Search found 108 matches

by Sjeffrey_1C
Sat Mar 14, 2020 12:54 pm
Forum: Zero Order Reactions
Topic: Composition vs Decomposition
Replies: 3
Views: 64

Re: Composition vs Decomposition

Decomposition is when a substance is used up. Composition is when it is formed.
by Sjeffrey_1C
Sat Mar 14, 2020 12:25 pm
Forum: First Order Reactions
Topic: First order rxns
Replies: 6
Views: 47

Re: First order rxns

You look at the rate law to determine the order. So if the rate law is not given, they will just tell you the order so that you know which equations to use.
by Sjeffrey_1C
Sat Mar 14, 2020 12:22 pm
Forum: Administrative Questions and Class Announcements
Topic: final tech malfunctions
Replies: 5
Views: 116

Re: final tech malfunctions

Based on the email sent earlier with a message from someone who had taken it, it seems like you write out your answers. So I'm guessing you do your work on paper and submit pictures? So in that case you'd be fine. Not sure though if that's the case.
by Sjeffrey_1C
Sat Mar 14, 2020 12:08 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: pre equilibrium approach
Replies: 2
Views: 32

Re: pre equilibrium approach

To find the equilibrium constant, you use the step who's product is the intermediate. So yes, this would always (I think) be the first step. This K will allow you to solve for the concentration of the intermediate in other terms so that you eventually solve for the rate of formation of the final pro...
by Sjeffrey_1C
Sat Mar 14, 2020 12:06 pm
Forum: General Rate Laws
Topic: rate laws
Replies: 8
Views: 105

Re: rate laws

Since the slow step reaction mechanism is rate limiting, I believe this is true.
by Sjeffrey_1C
Sat Mar 14, 2020 12:03 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Elementary Reaction Definition
Replies: 3
Views: 23

Re: Elementary Reaction Definition

Additionally, an elementary reaction's rate law can be determined by using the stoichiometric coefficients, while a general reaction cannot be.
by Sjeffrey_1C
Sat Mar 14, 2020 12:02 pm
Forum: Environment, Ozone, CFCs
Topic: final thoughts
Replies: 2
Views: 94

Re: final thoughts

It would probably be good to review, but since we have access to the textbook if needed, I wouldn't focus on it.
by Sjeffrey_1C
Fri Mar 13, 2020 7:38 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Using Steady State Approx/Pre-Equilibrium Approx
Replies: 2
Views: 24

Using Steady State Approx/Pre-Equilibrium Approx

I'm confused as to when we would use a steady state approximation or equilibrium approximation, versus when we would just use the rate of the slow step? For example, question 7C.7 asks that we find the rate law for the formation of the product, and the answer provided is just the rate law of the slo...
by Sjeffrey_1C
Tue Mar 10, 2020 6:06 pm
Forum: Student Social/Study Group
Topic: Final
Replies: 21
Views: 278

Re: Final

The email says "Winter Quarter final exams will be offered remotely." so it seems like he has to find some alternative to having it in person.
by Sjeffrey_1C
Sun Mar 08, 2020 8:25 pm
Forum: General Science Questions
Topic: Who makes the Final
Replies: 23
Views: 287

Re: Who makes the Final

During the discussion before a test/midterm, it's seemed like my TA has not seen the tests/midterm or hasn't been asked for input. This might be because my discussion is early in the week though, so maybe the exams aren't ready by that point.
by Sjeffrey_1C
Sun Mar 08, 2020 8:21 pm
Forum: General Rate Laws
Topic: Fractional order and negative orders
Replies: 3
Views: 37

Re: Fractional order and negative orders

These weren't covered so I'd assume no.
by Sjeffrey_1C
Sun Mar 08, 2020 8:15 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Platinum
Replies: 10
Views: 45

Re: Platinum

Platinum is added to any side of a cell that is missing a solid conductor. This could be both sides, one side, or neither side depending.
by Sjeffrey_1C
Sun Mar 08, 2020 8:05 pm
Forum: Balancing Redox Reactions
Topic: Redox Table
Replies: 6
Views: 35

Re: Redox Table

The equation takes into consideration that the values are reduction potential values, even though half of the reaction is actually in oxidation. Thus, you don't need to convert the values to oxidation potential.
by Sjeffrey_1C
Mon Mar 02, 2020 4:50 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6N.3 c.
Replies: 1
Views: 42

6N.3 c.

The question asks you to predict the cell potential given this diagram: Pt(s)|Cl2 (g, 250 torr)| HCl (aq, 1M) || HCl (aq, .85M) | H2 (g, 125 torr) Based on the left being the anode and right being the cathode, I got 2Cl- -> 2e- + Cl2 and 2H+ + 2e- -> H2. But this doesn't seem to make sense with each...
by Sjeffrey_1C
Sun Mar 01, 2020 3:48 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: 6M.7 Strength as Reducing Agent
Replies: 3
Views: 44

6M.7 Strength as Reducing Agent

The question asks to list metals in order of increasing strength as reducing agents. I understand you determine this by looking at the standard reduction potentials, but am confused since there are multiple values for each metal depending on the charge. For example, Fe3+ + 3e- -> Fe is -0.04V but Fe...
by Sjeffrey_1C
Sun Mar 01, 2020 1:40 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.5 c)
Replies: 1
Views: 25

Re: 6L.5 c)

I think I saw some example where they did something similar, so I did this
Oxidation: H2 -> 2H+ + 2e-
Reduction: Cl2 + 2e- -> 2Cl-
by Sjeffrey_1C
Sun Mar 01, 2020 1:34 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Book Problem 5G13
Replies: 1
Views: 33

Re: Book Problem 5G13

I was also very confused about this. I think the book's answer may be a mistake.
by Sjeffrey_1C
Sun Mar 01, 2020 1:31 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Reaction Free Energy
Replies: 2
Views: 49

Re: Reaction Free Energy

For the equilibrium constant part, this is evident in the equation delta G naught = -RTlnK. I'm not sure how pressure plays a part. Maybe because the equilibrium constant can be calculated with the partial pressures of the products and reactants.
by Sjeffrey_1C
Sun Mar 01, 2020 1:29 pm
Forum: Van't Hoff Equation
Topic: Van't Hoff equation on 5J.15
Replies: 1
Views: 33

Re: Van't Hoff equation on 5J.15

At 150 C, I used the equation ln (k2/k1) = delta H naught/R * ((1/T1)-(1/T2)) You plug in the values you already know... For example for part a K1 = 1.07 x 10^-16. T1 = 298. K and T2 = 423. K You solve for delta H naught using the values in the appendix. R is a constant. This leaves you with an equa...
by Sjeffrey_1C
Sun Mar 01, 2020 1:25 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: cell diagrams: order of components in electrodes?
Replies: 3
Views: 30

Re: cell diagrams: order of components in electrodes?

Generally it is written as
electrode material (anode) | aqueous solution || aqueous solution | electrode material (cathode)

It seems like the book isn't consistent about this though.
by Sjeffrey_1C
Thu Feb 27, 2020 5:52 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 5G.13
Replies: 8
Views: 133

Re: 5G.13

The problem is that you are subtracting. Add delta G naught and RTlnQ and you will get the correct answer!
by Sjeffrey_1C
Tue Feb 25, 2020 3:23 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2
Replies: 4
Views: 60

Test 2

I know Test #2 covers the objectives from the second page of the thermodynamics outline, but which homework problems from the thermodynamics outline apply to test #2 content? Thanks!
by Sjeffrey_1C
Thu Feb 20, 2020 3:29 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: cell diagram
Replies: 4
Views: 49

Re: cell diagram

The importance of it is a visual representation of the contents of a galvanic cell, so you can do calculations/write half-reactions/balance redox reactions, etc.
by Sjeffrey_1C
Thu Feb 20, 2020 3:26 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: salt bridge
Replies: 5
Views: 44

Re: salt bridge

In the book, for the purpose of some of the hw problems, we also learn how to indicate the presence of a salt bridge in a cell diagram.
by Sjeffrey_1C
Thu Feb 20, 2020 3:23 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Standard reduction potential
Replies: 2
Views: 23

Re: Standard reduction potential

Standard reduction potential indicates the likelihood of a substance being reduced. So after reduction happens, I don't think the value would be applicable anymore because the substance has already been reduced. Not sure 100% that's the case though.
by Sjeffrey_1C
Thu Feb 20, 2020 3:01 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: potential difference
Replies: 2
Views: 25

Re: potential difference

High potential means a large difference in voltage, low potential means a small difference in voltage.
by Sjeffrey_1C
Thu Feb 20, 2020 2:24 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: potential difference
Replies: 2
Views: 25

Re: potential difference

High potential means a large difference in voltage, low potential means a small difference in voltage.
by Sjeffrey_1C
Thu Feb 20, 2020 2:22 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: cell potential equation
Replies: 5
Views: 46

Re: cell potential equation

F stands for Faraday's constant. Ecell can be calculated by subtracting the two values or will be given.
by Sjeffrey_1C
Sun Feb 16, 2020 10:42 am
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: 4H.5
Replies: 4
Views: 90

Re: 4H.5

For C, a polymerized substance generally has less disorder, thus less entropy.
by Sjeffrey_1C
Sun Feb 16, 2020 10:40 am
Forum: Student Social/Study Group
Topic: Preparing for Exam Content
Replies: 7
Views: 117

Re: Preparing for Exam Content

I definitely agree. I felt very prepared going in and then was very surprised by some of the questions. As said, a lot of it was high level problem solving. So I think it's important to just practice any sort of problem solving, and it will come easier during the tests. Next time, I'm going to go th...
by Sjeffrey_1C
Sun Feb 16, 2020 10:37 am
Forum: Van't Hoff Equation
Topic: Enthalpy, Entropy, and Gibbs Free Energy
Replies: 7
Views: 51

Re: Enthalpy, Entropy, and Gibbs Free Energy

The change in temperature is associated with the change in K.
by Sjeffrey_1C
Sun Feb 16, 2020 10:34 am
Forum: Van't Hoff Equation
Topic: Van Hoff's Constants
Replies: 6
Views: 36

Re: Van Hoff's Constants

Since you're using ΔH naught and ΔS naught, assume conditions are standard.
by Sjeffrey_1C
Sun Feb 16, 2020 10:33 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Delta E
Replies: 11
Views: 160

Re: Delta E

I'm pretty sure they're interchangeable.
by Sjeffrey_1C
Sun Feb 09, 2020 7:23 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Change in concentration
Replies: 2
Views: 27

Re: Change in concentration

Yes, since the equation is in equilibrium the concentrations will affect other concentrations to maintain equilibrium.
by Sjeffrey_1C
Sun Feb 09, 2020 7:22 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Pressure change
Replies: 3
Views: 39

Re: Pressure change

If pressure increases, according to Boyle's law, volume decreases. Thus, there would be more reactant per the amount of space, thus an increase in concentration.
by Sjeffrey_1C
Sun Feb 09, 2020 7:19 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Cp/Cv
Replies: 7
Views: 62

Re: Cp/Cv

Fatemah Yacoub 1F wrote:You must assume that it is constant pressure because otherwise you a reversible system which requires another set of equations.


In this case, you'd use work = -nRT ln (v2/v1)
by Sjeffrey_1C
Sun Feb 09, 2020 7:17 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 4F11
Replies: 1
Views: 27

Re: 4F11

I'm a little confused what you're asking. C refers to specific heat capacity, while R is a constant involved in calculating specific heat capacity.
by Sjeffrey_1C
Sun Feb 09, 2020 7:14 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: 4H.1 part B
Replies: 4
Views: 43

Re: 4H.1 part B

I think the order you'd look would be complexity, volume, temperature, then state. Not sure though. I assume it will be obvious when comparing two molecules what characteristic they're testing for your knowledge of.
by Sjeffrey_1C
Sun Feb 09, 2020 7:08 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible vs Irreversible
Replies: 7
Views: 123

Re: Reversible vs Irreversible

You use different formulas depending if it is reversible or irreversible.

Reversible: work = -nRT ln (v1/v2)

Irreversible: work = -Pext ΔV
by Sjeffrey_1C
Thu Jan 30, 2020 7:16 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: qp and qv
Replies: 8
Views: 62

Re: qp and qv

Enthalpy in this case is referring to heat at a specific pressure, not a specific volume. Thus, the p subscript instead of v.
by Sjeffrey_1C
Thu Jan 30, 2020 7:11 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Test 1 Problem 5
Replies: 1
Views: 42

Re: Test 1 Problem 5

You set up an ICE box so you end up with equilibrium values of N(CH3CH2)3 = .2 - x NH(CH3CH2)3 = x OH- = x Since the pKa is 11.04, Ka is 10^-11.04 Using Kw = (Ka)(Kb) = 10^-14, you solve for Kb and get .0010964 Then you set Kb = .0010964 - X^2/.2-x to solve for x. Once you have x = .014808, you know...
by Sjeffrey_1C
Thu Jan 30, 2020 7:04 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Mass of calorimeter
Replies: 1
Views: 21

Re: Mass of calorimeter

A calorimeter is just used to measure heat. Do you have a specific situation in which you were thinking the mass would be included?
by Sjeffrey_1C
Thu Jan 30, 2020 6:58 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Changing the energies of systems
Replies: 2
Views: 22

Re: Changing the energies of systems

For an open system, energy can be changed by adding/removing reactants or products.

For a closed system, energy can be changed by heating/cooling or compressing/expanding the system.

For an isolated system, energy cannot be changed.
by Sjeffrey_1C
Thu Jan 30, 2020 6:55 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Work of expansion equation
Replies: 4
Views: 33

Re: Work of expansion equation

I believe this is because work is being done by the system to the surroundings, so work is negative.
by Sjeffrey_1C
Sat Jan 25, 2020 9:00 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Energy of the reactants
Replies: 6
Views: 30

Re: Energy of the reactants

So in this case, visually the reaction's energy looks like this.
by Sjeffrey_1C
Sat Jan 25, 2020 8:58 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard enthalpy
Replies: 2
Views: 19

Re: Standard enthalpy

Because in a stable state, there isn't a release/absorption of energy during the reaction, or it is net 0.
by Sjeffrey_1C
Sat Jan 25, 2020 8:54 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpy Method
Replies: 5
Views: 41

Re: Bond Enthalpy Method

PranaviKolla2B wrote:What is the most accurate way to calculate H?


I assume Hess's method is most accurate.
by Sjeffrey_1C
Sat Jan 25, 2020 8:52 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies and gas phases
Replies: 2
Views: 24

Re: Bond Enthalpies and gas phases

I don't think that is the case. I may be wrong, but I remember in lecture it being said that you can use bond enthalpies for liquids or solids but you need to add the enthalpy of the phase change, or something along those lines.
by Sjeffrey_1C
Sat Jan 25, 2020 8:48 pm
Forum: Phase Changes & Related Calculations
Topic: Entropy vs Enthalpy
Replies: 9
Views: 55

Re: Entropy vs Enthalpy

PranaviKolla2B wrote:What does each term relate to in the equation deltaG= deltaH-T*deltaS?


I believe delta G is gibbs free energy, Delta H is enthalpy, and delta S is entropy. T is temperature.
by Sjeffrey_1C
Sun Jan 19, 2020 10:53 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE Table
Replies: 4
Views: 44

Re: ICE Table

You subtract or add x from the original concentration. X is either positive or negative depending on the direction of the reaction.
by Sjeffrey_1C
Sun Jan 19, 2020 10:51 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Approximations
Replies: 2
Views: 16

Re: Approximations

To be safe, I'd say just don't approximate on the test. But I'm not sure what you'd do in the case that you do.
by Sjeffrey_1C
Fri Jan 17, 2020 6:11 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.13 Equilibrium Composition
Replies: 2
Views: 44

5I.13 Equilibrium Composition

(a) in an experiment, 2.0 mmol Cl2 (g) was sealed in a reaction vessel of volume 2.0L and heated to 1000. K to study its dissociation into Cl atoms. Use info in table 5g.2 to calculate the equilibrium composition of the mixture. I keep getting the wrong answer. The table gives the k value to be 1.0 ...
by Sjeffrey_1C
Sun Jan 12, 2020 9:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids and Liquids
Replies: 6
Views: 41

Re: Solids and Liquids

Liquids and solids are essentially incompressible, unlike gas, which is compressible.
by Sjeffrey_1C
Sun Jan 12, 2020 9:23 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: What is this?
Replies: 23
Views: 402

Re: What is this?

It basically explains how a reaction will maintain stability.
by Sjeffrey_1C
Sun Jan 12, 2020 9:22 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: volume change with inert gas
Replies: 9
Views: 81

Re: volume change with inert gas

In class, he explained that if the pressure of a reaction vessel is increased by adding inert gas, then moles of reactant, product and volume are constant, so there's no change in [R] and [P].
by Sjeffrey_1C
Sun Jan 12, 2020 9:18 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Response of Equilibria to Change
Replies: 6
Views: 39

Re: Response of Equilibria to Change

He basically said that if volume decreases and there are more moles of gas on left, then the reaction shifts left, or if volume decreases and there are more moles of gas on the right, then the reaction shifts left. But this logic is incorrect.
by Sjeffrey_1C
Thu Jan 09, 2020 2:49 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K and Q
Replies: 5
Views: 40

Re: K and Q

Additionally, if K and Q aren't equal, you know the equation is not in equilibrium. So If Q < K at some time during reaction, then [R] > [P] and the forward reaction is favored. If Q > K at some time during reaction, then [P] > [R] and the reverse reaction is favored.
by Sjeffrey_1C
Fri Dec 06, 2019 8:48 pm
Forum: Bronsted Acids & Bases
Topic: bronsted base and acid
Replies: 4
Views: 125

Re: bronsted base and acid

Lewis refers to eLectrons. Bronstead refers to protons. Bronstead acids or bases are always a Lewis acid or base (respectively). Aka a bronstead base is also a lewis base. But the vice-versa is not true. Ex. BF3 is a lewis acid (it accepts electrons) but is not a bronstead acid (doesn't have protons...
by Sjeffrey_1C
Fri Dec 06, 2019 8:47 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: what is a ligand?
Replies: 7
Views: 71

Re: what is a ligand?

A ligand forms a coordinate covalent bond with a transition metal cation, so I guess if CO did this it would be considered a ligand. A ligand is anything directly bound to the central atom.
by Sjeffrey_1C
Fri Dec 06, 2019 8:45 pm
Forum: Polyprotic Acids & Bases
Topic: bases
Replies: 2
Views: 78

Re: bases

In the case of H2SO4, these are the reactions that show this:

H2SO4 + H2O -> HSO4- + H3O+

HSO4- + H2O -> SO42- + H3O+

overall equation: H2SO4 + 2H2O -> SO42- + 2H30+
by Sjeffrey_1C
Fri Dec 06, 2019 8:42 pm
Forum: Naming
Topic: Naming Cont
Replies: 3
Views: 37

Re: Naming Cont

Also don't forget if a cation is present outside the brackets... like sodium in Na[Fe(Ox)2(OH2)2)]... name it first. Ex. Sodium diaquabisoxalato ferrate (III)
by Sjeffrey_1C
Fri Dec 06, 2019 8:38 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Relative Acidity: e- withdrawing groups
Replies: 2
Views: 82

Re: Relative Acidity: e- withdrawing groups

An electron withdrawing group pulls electrons towards it from another source. It is a way of determining the relative strength of a conjugate base. E- with drawing groups delocalize a neg charge.

For example HClO or HBrO
by Sjeffrey_1C
Sun Dec 01, 2019 5:49 pm
Forum: Student Social/Study Group
Topic: final
Replies: 4
Views: 65

Re: final

I'm assuming information after Test #2 will be the most emphasized (since it's the only content we haven't been tested on), but I am not 100% sure. Maybe ask a TA during discussion.
by Sjeffrey_1C
Sun Dec 01, 2019 5:46 pm
Forum: Bronsted Acids & Bases
Topic: Strong/Weak Acid/Base
Replies: 2
Views: 23

Re: Strong/Weak Acid/Base

The strong acid I see most often is HCl!
by Sjeffrey_1C
Sun Dec 01, 2019 5:44 pm
Forum: Lewis Acids & Bases
Topic: 6.5 - how to identify which is the lewis acid and base?
Replies: 2
Views: 43

Re: 6.5 - how to identify which is the lewis acid and base?

If you draw the Lewis structures, look at which have lone pairs. This will give you an indication of which will donate electrons (lewis base) and which will accept electrons (lewis acid)!
by Sjeffrey_1C
Sun Dec 01, 2019 5:43 pm
Forum: General Science Questions
Topic: Memorization for Final
Replies: 2
Views: 44

Re: Memorization for Final

You definitely will have to know molecular geometry names and bond angles!
by Sjeffrey_1C
Sun Dec 01, 2019 5:36 pm
Forum: Conjugate Acids & Bases
Topic: NH3, acid or base?
Replies: 12
Views: 2101

Re: NH3, acid or base?

A bronsted base accepts a proton and a bonsted donates a proton. Thus, NH3, in most reactions, is a bronsted base.
by Sjeffrey_1C
Fri Nov 15, 2019 3:12 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizing power vs polarizability
Replies: 5
Views: 127

Re: Polarizing power vs polarizability

Generally atoms with polarizing power have small atomic radii and are partial negative. Atoms that are polarizable have large atomic radii and are partial positive.
by Sjeffrey_1C
Fri Nov 15, 2019 3:10 pm
Forum: Dipole Moments
Topic: 3f.1
Replies: 3
Views: 50

Re: 3f.1

Also keep in mind that the dipole moment is a permanent dipole moment, meaning its polar.
by Sjeffrey_1C
Fri Nov 15, 2019 3:03 pm
Forum: Trends in The Periodic Table
Topic: Question
Replies: 17
Views: 370

Re: Question

Also keep in mind that although the trend is the same for both, ionization dips at oxygen (meaning oxygen is an exception to the trend) while electronegativity trend continues through oxygen.
by Sjeffrey_1C
Fri Nov 15, 2019 2:59 pm
Forum: Dipole Moments
Topic: IMFs
Replies: 2
Views: 43

Re: IMFs

Each IMF has defining characteristics. This image might help.
by Sjeffrey_1C
Fri Nov 15, 2019 2:55 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: polar/nonpolar
Replies: 2
Views: 24

Re: polar/nonpolar

Look at the charges. If there are partial positive or partial negative components, it's likely that dipole moments will occur.
by Sjeffrey_1C
Fri Nov 08, 2019 5:10 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 18
Views: 332

Re: Resonance Structures

Also resonance structures are used to determine the true most stable structure. So if multiple resonance structures contribute equally, the structure will be a hybrid of all the resonance structures. This is why sometimes if there's resonance, bond lengths will be between that of a single bond and a...
by Sjeffrey_1C
Fri Nov 08, 2019 5:07 pm
Forum: Student Social/Study Group
Topic: Class Grading
Replies: 44
Views: 1706

Re: Class Grading

I think when he says there isn't a curve he means a bell curve, meaning there isn't a specific grade distribution he wants. But it does seem like he will be curving the class, or not using a standard grading scale. This way if the overall grades aren't very high, he will shift the cutoffs so that pe...
by Sjeffrey_1C
Fri Nov 08, 2019 5:04 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 2
Replies: 6
Views: 79

Re: Test 2

Just to clarify so there's no confusion, someone above said next week but it is actually in 2 weeks! Its the week of the 18th - 22nd!
by Sjeffrey_1C
Fri Nov 08, 2019 5:00 pm
Forum: Electronegativity
Topic: Periodic Trend
Replies: 13
Views: 130

Re: Periodic Trend

Additionally, these are basically the same trends as electron affinity and ionization energy. (Although ionization energy does dip for oxygen)
by Sjeffrey_1C
Fri Nov 08, 2019 4:59 pm
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 18
Views: 156

Re: Drawing Lewis Structures

The main goal is to minimize charges. So however you can get the charges to be lowest, while still adding up to the total charge and following octet rules etc. Placing larger charges on more electronegative elements is also important.
by Sjeffrey_1C
Wed Nov 06, 2019 8:46 am
Forum: SI Units, Unit Conversions
Topic: units for Equations Sheet
Replies: 2
Views: 119

units for Equations Sheet

Could someone give me a quick reminder of the units different things should be in for the constants and equations sheet? Like when to use nm vs m or kg vs g. Just for the most important equations! Thank you!
by Sjeffrey_1C
Wed Oct 30, 2019 9:55 pm
Forum: Ionic & Covalent Bonds
Topic: Format of midterm?
Replies: 12
Views: 105

Re: Format of midterm?

When it says questions come from hw and online, does this mean word for word or just similar format/topic?
by Sjeffrey_1C
Wed Oct 30, 2019 9:54 pm
Forum: Student Social/Study Group
Topic: Will different midterm review sessions cover the same material?
Replies: 8
Views: 104

Re: Will different midterm review sessions cover the same material?

Would someone mind posting the midterm review session times? I didn't write them down.
by Sjeffrey_1C
Wed Oct 30, 2019 9:50 pm
Forum: Lewis Structures
Topic: 4s and 3d
Replies: 4
Views: 72

Re: 4s and 3d

This confused me at first too. If writing the electron configuration for Ga itself you would first fill 4S before 3D, which made me believe that when Ga loses 3 electrons to become 3+, electrons would be removed from 3D since it was filled last. This though, is not the case. Electrons are removed fr...
by Sjeffrey_1C
Wed Oct 30, 2019 9:47 pm
Forum: Ionic & Covalent Bonds
Topic: 2A.21
Replies: 4
Views: 56

Re: 2A.21

You can tell that all of these have 0 unpaired electrons because the last orbitals are full in each case.
by Sjeffrey_1C
Wed Oct 30, 2019 9:45 pm
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 4
Views: 36

Re: Drawing Lewis Structures

Generally, if there is a singular of one element and multiple of another, the singular one will go in the middle. For example, CCl4, NF3, H2O, etc.
by Sjeffrey_1C
Sun Oct 27, 2019 8:24 pm
Forum: Ionic & Covalent Bonds
Topic: Videos
Replies: 2
Views: 46

Re: Videos

https://www.khanacademy.org/science/che ... structures This video is also helpful for drawing lewis diagrams!
by Sjeffrey_1C
Sun Oct 27, 2019 8:20 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Questions with Heisenburg uncertainty principle
Replies: 2
Views: 50

Re: Questions with Heisenburg uncertainty principle

These are important because the more you know about the position (delta x) of an electron, the less you know about its momentum (delta p), and vice-versa. Thus, it's impossible to know both an electron's position and momentum.
by Sjeffrey_1C
Sun Oct 27, 2019 8:15 pm
Forum: Ionic & Covalent Bonds
Topic: Homework
Replies: 13
Views: 176

Re: Homework

As said, we can probably do some quantum problems. But since the past 3 weeks have been quantum, it might be good to move onto some new content in preparation.
by Sjeffrey_1C
Sun Oct 27, 2019 8:12 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Bonds
Replies: 14
Views: 152

Re: Covalent Bonds

I think only two non-metals. A non-metal and a metal would form an ionic bond. Two metals would form a metallic bond.
by Sjeffrey_1C
Sun Oct 27, 2019 7:59 pm
Forum: Resonance Structures
Topic: Octet
Replies: 13
Views: 162

Re: Octet

My TA mentioned that the 8th group is composed on octets. These are noble gases I believe.
by Sjeffrey_1C
Sun Oct 27, 2019 7:51 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 4f Subshell Clarification
Replies: 3
Views: 60

Re: 4f Subshell Clarification

I'm not sure about the order they fill. But yes, the 4f subshell can hold 14 electrons as it has 7 orbitals, and each can hold 2 electrons. (And each electron has to have an opposite spin bc of Pauli)
by Sjeffrey_1C
Sat Oct 19, 2019 9:29 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Shell, Subshell, Orbital Terminology
Replies: 8
Views: 133

Re: Shell, Subshell, Orbital Terminology

This is really important, thanks! I feel like most high school teachers didn't make those distinctions very clear, so it's easy to get confused.
by Sjeffrey_1C
Sat Oct 19, 2019 9:27 pm
Forum: *Shrodinger Equation
Topic: Wave functions
Replies: 9
Views: 106

Re: Wave functions

A wave function I believe gives you specific info regarding the wave's properties.
by Sjeffrey_1C
Sat Oct 19, 2019 9:26 pm
Forum: Properties of Light
Topic: Midterm Exam
Replies: 21
Views: 255

Re: Midterm Exam

On that note, does anyone know which topics will be covered which weeks? I expected to see weeks on the syllabus next to each new topic, but didn't notice anything like that.
by Sjeffrey_1C
Sat Oct 19, 2019 9:23 pm
Forum: *Black Body Radiation
Topic: General Question about this
Replies: 2
Views: 122

Re: General Question about this

I believe we went over it earlier last week but I might have just read about it in the textbook. It refers to something that can absorb all light frequencies.
by Sjeffrey_1C
Sat Oct 19, 2019 9:21 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: determining types of orbitals (?)
Replies: 4
Views: 54

Re: determining types of orbitals (?)

Also during lecture, he provided some specific things you just need to know regarding orbitals. I'd recommend going through those and making sure you know those as they might help.
by Sjeffrey_1C
Wed Oct 16, 2019 8:04 pm
Forum: DeBroglie Equation
Topic: Textbook Question 1B21
Replies: 3
Views: 57

Re: Textbook Question 1B21

I had a similar issue where I kept getting an answer that was slightly off. Make sure you check all your conversions. For the mass, make sure you convert to grams, and then kg... you should get .145745kg. For the velocity, you need to convert miles to meters and hours to seconds. Remember that 1 met...
by Sjeffrey_1C
Sun Oct 13, 2019 12:59 pm
Forum: DeBroglie Equation
Topic: De Broglie Equation Clarification
Replies: 4
Views: 58

Re: De Broglie Equation Clarification

To add on, the concepts mentioned above are that in constructive interference, the amplitudes of the two waves summate (add together). In destructive interference, the amplitude's of the two waves cancel each other out.
by Sjeffrey_1C
Sun Oct 13, 2019 12:56 pm
Forum: Properties of Light
Topic: wavelike properties
Replies: 6
Views: 56

Re: wavelike properties

As others explained, electrons have wave-like properties, which are explained in the textbook, as well as particle properties. This concept as a whole is know as wave-particle duality, meaning electrons cannot be explained as merely a wave, or merely a particle, but as a combination of the two.
by Sjeffrey_1C
Sun Oct 13, 2019 12:52 pm
Forum: Significant Figures
Topic: Sig Figs at the Beginning or End
Replies: 14
Views: 380

Re: Sig Figs at the Beginning or End

As said above, you shouldn't convert to sig figs till the end so storing in your calculator as you go is very helpful. You can generally assign values to a letter so you can call it back later. For example, on the TI-30X, once you have a value you click "STO" and select a a letter to assig...

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