## Search found 115 matches

Sat Mar 14, 2020 2:46 pm
Forum: Administrative Questions and Class Announcements
Topic: UA Final Review - Kate, Riya, Matthew
Replies: 13
Views: 1213

### Re: UA Final Review - Kate, Riya, Matthew

For question 4 part b, how do you get the two equations for k1 and k2?
Fri Mar 13, 2020 1:48 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: test 2 #6 steps
Replies: 4
Views: 129

### Re: test 2 #6 steps

Can someone please explain the math steps involved to get the correct answer for this problem? I understand the set up, just not the steps you need to take to get the right answer of 0.42M. Thank you! Well first you’d multiply both sides by -2/0.0257 ( the reciprocal of the constant on the left sid...
Fri Mar 13, 2020 1:23 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: test 2 #6 steps
Replies: 4
Views: 129

### Re: test 2 #6 steps

I think the mistake you did was using a wrong value in the equation, instead of using 0.257/2, you should've used 0.0592/n, where n is the number of mole of electrons. That change in value shouldn't matter because you should still receive the same answer. I'm just having trouble with the calculus p...
Fri Mar 13, 2020 1:01 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: test 2 #6 steps
Replies: 4
Views: 129

### test 2 #6 steps

Can someone please explain the math steps involved to get the correct answer for this problem? I understand the set up, just not the steps you need to take to get the right answer of 0.42M. Thank you!
Tue Mar 10, 2020 8:19 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Identifying Catalysts and intermediates
Replies: 4
Views: 49

### Identifying Catalysts and intermediates

How do you identify catalysts and intermediates in a reaction?
Mon Mar 09, 2020 9:12 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Molecularity
Replies: 4
Views: 55

### Re: Molecularity

Molecularity would be the number of molecules or species in an elementary step, and also determine the rate. Rate law for each elementary steps comes directly from molecularity.
Mon Mar 09, 2020 9:08 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Activation Energy vs. Free energy of activation
Replies: 2
Views: 44

### Re: Activation Energy vs. Free energy of activation

Activation energy, Ea, is the energy that's needed to get over an energy barrier during a transition step. The free energy of activation refers to Gibbs free energy, and it is what is used when we are looking at the energy barriers of chemical reactions/ allows us to determine how likely a reaction ...
Mon Mar 09, 2020 9:02 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: k' vs kr
Replies: 13
Views: 158

### Re: k' vs kr

k' is the rate of the reverse reaction. kr is the rate constant of a reaction that depicts the rate of a chemical reaction.
Mon Mar 09, 2020 8:57 am
Forum: Administrative Questions and Class Announcements
Topic: Review session on Friday
Replies: 3
Views: 65

### Re: Review session on Friday

As far as I know, review sessions don't get Bruin casted. But, like the previous post said, the worksheet and only the answers (no explanations or work) do get posted on Chemistry Community.
Mon Mar 09, 2020 8:53 am
Forum: First Order Reactions
Topic: equation derivations
Replies: 9
Views: 148

### Re: equation derivations

I don't think that we will be asked to know how to derive the different equations given in this unit, but it is important and helpful to see the steps that it takes to get to a specific equation.
Mon Mar 02, 2020 8:55 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: free energy and work
Replies: 5
Views: 93

### Re: free energy and work

Gibbs' free energy corresponds to the amount of work that can be performed in a given system. A positive delta G means that the system is not spontaneous, and a negative delta G means that the system is spontaneous.
Mon Mar 02, 2020 8:48 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.7 C cell diagram
Replies: 1
Views: 42

### 6L.7 C cell diagram

For 6L.7 C where do KOH(aq) and Ni(s) come from ? The half-reactions look like this:
Cd(OH)2(s)+2e- →Cd(s)+2OH^-(aq)
E°(anode)=-0.81V
Ni(OH)3(s)+e-→ Ni(OH)2(s)+OH^-(aq)
E°(cathode)=+0.49V

Cell Diagram: Cd(s)|Cd(OH)2(s)|KOH(aq)||Ni(OH)3(s)|NI(OH)2(s)|Ni(s)
Mon Mar 02, 2020 8:44 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: deriving nernst equation
Replies: 4
Views: 61

### Re: deriving nernst equation

it might help to see a visual of deriving the Nernst Equation!
Mon Mar 02, 2020 8:35 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: k
Replies: 10
Views: 124

### Re: k

Typically, K doesn't have units since it is a ratio of similar quantities rather than specific concentrations.
Mon Mar 02, 2020 8:29 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: Determining n
Replies: 5
Views: 107

### Re: Determining n

You should determine n from the number of moles of electrons that are present in your half-reactions. It should be the same number for both half-reactions.
Mon Feb 24, 2020 9:07 am
Forum: Administrative Questions and Class Announcements
Topic: Test 2
Replies: 5
Views: 108

### Re: Test 2

Yes, Test 2 would be starting Tuesday, March 3 in discussion sections.
Mon Feb 24, 2020 9:05 am
Forum: Administrative Questions and Class Announcements
Topic: Extra Credit
Replies: 17
Views: 241

### Re: Extra Credit

From my experience in the 14 series, Dr. Lavelle doesn't offer extra credit opportunities in his courses.
Mon Feb 24, 2020 9:03 am
Forum: Administrative Questions and Class Announcements
Topic: Hw 8
Replies: 10
Views: 148

### Re: Hw 8

For homework 8, I would suggest doing any of the problems from outline 5 (electrochemistry and its applications) since those topics are what we have been covering this past week in lecture.
Mon Feb 24, 2020 9:00 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst equation
Replies: 2
Views: 69

### Re: Nernst equation

The Nernst equation can be used to quantitatively determine the direction of electron transfer under non-standard conditions. Also, it has an important relation in determining a reaction's equilibrium constants and concentration potentials.
Mon Feb 24, 2020 8:55 am
Forum: Administrative Questions and Class Announcements
Topic: Study guide
Replies: 7
Views: 154

### Re: Study guide

Official study guides haven't been made for this class, but I would recommend making your own with the notes from class as well as going to multiple peer learning sessions since they give worksheets/additional notes.
Mon Feb 17, 2020 10:47 am
Forum: Van't Hoff Equation
Topic: Derivation of Van't Hoff
Replies: 3
Views: 55

### Re: Derivation of Van't Hoff

Van't Hoff Equation is derived from ∆G°=∆H°-T∆S°and ∆G°=-RTlnK.
Mon Feb 17, 2020 10:45 am
Forum: Administrative Questions and Class Announcements
Topic: Step Up Sessions
Replies: 71
Views: 4398

### Re: Step Up Sessions

GFolk_1D wrote:Hi! Will there still be UA review sessions today despite the holiday?

Dr. Lavelle sent an email out yesterday saying that all peer learning sessions are cancelled Sunday and Monday, and everything will resume back to usual on Tuesday.
Mon Feb 17, 2020 10:43 am
Forum: Administrative Questions and Class Announcements
Topic: HW7
Replies: 14
Views: 172

### Re: HW7

My TA said that any homework problems from outline 4 should be okay to turn in since we are barely starting outline 5 this week.
Mon Feb 17, 2020 10:40 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: When to use the different equations
Replies: 5
Views: 85

### Re: When to use the different equations

I found this comment in a previous Chemistry Community post and thought it might be helpful to answer your question: "The standard enthalpy of formation is at 25C, if the temperature of the reaction is different, then you can't use the listed delta G values to calculate G. Then you would use th...
Mon Feb 17, 2020 10:36 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Boltzmann Formula
Replies: 11
Views: 204

### Re: Boltzmann Formula

W, or degeneracy, in the Boltzmann formula would be defined as the number of ways that are possible to achieve a given energy state.
W would equal (# states)^(#species).
Mon Feb 10, 2020 8:55 am
Forum: Calculating Work of Expansion
Topic: Derivation of Formula
Replies: 3
Views: 54

### Re: Derivation of Formula

I think the derivation of the formula was done to show how a specific formula that we would need to know resulted from it. So, I don’t think we’ll need to know how to derive equations.
Mon Feb 10, 2020 8:50 am
Forum: Administrative Questions and Class Announcements
Topic: Midterm Conversion
Replies: 3
Views: 48

### Re: Midterm Conversion

Yes, conversions that we would to do on the midterm are given on the formula sheet.
I would recommend looking at the constants and equations sheet on Dr.Lavelle’s website to familiarize yourself with what you will be given.
Mon Feb 10, 2020 8:46 am
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Why is delta U = 0 for isothermal reactions?
Replies: 11
Views: 252

### Re: Why is delta U = 0 for isothermal reactions?

For an isothermal reaction, the temperature is constant so the internal energy would also be constant (delta U=0).
Mon Feb 10, 2020 8:43 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy Definition
Replies: 2
Views: 28

### Re: Enthalpy Definition

Enthalpy would be defined as the study of heat absorbed or released during chemical reactions and physical changes.
Mon Feb 10, 2020 8:39 am
Forum: Administrative Questions and Class Announcements
Topic: Midterm
Replies: 12
Views: 186

### Re: Midterm

AGaeta_2C wrote:Will the review session on that day be covering past exam problems?

On Dr. Lavelle’s website it says that there will be a small group Q&A on the day of the exam.
Dr. Lavelle will be going over past exam questions today during lecture.
Mon Feb 03, 2020 9:02 am
Forum: Student Social/Study Group
Topic: Midterm and Final Question
Replies: 18
Views: 267

### Re: Midterm and Final Question

I would suggest going to the midterm review sessions that Dr. Lavelle has organized. These are helpful, taught by TAs and UAs, and each section has a specific topic that they cover which is extremely convenient.
Mon Feb 03, 2020 8:54 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Reversible/ Irreversible Expansion
Replies: 3
Views: 40

### Re: Reversible/ Irreversible Expansion

To add onto previous posts, in reversible expansion, the equilibrium isn't affected at any stage and the process is slower. While in a irreversible expansion, equilibrium may exist only after completing the process and the process is much quicker.
Mon Feb 03, 2020 8:49 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: when is w=0 and when is q=0?
Replies: 6
Views: 478

### Re: when is w=0 and when is q=0?

W=0 when the volume of the work done on a gas is constant. Q=0 when there is no heat exchanged (happens if the container is thermally insulated).
Mon Feb 03, 2020 8:45 am
Forum: Administrative Questions and Class Announcements
Topic: TeST 1
Replies: 3
Views: 50

### Re: TeST 1

You should've got your test back in discussion during week 4, but if you didn't I would suggest emailing your TA or asking them in discussion about your test.
Mon Feb 03, 2020 8:44 am
Forum: Student Social/Study Group
Topic: Test 1 Solution
Replies: 6
Views: 139

### Re: Test 1 Solution

Dr. Lavelle doesn't post answer keys for tests, but he does for the midterm. However, many TA's are willing to help you get clarification on the problems and understand how to do them.
Mon Jan 27, 2020 2:06 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Week 4 Homework
Replies: 11
Views: 118

### Re: Week 4 Homework

This week we are going over outline 3 which is thermochemistry. I would suggest doing homework problems that come from focus 4 in the textbook.
Mon Jan 27, 2020 2:02 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: 4A 1 Part c)
Replies: 5
Views: 88

### Re: 4A 1 Part c)

A bomb calorimeter would be a isolated system that works at a constant volume where heat (energy) is exchanged and volume is constant (isochoric).
Mon Jan 27, 2020 1:54 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Units for enthalpy
Replies: 3
Views: 42

### Re: Units for enthalpy

For the standard enthalpy of reaction, the units would be kJ/mol.
Mon Jan 27, 2020 1:49 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: bomb calorimeter
Replies: 5
Views: 45

### Re: bomb calorimeter

A bomb calorimeter is a constant volume calorimeter that is used to measure the heat of specific reactions.
Mon Jan 27, 2020 10:46 am
Forum: General Science Questions
Topic: Fall 2019 final
Replies: 7
Views: 101

### Re: Fall 2019 final

Although Lavelle said we can pick up the finals during week 3 from Young Hall 3034, I would recommend to go check to see if it’s available to pick up. I went around 8:40am and the office was open.
Tue Jan 21, 2020 9:30 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kw
Replies: 1
Views: 31

### Kw

How would you know when to use Ka x Kb= Kw when solving for pH? For example in 6D.17 (a) you would need to find the Kb value using Kb= Kw/Ka.
I know you would use it for finding the pH of salt solutions, but what are some indicators to help let us know that we need to use that constant?
Mon Jan 20, 2020 2:46 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pH of salt solutions
Replies: 2
Views: 47

### pH of salt solutions

If we are given a problem and asked to calculate the pH, how would we know if we should follow the steps for calculating the pH of salt solutions (like finding the Ka value if we are given the Kb value) or just continue with the calculations and not solve for either Ka or Kb and just use the value w...
Mon Jan 20, 2020 9:48 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5% rule clarification
Replies: 2
Views: 32

### Re: 5% rule clarification

If k<10^-3 you can attempt an approximation. To ensure the validity of your approximation, you should check by dividing the x value you received over the initial concentration. If this value is less than 5%, your approximation is valid.
Mon Jan 20, 2020 9:37 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Effect of Increasing Temperature on an Equilibrium System
Replies: 4
Views: 76

### Re: Effect of Increasing Temperature on an Equilibrium System

Exothermic reactions give off heat while forming product, and reactant formation will be favored. For exothermic reactions, you can picture heat as being a product and apply Le Chatelier's principle of what happens when you add product to a system. Therefore, increasing the temperature will shift th...
Mon Jan 20, 2020 9:32 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Replies: 9
Views: 151

An inert gas is another term for noble gas. Also, the addition of an inert gas, for example argon or krypton, to a reaction will have no effect on the system.
Mon Jan 20, 2020 9:28 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: q vs k
Replies: 9
Views: 52

### Re: q vs k

Yes, when Q=K the solution has reached its equilibrium composition and doesn't change in either direction.
Mon Jan 20, 2020 9:26 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: pKa and pKb
Replies: 17
Views: 217

### Re: pKa and pKb

pKa is the negative base-10 logarithm of the acid dissociation constant (Ka) of a solution and pKb is the negative base-10 logarithm of the base dissociation constant (Kb). pKa and pKb added together equals 14.
Wed Jan 15, 2020 9:47 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 5I.11 units
Replies: 5
Views: 73

### 5I.11 units

For HW 5I.11 how would the concentration of SO2, O2, and SO3 be converted from nmol to mol. For example how is the concentration of SO2=1.20nmol converted to 1.20x10^-3 mol?
Mon Jan 13, 2020 4:05 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: lecture 1/13 topic
Replies: 1
Views: 38

### lecture 1/13 topic

What did Dr. Lavelle mean in lecture 1 today when he said that 10^-12 is actually and would be correct if it were written as 10^-7 for the concentration of H3O+?
Mon Jan 13, 2020 4:02 pm
Forum: Student Social/Study Group
Topic: Notes for 1/13 Lecture
Replies: 4
Views: 91

### Re: Notes for 1/13 Lecture

In addition to the post made before this, we also reviewed the meanings of neutralization (reaction between acid and base, product is salt and water), amphiprotic (proton donor and acceptor, like water), and autoprotolysis (proton transfer between same type of molecule).
Mon Jan 13, 2020 3:58 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J.3
Replies: 5
Views: 50

### Re: 5J.3

According to Le Chatelier's principle, removing NO will lead to the formation of more products. So to maintain equilibrium, the amount of NH3 will decrease. Hope this helps!
Mon Jan 13, 2020 3:53 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J.1
Replies: 3
Views: 40

### Re: 5J.1

You would use Le Chatelier's principle and know that if a reactant is increased, in this example being CO, the system will shift the equilibrium to the right towards the products, thus increasing the concentration of H2.
Mon Jan 13, 2020 3:49 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 5.39
Replies: 1
Views: 41

### Re: Textbook question 5.39

For part (a) you should double check their I.C.E table as well as the expression for Kc which should be (N2O4)/(NO2)^2. After inputting the values from your I.C.E table into the Kc expression, you should be solving for the equation: 6.4x10^2 x^2 - 14x + 0.064=0. After you plug this equation into the...
Thu Jan 09, 2020 9:19 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: units of K
Replies: 10
Views: 105

### Re: units of K

Equilibrium constants don't have units because we used the active masses of the substances, hence why they are unit less/eliminated from the equilibrium constant expression.
Thu Jan 09, 2020 9:11 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: solids/liquids
Replies: 4
Views: 55

### Re: solids/liquids

Gases and aqueous solutions would only be used and considered in equilibrium expressions since the concentration of pure solids and liquids does not change.
Thu Jan 09, 2020 9:06 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5H.3
Replies: 4
Views: 61

### Re: 5H.3

You would use the values of K in the table to determine the value of K for the reaction. So you would use K=377 for the expression 2BrCl<->Br2+Cl2 and K=4.0x10^31 for the expression H2+Cl2<->2HCl. You would then multiply the values of K1 and K2 to get your answer.
Thu Jan 09, 2020 9:02 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5G3
Replies: 8
Views: 68

### Re: 5G3

Yes, you would include gases in equilibrium expressions, but you wouldn't include solids or liquids.
Thu Jan 09, 2020 9:00 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K vs. Q
Replies: 10
Views: 107

### Re: K vs. Q

K would be known as the equilibrium constant, Kc. K can also be used to calculate the partial pressure of a species at equilibrium, Kp. Q is the reaction quotient and it is used to determine which direction a reaction will proceed. Q or Qc or Qp are calculated the same way as K, but for Q, the react...
Sat Dec 07, 2019 9:45 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 2oh- and oh-
Replies: 1
Views: 31

### 2oh- and oh-

When solving for pH, how would you know to use 2OH- or OH- in your calculations? Does it have to do with the present of an oxide?
Mon Dec 02, 2019 9:34 pm
Forum: Bronsted Acids & Bases
Topic: stronger acid ?
Replies: 3
Views: 55

### stronger acid ?

why is HClO2 stronger than HBrO2 ?
Mon Dec 02, 2019 3:55 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: lecture example pKa Ka
Replies: 2
Views: 40

### lecture example pKa Ka

From the pKa and Ka example done in lecture today, what factors would show that the Ka=6.0x10^-5 is a weak acid and that the equilibrium constant is small?
Mon Dec 02, 2019 3:46 pm
Forum: Lewis Structures
Topic: 2D.1
Replies: 1
Views: 142

### Re: 2D.1

Remember that the trends for electronegativity are that it increases as you go up a group and increases as you go across a period. To answer your question it will be: indium<tin<antimony<selenium
Mon Dec 02, 2019 3:01 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: H-F, H-Cl, H-Br, and H-I
Replies: 3
Views: 64

### Re: H-F, H-Cl, H-Br, and H-I

Remember that bond length increases with atomic radius. So, the longer the bond is between two elements, the stronger the acid is. For example, H-I has the longest bond, so it will be the strongest acid. And vice versa, the shorter the bond is, the weaker the acid is. So, H-F would be the weakest ac...
Mon Dec 02, 2019 9:31 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pH vs pOH
Replies: 4
Views: 60

### pH vs pOH

For example in 6B. 5D how would you determine that 3.15 is your pOH and 10.85 is your pH?
Mon Dec 02, 2019 9:25 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pH scale
Replies: 12
Views: 137

### Re: pH scale

The pH scale is most common between 0-14, but it is possible to go above or below 0 or 14. In the case of very acidic acids known as super acids, the pH scale goes below 0.
Mon Nov 25, 2019 3:47 pm
Forum: Bronsted Acids & Bases
Topic: J.9C and ionic equations
Replies: 1
Views: 66

### J.9C and ionic equations

How would you write the complete ionic equation for reactions?
For example, J.9C which asks to write the ionic equation and identify the salt produced from calcium hydroxide and bromous acid.
Mon Nov 25, 2019 2:56 pm
Forum: Bronsted Acids & Bases
Topic: 6A.5
Replies: 1
Views: 32

### Re: 6A.5

The acid which would be HNO3 would be determined because acids usually have a H atom attached to it and you can see that the conjugate base to the HNO3 would be NO3-. As for the base, it will be HPO4^2- because you can see that its conjugate acid, which is H2PO4-, has a one extra H atom attached to ...
Mon Nov 25, 2019 2:46 pm
Forum: Amphoteric Compounds
Topic: amphoteric compounds
Replies: 2
Views: 63

### amphoteric compounds

How would you know that As2O3 and Bi2O3 are amphoteric, while BaO is basic?
Mon Nov 25, 2019 2:35 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: charge and oxidation state
Replies: 2
Views: 34

### charge and oxidation state

How do you find the charge of a ligand and also the oxidation state?
Mon Nov 25, 2019 9:25 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: brackets
Replies: 13
Views: 152

### Re: brackets

Whatever is inside the brackets is directly bound to the transition metal and is in the coordination sphere. Hope this helps!
Tue Nov 19, 2019 7:18 pm
Forum: Dipole Moments
Topic: boiling point
Replies: 6
Views: 244

### boiling point

Why would HI have a higher boiling point than HBr if HBr has a stronger dipole-dipole force? Would we go based off of the fact that HI is larger than HBr?
Tue Nov 19, 2019 7:00 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: polarizability
Replies: 9
Views: 224

### polarizability

What is the role of polarizability when determining higher and lower melting/boiling points of compounds?
Mon Nov 18, 2019 2:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: wedge and dash
Replies: 2
Views: 45

### Re: wedge and dash

The wedge and dash would be used for VSEPR 3D structures of molecules. The wedge would be used to show that the element is sticking forward/coming towards us and the dash would be used to show that the element is pointing away from us/sticking back.
Hope this helps!
Mon Nov 18, 2019 1:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: lone pairs VSEPR
Replies: 1
Views: 36

### lone pairs VSEPR

In terms of repulsion and VSEPR, if a compound has lone pairs, should they always be placed in the equatorial plane instead of the axial plane?
Mon Nov 18, 2019 1:57 pm
Forum: Student Social/Study Group
Topic: Test 2 Study Worksheets
Replies: 9
Views: 328

### Re: Test 2 Study Worksheets

Naren_Ramesh_4D wrote:What room in Covel is the study session in?

The study sessions are in Covel 210
Mon Nov 18, 2019 1:55 pm
Forum: Dipole Moments
Topic: Dipole moments
Replies: 4
Views: 67

### Re: Dipole moments

Dipole moments will be drawn with the arrow pointing towards the partial negative element, rather than the partial positive.
Mon Nov 18, 2019 1:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 6
Views: 90

### Re: Test 2

The final is cumulative, so yes I'm assuming hybridization will be covered on the final.
Mon Nov 11, 2019 8:24 pm
Forum: Ionic & Covalent Bonds
Topic: Exam 2 & Homework
Replies: 5
Views: 97

### Re: Exam 2 & Homework

Test 2 will start the week of November 19 in discussion.
Mon Nov 11, 2019 10:09 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 water
Replies: 3
Views: 45

### hydrogen bonding in water

What do the series of short lines represent in bonds? For example, the hydrogen bonding in water example that was shown in class on Friday.
Mon Nov 11, 2019 10:03 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Difference Between Lewis Structure and VSEPR Model
Replies: 3
Views: 1124

### Re: Difference Between Lewis Structure and VSEPR Model

A lewis structure is a dot diagram that shows the valence electrons as well as various bonds present in elements. While VSEPR is used to draw and name the different molecular shapes like bent, linear, tetrahedral, etc. These shapes are determined based off of the lewis structure and the VSEPR theory.
Mon Nov 11, 2019 9:58 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: Dimers
Replies: 1
Views: 37

### Re: Dimers

A dimer would be two monomers that are linked together by intermolecular or covalent bonds and/or interactions.
Mon Nov 11, 2019 9:53 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: difference between intermolecular forces
Replies: 3
Views: 44

### difference between intermolecular forces

What are some key factors to remember when trying to distinguish between dipole-dipole, London forces, induced dipole-induced dipole, and hydrogen bonding?
Mon Nov 04, 2019 4:15 pm
Forum: DeBroglie Equation
Topic: de Broglie vs electromagnetic radiation
Replies: 3
Views: 77

### de Broglie vs electromagnetic radiation

How do you know when to use the De Broglie equation or the equations for electromagnetic radiation like E=hV
Mon Nov 04, 2019 3:44 pm
Forum: Quantum Numbers and The H-Atom
Topic: Orbital vs Subshells
Replies: 3
Views: 77

### Re: Orbital vs Subshells

Orbitals within a shell are divided into subshells that have the same value of the angular quantum number l, which determines which orbital the element is in (s,p,d,or f). l=0, corresponds to the s orbital, l=1 corresponds to the p orbital, l=2 corresponds to the d orbital, and l=3 corresponds to th...
Mon Nov 04, 2019 2:35 pm
Forum: Lewis Structures
Topic: Lewis Structure
Replies: 4
Views: 85

### Re: Lewis Structure

After determining the number of valence electrons for each element, you would use the element with the lowest ionization energy. Also, know that H can never be the central atom.
Mon Nov 04, 2019 2:31 pm
Forum: Lewis Structures
Topic: When to use brackets
Replies: 2
Views: 76

### Re: When to use brackets

When writing shorthand electron configurations, you would use brackets to indicate the element that comes before the compound you are writing the configuration for. For example, for Sc you will write [Ar] 3d^1 4s^2
Mon Nov 04, 2019 2:26 pm
Forum: General Science Questions
Topic: Concept Questions
Replies: 2
Views: 65

### Re: Concept Questions

Attending the review sessions are helpful as well if you need help on specific concepts/sections.
Mon Nov 04, 2019 2:18 pm
Forum: General Science Questions
Topic: Midterm
Replies: 12
Views: 261

### Re: Midterm

Every student is assigned to a specific testing location based on their last name and if they're either in a 10am, 12pm, or 2pm lecture. The list is on the class website.
Sat Nov 02, 2019 4:08 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: dino nuggets 13 (c)
Replies: 1
Views: 100

### dino nuggets 13 (c)

I understand that we are supposed to use the indeterminacy equation to solve 13 (c), from the midterm practice, but when I input the values into the calculator, I am not getting the correct answer, which is supposed to be 2.8x10^-32 m. I have converted the 2.8 g to kg and am solving for delta x. Can...
Mon Oct 28, 2019 7:28 pm
Forum: Trends in The Periodic Table
Topic: electronegativity table
Replies: 5
Views: 113

### electronegativity table

Would we be given a table on tests in order to determine electronegativity of elements?
Mon Oct 28, 2019 6:40 pm
Forum: Ionic & Covalent Bonds
Topic: ionic bonding 2A.13
Replies: 1
Views: 26

### ionic bonding 2A.13

In homework problem 2A.13, part (b), why would a 3p orbital need to be removed from Cl in order to form a +1 ion?
Mon Oct 28, 2019 6:22 pm
Forum: Octet Exceptions
Topic: Unpaired Electrons
Replies: 1
Views: 61

### Re: Unpaired Electrons

I had trouble figuring out why this occurred as well, but I found a post made by Dr. Lavelle a few years ago on Chemistry Community stating, "It seems that the correct answer is based off molecular orbital arguments that are outside of the scope of this course."
Hope this helps!
Mon Oct 28, 2019 6:12 pm
Forum: Lewis Structures
Topic: 2B.11c
Replies: 2
Views: 71

### Re: 2B.11c

I recommend taking it step by step or by portions because this will ensure that the correct atoms as well as the correct number of atoms will be bonded with each other. You can also take a look at the solutions manual for help with drawing the lewis structure. Hope this helps!
Mon Oct 28, 2019 6:08 pm
Forum: Properties of Light
Topic: Midterm formulas
Replies: 6
Views: 177

### Re: Midterm formulas

I believe it will be the same as our first test, where we were given formulas as well as the periodic table.
Tue Oct 22, 2019 5:59 pm
Forum: Student Social/Study Group
Topic: Video Module For New Material
Replies: 4
Views: 126

### Re: Video Module For New Material

He has not said anything recently about posting any new modules
Mon Oct 21, 2019 4:31 pm
Forum: Properties of Electrons
Topic: Angstrom
Replies: 2
Views: 102

### Re: Angstrom

700 nm would be 7000 angstrom
(1nm is equal to 10 angstrom)
Mon Oct 21, 2019 4:27 pm
Forum: Einstein Equation
Topic: Converting Energy Units
Replies: 2
Views: 51

### Re: Converting Energy Units

You would use 1.6022 x 10^-19 J/eV to convert between the two units
Mon Oct 21, 2019 4:24 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: determining the number of orbitals
Replies: 1
Views: 40

### determining the number of orbitals

Is it possible to determine the number of orbitals in a shell by only being given the principle quantum number, n, or would you need the angular momentum quantum number as well?
Mon Oct 21, 2019 4:11 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Shell vs. Orbital
Replies: 3
Views: 45

### Re: Shell vs. Orbital

Shell=All electrons are in the same shell when they have the same value for n (the principle quantum number) Sub-shell= Within a shell (same n), all electrons that share the same l (the angular momentum quantum number, or orbital shape) are in the same sub-shell Orbital= When electrons share the sam...
Tue Oct 15, 2019 6:56 pm
Forum: Quantum Numbers and The H-Atom
Topic: 1D 11
Replies: 4
Views: 81

### Re: 1D 11

l, which is the angular quantum number, represents the shape of the orbital.
m shows the number of orbitals in a sublevel. For example, m=-1,0,+1 shows that there is 3 orbitals in the p sublevel.
n is the energy level of the orbital.