Search found 100 matches

by MaggieHan1L
Sun Mar 15, 2020 4:42 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: exam order
Replies: 2
Views: 34

Re: exam order

k=Ae^{-Ea/RT} is the equation and doesn't have anything that is affected by order.
by MaggieHan1L
Sun Mar 15, 2020 4:40 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: catalyst
Replies: 4
Views: 24

Re: catalyst

It is present at the beginning and reappears at the end as opposed to an intermediate which forms and disappears during the reaction
by MaggieHan1L
Sun Mar 15, 2020 4:38 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Arrhenius eq
Replies: 5
Views: 25

Re: Arrhenius eq

Also when you are looking at activation energy
by MaggieHan1L
Sun Mar 15, 2020 4:37 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: heterogeneous vs homogeneous catalysts
Replies: 2
Views: 19

Re: heterogeneous vs homogeneous catalysts

I think it's helpful in the future when you are working in the lab and you need to choose a catalyst.
by MaggieHan1L
Sat Mar 07, 2020 11:11 pm
Forum: Second Order Reactions
Topic: Termolecular
Replies: 15
Views: 309

Re: Termolecular

Its not commonly seen though because the chances of 3 molecules hitting simultaneously is super low which is why we don't cover third order
by MaggieHan1L
Sat Mar 07, 2020 11:11 pm
Forum: Second Order Reactions
Topic: Half-life of Second-Order
Replies: 4
Views: 278

Re: Half-life of Second-Order

Second order half life is 1/k[A]0 and it is used.
by MaggieHan1L
Sat Mar 07, 2020 11:03 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: activation energy/ energy barrier
Replies: 6
Views: 49

Re: activation energy/ energy barrier

Activation energy is the amount of energy needed before a reaction could proceed. There is a numerical value and it's important because a larger activation energy tends to have a slower reaction. Also this is important when it comes to enzymes
by MaggieHan1L
Sat Mar 07, 2020 11:00 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: linear plots
Replies: 7
Views: 58

Re: linear plots

I think he could give us a question with a plot and ask us what order the reaction is.
by MaggieHan1L
Sat Mar 07, 2020 10:54 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Rate Determining Steps in a series of Elementary Steps
Replies: 2
Views: 35

Re: Rate Determining Steps in a series of Elementary Steps

Dr. Lavelle said he would show us an example Monday but yeah since there is a buildup of B the B reverts back to A so thus we can treat it as if the step is in equilibrium.
by MaggieHan1L
Sun Mar 01, 2020 1:03 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Order of reaction
Replies: 3
Views: 311

Re: Order of reaction

I found this on a website and it feels like an apt summary

Zero order: No effect
First order: Rate doubles when reactant doubled
Second order: Rate quadruples when reactant doubled
Third order: Rate increases eightfold when reactant doubled.
by MaggieHan1L
Sun Mar 01, 2020 12:58 pm
Forum: General Rate Laws
Topic: Unique Rate Applications
Replies: 2
Views: 44

Re: Unique Rate Applications

I think they might ask you to try to find the order of reactions if they give you experimental data.
by MaggieHan1L
Sun Mar 01, 2020 12:54 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: determine n
Replies: 16
Views: 469

Re: determine n

If you're talking about kinetics n is the order of the reactant.
by MaggieHan1L
Sun Mar 01, 2020 12:52 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Units k
Replies: 3
Views: 266

Re: Units k

you're trying to get a rate of M/s so if you set up the rate calculations you can see that for first order you get k times M. Thus k would need units of s^-1 to obtain M/s. So you can calculate the units of k like this for each order. Its easier to be able to calculate then remembering.
by MaggieHan1L
Sun Mar 01, 2020 12:46 pm
Forum: General Rate Laws
Topic: Reaction Rates
Replies: 5
Views: 48

Re: Reaction Rates

It's all about how the rates are calculated for products its d[P]/dt while for reactants its -d[R]/dt. Its just easier to think about rates in terms of being positive.
by MaggieHan1L
Sat Feb 22, 2020 4:40 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: max potential in Galvanic Cell
Replies: 4
Views: 21

Re: max potential in Galvanic Cell

I think that this was when Professor Lavelle was talking about the switch being opened
by MaggieHan1L
Sat Feb 22, 2020 4:39 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge
Replies: 10
Views: 65

Re: Salt Bridge

It lets ions flow freely and thus the reaction won't be influenced by all of the free ions.
by MaggieHan1L
Sat Feb 22, 2020 4:34 pm
Forum: Balancing Redox Reactions
Topic: Homework 6K.5
Replies: 2
Views: 31

Re: Homework 6K.5

Remember OIL RIG or LEO says GER. Look at oxidation states of elements. When oxidation states get more positive they are losing electrons and thus being oxidized.
by MaggieHan1L
Sat Feb 22, 2020 3:44 pm
Forum: Balancing Redox Reactions
Topic: 6K3, part d
Replies: 2
Views: 32

Re: 6K3, part d

If you look at it, it doesn't make sense for it to go from Cl2 to Cl2. Even if I didn't know its a typo, I would change the products because it feels wrong to have the reactant also be a product. Or at the very least ask about it if its on an exam.
by MaggieHan1L
Sat Feb 22, 2020 3:39 pm
Forum: Balancing Redox Reactions
Topic: Finding moles of the reaction
Replies: 4
Views: 41

Re: Finding moles of the reaction

The n stands for the number of moles of electrons. Look at the oxidation states of the reactions and figure out how many moles of electrons are exchanged.
by MaggieHan1L
Sun Feb 16, 2020 9:37 pm
Forum: Van't Hoff Equation
Topic: Variable Explanations
Replies: 3
Views: 32

Re: Variable Explanations

K2 is K at one temperature while K2 is K at another temperature. K means equilibrium constant. Delta H is enthalpy and delta s is entropy. R is the gas constant and T is temperature.
by MaggieHan1L
Sun Feb 16, 2020 9:35 pm
Forum: Van't Hoff Equation
Topic: Temperature and K
Replies: 2
Views: 30

Re: Temperature and K

I think it’s harder to relate K to temperature since the equation compares the two Ks as a ratio of ln(K2/k1)
by MaggieHan1L
Sun Feb 16, 2020 9:32 pm
Forum: Van't Hoff Equation
Topic: K in Van't Hoff
Replies: 3
Views: 30

Re: K in Van't Hoff

The Van’t Hoff equation is to compare Ks at different temperatures. Thus if you know K at one temperature you can find K at another temperature as long as you know delta H, delta S, and R
by MaggieHan1L
Sun Feb 16, 2020 9:30 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Van't Hoff Equation
Replies: 2
Views: 28

Re: Van't Hoff Equation

I think that there are certain caveats, but the assumption is that the two temperatures wouldn’t be different enough to change the delta S
by MaggieHan1L
Sun Feb 16, 2020 9:26 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: K equation with Gibbs free energy
Replies: 3
Views: 37

Re: K equation with Gibbs free energy

I think the problems usually use -G=RTlnK more, but you would probably use G=G*+RTlnK to compare G at non standard conditions
by MaggieHan1L
Sun Feb 09, 2020 8:54 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Types of reaction & Equations
Replies: 3
Views: 37

Re: Types of reaction & Equations

Try writing down the tidbits given to you in problem and looking for equations that have the variables that you know. Sorry if this isn't helpful
by MaggieHan1L
Sun Feb 09, 2020 8:48 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: How to find the W?
Replies: 3
Views: 37

Re: How to find the W?

W= #microstates ^ # of particles. There are 12 micro states and 6.02*10^23 is the amount of particles in one mole
by MaggieHan1L
Sun Feb 09, 2020 8:44 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Degrees of Change in Entropy
Replies: 5
Views: 32

Re: Degrees of Change in Entropy

When there is a degrees symbol and it's not attached to C, it means standard so under standard conditions.
by MaggieHan1L
Sun Feb 09, 2020 8:41 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Finding whether exothermic or Endothermic
Replies: 4
Views: 38

Re: Finding whether exothermic or Endothermic

You can also tell by the reactions. For example a solid going to liquids or gas. You need heat to provide energy to break up intermolecular forces and thus the reaction is endothermic. Try thinking about the forces and bonds and how you need energy to break them
by MaggieHan1L
Sun Feb 09, 2020 8:38 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: 4H.9
Replies: 2
Views: 25

Re: 4H.9

I think it has to do with the fact that it is a monatomic gas compared to b and c which are diatomic gases. Because each particle is not bound to another, the monatomic gas probably has more available positions and entropy.
by MaggieHan1L
Sun Feb 02, 2020 1:33 pm
Forum: Phase Changes & Related Calculations
Topic: Homework 4A.9
Replies: 3
Views: 48

Re: Homework 4A.9

The negative sign is there to help signify the relationship between the two temperatures and it doesn't really matter because you just want to have the right amounts of negatives on both sides.
by MaggieHan1L
Sun Feb 02, 2020 1:30 pm
Forum: Phase Changes & Related Calculations
Topic: 4C.13
Replies: 2
Views: 36

Re: 4C.13

Whenever there is phase change you add the heat of fusion/vaporization to the amount of energy it takes to raise the substance a certain amount of degrees. If you look at the phase change curve you can see it's flat then it starts increasing in temperature. The flat area is the phase change.
by MaggieHan1L
Sun Feb 02, 2020 1:22 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: kinetics
Replies: 8
Views: 43

Re: kinetics

We haven't gone over kinetics but is more about rate while thermodynamics is more like the transference of energy.
by MaggieHan1L
Sun Feb 02, 2020 1:19 pm
Forum: Calculating Work of Expansion
Topic: Gas constant
Replies: 5
Views: 37

Re: Gas constant

Where are you getting 3.314?
by MaggieHan1L
Sun Feb 02, 2020 1:18 pm
Forum: Calculating Work of Expansion
Topic: L atm and J
Replies: 3
Views: 31

Re: L atm and J

when you use -p delta v you get units of 1 L atm so you use 1 L atm = 101.33 J to get to J
by MaggieHan1L
Sun Jan 26, 2020 9:34 pm
Forum: Phase Changes & Related Calculations
Topic: Standard reaction enthalpy vs. Standard enthalpy of formation
Replies: 2
Views: 17

Re: Standard reaction enthalpy vs. Standard enthalpy of formation

Standard enthalpy of reaction can be any type of reaction but standard enthalpy of formation is specifically forming one mole of a compound using elements in standard states.
by MaggieHan1L
Sun Jan 26, 2020 9:32 pm
Forum: Phase Changes & Related Calculations
Topic: Phase changes
Replies: 8
Views: 52

Re: Phase changes

standard enthalpy changes will be in a certain phase and sometimes you have to add enthalpy of phase changes to calculate enthalpy of reactions.
by MaggieHan1L
Sun Jan 26, 2020 9:18 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard enthalpy of formation of O2
Replies: 4
Views: 23

Re: Standard enthalpy of formation of O2

02 is already the most stable form of oxygen and so if you look at 02 to 02 the enthalpy of formation would be enthalpy of 02-enthalpy of 02 equaling 0
by MaggieHan1L
Sun Jan 26, 2020 9:14 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Meaning of State Function
Replies: 8
Views: 43

Re: Meaning of State Function

All you care about is final and initial so enthalpy of product minus enthalpy of reactants
by MaggieHan1L
Sun Jan 26, 2020 9:12 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 3
Views: 18

Re: Bond Enthalpies

There are tables where all of the enthalpies have been found.
by MaggieHan1L
Sun Jan 19, 2020 5:43 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J.5
Replies: 2
Views: 16

Re: 5J.5

When volume decreases, the reaction favors the side with less moles of gas.
by MaggieHan1L
Sun Jan 19, 2020 5:42 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: pKa
Replies: 13
Views: 70

Re: pKa

Lower pKa means a less negative Ka which means that there is a high amount of dissociation and thus a stronger acid.
by MaggieHan1L
Sun Jan 19, 2020 5:39 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I 33
Replies: 2
Views: 18

Re: 5I 33

It's not a part of the problem. It's most likely put there to trick you. You don't need to know about the reactants since it is a solid and thus wouldn't go into calculations. Since you know the mass of CO2 then you know molarity of CO2 and molarity of NH3. CO2 would be equivalent to X and NH3 would...
by MaggieHan1L
Sun Jan 19, 2020 5:34 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Acids/Bases and Chemical Equilibrium
Replies: 2
Views: 20

Re: Acids/Bases and Chemical Equilibrium

Acids/Bases usually require a lot of ICE tables since weak acids/bases don't dissociate completely
by MaggieHan1L
Sun Jan 19, 2020 5:32 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: temperature change in reactions
Replies: 2
Views: 17

Re: temperature change in reactions

If a reaction is endothermic than it requires heat to get to the products so adding heat is favoring the products. If a reaction is exothermic, that is saying the same thing as the reverse reaction is endothermic so increasing temperature favors the reactants.
by MaggieHan1L
Sun Jan 12, 2020 12:25 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: When to do ice tables [ENDORSED]
Replies: 4
Views: 34

Re: When to do ice tables [ENDORSED]

A hint to do an ICE might be when you get only a few concentrations and you get K
by MaggieHan1L
Sun Jan 12, 2020 12:23 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: States of matter [ENDORSED]
Replies: 4
Views: 23

Re: States of matter [ENDORSED]

Solids and liquids have a basically constant concentration so it won't change K because it would just cancel out if you write it out.
by MaggieHan1L
Sun Jan 12, 2020 12:21 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Meaning of K [ENDORSED]
Replies: 4
Views: 37

Re: Meaning of K [ENDORSED]

K is the ratio of products and reactants. Things like increasing temperature and adding a catalyst speed up the rates.
by MaggieHan1L
Sun Jan 12, 2020 12:19 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Calculating K
Replies: 5
Views: 37

Re: Calculating K

If you included it since the concentration doesn't change, the liquid and solid would just cancel out.
by MaggieHan1L
Sun Jan 12, 2020 12:15 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc vs. Kp [ENDORSED]
Replies: 4
Views: 38

Re: Kc vs. Kp [ENDORSED]

Yes when we see gas we assume Kp and when we see aqueous we assume Kc.
by MaggieHan1L
Sun Dec 08, 2019 11:33 pm
Forum: Naming
Topic: Cyanido
Replies: 2
Views: 66

Re: Cyanido

The rule is if it ends in ide it turns to ido
by MaggieHan1L
Sun Dec 08, 2019 11:31 pm
Forum: Conjugate Acids & Bases
Topic: Neutralization Equations
Replies: 3
Views: 90

Re: Neutralization Equations

neutralization is usually strong acids and bases I think
by MaggieHan1L
Sun Dec 08, 2019 11:28 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6B.1
Replies: 2
Views: 55

Re: 6B.1

That's the only way to get a number without knowing the concentrations. Since it's -log (0.12H+)-(-log (H+), you can change it to log (H+)-(log 0.12(H+)) and thus you can take log 1/0.12 since the H+ will cancel.
by MaggieHan1L
Sun Dec 08, 2019 11:11 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: common acids and bases
Replies: 4
Views: 57

Re: common acids and bases

My TA mentioned that usually the organic molecules were the weak ones.
by MaggieHan1L
Sun Dec 08, 2019 11:09 pm
Forum: Polyprotic Acids & Bases
Topic: Amphiprotic vs Amphoteric
Replies: 6
Views: 90

Re: Amphiprotic vs Amphoteric

Amphiprotic is always amphoteric but amphoteric is not always amphiprotic.
by MaggieHan1L
Sun Dec 01, 2019 3:31 pm
Forum: Bronsted Acids & Bases
Topic: Net Ionic Equations
Replies: 3
Views: 30

Re: Net Ionic Equations

It depends on whether or not they dissociate completely in water.
by MaggieHan1L
Sun Dec 01, 2019 3:27 pm
Forum: Amphoteric Compounds
Topic: 6A.11
Replies: 2
Views: 30

Re: 6A.11

I think the easiest way when you're told that the molecule is amphoteric is to just add a proton and minus a proton. So you would end up with PO4 (3-) and H2PO4 for HPO4.
by MaggieHan1L
Sun Dec 01, 2019 3:22 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: [H3O+] and [OH-]
Replies: 3
Views: 55

Re: [H3O+] and [OH-]

If you want to calculate directly [H3O+][OH-]=10^-14.
by MaggieHan1L
Sun Dec 01, 2019 3:19 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acid Strength
Replies: 3
Views: 45

Re: Acid Strength

My TA explained it as those molecules having more resonance usually and thus without the proton they are more stable so they are more willing to be dissociated. At least this is how I understood it.
by MaggieHan1L
Sun Dec 01, 2019 3:18 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Strong vs Weak Acids
Replies: 7
Views: 56

Re: Strong vs Weak Acids

Usually acids that have an atom which is more electronegative will be stronger
by MaggieHan1L
Sun Nov 24, 2019 4:33 pm
Forum: Biological Examples
Topic: Transition metals and their biological importance
Replies: 2
Views: 25

Re: Transition metals and their biological importance

I don't think you actually have to memorize them because he probably just wanted to show us the importance of these metals.
by MaggieHan1L
Sun Nov 24, 2019 4:31 pm
Forum: Naming
Topic: #9C3 d
Replies: 2
Views: 62

Re: #9C3 d

Doesn't it have to do with alphabetical order?
by MaggieHan1L
Sun Nov 24, 2019 4:28 pm
Forum: Bronsted Acids & Bases
Topic: Acid Naming
Replies: 2
Views: 40

Re: Acid Naming

Yes cation before anion
by MaggieHan1L
Sun Nov 24, 2019 4:27 pm
Forum: Naming
Topic: Coordination number
Replies: 7
Views: 47

Re: Coordination number

Coordination numbers depend on the number of bonds.
by MaggieHan1L
Sun Nov 24, 2019 4:24 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: transition metals
Replies: 2
Views: 21

Re: transition metals

You calculate oxidation numbers based on charges of the rest of the compound.
by MaggieHan1L
Sun Nov 17, 2019 2:18 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR notation
Replies: 8
Views: 71

Re: VSEPR notation

A for the central atom. X for the bonded atoms. E for the lone pairs.
by MaggieHan1L
Sun Nov 17, 2019 2:15 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw
Replies: 23
Views: 172

Re: Seesaw

I don't know if the angle has a difference that is significant. 90 and 120 should be fine.
by MaggieHan1L
Sun Nov 17, 2019 11:20 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Shapes We Are Expected to Know
Replies: 6
Views: 53

Re: Shapes We Are Expected to Know

He said that the ones we discussed in class in Friday we need to know and we also need to know Monday's lecture.
by MaggieHan1L
Sun Nov 17, 2019 11:19 am
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Model
Replies: 5
Views: 35

Re: VSEPR Model

Electron focuses more on how the electrons are placed and bonding than molecular. So molecular tends to be more general focusing on regions of electron density while electron focuses on lone pairs and where they are placed because of the electron electron repulsion.
by MaggieHan1L
Sun Nov 17, 2019 11:16 am
Forum: Determining Molecular Shape (VSEPR)
Topic: identifying pi & sigma bonds
Replies: 3
Views: 47

Re: identifying pi & sigma bonds

I think he's going to cover this more in depth on Monday
by MaggieHan1L
Sun Nov 10, 2019 5:20 pm
Forum: Dipole Moments
Topic: 3F. 5
Replies: 2
Views: 44

Re: 3F. 5

H bond needs a hydrogen bonded to a highly electronegative atom such as F, O, and N.
by MaggieHan1L
Sun Nov 10, 2019 5:06 pm
Forum: Electronegativity
Topic: Ionization Energy vs. Electronegativity
Replies: 9
Views: 95

Re: Ionization Energy vs. Electronegativity

Think of ionization energy as what it takes to make an anion and electronegativity is how badly it wants to be negative. That's how I remember it. Don't know if that helps
by MaggieHan1L
Sun Nov 10, 2019 5:02 pm
Forum: Bond Lengths & Energies
Topic: Interaction Potential Energy Formula
Replies: 2
Views: 32

Re: Interaction Potential Energy Formula

You just have to be aware of the proportionality and that r is to the power of 6 so it has a pretty big impact.
by MaggieHan1L
Sun Nov 10, 2019 4:51 pm
Forum: Bond Lengths & Energies
Topic: London Forces
Replies: 6
Views: 56

Re: London Forces

London forces are created when there are slight e density fluctuations and these are just in all compounds
by MaggieHan1L
Sun Nov 10, 2019 4:42 pm
Forum: Bond Lengths & Energies
Topic: Bond strength
Replies: 4
Views: 37

Re: Bond strength

It also has to do with size. Larger atoms results in longer bond length and a weaker bond.
by MaggieHan1L
Sun Nov 03, 2019 2:54 pm
Forum: Dipole Moments
Topic: Midterm
Replies: 8
Views: 109

Re: Midterm

Friday's lecture. The last slide was going to be on it but then we got class canceled on Monday.
by MaggieHan1L
Sun Nov 03, 2019 2:52 pm
Forum: Resonance Structures
Topic: Defining Resonance Structures
Replies: 3
Views: 27

Re: Defining Resonance Structures

I think that formal charge also comes into play.
by MaggieHan1L
Sun Nov 03, 2019 2:45 pm
Forum: Octet Exceptions
Topic: Expanded Valence Shells
Replies: 2
Views: 29

Re: Expanded Valence Shells

My TA said that it has to do with energies and hybridizations. An easy way is just to think about it in terms of being able to draw from the d subshells which only start when n=3
by MaggieHan1L
Sun Nov 03, 2019 2:43 pm
Forum: Octet Exceptions
Topic: What are radicals
Replies: 7
Views: 59

Re: What are radicals

Because they are exceptions to the octet rule, they are highly reactive and unstable. They're very dangerous because they can modify DNA and other biologic molecules. They usually don't remain in that state for long.
by MaggieHan1L
Sun Nov 03, 2019 2:29 pm
Forum: Ionic & Covalent Bonds
Topic: Relationship with Polarity
Replies: 3
Views: 36

Re: Relationship with Polarity

You can think of bigger polarity as one element wanting and pulling on electrons more. Thus ionic is just when there is such a big difference that one element "gets" the electron instead of sharing it.
by MaggieHan1L
Sun Oct 27, 2019 1:52 pm
Forum: Formal Charge and Oxidation Numbers
Topic: 2B. 23
Replies: 2
Views: 38

Re: 2B. 23

The preferred formal charge is 0. When he gave the example of sulphate SO4, the lewis structure was technically correct but the formal charges weren't ideal. We use formal charge to give us better lewis dot structures. When you're drawing lewis dot structures and you can't get all of the formal char...
by MaggieHan1L
Sun Oct 27, 2019 1:47 pm
Forum: Lewis Structures
Topic: Bond Lengths
Replies: 2
Views: 36

Re: Bond Lengths

When he was talking about Benzene, he was pointing out that the bonds are neither the length of a single or a double bond because of the resonance. The bond lengths depend based on the elements and what type of bond it is. For example N-O in nitrate was 1.24 A while C-C in benzene was 1.39 A.
by MaggieHan1L
Sun Oct 27, 2019 1:43 pm
Forum: Ionic & Covalent Bonds
Topic: P, Cl, and S octet tule exceptions
Replies: 4
Views: 37

Re: P, Cl, and S octet tule exceptions

Other elements such as N and O and F can't because they are in N=2 meaning they only have access to s and p and can only form an octet. In general just remember n=3 as what makes it an exception.
by MaggieHan1L
Sun Oct 27, 2019 1:41 pm
Forum: Ionic & Covalent Bonds
Topic: 2.A.17
Replies: 3
Views: 42

Re: 2.A.17

Positive means that they lost electrons so that's why you subtract from the ground state. If they were negative you would add because they gained electrons.
by MaggieHan1L
Sun Oct 27, 2019 1:39 pm
Forum: Ionic & Covalent Bonds
Topic: 2A.15
Replies: 4
Views: 42

Re: 2A.15

Losing 1 electron in the p orbital doesn't lead to an octet because there are still 2 electrons in the s orbital
by MaggieHan1L
Sun Oct 20, 2019 11:02 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heinsberg Uncertainty Equation Post-Module Question #18
Replies: 2
Views: 43

Re: Heinsberg Uncertainty Equation Post-Module Question #18

The uncertainty of the electron would be diameter and you used radius.
by MaggieHan1L
Sun Oct 20, 2019 10:59 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: 1.B #15
Replies: 2
Views: 35

Re: 1.B #15

The part where they say "Model the atom as a one-dimensional box with a length equal to the diameter of the actual atom." just means make delta x = to diameter. That's basically what you always do when you see diameter and uncertainty. Then you get speed by changing delta p into m times de...
by MaggieHan1L
Sun Oct 20, 2019 10:54 am
Forum: Properties of Electrons
Topic: Shared Electrons
Replies: 4
Views: 60

Re: Shared Electrons

It has to do with electron repulsions. The electrons make sure every orbital has one electron first because two electrons in the orbital has repulsions. At least that's what I remember from high school.
by MaggieHan1L
Sun Oct 20, 2019 10:52 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: p- orbital
Replies: 3
Views: 44

Re: p- orbital

Hung Indy Bui 3H is right, it all depends on how you label it and look at it. You can go any way you want.
by MaggieHan1L
Sun Oct 20, 2019 10:37 am
Forum: *Shrodinger Equation
Topic: Shrodinger Equation
Replies: 3
Views: 43

Re: Shrodinger Equation

Dr. Lavelle said he wouldn't go into the deriving of the equation because that was out of the scope of the class.
by MaggieHan1L
Sat Oct 12, 2019 1:04 pm
Forum: Properties of Electrons
Topic: Mass of Electron in De Broglie Equation
Replies: 4
Views: 57

Re: Mass of Electron in De Broglie Equation

Even though we didn't need it, I'm pretty sure on the last test Dr. Lavelle printed out the mass of an electron on the formula sheet
by MaggieHan1L
Sat Oct 12, 2019 1:02 pm
Forum: Properties of Electrons
Topic: Clarification on particle vs wave properties
Replies: 3
Views: 41

Re: Clarification on particle vs wave properties

I think that many things have wavelike properties but they aren't really detectable such as when they are smaller than 10^-15 and then you say they have more particle like properties
by MaggieHan1L
Sat Oct 12, 2019 1:00 pm
Forum: Properties of Electrons
Topic: Circular Standing Wave
Replies: 4
Views: 58

Re: Circular Standing Wave

Everything is quantized. It's not like a normal equation where you can plug in any number. There are only specific energies.
by MaggieHan1L
Sat Oct 12, 2019 12:58 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 2 Homework Problems [ENDORSED]
Replies: 67
Views: 2010

Re: Week 2 Homework Problems [ENDORSED]

For week 3, we definitely have to do quantum.
by MaggieHan1L
Sat Oct 12, 2019 12:55 pm
Forum: Limiting Reactant Calculations
Topic: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
Replies: 68
Views: 2341

Re: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]

Showing your work can also make it easier for you to double check your answers too!
by MaggieHan1L
Sat Oct 12, 2019 12:54 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg equation [ENDORSED]
Replies: 73
Views: 2577

Re: Rydberg equation [ENDORSED]

The rydberg equation I think is just an equation that combines a few steps of the Einitial - Efinal method.
by MaggieHan1L
Wed Oct 02, 2019 10:46 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical and Molecular Formula Masses
Replies: 5
Views: 99

Re: Empirical and Molecular Formula Masses

Empirical formula is the lowest ratio so molecular formula should not be greater than the empirical.
by MaggieHan1L
Wed Oct 02, 2019 10:39 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Molar Mass
Replies: 10
Views: 105

Re: Molar Mass

For some problems where you have to find the molar mass of a sample with a lot of isotopes just multiply the isotope percentage by the isotope weight and add all of them together.
by MaggieHan1L
Wed Oct 02, 2019 10:34 pm
Forum: Balancing Chemical Reactions
Topic: Combustion Reaction Notation
Replies: 6
Views: 81

Re: Combustion Reaction Notation

One thing we talked about today in discussion is that when you see oxidized that also means that it is combustion. Thought that would be useful in decoding problems.
by MaggieHan1L
Wed Oct 02, 2019 10:31 pm
Forum: Limiting Reactant Calculations
Topic: limiting reactant
Replies: 5
Views: 107

Re: limiting reactant

One thing that stuck with me throughout high school chemistry is the mole tunnel. If you're having trouble just always remember grams to moles to moles to grams.
by MaggieHan1L
Wed Oct 02, 2019 10:29 pm
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student - Part II [ENDORSED]
Replies: 150
Views: 5626

Re: Advice from a Medical Student - Part II [ENDORSED]

Thanks so much for taking the time to help out all of us who are so clueless. You gave such great and meaningful advice.

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