 9:47 pm
Forum: Phase Changes & Related Calculations
Topic: Units
Replies: 16
Views: 165

### Re: Units

They are interchangeable because the change in temperature is the same whether you use Celsius or Kelvin. The change in degrees Celsius is the same as the change in degrees Kelvin.
Wed Jan 22, 2020 11:03 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: suggestions
Replies: 16
Views: 163

### Re: suggestions

Wed Jan 22, 2020 10:48 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5.33
Replies: 4
Views: 47

### Re: 5.33

A catalyst only increases the rate of reaction, it would not favor the formation of reactants or products.
Mon Jan 20, 2020 11:10 pm
Forum: Ideal Gases
Topic: homework #3
Replies: 16
Views: 248

### Re: homework #3

It would be better practice to do the homework from outline 2 since it will also be on the test.
Mon Jan 20, 2020 10:30 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Writing K Expression
Replies: 6
Views: 57

### Re: Writing K Expression

Yes, all aqueous and gases are included in the equilibrium expression
Mon Jan 20, 2020 9:04 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Does order matter?
Replies: 5
Views: 43

### Re: Does order matter?

No, the order in which you write the reactants and products do not matter as long as the products are in the numerator and reactants in the denominator
Sun Jan 19, 2020 12:10 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q < K
Replies: 16
Views: 142

### Re: Q < K

Yes, both statements mean the same thing. When Q<K, there is more reactants than products and it is not at equilibrium. In order for it to get to equilibrium, the reaction proceeds to the right to form products.
Fri Jan 17, 2020 12:24 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Replies: 11
Views: 101

### Re: ICE and quadratic formula

Using the quadratic formula can be skipped if the equilibrium constant is less than 10^-3. The value of x would be so small that it would be negligible in the final answer when figuring out the equilibrium concentrations.
Thu Jan 16, 2020 11:48 am
Forum: Equilibrium Constants & Calculating Concentrations
Replies: 10
Views: 102

If you get two positive answers, you could rule out the value that is greater than your initial concentration since it would result in a negative number when plugged in to the equilibrium expression.
Thu Jan 16, 2020 11:44 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc vs Kp
Replies: 5
Views: 46

### Re: Kc vs Kp

Kc can be used with gases if they give the concentrations of reactants and products in molarity.
Wed Jan 15, 2020 4:40 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: When to omit "x-term"
Replies: 6
Views: 69

### Re: When to omit "x-term"

The x-term can be omitted when the equilibrium constant is small (less than 10^-3) since the difference would be negligible.
Sun Jan 12, 2020 4:04 pm
Forum: Ideal Gases
Topic: Bars vs atmospheres
Replies: 13
Views: 95

### Re: Bars vs atmospheres

Both are applicable because they are both units for measuring pressure.
Sun Jan 12, 2020 2:41 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homogenous Equilibrium
Replies: 13
Views: 95

### Re: Homogenous Equilibrium

A homogeneous equilibrium has to have all reactions and products in the same phase. Such as they all have to be gases, or all aqueous,... If even one of the reactants or products are in a different phase then it is a heterogeneous equilibrium.
Sun Jan 12, 2020 2:35 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: when to use Kc vs Kp
Replies: 11
Views: 81

### Re: when to use Kc vs Kp

Kc uses brackets because it is dealing with the molar concentration while it isn't used with Kp because it is dealing with gases which is in the units of bar or atm.
Sun Jan 12, 2020 2:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc vs Kp
Replies: 10
Views: 80

### Re: Kc vs Kp

Kc and Kp will be two different values since Kc uses the molar concentration value while Kp is uses partial pressure.
Sat Jan 11, 2020 11:30 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE tables
Replies: 3
Views: 59

### Re: ICE tables

The C stands for the change in molar concentration. C is figured out by looking at the chemical equation and its coefficient for the reactants and products.
Sun Dec 08, 2019 8:05 pm
Forum: Lewis Acids & Bases
Topic: bases
Replies: 5
Views: 204

### Re: bases

Strong bases dissociate completely in water unlike weak bases which don't dissociate completely.
Sun Dec 08, 2019 7:56 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Ph and poH of weak acids
Replies: 8
Views: 96

### Re: Ph and poH of weak acids

This will be covered in Chem 14B
Sun Dec 08, 2019 7:26 pm
Forum: Hybridization
Topic: 2sp2 and sp2
Replies: 10
Views: 193

### Re: 2sp2 and sp2

sp2 should be fine if the question didn't specifically ask for the orbitals that they were in.
Sun Dec 08, 2019 7:24 pm
Forum: Administrative Questions and Class Announcements
Topic: Saying Thank You to Dr. Lavelle
Replies: 291
Views: 136209

### Re: Saying Thank You to Dr. Lavelle

Thank you Dr. Lavelle for providing us with many resources to assist us in our learning!
Sun Dec 08, 2019 7:07 pm
Forum: Naming
Topic: -ate
Replies: 11
Views: 284

### Re: -ate

You do not have to add anything to positively or neutral charged ones. It is only if it is negatively charged that you add the -ate
Sun Dec 01, 2019 9:47 pm
Forum: Hybridization
Topic: Hybridization (Lone Pairs)
Replies: 4
Views: 81

### Re: Hybridization (Lone Pairs)

Yes, they do have hybrid orbitals. The lone pairs count as a region of electron density.
Sun Dec 01, 2019 9:41 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sigma Bond
Replies: 10
Views: 154

### Re: Sigma Bond

Yes, single bonds always have one sigma bond.
Sun Dec 01, 2019 9:35 pm
Forum: Naming
Topic: Memorizing ligand names
Replies: 5
Views: 55

### Re: Memorizing ligand names

We won't be provided a chart so we have to have the common ligands memorized.
Sun Dec 01, 2019 9:25 pm
Forum: Hybridization
Topic: Hybridization
Replies: 7
Views: 93

### Re: Hybridization

I believe that this is all that we need to know. As long as you know how this is applied in the homework problems then it should be fine.
Sun Dec 01, 2019 9:23 pm
Forum: Hybridization
Topic: Order When Writing
Replies: 5
Views: 65

### Re: Order When Writing

It can be written as either!
Sun Dec 01, 2019 8:28 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Atoms in the same plane
Replies: 4
Views: 66

### Re: Atoms in the same plane

Atoms will be in the same plane if they have a double or triple bond since they can't rotate due to having a pi bond. Furthermore, if they are either trigonal or square planar the atoms also lie in the same plane.
Sun Nov 24, 2019 11:09 pm
Forum: Hybridization
Topic: hybridization number
Replies: 5
Views: 66

### Re: hybridization number

Yes, lone pairs do count. Hybridization takes into account all areas of electron density.
Sun Nov 24, 2019 10:54 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Final
Replies: 10
Views: 138

### Re: Final

Yes, it is.
Sun Nov 24, 2019 10:43 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: london forces
Replies: 9
Views: 101

### Re: london forces

London dispersion forces increase in strength with increasing polarizability of the molecule. The polarizability of a molecule increases with the number of electrons, therefore the larger molecule will have stronger London Dispersion force.
Sun Nov 24, 2019 10:34 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: How to draw dipoles
Replies: 7
Views: 130

### Re: How to draw dipoles

Dipoles have the arrow pointing towards the more electronegative atom.
Sun Nov 24, 2019 9:44 pm
Forum: Sigma & Pi Bonds
Topic: sigma and pi bonds
Replies: 27
Views: 564

### Re: sigma and pi bonds

Yes, you are correct.
Sun Nov 24, 2019 3:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent Shape
Replies: 31
Views: 837

### Re: Bent Shape

The bent shape can have 1 lone pair when its electron geometry is trigonal planar and 2 lone pairs when its electron geometry is tetrahedral.
Sun Nov 17, 2019 8:08 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: Dipole
Replies: 3
Views: 45

### Re: Dipole

Dipole moments cancel out when there are same signs on different sides of the molecule.
Lavelle explained it further in this post:https://lavelle.chem.ucla.edu/forum/viewtopic.php?t=2234#p4519
Sun Nov 17, 2019 7:21 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: dipole moments
Replies: 7
Views: 62

### Re: dipole moments

Yes, dipole moments occur when there is a difference in electronegativity. If there is a greater difference in electronegativity, there is a larger dipole moment.
Sat Nov 16, 2019 4:19 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: Test Topics
Replies: 11
Views: 295

### Re: Test Topics

Anything after the midterm, so anything after 2D and up to Monday's lecture.
Sat Nov 16, 2019 4:08 pm
Forum: Bond Lengths & Energies
Topic: Quiz for Next week dashes/wedges
Replies: 11
Views: 150

### Re: Quiz for Next week dashes/wedges

I believe Lavelle said that we wouldn't have to draw the dash/wedges during lecture.
Sat Nov 16, 2019 3:14 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: All VSEPR structures or just ones from class?
Replies: 11
Views: 197

### Re: All VSEPR structures or just ones from class?

I think it is best to remember all of them, just to be safe.
Sun Nov 10, 2019 9:15 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: The exceptions
Replies: 6
Views: 220

### Re: The exceptions

The exceptions are chromium and copper. Chromium is an exception because a half filled d-sub level is more stable than a partially filled d sub level. The same goes for Copper where it is more stable as a completely filled d-sub level.
Sun Nov 10, 2019 7:00 pm
Forum: *Shrodinger Equation
Topic: Shrodinger Equation
Replies: 4
Views: 191

### Re: Shrodinger Equation

It uses a wave function to describe an electron in an atom. The wave function squared shows the probability of finding a region of electron density at some point. Orbitals are solutions to Schrodinger's equation and gives the energy of the electron.
Sun Nov 10, 2019 6:31 pm
Forum: Dipole Moments
Topic: HW this week
Replies: 6
Views: 60

### Re: HW this week

I think it would be fine to do problems from either section since we haven't really gone in depth in the new section yet.
Sun Nov 10, 2019 6:20 pm
Forum: Lewis Structures
Topic: Electronegative
Replies: 14
Views: 181

### Re: Electronegative

Yes, electronegativity is an atom's tendency to attract electrons to itself. Fluorine is the most electronegative atom in the periodic table.
Sun Nov 10, 2019 2:17 pm
Forum: Octet Exceptions
Topic: Octet Exception
Replies: 8
Views: 231

### Re: Octet Exception

Any element below and including the 3rd period is able to have expanded octet. The first two periods cannot have expanded octets because they only go up to the p block.
Sun Nov 03, 2019 9:54 pm
Forum: Trends in The Periodic Table
Topic: Electronegativity
Replies: 3
Views: 71

### Re: Electronegativity

Oxygen has a higher electronegativity when you look at the periodic trend for increasing electronegativity.
Sun Nov 03, 2019 8:51 pm
Topic: Midterm
Replies: 14
Views: 208

### Re: Midterm

It's not going to be on the midterm since there are no homework problems on it.
Sun Nov 03, 2019 8:04 pm
Forum: Photoelectric Effect
Topic: Threshold Energy
Replies: 5
Views: 96

### Re: Threshold Energy

Yes, the threshold energy is represented by the work function. In order for an electron to be ejected from the metal surface, the photon has to have more energy than the work function.
Sun Nov 03, 2019 7:08 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: 1B.26
Replies: 4
Views: 88

### Re: 1B.26

The uncertainty in velocity would be 10 m/s because that is the range that velocity could be between.
Sun Nov 03, 2019 4:15 pm
Forum: Ionic & Covalent Bonds
Topic: middle atom
Replies: 13
Views: 105

### Re: middle atom

The central atom is usually the least electronegative one. Electronegativity increases as you go from left to right across a period and increases as you go up a group in the periodic table.
Sun Oct 27, 2019 6:25 pm
Forum: Properties of Electrons
Topic: Electron removal
Replies: 11
Views: 172

### Re: Electron removal

Electrons that are further away from the nucleus are easier to remove because there is less attraction between the electron and the nucleus due to the distance between them.
Sun Oct 27, 2019 6:14 pm
Forum: Photoelectric Effect
Topic: Increasing Light Intensity Photoelectric Effect
Replies: 7
Views: 91

### Re: Increasing Light Intensity Photoelectric Effect

Yes, changing the intensity of a particular light will cause a change in the number of electrons being ejected. So if the intensity of a light is increased, the number of electrons being ejected will increase as well.
Sun Oct 27, 2019 5:54 pm
Forum: Resonance Structures
Topic: Bond lenghts.
Replies: 11
Views: 148

### Re: Bond lenghts.

I don't think you have to know how to find the bond lengths but rather the general concepts that double bonds are shorter than single bonds
Sun Oct 27, 2019 5:43 pm
Forum: Ionic & Covalent Bonds
Topic: Week 5 HW
Replies: 4
Views: 83

### Re: Week 5 HW

I would think it would be on Chemical Bonds since we are moving into this topic more this week
Sun Oct 27, 2019 4:04 pm
Forum: Properties of Light
Topic: Value for C
Replies: 8
Views: 108

### Re: Value for C

Either one would be fine but on tests you should use the one given on the equations and constant sheet in order to be precise as possible.
Sun Oct 20, 2019 7:28 pm
Forum: Properties of Light
Topic: Week 3 Homework
Replies: 9
Views: 184

### Re: Week 3 Homework

This week we can still do the problems from "The Quantum World" section since we will be working on this unit on Monday.
Sun Oct 20, 2019 7:16 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Best Way To Study?
Replies: 56
Views: 1225

### Re: Best Way To Study?

I find that going through all the suggested practice problems on the syllabus works best for me. I work through as many problems as I can and also go to some of the workshops provided.
Sun Oct 20, 2019 7:13 pm
Forum: Properties of Electrons
Topic: Mass of an Electron
Replies: 14
Views: 237

### Re: Mass of an Electron

The mass of an electron, proton, and neutron is a set mass that is provided on the constants and equations sheet.
Sun Oct 20, 2019 7:07 pm
Forum: DeBroglie Equation
Topic: Units for mass
Replies: 4
Views: 84

### Re: Units for mass

Kg is used often because it is an SI unit which is used in DeBroglie's equation.
Sun Oct 20, 2019 6:33 pm
Forum: Photoelectric Effect
Topic: Speed of Light
Replies: 29
Views: 340

### Re: Speed of Light

The speed of light is always a constant. It would be better to use the exact number provided on the equation sheet (2.99792*10^8) on the exams.
Sun Oct 20, 2019 6:25 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect
Replies: 7
Views: 104

### Re: Photoelectric Effect

Increasing the intensity of light would only increase the number of photons. If the photons don't have sufficient energy to overcome the binding between the electron and the metal then just increasing the number of photons won't cause an electron to eject since each photon has the same energy. You w...
Sat Oct 19, 2019 11:51 pm
Forum: Properties of Light
Topic: Homework due Next Week
Replies: 9
Views: 153

### Re: Homework due Next Week

Yes, we would submit a different set of 5 problems within "The Quantum World" section.
Sun Oct 13, 2019 8:53 pm
Forum: SI Units, Unit Conversions
Topic: Percent Yield
Replies: 6
Views: 268

### Re: Percent Yield

Actual yield is usually given in the problem if you are trying to find percent yield. Also, theoretical yield is usually less than the actual yield due to impurities or other side reactions that occur.
Sun Oct 13, 2019 8:33 pm
Forum: SI Units, Unit Conversions
Topic: Practice Problems?
Replies: 11
Views: 245

### Re: Practice Problems?

For the peer learning groups/sessions, do you come ready with your own questions, do other people lead what you're going to be talking about? Or do you guys all do it together? For the peer learning sessions that Dr Lavelle provides, the workshops are led by a UA and they provide additional workshe...
Sun Oct 13, 2019 9:34 am
Forum: Empirical & Molecular Formulas
Topic: Nomenclature
Replies: 11
Views: 501

### Re: Nomenclature

I think that as of right now, you shouldn't worry about knowing them but you should know some of the more common or simple ones that are usually used.