Search found 107 matches

by 005206171
Sun Mar 15, 2020 6:45 am
Forum: Administrative Questions and Class Announcements
Topic: final tech malfunctions
Replies: 5
Views: 116

Re: final tech malfunctions

It auto saves every 2 min and you’ll be able to log back on it once you’ve started it (according to email)
by 005206171
Sun Mar 15, 2020 2:17 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts
Replies: 3
Views: 53

Re: Catalysts

Rule of thumb for me is that they show up as a reactant first then a product. An intermediate will show up as a product first then a reactant
by 005206171
Sun Mar 15, 2020 2:15 am
Forum: Van't Hoff Equation
Topic: Celcius vs Kelvin for T1 and T2
Replies: 6
Views: 82

Re: Celcius vs Kelvin for T1 and T2

Always use kelvin. You won’t get the right answer if you use Celsius
by 005206171
Sun Mar 15, 2020 2:15 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Gibbs free energy
Replies: 8
Views: 90

Re: Gibbs free energy

Standard Gibbs free energy is at constant temp and constant pressure at 1M
by 005206171
Sun Mar 15, 2020 2:14 am
Forum: Balancing Redox Reactions
Topic: cathode vs anode
Replies: 11
Views: 124

Re: cathode vs anode

The one with the lower reduction potential is your anode for galvanic cells
by 005206171
Sat Mar 14, 2020 11:31 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: linear plots
Replies: 7
Views: 95

Re: linear plots

He’s asked for the plots of different orders before but with the online final you might just need to able to recognize them
by 005206171
Sat Mar 14, 2020 11:13 pm
Forum: General Rate Laws
Topic: Rate-determining step
Replies: 7
Views: 94

Re: Rate-determining step

If they give you a rate law and ask to find the rate determining step out of given elementary steps, look for the step that has all of the molecules in the given rate law/ match them.
by 005206171
Sat Mar 14, 2020 10:56 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Exam Time
Replies: 13
Views: 197

Re: Final Exam Time

It’s 3 and a half hours. I believe it will automatically submit when you reach the time limit or at 2:45
by 005206171
Sat Mar 14, 2020 10:17 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Molecularity
Replies: 4
Views: 57

Re: Molecularity

Homework problems have asked to identify the molecularity of chemical reactions, so definitely be able to do that on the final
by 005206171
Sat Mar 14, 2020 7:41 pm
Forum: Balancing Redox Reactions
Topic: QD3 Midterm
Replies: 5
Views: 93

Re: QD3 Midterm

Acetic acid will lose its proton/H+ because it’s an acid. Its conjugate base is CH3COO which makes its charge -1
by 005206171
Sat Mar 14, 2020 7:36 pm
Forum: General Rate Laws
Topic: integrals and derivatives
Replies: 7
Views: 88

Re: integrals and derivatives

Not to solve problems or anything, but I think you should at least be familiar with using them in derivations.
by 005206171
Sat Mar 14, 2020 7:35 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kw and other constants
Replies: 9
Views: 91

Re: Kw and other constants

Kw is the equilibrium constant of water. Since it’s neutral Ka and kw = 1 x 10^(-7). When multiplied you get 1x 10^-14 (kw value)
by 005206171
Sat Mar 14, 2020 7:33 pm
Forum: Zero Order Reactions
Topic: units of k
Replies: 5
Views: 77

Re: units of k

When you have reactions of different orders, you end up getting mol^n/L^n on the side of k. Since The rate is always mol/Ls, the kr for different orders will change to always cancel out and get mol/Ls for the units of the final answer/rate.
by 005206171
Sat Mar 14, 2020 7:25 pm
Forum: General Science Questions
Topic: Final Content
Replies: 5
Views: 106

Final Content

Since it’s online now, will there still be homework questions on the final?
by 005206171
Tue Mar 03, 2020 10:46 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: HW Question 6N.23 Part A
Replies: 2
Views: 58

Re: HW Question 6N.23 Part A

Hi Fiona Latifi 1A! When something is below another metal in the elctrochemical series it means that the species that is below is better at reducing the metal that's above. Cathodic protection involves connecting the pipeline to something that's more strongly reducing—that is the metal that is more...
by 005206171
Mon Mar 02, 2020 5:05 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6M.5
Replies: 4
Views: 89

Re: 6M.5

Luyan Zhang - 2D wrote:
Kevin Antony 2B wrote:We need a solid to be the electrode. As there is no solid on the right hand side, we use Platinum.


Well, there are no solids on the left either, so wouldn't we need to add Pt on the left too?


Hg(l) is an exception. I believe it can conduct electricity on its own
by 005206171
Sun Mar 01, 2020 10:00 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Current flow
Replies: 2
Views: 43

Re: Current flow

I’m having trouble understanding why a current flows from cathode to anode, and electron flows from anode to cathode. What is another way to visualize this? Hi there, After reading up, it seems that the current is always flowing in the opposite direction of electrons. Therefore, if electrons flow f...
by 005206171
Sun Mar 01, 2020 9:57 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.5
Replies: 1
Views: 25

6L.5

For part a, it has: AgBr(s) —> Ag+ + Br-
It has an Ag(s) at the beginning of the cell diagram, on the anode end. Why is this? What rule does it follow?
by 005206171
Fri Feb 28, 2020 7:46 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Spontaneity
Replies: 12
Views: 178

Re: Spontaneity

Spontaneous reactions can be detected by a negative Gibbs free energy and positive potential difference.
by 005206171
Fri Feb 28, 2020 7:45 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Why is E Standard=0 in a concentration cell?
Replies: 4
Views: 49

Re: Why is E Standard=0 in a concentration cell?

At standard conditions, each compartment of the cell will be 1M. Assuming that a concentration cell uses the same solutions, then the potential difference at standard conditions is 0.
by 005206171
Fri Feb 28, 2020 7:32 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Current flow
Replies: 2
Views: 43

Current flow

I’m having trouble understanding why a current flows from cathode to anode, and electron flows from anode to cathode. What is another way to visualize this?
by 005206171
Sun Feb 23, 2020 12:56 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic Cell emf
Replies: 3
Views: 31

Galvanic Cell emf

What’s happening in the Galvanic Cell when emf is negative and the cell is absorbing energy (Delta G >0)? Whats happening when the cell is absorbing energy?
by 005206171
Sun Feb 23, 2020 12:26 am
Forum: Balancing Redox Reactions
Topic: Oxidation Numbers
Replies: 3
Views: 46

Oxidation Numbers

What is the difference between formal charge and oxidation number?
by 005206171
Sat Feb 22, 2020 5:41 pm
Forum: General Science Questions
Topic: What are Workshops?
Replies: 10
Views: 186

Re: What are Workshops?

Hi, in my experience step up is usually going over hw problems. Workshops sometimes have worksheets
by 005206171
Sat Feb 22, 2020 5:36 pm
Forum: Balancing Redox Reactions
Topic: Charge of oxygen
Replies: 15
Views: 119

Re: Charge of oxygen

I believe O2 and hydrogen peroxide are some exceptions to Oxygen’s -2 rule
by 005206171
Sat Feb 22, 2020 5:34 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Potential difference
Replies: 3
Views: 51

Re: Potential difference

Altamash Mahsud 1I wrote:Potential difference is simply the amount of energy (work) it takes to move a certain amount of charge some distance.


Hi, is this different from one coulomb able to do 1J of work?
by 005206171
Sat Feb 22, 2020 5:29 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge
Replies: 10
Views: 83

Re: Salt Bridge

nehashetty_2G wrote:A salt bridge comes is significant to a galvanic cell because it eases the charge buildup. It allows the ions to transfer when which allows the solutions to stay neutral overtime.


Why do the solutions need to stay neutral?
by 005206171
Sat Feb 22, 2020 5:23 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Electrochemical Cells
Replies: 2
Views: 28

Electrochemical Cells

Can anyone explain what is the difference between electric potential and voltage?
by 005206171
Sun Feb 09, 2020 9:11 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: closed system
Replies: 7
Views: 52

Re: closed system

It’s sealed so no matter can leave or come in. But since it’s not insulated, heat can still be exchanged. So it is a closed system.
by 005206171
Sun Feb 09, 2020 9:08 pm
Forum: Phase Changes & Related Calculations
Topic: heat added/released
Replies: 6
Views: 55

Re: heat added/released

Forming new bonds releases energy. In a synthesis reaction where you’re forming a new product from its reactants, energy will be released because the new product is more stable. Breaking bonds requires energy. In decomposition reactions where you’re breaking apart a molecule into its simpler parts, ...
by 005206171
Sun Feb 09, 2020 9:03 pm
Forum: Administrative Questions and Class Announcements
Topic: Pizza Rolls REVIEW Session DOWNLOAD HERE
Replies: 67
Views: 2646

Re: Pizza Rolls REVIEW Session DOWNLOAD HERE

Why is delta H always q but q is not always delta H? What exactly does he mean by that? The definition of enthalpy is energy/heat absorbed or released at constant pressure (state function). So delta H is always q. Heat only describes energy transfer due to a temperature difference. Heat can be exch...
by 005206171
Mon Feb 03, 2020 12:58 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Closed System
Replies: 7
Views: 78

Re: Closed System

DHavo_1E wrote:Hello,

Could I ask whether anyone could give an example of a closed system? Thank you!


Hi, an example of a closed system is a closed beaker. matter can't enter or leave the system, but the beaker isn't insulated to heat can still be exchanged. Hope this helps!
by 005206171
Mon Feb 03, 2020 12:53 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Double bonds
Replies: 4
Views: 41

Re: Double bonds

I'm not sure if this is the answer you're looking for, but you can't break one bond of a double bond. You have to break the whole thing and reform it as a single bond. You'll have different bond enthalpies for the same atoms bonded with a single bond versus a double bond.
by 005206171
Mon Feb 03, 2020 12:50 am
Forum: Calculating Work of Expansion
Topic: temperature
Replies: 7
Views: 50

Re: temperature

It's because you're measuring the change in units. It doesn't really matter whether you're using one unit or another. There is no difference between going up 1 unit of kelvin and going up 1 unit of Celsius because the change is still one unit.
by 005206171
Mon Feb 03, 2020 12:44 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Spontaneous vs. Energetically Favorable
Replies: 3
Views: 24

Re: Spontaneous vs. Energetically Favorable

Nick Lewis 4F wrote:So all energetically favorable reactions are spontaneous but not all spontaneous reactions are energetically favorable?


Yes. Energetically favorable reactions don't require energy input so they are exothermic reactions. But not all exothermic reactions occur spontaneously.
by 005206171
Mon Feb 03, 2020 12:37 am
Forum: Calculating Work of Expansion
Topic: Intergral
Replies: 6
Views: 50

Re: Intergral

It's because the integral calculates the area under the curve. In the pressure v volume graph, calculating the area under the curve will give you the amount of work done to the surroundings.
by 005206171
Mon Feb 03, 2020 12:36 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Piston Example
Replies: 3
Views: 32

Re: Piston Example

In expansion work, the work done to the surroundings is the energy lost to push against the external pressure. This is one way you can change the energy of the system.
by 005206171
Mon Feb 03, 2020 12:32 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Types of Systems
Replies: 7
Views: 49

Re: Types of Systems

VLi_2B wrote:Can someone please give an example of an isolated system that is not a bomb calorimeter or a hydroflask?


The universe since energy is conserved.
by 005206171
Mon Feb 03, 2020 12:28 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: closed vs isolated?
Replies: 7
Views: 58

Re: closed vs isolated?

A closed beaker is an example of a Closed system. Matter can't leave/enter but the beaker isn't insulated so heat can still be transferred.

The bomb calorimeter is an example of an isolated system. No heat or matter can be exchanged.
by 005206171
Mon Feb 03, 2020 12:26 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Specific heat capacity
Replies: 7
Views: 58

Re: Specific heat capacity

Molar heat capacity deals with 1 mole so it will use moles. Specific heat deals with 1 gram of a substance so it will use grams in its units.
by 005206171
Mon Feb 03, 2020 12:24 am
Forum: Calculating Work of Expansion
Topic: Reversible
Replies: 7
Views: 58

Re: Reversible

^^ What he said. If it's at equilibrium, it's reversible because it's done in infinitesimally small amounts.
by 005206171
Mon Feb 03, 2020 12:22 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: enthalpy
Replies: 7
Views: 63

Re: enthalpy

At constant pressure, enthalpy is the amount of heat released or absorbed by the reaction.
by 005206171
Mon Feb 03, 2020 12:19 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Enthalpy and Internal Energy
Replies: 2
Views: 23

Re: Enthalpy and Internal Energy

Enthalpy doesn't have to be at constant pressure. It's just that at constant pressure, enthalpy will just be the heat released or absorbed by the reaction. All of the work will be done will be to change the volume of the system. We just use constant pressure to relate heat to enthalpy. Most reaction...
by 005206171
Sun Feb 02, 2020 11:58 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: state functions
Replies: 10
Views: 71

Re: state functions

State functions don't depend on the "path" they take. Usually they'll usually just involve the intial and final states. Some examples are enthalpy, temperature, density, volume, and pressure. Nonexamples have many parameters/variables in their equations because we have to consider them whe...
by 005206171
Sun Feb 02, 2020 11:50 pm
Forum: Calculating Work of Expansion
Topic: Area under the curve
Replies: 3
Views: 36

Re: Area under the curve

It's because on a pressure vs volume graph, calculating the area under the curve gives you the amount of work done to the surroundings. For reversible expansions, this is the entire area under the curve from V1 to V2. For irreversible expansions, it's gonna be the rectangle formed from V1 to V2 at t...
by 005206171
Sun Feb 02, 2020 11:46 pm
Forum: Phase Changes & Related Calculations
Topic: intensive/extensive
Replies: 4
Views: 39

Re: intensive/extensive

Intensive properties don't depend on how much material you have in the system. Some examples are temperature, density, molar heat capacity, and pressure. Extensive properties do depend on how much material you have in the system. Examples are volume, mass, enthalpy, entropy, heat capacity, and inter...
by 005206171
Sun Jan 26, 2020 9:43 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Weak acid/base
Replies: 14
Views: 138

Re: Weak acid/base

Lavelle says to memorize all the strong acids and bases so that anything else you see, you immediately know is weak. Also, as someone mentioned above, having ka or kb as a given means you have a weak acid or base. Remember that strong acids and bases completely disassociate, giving an infinity disas...
by 005206171
Sun Jan 26, 2020 9:39 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: protonization/ionization
Replies: 4
Views: 52

Re: protonization/ionization

its the conjugate base/original acid or conjugate acid/original base. What it's really comparing is the original acid/base you started with and how many of those gained/lost a proton to become its conjugate. The formula gives you a ratio/percent
by 005206171
Sun Jan 26, 2020 9:36 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction Shifts Left or Right
Replies: 15
Views: 113

Re: Reaction Shifts Left or Right

In this scenario, I think of heat as a product. This will make sense as to why it shifts left. On the molecular level, heat is added to the products side of the equation so when heat goes up it increases the number of collisions of products to become reactants.
by 005206171
Sun Jan 26, 2020 9:31 pm
Forum: Phase Changes & Related Calculations
Topic: Heat v Enthalpy
Replies: 3
Views: 41

Re: Heat v Enthalpy

What helps me is to look at the formula of heat and enthalpy. Enthalpy can be calculated using the initial and finals states. Heat is calculated using a bunch of parameters meaning it depends on the path taken.
by 005206171
Sun Jan 26, 2020 9:13 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Meaning of State Function
Replies: 8
Views: 60

Re: Meaning of State Function

Enthalpy is a state function because it does not depend on the path taken, only the initial and final values matter.
by 005206171
Sun Jan 19, 2020 11:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: identifying acids & bases
Replies: 5
Views: 41

Re: identifying acids & bases

You should familiarize yourself with the strong acids and strong bases. There's a list online and videos on youtube to help you memorize. Like what people said, you could also look for acids and bases using the Lewis and Bronsted-Lowry definitions. But I think to prepare for the test, knowing that l...
by 005206171
Sun Jan 19, 2020 11:23 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K for Gases
Replies: 12
Views: 95

Re: K for Gases

Kp is the specific notation used for gases or when given partial pressures.
by 005206171
Sun Jan 19, 2020 11:20 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: reaction quotient
Replies: 4
Views: 36

Re: reaction quotient

if you calculate q and it equals k then it is at equilibrium. If they don't equal, then it's not and the reaction is still occurring. From there you can compare q and k to determine which way the reaction will proceed to reach equilibrium.
by 005206171
Sun Jan 19, 2020 11:16 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: lewis structure
Replies: 11
Views: 75

Re: lewis structure

No lavelle just does to build on 14a material and for visualization, but on the test you won't get extra points for it. You could anyway if it helps to understand the chemistry
by 005206171
Sun Jan 19, 2020 11:15 pm
Forum: Ideal Gases
Topic: Using PV=nRT
Replies: 7
Views: 62

Re: Using PV=nRT

If it does, it will be in the context of converting partial pressure to concentration or vice versa
by 005206171
Mon Dec 09, 2019 12:52 am
Forum: Naming
Topic: "Ferrate"
Replies: 14
Views: 641

Re: "Ferrate"

Ferrate follows the rule of naming anions with adding -ate at the end, but use the latin name for Iron just cause it sounds better.
by 005206171
Mon Dec 09, 2019 12:50 am
Forum: Hybridization
Topic: Identifying Hybrid Orbitals
Replies: 5
Views: 110

Re: Identifying Hybrid Orbitals

I just count the electron density regions from s, p2, p3, d, d2, d3. Rarely if ever do I go higher than that.
by 005206171
Mon Dec 09, 2019 12:47 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Nitro vs Nitrito
Replies: 6
Views: 156

Re: Nitro vs Nitrito

I believe he wants us to use Nitro for NO2 and nitrito for ONO
by 005206171
Thu Dec 05, 2019 7:18 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Emission Spectrum of Hydrogen
Replies: 1
Views: 110

Emission Spectrum of Hydrogen

When would we get positive values when using -hR/n^2? Or is it always negative? Does emission/absorption change the sign?
by 005206171
Thu Dec 05, 2019 7:12 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Uncertainty in Position
Replies: 1
Views: 109

Uncertainty in Position

When we are given the value for the uncertainty in position, when do I multiply it by 2? Sometimes the solution will require double the uncertainty given and other times it's not.
by 005206171
Sun Dec 01, 2019 8:05 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Calculating pH of bases
Replies: 3
Views: 42

Re: Calculating pH of bases

TO find ph, take the negative log of the base concentration (pOH) then subtract that amount from 14 to give you pH.
by 005206171
Sun Dec 01, 2019 7:59 pm
Forum: Dipole Moments
Topic: dipole moments
Replies: 6
Views: 125

Re: dipole moments

Yes. If you draw a Lewis structure with a dipole it is polar. Sometimes, a molecule will have dipole movements but cancel each other out. In this case, the molecular is going to be non polar.
by 005206171
Sun Dec 01, 2019 7:52 pm
Forum: SI Units, Unit Conversions
Topic: midterm/final
Replies: 18
Views: 539

Re: midterm/final

I think it’s going to be more calculation heavy based on the midterm mixed with conceptual questions so I wouldn’t neglect studying them.
by 005206171
Sun Dec 01, 2019 7:40 pm
Forum: Hybridization
Topic: Writing the hydrization
Replies: 10
Views: 168

Re: Writing the hydrization

Hello, I have a question about the difference between 2sp3 and sp3. How do you know if the "2" in front of the sp3 is supposed to be there? What's the difference between the two? It’s the quantum number of the central atom when you’re talking about the hybridization of a molecule. Describ...
by 005206171
Sun Dec 01, 2019 7:35 pm
Forum: Lewis Structures
Topic: Bent or Angular?
Replies: 15
Views: 306

Re: Bent or Angular?

Both bent and angular refer to the same shape
by 005206171
Sun Nov 24, 2019 9:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Intermolecular forces
Replies: 5
Views: 57

Re: Intermolecular forces

Hydrogen bonding: H bonded to FON with a LP. Only H bonded to FON will be attracted to other regions with H bonded to FON Ions can have: ion-dipole, ion-ion anything with dipole moments will have: dipole-dipole molecule w dipole + molecule w no dipole = dipole-induced-dipole All Molecules (polar and...
by 005206171
Sun Nov 24, 2019 9:17 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarity
Replies: 3
Views: 54

Re: Polarity

I don't know if big molecules are going to be tested, but it'd only be helpful to know how to draw any lewis structure and determine polarity.
by 005206171
Sun Nov 24, 2019 9:15 pm
Forum: Hybridization
Topic: d orbital
Replies: 4
Views: 52

Re: d orbital

it's because d is a lower energy state than p or s. When we do electron configuration, it's why we do n-1 when passing thru the transition metals/d block.
by 005206171
Sun Nov 24, 2019 9:14 pm
Forum: Biological Examples
Topic: Biological Examples
Replies: 10
Views: 83

Re: Biological Examples

I noticed he likes to use those as examples in questions he gives out. I would study concepts around these examples since they seem to be fair game.
by 005206171
Sun Nov 24, 2019 9:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: T Shape
Replies: 3
Views: 43

Re: T Shape

Yes, T shape has 5 bonding regions giving it bipyramidal geometry. And 2 Lone pairs that push/repel the 3 bonding regions into a T shape.
by 005206171
Sun Nov 17, 2019 8:25 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Radicals
Replies: 5
Views: 58

Re: Radicals

I thought CH3 would be trigonal pyramidal because of its tetrahedral geometry and 1 LP bonding region but it's trigonal planar.
by 005206171
Sun Nov 17, 2019 8:07 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Influence of Lone Pair e- on Model
Replies: 5
Views: 69

Re: Influence of Lone Pair e- on Model

Greater. A lone pair will increase e- repulsion, causing the bond angles to be slightly smaller than if there was an atom in place.
by 005206171
Sun Nov 17, 2019 8:02 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Linear molecule with lone pairs
Replies: 3
Views: 39

Re: Linear molecule with lone pairs

A linear molecule can have 3 lone pairs with a geometry of trigonal pyramidal (5 bonding regions). The lone pairs will push the bonds into a linear shape. Same thing with 4 lone pairs with a geometry of an octahedral. The 2 bonding regions will be farthest apart in a linear shape.
by 005206171
Sun Nov 17, 2019 6:40 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pairs
Replies: 5
Views: 47

Re: Lone Pairs

Bent = 1 or 2 LPs
trigonal pyramidal = 1 LP
linear = when 3 or 4 LPs
See-saw = 1 LP
T shaped = 2 LPs
Square planar = 1 LP
Square pyramidal = 2 LP
by 005206171
Sun Nov 10, 2019 11:02 pm
Forum: Ionic & Covalent Bonds
Topic: Hydrogen Bond Strength
Replies: 8
Views: 88

Re: Hydrogen Bond Strength

ShreyaKannan1B wrote:Which elements does hydrogen form hydrogen bonds with?



FON - Fluorine, oxygen, and nitrogen
by 005206171
Sun Nov 10, 2019 10:53 pm
Forum: Bond Lengths & Energies
Topic: Bond lengths and strength
Replies: 4
Views: 34

Re: Bond lengths and strength

It's because they're shorter that makes them stronger. More shared electrons create a stronger bond because more electrons are present that can pull on the nuclei which means the atoms get even closer and stronger bond forms.
by 005206171
Sun Nov 10, 2019 10:48 pm
Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
Topic: Viscosity
Replies: 15
Views: 302

Re: Viscosity

I like to think of viscosity as how easily a liquid flows. Something that has high vicosity, like molasses, has strong intermolecular forces. Something with high viscosity is also described as being really thick, like molasses. Water has lower viscosity and flows much easier than molasses because it...
by 005206171
Sun Nov 10, 2019 10:43 pm
Forum: Dipole Moments
Topic: dipole moments
Replies: 2
Views: 31

Re: dipole moments

Dipole moments exist because electrons move in a cloud. Electrons occupy one side over another at random times, producing a temporary separation of charge. Molecules with no charges still experience attraction on the intermolecular level because of these temporary dipoles. The tendency of electrons ...
by 005206171
Fri Nov 01, 2019 2:11 am
Forum: Bond Lengths & Energies
Topic: Lattice Energy
Replies: 9
Views: 67

Re: Lattice Energy

Ionic bonds form crystalline lattices in their solid form. Forming bonds releases energy (they become more stable). If a molecule has ionic bonds (cation and anion) and is in the gas phase, the amount of energy released as it condenses into a solid is called lattice energy.
by 005206171
Fri Nov 01, 2019 2:07 am
Forum: Electronegativity
Topic: electronegative
Replies: 6
Views: 65

Re: electronegative

It depends. If the difference is really big, the atom w the higher electronegativity will literally "pull" electron(s) from the other atom. The result is a cation and anion, and an ionic bond forms because of electrostatic forces between opposite charges (another way of saying opposites at...
by 005206171
Fri Nov 01, 2019 1:58 am
Forum: Ionic & Covalent Bonds
Topic: Valence Electrons?
Replies: 15
Views: 141

Re: Valence Electrons?

I just count across the period. For transition metals, if they ask, go off the number of electrons in the highest principle quantum number. If they ask for the d block electrons, then add those in too. Problem 2A1 letter c is an example. Mn is said to have 7 VE - 2 from 4p2 and 5 from 3d5
by 005206171
Fri Nov 01, 2019 1:55 am
Forum: Ionic & Covalent Bonds
Topic: Electrostatic Potential Energy
Replies: 3
Views: 39

Re: Electrostatic Potential Energy

I dont think so either. But it would be good to know that the formula just says that as the radius gets bigger, the electrostatic/Coulomb's force decreases.
by 005206171
Thu Oct 31, 2019 9:21 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Relationship between uncertainties of position and momentum
Replies: 2
Views: 44

Re: Relationship between uncertainties of position and momentum

Heisenberg's uncertainty principle is different from Bohr's (classical) model. Bohr's model assumes that electrons are orbitting an electron and that is not the case. Electrons are really moving in a "cloud". So if you wanna know its position, that means you have to stop the electron so yo...
by 005206171
Fri Oct 25, 2019 12:45 am
Forum: Properties of Light
Topic: photoelectric effect
Replies: 4
Views: 70

Re: photoelectric effect

I like to think of light intensity a how strong a light shines - the number of photons a light emits. If it changed frequency, i'd see a different color light. But Einstein's experiment shows that's what you need to do to knock off more electrons because colors with higher frequencies (lower wavelen...
by 005206171
Fri Oct 25, 2019 12:36 am
Forum: Ionic & Covalent Bonds
Topic: Resonance
Replies: 12
Views: 134

Re: Resonance

When molecules have resonance their e- exist in a hybrid of their lewis structures. Their e- can make those bonds (delocalized) to lower their repulsion. The result is a more stable atom. A molecule with more Lewis structures is more stable.
by 005206171
Fri Oct 25, 2019 12:21 am
Forum: Ionic & Covalent Bonds
Topic: Isoelectronic Atoms
Replies: 6
Views: 71

Re: Isoelectronic Atoms

It's valence electrons. They could ask you for isoelectronic atoms (like as anions or cations) given a periodic table but idk
by 005206171
Fri Oct 25, 2019 12:13 am
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 4
Views: 69

Re: Resonance Structures

The Lewis structure isn't perfect & sometimes we're able to draw many Lewis structures for a molecule. This is called resonance. In this case, the molecule actually exists as a hybrid of all its resonance structures. And probably not, and he's said that he'll accept any correct structure.
by 005206171
Fri Oct 18, 2019 2:14 am
Forum: Photoelectric Effect
Topic: E = pc
Replies: 3
Views: 65

Re: E = pc

E=pc is especially helpful to find the momentum of light which does not have rest mass (so you can't use p=mv). Light has no rest mass but does have momentum in the form of energy.
by 005206171
Fri Oct 18, 2019 2:12 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: electron configurations
Replies: 3
Views: 41

Re: electron configurations

We remove electrons from the highest energy subshell because these electrons are the most unstable and the atom will readily give them up to become more stable.
by 005206171
Fri Oct 18, 2019 2:05 am
Forum: Properties of Electrons
Topic: Wave Function
Replies: 5
Views: 122

Re: Wave Function

We use the wave function to find the probability of where an electron is going to be. As we get down to the very small, light acts more like a wave. The wave function helps us model the location of the electrons and determines which orbitals are going to be present.
by 005206171
Fri Oct 18, 2019 1:56 am
Forum: Properties of Light
Topic: How does light have momentum but we assume it has no mass?
Replies: 4
Views: 62

Re: How does light have momentum but we assume it has no mass?

Light doesn't have rest mass at least. So we can't really use the mv equation. But it does have momentum in the form of energy. We can use another equation instead to find its momentum, E=pc where E is the energy of the photon, and c is the speed of light.
by 005206171
Fri Oct 18, 2019 1:38 am
Forum: Properties of Light
Topic: Unit for Wavelength
Replies: 34
Views: 290

Re: Unit for Wavelength

wavelength is just measuring one peak to the next so this distance is in meters
by 005206171
Fri Oct 18, 2019 1:36 am
Forum: Properties of Light
Topic: Unit Conversions
Replies: 6
Views: 95

Re: Unit Conversions

This is my method: I put the units that i have on the bottom, and the units i want on top. I put a 1 next to the bigger units. Then for the smaller units, I subtract the scientific notations of the bigger unit from the smaller unit. Then I multiply these factors. Ex: 18.2 nm in cm? 18.2 x 1 cm/10^7 ...
by 005206171
Thu Oct 10, 2019 8:31 pm
Forum: Properties of Electrons
Topic: Energy of Electron
Replies: 10
Views: 156

Re: Energy of Electron

when you say energy is quantized, this means energy can only be absorbed or emitted in specific (discrete) amounts. This means at some point, you can't divide energy into smaller amounts.
by 005206171
Thu Oct 10, 2019 8:29 pm
Forum: Significant Figures
Topic: How many significant figures are in 7.00 x 10^2?
Replies: 12
Views: 311

Re: How many significant figures are in 7.00 x 10^2?

7.00 x 10^3 has three sig figs because when there is a decimal, all the zeroes are significant (including those inbetween integers and after them). 700 is another way of saying the same thing, but only has 1 sig fig because when there are no decimals, only 0s in between numbers are significant, not ...
by 005206171
Thu Oct 10, 2019 8:25 pm
Forum: Properties of Light
Topic: "Work Function" (from Post-Assessment Module)
Replies: 4
Views: 59

Re: "Work Function" (from Post-Assessment Module)

In the context of the photoelectric effect and experiment, the work functions describe the minimum energy a photon needs to knock off an electron so that the electron can overcome it's an attraction to the plate. Some electrons are more attracted to the metal than others. Those with the highest max ...

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