Search found 116 matches

by Nikki Razal 1L
Thu Mar 12, 2020 9:09 am
Forum: Administrative Questions and Class Announcements
Topic: FinalReview Sessions
Replies: 3
Views: 67

FinalReview Sessions

Does anyone know if Matthew's and Lyndon's final review got posted for us to work on? or was that canceled because of the current situation?
by Nikki Razal 1L
Thu Mar 12, 2020 9:07 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Steady state
Replies: 3
Views: 22

Re: Steady state

no, Lavelle said we would focus on using pre-equilibrium only
by Nikki Razal 1L
Thu Mar 12, 2020 9:06 am
Forum: *Enzyme Kinetics
Topic: How to distinguish the intermediates and catalysts?
Replies: 8
Views: 32

Re: How to distinguish the intermediates and catalysts?

Intermediates are produced and then consumed, and catalysts are consumed and then (re)produced
by Nikki Razal 1L
Thu Mar 12, 2020 9:04 am
Forum: Administrative Questions and Class Announcements
Topic: Final exam content
Replies: 15
Views: 180

Re: Final exam content

I assume the final would be similar to the previous exams we have taken, where not every question is from the homework, but the concepts from the hw would be tested and a couple problems would mirror hw problems
by Nikki Razal 1L
Thu Mar 12, 2020 9:02 am
Forum: Balancing Redox Reactions
Topic: Determining the oxidizer and reducer
Replies: 10
Views: 43

Re: Determining the oxidizer and reducer

the oxidizing agent is the reactant that gets reduced, whereas the reducing agent is the one that gets oxidized
by Nikki Razal 1L
Sun Mar 08, 2020 7:36 pm
Forum: General Rate Laws
Topic: 7A.3
Replies: 4
Views: 31

Re: 7A.3

I feel like the rates would both be positive because I think they are technically the same, just working in the opposite direction. either way, the book says that positive reaction rate is the normal convention in chemical kinetics
by Nikki Razal 1L
Sun Mar 08, 2020 7:33 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams
Replies: 13
Views: 36

Re: Cell Diagrams

^ one thing to note though is that you should only add an inert solid if there is not a solid METAL at the cathode or anode side
by Nikki Razal 1L
Sun Mar 08, 2020 7:29 pm
Forum: Balancing Redox Reactions
Topic: Balancing Basic Redox Reactions
Replies: 6
Views: 21

Re: Balancing Basic Redox Reactions

^^ for each half reaction, instead of adding H+ to an equation, add water, then add that same amount of OH- to the other side of the reaction
by Nikki Razal 1L
Sun Mar 08, 2020 7:26 pm
Forum: Zero Order Reactions
Topic: examples of zero order reactions?
Replies: 6
Views: 27

Re: examples of zero order reactions?

just to add on, one way you can decipher between a 0, 1st, and 2nd order reaction is by looking at what the units of the rate constant, "k", is:
0 order= conc/s
1st= 1/s
2nd= 1/(conc*s)
by Nikki Razal 1L
Sun Mar 08, 2020 7:22 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Slow step
Replies: 2
Views: 21

Re: Slow step

the elementary step with the rate matching the overall reaction should be the slow step considering 1) the sum of elementary steps=overall rate and 2) the mechanism agrees w the experimentally determined rate law
by Nikki Razal 1L
Tue Mar 03, 2020 3:40 am
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: hw 6O1
Replies: 1
Views: 59

hw 6O1

How would you go about solving the question: A 1.0 m NiSO4(aq) solution was electrolyzed by using inert electrodes. Write (a) the cathode reaction; (b) the anode reaction. (c) With no overpotential at the electrodes, what is the minimum potential that must be supplied to the cell for the onset of el...
by Nikki Razal 1L
Sun Mar 01, 2020 3:26 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Finding N
Replies: 6
Views: 43

Re: Finding N

n refers to the number of moles of electrons transferred, basically it is the total number of electrons you end up cancelling out in your half reaction equations
by Nikki Razal 1L
Sun Mar 01, 2020 2:17 am
Forum: Balancing Redox Reactions
Topic: hw 6l7c
Replies: 1
Views: 34

hw 6l7c

how do you balance the reaction:
Cd(s) + 2 Ni(OH)3 (s) --> Cd(OH)2 (s) + 2 Ni(OH)2 (s)?
by Nikki Razal 1L
Sun Mar 01, 2020 1:57 am
Forum: Balancing Redox Reactions
Topic: hw 6l7a
Replies: 1
Views: 39

hw 6l7a

when writing the cell diagram for AgBr(s) <--> Ag+(aq) + Br-(aq), where does the AgBr(s) in Ag(s)|AgBr(s)|Br-(aq)||Ag+(aq)|Ag(s) come from?
by Nikki Razal 1L
Sun Mar 01, 2020 1:52 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Flipping the sign
Replies: 10
Views: 58

Re: Flipping the sign

you flip the sign when you are given the reduction potential of a reaction but you have an oxidation reaction you are trying to find the Ecell for
by Nikki Razal 1L
Sun Mar 01, 2020 1:50 am
Forum: Balancing Redox Reactions
Topic: hw 6l7b
Replies: 2
Views: 40

hw 6l7b

How would you balance the redox reaction: H+(aq) + OH-(aq) --> H2O(l), the Brønsted neutralization reaction?
In the answer key, they use o2(g) to balance out the oxygens, but how would you know to do that?
by Nikki Razal 1L
Sun Feb 23, 2020 1:44 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic cell vs battery system
Replies: 3
Views: 17

Re: Galvanic cell vs battery system

I think they basically are the same. The textbook states that a battery is a collection of galvanic cells connected in a series
by Nikki Razal 1L
Sun Feb 23, 2020 1:41 pm
Forum: Balancing Redox Reactions
Topic: Acidic vs Basic
Replies: 4
Views: 36

Re: Acidic vs Basic

when balancing reactions in a basic solution, you end up having OH- as a product, whereas in acidic solution, you have H+
by Nikki Razal 1L
Sun Feb 23, 2020 1:40 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: standard conditions
Replies: 8
Views: 53

Re: standard conditions

standard conditions refers to a 1M solution at 1 atm and 273.15 K
by Nikki Razal 1L
Sun Feb 23, 2020 1:36 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Use of Platinum
Replies: 10
Views: 48

Re: Use of Platinum

You use platinum whenever you need to carry electrons into or out of the electrode compartment. Platinum is an inert conductor
by Nikki Razal 1L
Sun Feb 23, 2020 1:31 pm
Forum: Balancing Redox Reactions
Topic: balancing acidic vs. basic solutions
Replies: 3
Views: 30

Re: balancing acidic vs. basic solutions

as far as i know, it would tell you because whether it is in an acidic or basic solution determines the products
by Nikki Razal 1L
Sun Feb 16, 2020 10:10 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: endo/exo and temp
Replies: 12
Views: 235

Re: endo/exo and temp

the way i think abt is where heat is placed when it's written in a chemical rxn, when the rxn is endothermic, heat is on the left, and when it's exothermic it's on the left (you can think of this happening bc when heat is released, it is written as -)
by Nikki Razal 1L
Sun Feb 16, 2020 10:00 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Negative work
Replies: 14
Views: 139

Re: Negative work

when a system does work, it is by a negative sign
by Nikki Razal 1L
Sun Feb 16, 2020 9:59 pm
Forum: Ideal Gases
Topic: Equation
Replies: 4
Views: 53

Re: Equation

or you could be talking about the boltzmann formula for entropy , "S=klnW" where, S=entropy, k=1.381*10^-23 j/k (the boltzmann constant), and W is the number of ways that the atoms or molecules in the sample can be arranged with the same total energy
by Nikki Razal 1L
Sun Feb 16, 2020 9:52 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated versus closed
Replies: 7
Views: 76

Re: Isolated versus closed

a closed system has a fixed amt of matter but can exchange energy w the surroundings, while an isolated system cannot exchange matter or energy with the surroundings
by Nikki Razal 1L
Sun Feb 16, 2020 9:28 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2
Replies: 11
Views: 72

Re: Test 2

I think the person above is right, in chem 14a, test 2 wasn't cumulative
by Nikki Razal 1L
Sun Feb 09, 2020 6:48 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Intensive vs Extensive
Replies: 7
Views: 53

Re: Intensive vs Extensive

for an intensive property, the value of something will be the same no matter how much of a substance you have (ie, specific heat). for an extensive property, the value of something depends on how much substance you have (ie heat capacity)
by Nikki Razal 1L
Sun Feb 09, 2020 6:46 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Homework 4C3
Replies: 2
Views: 34

Re: Homework 4C3

for parts a and b, you would use similar processes. for part a, you would use the equation q=nCpdeltaT, and for part b, the equation q=nCvdeltaT. These are pretty much the same equations, just one is for constant pressure, whereas the other one is for constant volume. Plug in the values in each equa...
by Nikki Razal 1L
Sun Feb 09, 2020 6:41 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: System releasing energy
Replies: 2
Views: 19

Re: System releasing energy

If I'm reading this correctly, I think you are correct because when energy is released, deltaH is negative, and when delta H is negative, delta G is also negative in most cases
by Nikki Razal 1L
Sun Feb 09, 2020 6:37 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law
Replies: 10
Views: 55

Re: Hess's Law

Enthalpy is a state function, so enthalpy is additive
by Nikki Razal 1L
Sun Feb 09, 2020 6:37 pm
Forum: Phase Changes & Related Calculations
Topic: relationship between heat capacity and heating curve
Replies: 6
Views: 33

Re: relationship between heat capacity and heating curve

substances with a lower heat capacity are easier to heat up, so the change in temperature is more extreme after the same period of time taken to heat up a substance with a higher heat capacity. as a result, the heating curve is steeper for a substance with a low heat capacity
by Nikki Razal 1L
Sun Feb 09, 2020 6:33 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Entropy Question
Replies: 3
Views: 39

Re: Entropy Question

i believe so because one of the causes of entropy is change in position (of the molecules in a substance)
by Nikki Razal 1L
Sun Feb 02, 2020 4:50 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Calorimeter vs. Bomb Calorimeter
Replies: 4
Views: 30

Re: Calorimeter vs. Bomb Calorimeter

a calorimeter is "a device in which energy transferred as heat is monitored by recording the change in temperature produced by a process taking place within it" a bomb calorimeter is a more sophisticated version of the calorimeter. it is a sturdy sealed metal vessel of constant volume (the...
by Nikki Razal 1L
Sun Feb 02, 2020 4:47 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 3 Methods
Replies: 3
Views: 34

Re: 3 Methods

1) Hess's Law: use when you know delta H, use addition/subtraction to add up total enthalpy changes 2) using bonding enthalpies to calculate deltaH: add together energy required for the bonds in the reactants to break (positive values) and the energy released when bonds break (the energy of the prod...
by Nikki Razal 1L
Sun Feb 02, 2020 4:35 pm
Forum: Calculating Work of Expansion
Topic: Reversible and Irreversible
Replies: 5
Views: 36

Re: Reversible and Irreversible

to add, i think dr. lavelle stated that if a system is at equilibrium, it is a reversible process
by Nikki Razal 1L
Sun Feb 02, 2020 3:54 pm
Forum: Phase Changes & Related Calculations
Topic: phase change from liquid to vapor
Replies: 8
Views: 69

Re: phase change from liquid to vapor

^^ the longer line going from liquid to vapor indicates that more heat was released, making the steam burn more than liquid water
by Nikki Razal 1L
Sun Feb 02, 2020 3:46 pm
Forum: Administrative Questions and Class Announcements
Topic: Extra Credit
Replies: 7
Views: 97

Re: Extra Credit

I dont think Lavelle ever offers extra credit, but I would just talk to your ta about it, or just do five chemistry community submissions late
by Nikki Razal 1L
Sun Jan 26, 2020 8:07 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Reversible Reactions
Replies: 3
Views: 26

Re: Reversible Reactions

a reaction is reversible when the products of a chemical reaction can convert back to reactants. this is commonly shown in equilibrium reactions in which reactants and products form simultaneously. reversible reactions are written with a double arrow denoting the forward and reverse reactions
by Nikki Razal 1L
Sun Jan 26, 2020 8:02 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: exo thermic
Replies: 11
Views: 88

Re: exo thermic

left because in an exothermic reaction, heat will start on the right side because deltaH is negative, and heating favors reactant formation
by Nikki Razal 1L
Sun Jan 26, 2020 7:57 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: solvent
Replies: 10
Views: 44

Re: solvent

pure substances (solids and liquids) won't be included in the equilibrium constant
by Nikki Razal 1L
Sun Jan 26, 2020 7:53 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy
Replies: 3
Views: 18

Re: Enthalpy

to add, enthalpy is a state property, means that its value is determined only by its current state, and it is not dependent on the path taken to obtain that state
by Nikki Razal 1L
Sun Jan 26, 2020 7:50 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law
Replies: 9
Views: 52

Re: Hess's Law

Hess's Law states that enthalpy changes are additive because enthalpy changes are a state function, which must be additive.
by Nikki Razal 1L
Fri Jan 17, 2020 2:17 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Tips for Test
Replies: 23
Views: 176

Re: Tips for Test

^^ a lot of homework problems should help because Dr. Lavelle often gets problems from homework and put them on the test
by Nikki Razal 1L
Fri Jan 17, 2020 2:14 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Determining molar concentration
Replies: 2
Views: 26

Re: Determining molar concentration

I feel like you would start by changing grams of PCl5 to moles then finding the molarity of the initial PCl5 by dividing this number by the liters, then continue solving the problem as an ICE box
by Nikki Razal 1L
Fri Jan 17, 2020 2:08 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids and Equilibrium
Replies: 9
Views: 51

Re: Solids and Equilibrium

neither affects equilibrium because they are both pure substances
by Nikki Razal 1L
Fri Jan 17, 2020 2:07 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Solids and Liquids in Le Chatelier
Replies: 5
Views: 42

Re: Solids and Liquids in Le Chatelier

no, solids or liquids (pure substances) would not affect le chatelier because they are not technically included in the equilibrium expression
by Nikki Razal 1L
Fri Jan 17, 2020 2:05 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE and quadratic formula
Replies: 11
Views: 62

Re: ICE and quadratic formula

you can only avoid using the quadratic formula when you are given a small k value (<10^-3), otherwise you would have to solve for x normally, which may require you to use the quadratic formula
by Nikki Razal 1L
Sat Jan 11, 2020 3:46 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction quotient
Replies: 8
Views: 49

Re: Reaction quotient

K is calculated at equilibrium , while Q is calculated anytime during the reaction
by Nikki Razal 1L
Sat Jan 11, 2020 3:45 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Partial Pressure
Replies: 7
Views: 43

Re: Partial Pressure

yes, you use partial pressure when all products and reactants are in the gas phase, and you use the equilibrium constant Kp
by Nikki Razal 1L
Sat Jan 11, 2020 3:42 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: HW 5J.5
Replies: 8
Views: 44

Re: HW 5J.5

^^^ the molar concentrations of a pure substance (solid or liquid) does not affect K
by Nikki Razal 1L
Sat Jan 11, 2020 3:36 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q
Replies: 10
Views: 53

Re: Q

Yes! Q or Qc or Qp is calculated the same way as K :)
by Nikki Razal 1L
Sat Jan 11, 2020 3:35 pm
Forum: Ideal Gases
Topic: K vs Q [ENDORSED]
Replies: 7
Views: 62

Re: K vs Q [ENDORSED]

K is the equilibrium constant (this tells us where the equilbrium sits), while Q is the reaction quotient (this determines which direction a rxn will proceed)
by Nikki Razal 1L
Sat Jan 11, 2020 3:32 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5G.1 [ENDORSED]
Replies: 4
Views: 36

Re: 5G.1 [ENDORSED]

for this question, the statement, "If one starts with a higher pressure of reactant, the equilibrium constant will be larger" is false because your initial concentration increases, causing the equilibrium constant to be smaller. For example,if you had the equation N2+3H2 <-->2NH3 and an in...
by Nikki Razal 1L
Sat Dec 07, 2019 1:13 am
Forum: Administrative Questions and Class Announcements
Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Replies: 111
Views: 4471

Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]

for question 40c, how do you know whether o2 or o3 has the stronger bond and why?
by Nikki Razal 1L
Sat Dec 07, 2019 1:10 am
Forum: Dipole Moments
Topic: Lone pairs
Replies: 5
Views: 81

Re: Lone pairs

^^ to add on to that, dipole moments are created by lone pairs if the lone pairs don't cancel each other out, and one factor that can influence whether or not they cancel out is by looking at the bond angles
by Nikki Razal 1L
Sat Dec 07, 2019 1:01 am
Forum: Amphoteric Compounds
Topic: As2O3
Replies: 2
Views: 53

Re: As2O3

between the metal oxides (bases) and nonmetal oxides (acids), there is a diagonal band of amphoteric oxides closely matching the diagonal band of metalloids
by Nikki Razal 1L
Sat Dec 07, 2019 12:59 am
Forum: Amphoteric Compounds
Topic: how to identify?
Replies: 5
Views: 107

Re: how to identify?

amphiprotic= means that a molecule has the ability to either donate and accept H+
amphoteric= means that a molecule can either act as an acid or a base
by Nikki Razal 1L
Sat Dec 07, 2019 12:55 am
Forum: Hybridization
Topic: N-triple bond-N pi bond hybridization
Replies: 4
Views: 70

Re: N-triple bond-N pi bond hybridization

AngieGarcia_4F wrote:(N2p, N2p) because pi bonds happen when p orbitals overlap.


does this mean that pi bonds can only be formed in p orbitals only?
by Nikki Razal 1L
Sat Dec 07, 2019 12:52 am
Forum: Naming
Topic: oxidation number
Replies: 3
Views: 44

Re: oxidation number

^^ tungsten and molybdenum can get up to +6 I believe, and arsenic can be +5
by Nikki Razal 1L
Sat Dec 07, 2019 12:50 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals
Replies: 2
Views: 71

Re: Orbitals

Once you find out what "l" is, you can figure out how many orbitals there are because to find the number of orbitals you can plug "l" into the equation 2*l+1, and that will give you the number of orbitals. Or you can think that ml=-l,...0...,+l, and the number of values you get a...
by Nikki Razal 1L
Sat Dec 07, 2019 12:36 am
Forum: Hybridization
Topic: 2s for Carbon hybridization
Replies: 3
Views: 40

Re: 2s for Carbon hybridization

carbon is from the energy level, n=2
by Nikki Razal 1L
Sun Dec 01, 2019 3:39 am
Forum: Lewis Acids & Bases
Topic: Conjugate acid and conjugate base
Replies: 2
Views: 28

Re: Conjugate acid and conjugate base

I usually just look at the products of the equation, and the product with an additional H+ is the conjugate acid because bases accept protons based on the Bronsted- Lowry definition. Similarly, since acids donate protons, the product with an H+ taken away from it will be the conjugate base
by Nikki Razal 1L
Sun Dec 01, 2019 3:34 am
Forum: Biological Examples
Topic: How many do we need to know?
Replies: 1
Views: 44

Re: How many do we need to know?

On the syllabus, Dr. Lavelle said to know 3: hemoglobin, myoglobin, and vitamin B12
by Nikki Razal 1L
Sun Dec 01, 2019 3:29 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Dimagnetism & Paramagnetism
Replies: 6
Views: 96

Re: Dimagnetism & Paramagnetism

I don't think it will be heavily tested either, but just so you know "diamagnetic" means that all electrons are paired, whereas "paramagnetic"means that not all electrons are paired
by Nikki Razal 1L
Sun Dec 01, 2019 3:20 am
Forum: Biological Examples
Topic: Vitamin B12
Replies: 3
Views: 32

Vitamin B12

What is the biological function of the naturally occurring coordination compound, vitamin B12?
by Nikki Razal 1L
Sun Dec 01, 2019 3:17 am
Forum: Amphoteric Compounds
Topic: 6A.17
Replies: 3
Views: 39

Re: 6A.17

How would you know that Bi2O3 is amphoteric?
by Nikki Razal 1L
Sun Dec 01, 2019 3:11 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Difference between Arrhenius, Bronsted, and Lewis
Replies: 5
Views: 73

Re: Difference between Arrhenius, Bronsted, and Lewis

An arrhenius:
- acid: gives off H+
- base: gives off OH-

Bronsted-Lowry
- acid: is a proton donor
- base: is a proton acceptor

Lewis
- acid: is an electron acceptor
-base: is an electron donor
by Nikki Razal 1L
Sun Dec 01, 2019 2:48 am
Forum: Administrative Questions and Class Announcements
Topic: Difficulty
Replies: 14
Views: 134

Re: Difficulty

I agree with Kayley and Megan, I took AP chem in high school, and I think it definitely helped, but I also am not having an easy time in the class either. There's a lot of concepts like they were saying that go more in depth here in college
by Nikki Razal 1L
Sat Nov 23, 2019 7:37 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Forming Chelating Complexes: HW 9C.7
Replies: 1
Views: 41

Forming Chelating Complexes: HW 9C.7

In reference to HW 9C.7 (Which of the following isomers of diaminobenzene can form chelating complexes? Explain your reasoning.) and/or 9C.8 (Which of the following ligands do you expect to form chelating complexes? Explain your reasoning.) How do you know what isomers or ligands can form chelating ...
by Nikki Razal 1L
Sat Nov 23, 2019 7:27 pm
Forum: Naming
Topic: Latin Names of Atoms
Replies: 4
Views: 38

Re: Latin Names of Atoms

^^ in Lavelle's lectures I feel like he uses the English name, plus the book uses the English name from what I've seen
by Nikki Razal 1L
Sat Nov 23, 2019 7:25 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligand
Replies: 4
Views: 32

Re: Ligand

In the book, a ligand refers to "A group attached to the central metal ion in a complex"
by Nikki Razal 1L
Sat Nov 23, 2019 7:22 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 15
Views: 135

Re: Cisplatin

^^ just to add on, Lavelle was saying how transplatin is only able to form one bond in DNA (which is weak, so it can't stop cell division), whereas cis platin is able to form 2 bonds in the DNA, causing for the DNA to be interfered with enough to the point of stopping cell division & ultimately,...
by Nikki Razal 1L
Sat Nov 23, 2019 7:03 pm
Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
Topic: Hydrogen Bonding/Pi bonds
Replies: 11
Views: 148

Re: Hydrogen Bonding/Pi bonds

805097738 wrote:
Zoya Mulji 1F wrote:Intermolecular forces:
ionic bonding --> H-bonding --> dipole-dipole bonding --> induced dipole/London dispersion


is this ascending or descending in strength?



this is in decreasing strength. hydrogen bonds are the strongest and LDF /induced dipole forces are the weakest
by Nikki Razal 1L
Sun Nov 17, 2019 8:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR
Replies: 7
Views: 62

Re: VSEPR

^^ i think we would also need to know the bond angles and were not necessarily graded on the lewis structure, but in order to determine the shape, we'd have to know how to draw the lewis structure
by Nikki Razal 1L
Sun Nov 17, 2019 8:25 pm
Forum: Sigma & Pi Bonds
Topic: sigma and pi bonds
Replies: 4
Views: 26

Re: sigma and pi bonds

sigma bonds are just single bonds, pi bonds occur when you have a double bond or triple bond. if you have a double bond, you would have one sigma and one pi bond, and if you had a triple bond, youd have one sigma and two pi bonds
by Nikki Razal 1L
Sun Nov 17, 2019 8:21 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar vs non polar
Replies: 5
Views: 40

Re: Polar vs non polar

no, some of the lone pairs will create dipole moments that cancel each other out, resulting in a molecule not necessarily becoming polar
by Nikki Razal 1L
Sun Nov 17, 2019 8:17 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 3
Views: 29

Re: Bond Angles

They'll always be smaller because the lone pairs repel shared electrons, reducing bond angles. In general, atoms/electrons want to be as far away as possible due to electron repulsion. Molecules w/ lone pairs lower bond angles because lone pairs repel shared electrons, leading shared electrons to be...
by Nikki Razal 1L
Sun Nov 17, 2019 5:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: geometric angles
Replies: 4
Views: 26

Re: geometric angles

^^^ the geometric angles correspond with the VSEPR chart which depends on how many bonding pairs and lone pairs you have. for example a structure with 2 bonding pairs and 2 lone pairs would be bent and would have bond angles of less than 109.5 because of the lone pairs “pushing” on the angles in the...
by Nikki Razal 1L
Sun Nov 17, 2019 5:01 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Cis-Dichloroethene vs Trans-Dichloroethene
Replies: 3
Views: 38

Re: Cis-Dichloroethene vs Trans-Dichloroethene

just to add on, cis structures will have the same elements on one side of a structure, making it polar, whereas trans structures will have the same elements on opposite sides of the structure, making it nonpolar
by Nikki Razal 1L
Wed Nov 06, 2019 4:18 am
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: HW 2D.3
Replies: 5
Views: 97

HW 2D.3

Can someone explain to me why BaBr2 has bonds primarily ionic?
(in reference to HW question 2D.3:
"Which of these compounds has bonds that are primarily ionic? (a) BBr3; (b) BaBr2; (c) BeBr2."
by Nikki Razal 1L
Wed Nov 06, 2019 4:15 am
Forum: Photoelectric Effect
Topic: HW Question Focus 1, 1.3
Replies: 1
Views: 75

HW Question Focus 1, 1.3

How would you solve the problem Focus 1.3 in the textbook: "In each second, a certain lamp produces 2.4 x 10^21 photons with a wavelength of 633 nm. How much power (in watts) is produced as radiation at this wavelength (1W = 1 J x s^-1)?" I tried using E=hv and c=wavelength(frequency) and ...
by Nikki Razal 1L
Mon Nov 04, 2019 1:07 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg Uncertainty Quantum World Worksheet
Replies: 3
Views: 80

Heisenberg Uncertainty Quantum World Worksheet

The question: "Your bowling ball of mass 4.02kg rolls down a lane with a speed of 2.35+/-0.1m/s. What is the minimum indeterminancy of its position? Can you blame the Heisenberg Uncertainty Principle when your ball misses the pins" appeared in Karen's Quantum World WS. How do you know when...
by Nikki Razal 1L
Mon Nov 04, 2019 1:00 pm
Forum: SI Units, Unit Conversions
Topic: Memorizing Conversions
Replies: 23
Views: 321

Re: Memorizing Conversions

There's a few conversions on the sheet, such as 1nm=10^-9m, but I would look at the conversion sheet to see what conversions you should become more familiar with
by Nikki Razal 1L
Sun Nov 03, 2019 6:54 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge and Energy
Replies: 4
Views: 33

Re: Formal Charge and Energy

the lowest energy lewis structure has an overall formal charge of 0/close to 0
by Nikki Razal 1L
Sun Nov 03, 2019 6:42 pm
Forum: Octet Exceptions
Topic: Expanded Valence Shells
Replies: 6
Views: 46

Expanded Valence Shells

Why can only some elements in the 3rd period have an expanded valence shell?
by Nikki Razal 1L
Sun Nov 03, 2019 6:38 pm
Forum: Trends in The Periodic Table
Topic: Drawing Structures
Replies: 3
Views: 29

Re: Drawing Structures

You can draw a molecule in different ways/ a molecule has resonance when you can draw a structure with multiple bonds in different positions (ie move one bond to another to create a double bond)
by Nikki Razal 1L
Sun Nov 03, 2019 6:36 pm
Forum: Resonance Structures
Topic: Resonance structures
Replies: 6
Views: 55

Re: Resonance structures

a resonance structure is a blending of lewis structures with the same arrangements of atoms but different arrangement of electrons. it spreads multiple bond character over a molecule and also can lower its energy
by Nikki Razal 1L
Sun Nov 03, 2019 6:31 pm
Forum: Lewis Structures
Topic: lowest energy
Replies: 5
Views: 41

Re: lowest energy

^^ the central atom/all atoms would have a formal charge of 0; basically the lowest energy lewis structure will be the lewis structure with the overall formal charge closest to zero
by Nikki Razal 1L
Sun Oct 27, 2019 9:43 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal charge
Replies: 3
Views: 46

Re: Formal charge

Find the formal charge of each bound atom then add up all the individual formal charges to find the overall formal charge. The most stable atoms have a formal charge of 0.
by Nikki Razal 1L
Sun Oct 27, 2019 9:39 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Finding Most Stable Structure
Replies: 9
Views: 74

Re: Finding Most Stable Structure

The most stable compounds typically have an overall total charge of zero (the exception would be if the compound or element is an anion or cation, that is, if they have an overall charge other than zero). And just a quick note, formal charge = # of valence electrons an atom has - (# bonds + lone pai...
by Nikki Razal 1L
Sun Oct 27, 2019 9:26 pm
Forum: Lewis Structures
Topic: Choosing the central atom
Replies: 16
Views: 141

Re: Choosing the central atom

The central atom is the element with the lowest ionization energy. Usually, it is the first element in a compound, and when it is placed in the middle, you are able to draw atoms symmetrically around it.
by Nikki Razal 1L
Sun Oct 27, 2019 9:23 pm
Forum: Octet Exceptions
Topic: octet exceptions
Replies: 5
Views: 52

Re: octet exceptions

^^ atoms in period 3 or higher have d-orbitals in valence shell that can accommodate additional electrons.
by Nikki Razal 1L
Sun Oct 27, 2019 9:17 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 1E.23 (unpaired electrons)
Replies: 2
Views: 54

Re: 1E.23 (unpaired electrons)

For me, the easiest way to determine how many atoms are unpaired or paired is just to draw out an energy diagram and fill up the orbitals until all electrons are accounted for. Just a note, when all electrons are paired, the compound is known to be diamagnetic, and when they're not al paired, it is ...
by Nikki Razal 1L
Sun Oct 27, 2019 9:11 pm
Forum: Trends in The Periodic Table
Topic: Electron affinity.
Replies: 8
Views: 36

Re: Electron affinity.

Electron affinity is the energy released when an electron is added to a neutral atom to become an anion.
by Nikki Razal 1L
Sun Oct 27, 2019 9:09 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic VS. Covalent Bond
Replies: 8
Views: 59

Re: Ionic VS. Covalent Bond

Ionic bonds form when a metal transfers its electrons with a nonmetal (this involves cation and anion interactions), and covalent bonds form when nonmetals share electrons. Nonmetals do not form cations because their ionization energies are too high.
by Nikki Razal 1L
Sun Oct 27, 2019 9:02 pm
Forum: Electronegativity
Topic: Electronegativity
Replies: 6
Views: 56

Electronegativity

If electronegativity increases from left to right and bottom to top of the periodic table, why is fluorine the most electronegative element?
by Nikki Razal 1L
Sun Oct 20, 2019 11:57 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Writing Electron Configurations
Replies: 7
Views: 72

Re: Writing Electron Configurations

yup just to add on, you could either write nitrogen is 1s^2, 2s^2, 2px^1, 2py^1, 2pz^1, or nitrogen is 1s^2, 2s^2, 2p^3 and both would be correct
by Nikki Razal 1L
Sun Oct 20, 2019 11:55 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Exceptions for Electron Configuration
Replies: 6
Views: 42

Re: Exceptions for Electron Configuration

He said the two exceptions were for the elements copper (Cu) and chromium (Cr)
by Nikki Razal 1L
Wed Oct 16, 2019 12:36 am
Forum: Quantum Numbers and The H-Atom
Topic: hw help
Replies: 1
Views: 64

hw help

In reference to question 1.E.1, "Which of the following increase when an electron in a lithium atom undergoes a transition from the 1s-orbital to a 2p-orbital? (a) Energy of the electron. (b) Value of n. (c) Value of l. (d) Radius of the atom. Which answers would be different for a hydrogen ato...
by Nikki Razal 1L
Wed Oct 16, 2019 12:21 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: HW Help
Replies: 3
Views: 42

HW Help

For HW problem 1.D.23: "How many orbitals can have the following quantum numbers in an atom:(a)n=2,l=1;(b)n=4,l=2,m1=-2; (c)n=2;(d)n=3,l=2,m1 =+1?" Would it be better to state the max number of orbitals, or all the different possibilities? For example, for part c, you can assume l = -1,0,1...

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