Search found 121 matches
- Sat Mar 16, 2019 9:11 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: [H2O] omitted??
- Replies: 2
- Views: 632
[H2O] omitted??
Is water omitted in rate laws in aqueous solutions because the concentration of water is basically doesn't change because it is the solvent???
- Sat Mar 16, 2019 8:58 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Kinetic Plot Graphs
- Replies: 1
- Views: 485
Kinetic Plot Graphs
Why is initial rate against [A] for a 1st Order linear?
Why is half life against [A] for 0th Order linear?
Why is half life against [A] for 0th Order linear?
- Sat Mar 16, 2019 8:34 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Frequency factor
- Replies: 2
- Views: 320
Re: Frequency factor
Frequency when molecules collide with good orientation and energy to induce a reaction.
- Sat Mar 16, 2019 8:26 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: THERMO with KINETICS
- Replies: 2
- Views: 587
THERMO with KINETICS
What concepts or problems could combine these two concepts and what the result be? Like temperature effects on rate, thermo equations that can be solved to provide info for kinetic equations?
- Sat Mar 16, 2019 8:06 pm
- Forum: Balancing Redox Reactions
- Topic: cell diagram
- Replies: 3
- Views: 554
Re: cell diagram
Only the side that still needs a functional electrode. Just because it has a solid in the reaction does not mean it is an electrode, because it could be just a salt, which you would still need an electrode.
- Sat Mar 16, 2019 8:04 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: standard cell potentials
- Replies: 5
- Views: 439
Re: standard cell potentials
Galvanic cells need to be spontaneous, so that's why it is positive. Electrolytic can be negative because they work in the reverse direction.
- Sat Mar 16, 2019 8:03 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: n and significant figures
- Replies: 5
- Views: 900
- Sat Mar 16, 2019 12:07 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Activation energy units
- Replies: 2
- Views: 731
Re: Activation energy units
Yeah, when given energy values, it means per mole or if it of a reaction then it is per reaction.
- Sat Mar 16, 2019 12:05 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalysts
- Replies: 4
- Views: 664
Re: Catalysts
Catalysts are not included.
- Sat Mar 16, 2019 12:04 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test Location 14B W19
- Replies: 3
- Views: 670
Re: Test Location 14B W19
Final exam info is on the website link that includes final exam info.
- Fri Mar 15, 2019 7:43 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Concentration Q
- Replies: 2
- Views: 358
Concentration Q
How do we set up Q in a concentration cell?
- Mon Mar 11, 2019 2:08 pm
- Forum: First Order Reactions
- Topic: First order rxn graphs [ENDORSED]
- Replies: 4
- Views: 528
Re: First order rxn graphs [ENDORSED]
They are all linear, but 0th is [A], 1st is ln[A], 2nd is 1/[A]. It is that way to linearize the graph, and second order have a positive k slope.
- Mon Mar 11, 2019 2:07 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Meaning of k
- Replies: 4
- Views: 658
Re: Meaning of k
There can be multiple lower case k's depending on how many elementary steps there are.
- Sat Mar 09, 2019 1:27 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: negative and k
- Replies: 3
- Views: 435
negative and k
A first order problem asks to find k, so we used ln[A]=-kt+ln[A]o, but in the solution ignore the negative k value. I thought k could be negative because dont 1st and 0th order have negative slopes in their graph. Do we ignore the negative or how does this work?
- Sat Mar 09, 2019 1:23 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: 7th edition 7A.11
- Replies: 1
- Views: 308
Re: 7th edition 7A.11
The temperature is given to show why the reaction will occur (because of a temperature change), but regarding solving the kinematics and what we need to do, it is unnecessary.
- Fri Mar 08, 2019 8:06 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Industrial on Final? [ENDORSED]
- Replies: 1
- Views: 480
Industrial on Final? [ENDORSED]
Will we need to know certain industrial and biological processes like rusting or cathodic protection on the FInal? If so, how in depth, like would the scenarios provide us with the chemical reactions, so we won't need to memorize them?
- Fri Mar 08, 2019 7:50 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: n and significant figures
- Replies: 5
- Views: 900
n and significant figures
In electrochemical problems like nernst involving n, the transfer of electrons, does that affect the final answer's signifcant figures, because that would make all the final answers 1 sig fig?
- Sun Mar 03, 2019 9:10 pm
- Forum: Van't Hoff Equation
- Topic: Van't Hoff use
- Replies: 13
- Views: 2143
Re: Van't Hoff use
The vant hoff equation can be rearranged to find different values, such as G values, enthalpy, entropy, temperature, and K values
- Sun Mar 03, 2019 9:06 pm
- Forum: General Rate Laws
- Topic: Final Grades
- Replies: 3
- Views: 469
Re: Final Grades
There is no curve
- Sun Mar 03, 2019 9:06 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Cell Diagram
- Replies: 4
- Views: 422
Re: Cell Diagram
H+ is included if it is need in the half cell to balance out the hydrogen, or else the half cell reaction wouldn't happen.
- Sun Mar 03, 2019 9:05 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell diagrams and solids
- Replies: 9
- Views: 1020
Re: Cell diagrams and solids
You need Pt if there is not a solid electrode present.
- Sun Mar 03, 2019 9:03 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Pt(s)
- Replies: 10
- Views: 1073
Re: Pt(s)
When a conductor is not present. Know that if there is a solid,it does not mean it is automatically a conductor, because some solids are salts,so the Pt will still be needed.
- Sun Mar 03, 2019 9:01 pm
- Forum: First Order Reactions
- Topic: homework problems
- Replies: 2
- Views: 219
Re: homework problems
Nernst, electrolytic, and kinetics should work
- Sun Feb 24, 2019 9:45 pm
- Forum: Balancing Redox Reactions
- Topic: 2/22 in class example E(nought)
- Replies: 2
- Views: 292
Re: 2/22 in class example E(nought)
E is an intensive property, so it doesn't matter how many reactions or the ratio's of it. But reversing does affect if it is positive or negative.
- Sun Feb 24, 2019 9:43 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram Order
- Replies: 2
- Views: 328
Cell Diagram Order
In a cell diagram, knowing that the anode is the left side and cathode is the right side, on each respective side, does the order of the substances matter?
For example, is there a difference between these,
Zn/Zn2+//Ni2+/Ni versus Zn2+/Zn//Ni2+/Ni
For example, is there a difference between these,
Zn/Zn2+//Ni2+/Ni versus Zn2+/Zn//Ni2+/Ni
- Sun Feb 24, 2019 4:27 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Reversing Anode
- Replies: 2
- Views: 295
Reversing Anode
Is the anode always reversed to get the full balanced equation? I thought we wanted the most positive voltage everytime, if not then what was that too?
- Sun Feb 24, 2019 1:33 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: n value
- Replies: 11
- Views: 952
n value
How do you find n in deltaG=-nFE
- Sat Feb 23, 2019 10:17 pm
- Forum: Balancing Redox Reactions
- Topic: H OH and H20
- Replies: 2
- Views: 299
Re: H OH and H20
Use H20 to first balance the oxygen, then use H+ to balance the hydrogens, the e- to balance the charge
- Sat Feb 23, 2019 5:12 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Stability
- Replies: 2
- Views: 2235
Re: Stability
Things with less energy are more stable, stuff with more energy are less stable. So if G is positive, that means energy is going up and it's less stable, versus if it was negative then it would become more stable.
- Sat Feb 23, 2019 5:09 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic Cell Diagram
- Replies: 6
- Views: 583
Re: Galvanic Cell Diagram
Understand the purposes of the parts of the galvanic cells.
- Sat Feb 23, 2019 5:03 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt Bridge
- Replies: 2
- Views: 260
Re: Salt Bridge
The reason the cell potential would be affected because with the salt bridge allowing the ion transfer, then there would be a charge buildup, thus affecting the negatively charged electrons.
- Mon Feb 18, 2019 8:45 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy
- Replies: 4
- Views: 438
Re: Gibbs Free Energy
yeah it's the equilibrium constant
- Mon Feb 18, 2019 8:43 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Spontaneity and exothermic reactions
- Replies: 3
- Views: 409
Re: Spontaneity and exothermic reactions
All chemical things want to go to a lower energy, so exothermics release energy, that is why it is spontaneous.
- Mon Feb 18, 2019 8:36 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: reversible and irreversible processes
- Replies: 9
- Views: 1542
Re: reversible and irreversible processes
reversible happens slowly so heat change can occur and the pressure usually is changing
- Mon Feb 18, 2019 8:35 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Delta G a state function?
- Replies: 23
- Views: 2840
Re: Delta G a state function?
yes, it involves enthalpy and temperature
- Mon Feb 18, 2019 8:33 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Internal energy (U) of an isolated system
- Replies: 17
- Views: 2715
Re: Internal energy (U) of an isolated system
isolated system transfers no matter or energy, so deltaU is 0, however U can have a specific value.
- Mon Feb 18, 2019 8:32 pm
- Forum: Calculating Work of Expansion
- Topic: Units for R
- Replies: 10
- Views: 1395
Re: Units for R
using which R depends on if the answer is looking for joules or looking for something else, like liters per mol. But, you can always convert after using 101.325 to get the correct units and value
- Mon Feb 18, 2019 8:30 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: standard Gibbs Free Energy
- Replies: 4
- Views: 541
Re: standard Gibbs Free Energy
the numerical values will have the little dot showing it is standard
- Mon Feb 11, 2019 10:19 am
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: General entropy question
- Replies: 9
- Views: 854
Re: General entropy question
complexity of the molecule effects entropy
- Mon Feb 11, 2019 10:18 am
- Forum: Calculating Work of Expansion
- Topic: Reversible vs Irreversible
- Replies: 10
- Views: 1007
Re: Reversible vs Irreversible
irreversable needs to occur slowly for heat to equal out and pressure
- Sat Feb 09, 2019 10:29 am
- Forum: Calculating Work of Expansion
- Topic: Reversible and constant pressure
- Replies: 2
- Views: 306
Reversible and constant pressure
I thought the main point of reversible was a changing pressure, but a homework problem asks us to solve a reversible at constant pressure. Can you explain the relationship between reversible and pressure.
- Wed Feb 06, 2019 4:37 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Calorimeter and Heat
- Replies: 1
- Views: 203
Calorimeter and Heat
Why does q=(C)(deltaT) for the q of a calorimeter. Why can we omit moles, n, from the equation when dealing with heat transfer with the calorimeter.
- Sun Feb 03, 2019 10:48 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Constant numbers
- Replies: 4
- Views: 526
Re: Constant numbers
We are provided the constants and equations. Ones specific for this chapter are the ideal gas constants, ideal gas law, heat, the two work equations, etc.
- Sat Feb 02, 2019 7:51 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Enthalpy & Constant Pressure and Volume
- Replies: 2
- Views: 329
Enthalpy & Constant Pressure and Volume
Why does deltaH=q at constant pressure?
Why does deltaH=q at constant volume?
Thanks CC
Why does deltaH=q at constant volume?
Thanks CC
- Wed Jan 30, 2019 8:24 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Engine and Body Open system
- Replies: 3
- Views: 356
Engine and Body Open system
Why is a motor engine and a body considered open systems?
- Sun Jan 27, 2019 3:43 pm
- Forum: Phase Changes & Related Calculations
- Topic: Why are phase changes endothermic?
- Replies: 11
- Views: 1028
Re: Why are phase changes endothermic?
Think of how we looked at endothermic reactions in equilibrium and boiling water. If you boil water (add heat), what happens. Water vapor is formed (product), so the added heat from the stove created more products, which is the characteristic of an endothermic reaction. H2O(l) + heat <> H2O(g) , shi...
- Sun Jan 27, 2019 3:39 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: pKa values
- Replies: 3
- Views: 463
Re: pKa values
A table will be given in the book. Sometimes though it will give us the K value for the conjugate base/acid, so we would need to manipulate Kw=Ka*Kb.
- Sun Jan 27, 2019 3:37 pm
- Forum: Ideal Gases
- Topic: Approximations for ICE
- Replies: 20
- Views: 1648
Re: Approximations for ICE
When the k value is small, 10^-3 , because so little of the reactants go to products it is negligable.
- Mon Jan 21, 2019 2:21 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Aluminum Conjugate
- Replies: 1
- Views: 289
Aluminum Conjugate
In 6D15, why does the AlCl3 become Al(H2O)^6 in the chemical equation, why doesn't it just become Al^3+, and why would it get 6 water molecules? And where was the Ka value provided? Thanks.
- Mon Jan 21, 2019 2:14 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Conjugates
- Replies: 2
- Views: 204
Re: Conjugates
If it contains one more or less H, and the other atoms are the same. in the 6C1 table, they are there, the conjugate would be slightly different and would have the other Ka or Kb, depending if it is a conjugate acid or base.
- Sun Jan 20, 2019 8:58 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Inert Gases
- Replies: 7
- Views: 832
Re: Inert Gases
There is no equilibrium change because the concentration of the gases at interest have not changed. Neither the n nor V have changed.
- Sun Jan 20, 2019 8:45 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Pressure
- Replies: 8
- Views: 772
Re: Pressure
The K value is same though.
- Sun Jan 20, 2019 8:34 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: The Conjugate Seesaw
- Replies: 13
- Views: 998
Re: The Conjugate Seesaw
Ka*Kb = Kw
Kw is always 1.0x10^-14, so is one value increases, the other decreases.
Kw is always 1.0x10^-14, so is one value increases, the other decreases.
- Sun Jan 20, 2019 8:32 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q and K
- Replies: 10
- Views: 825
Re: Q and K
K uses only equilibrium concentrations. Q can use any concentration at any time, which tells us where the reaction will go.
- Sun Jan 13, 2019 2:52 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kc and Kp
- Replies: 5
- Views: 302
Re: Kc and Kp
Use the one your given, don't use the one your not given.
- Sun Jan 13, 2019 2:46 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Exothermic Reactions
- Replies: 9
- Views: 848
Re: Exothermic Reactions
Stability also relates to exo or endo, such as the HW question using a halogen, which makes us have to know that halogens are stable diatomically, so dissociating to monotomic would have to be endothermic.
- Sun Jan 13, 2019 2:38 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Changes in Partial Pressure
- Replies: 5
- Views: 439
Re: Changes in Partial Pressure
Everything is assumed to remain the same unless it is explicitly stated.
- Sun Jan 13, 2019 2:34 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Effect of Volume Given Equal Moles
- Replies: 2
- Views: 157
Re: Effect of Volume Given Equal Moles
Unaffected
- Sat Dec 08, 2018 2:55 pm
- Forum: Naming
- Topic: confusion name to formula
- Replies: 4
- Views: 523
Re: confusion name to formula
It has -ate either because the hexcyanidochromate(III) part, the complex, is negative or because the chromium had just eaten.
- Fri Dec 07, 2018 1:31 pm
- Forum: Lewis Acids & Bases
- Topic: Determining Factors
- Replies: 2
- Views: 308
Re: Determining Factors
Lone pairs or unfilled octet. Or if it's got extra H's or OH's.
- Fri Dec 07, 2018 1:29 pm
- Forum: Conjugate Acids & Bases
- Topic: Water as an Acid/Base
- Replies: 20
- Views: 1570
Re: Water as an Acid/Base
Depends if it loses or accepts and H.
- Fri Dec 07, 2018 1:28 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polarizing Power for Na+, Mg2+, Li+, Be2+
- Replies: 4
- Views: 4364
Re: Polarizing Power for Na+, Mg2+, Li+, Be2+
Lit is smaller so it has stronger polarizing power. You might be confusing poloarizing power with polarizability.
- Mon Nov 26, 2018 7:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Seesaw Bond Angles
- Replies: 6
- Views: 16114
- Mon Nov 26, 2018 7:52 pm
- Forum: Hybridization
- Topic: Atomic Orbitals
- Replies: 2
- Views: 127
Re: Atomic Orbitals
It means hybridization comes from atomic orbitals.
The orbitals hybridize so they can have more orbitals and a different shape that is necessary to form a bond.
The orbitals hybridize so they can have more orbitals and a different shape that is necessary to form a bond.
- Mon Nov 26, 2018 7:50 pm
- Forum: Resonance Structures
- Topic: Bond Lengths
- Replies: 3
- Views: 568
Re: Bond Lengths
For example, if molecule X has 2 double bonds and 1 single and molecule Y has 1 double bond and 2 single bonds, Molecule Y is longer because the averages are longer.
- Mon Nov 26, 2018 7:47 pm
- Forum: Hybridization
- Topic: bond angles
- Replies: 2
- Views: 329
Re: bond angles
For sure
- Mon Nov 26, 2018 7:40 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Location of Lone Pairs
- Replies: 2
- Views: 227
Re: Location of Lone Pairs
Octahedral is 90* between any atom, that's why it doesn't matter. But Trig Bipyr has angles of 90*(axial to equatorials) and 120*(trig planar atoms), that's why LP placement matters in Trig Bipyr.
- Mon Nov 26, 2018 7:37 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Dipole Moment
- Replies: 3
- Views: 423
Re: Dipole Moment
A good reminder is the tail of the arrow having a perpendicular line to represent the addition symbol, +, thus showing that is the positive side going towards the negative part.
- Mon Nov 26, 2018 7:36 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Boiling Point
- Replies: 3
- Views: 1918
Re: Boiling Point
Yes it depends on IMF's.
From those it looks like LiCl is ionic, C3H7OH is H Bonding, C4H8 is nonpolar Londons, and N2 is also nonpolar but I think weaker than C4H8 because it has less electrons, so less London strength.
Correct me if I'm wrong.
From those it looks like LiCl is ionic, C3H7OH is H Bonding, C4H8 is nonpolar Londons, and N2 is also nonpolar but I think weaker than C4H8 because it has less electrons, so less London strength.
Correct me if I'm wrong.
- Mon Nov 26, 2018 7:33 pm
- Forum: Sigma & Pi Bonds
- Topic: Resonance structure
- Replies: 2
- Views: 244
Re: Resonance structure
I believe Sigma and Pie bonds aren't meant to describe the actual thing, such as resonance being an average of the bond lengths, but instead describing how we describe bonded molecules as single, double, triple bonds.
- Mon Nov 26, 2018 7:31 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: London Forces
- Replies: 2
- Views: 287
London Forces
Are London forces a characteristic of all molecules, even polar molecules?
- Mon Nov 26, 2018 7:28 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Intermolecular forces and melting/boiling points
- Replies: 4
- Views: 1218
Re: Intermolecular forces and melting/boiling points
Dipole Dipole is molecules having a concentration of charge in a certain area due to polarity, which allows for greater attraction with another molecule that has its charges concentrated in certain areas. Hydrogen bonding is just super strong Dipole Dipole because of the Hydrogen with very electrone...
- Mon Nov 26, 2018 7:24 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: intermolecular forces
- Replies: 1
- Views: 199
- Sun Nov 25, 2018 6:47 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Sigma vs pi bonds
- Replies: 7
- Views: 774
Re: Sigma vs pi bonds
Sigma's bond along the same orientation axis. Pie bonds don't, so there is no rotation. Pie bonds are weaker than Sigma bonds because they don't have overlap, so weaker attraction
- Sun Nov 25, 2018 6:43 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Electron Arrangement vs. Molecular Shape
- Replies: 2
- Views: 454
Electron Arrangement vs. Molecular Shape
What is the difference? What terms are used to describe each one?
- Sun Nov 25, 2018 6:39 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Seesaw
- Replies: 2
- Views: 284
Re: Seesaw
If it was in axial position, it would be repelling with 3 atoms at 90 degrees, because all 3 equatorial atoms would be there. Because it is in the equatorial position, it is only 90 degrees with 2 atoms, the axial ones.
- Sat Nov 24, 2018 8:28 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Polarity and Boiling Point
- Replies: 3
- Views: 5258
Polarity and Boiling Point
Why does higher polarity lead to higher boiling point???
- Sat Nov 24, 2018 7:47 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Salts Dissolving
- Replies: 1
- Views: 239
Salts Dissolving
Is water's polarity the reason salts dissolve.
- Sat Nov 24, 2018 7:42 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Hydrogen Bonding
- Replies: 5
- Views: 562
Re: Hydrogen Bonding
Think of H bonded to Phone, b/c it sounds like FON, is Hydrogen Bonding
- Sat Nov 24, 2018 7:40 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Intermolecular energy
- Replies: 3
- Views: 767
Re: Intermolecular energy
I think it's Potential Energy of the London interaction between different molecules. The potential energy decreases very rapidly with distance increase because it is r^6.
- Sat Nov 24, 2018 7:18 pm
- Forum: Sigma & Pi Bonds
- Topic: Sigma and Pi bonds
- Replies: 5
- Views: 416
Re: Sigma and Pi bonds
Qualitative differences prob. Maybe why a double bond isn't twice as strong as a single bond, because Pie bond is weaker than Sigma bond.
- Sat Nov 24, 2018 7:15 pm
- Forum: Hybridization
- Topic: double bonds
- Replies: 14
- Views: 1249
Re: double bonds
Because Pie bonds don't overlap like Sigma bonds, they are weaker than Sigma bonds. That's why double bonds are less than twice as strong as single bond.
- Sat Nov 24, 2018 7:09 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lewis Structure N2O
- Replies: 4
- Views: 449
Re: Lewis Structure N2O
Formal charge wouldn't work out either
- Sat Nov 24, 2018 7:05 pm
- Forum: Electronegativity
- Topic: Arrows showing charge
- Replies: 4
- Views: 787
Re: Arrows showing charge
Some arrows have a plus sign, +, on the tail showing positive and then point of arrow is going to negative
- Sat Nov 24, 2018 6:35 pm
- Forum: Ionic & Covalent Bonds
- Topic: Determining the Difference between Ionic and Covalent Bonds
- Replies: 6
- Views: 714
Re: Determining the Difference between Ionic and Covalent Bonds
It's good to know about the 2 and 1.5 values, but understanding why is a better plan. Given ionic bonds have large electronegativity differences, of course they'll be greater than 2, so knowing bonds that are of an atom on the left and right of periodic table, thus large electronegativity difference...
- Sun Nov 18, 2018 9:58 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Trigonal Bipyramidal
- Replies: 3
- Views: 420
Re: Trigonal Bipyramidal
Trigonal Bipyramidal is like a totally blended version of linear, axial, and trigonal planar, equatorial.
- Sun Nov 18, 2018 9:50 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar/Nonpolar
- Replies: 3
- Views: 358
Polar/Nonpolar
Why is CH2Cl2 polar, I was thinking them H's would cancel each other and them Cl's would cancel each other. This problem 2E25D.
Thanks CC squad!
Thanks CC squad!
- Sun Nov 18, 2018 9:41 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: T Shaped
- Replies: 3
- Views: 583
Re: T Shaped
T-Shape is formed by 5 regions of electron density, which is the trigonal bipyramidal. Trigonal Bipyramidal is 3 equatorial bonds, 120* apart essentially making a trigonal planar, and 2 axial bonds, forming the top point of each pyramid and 90* from each of the equatorial atoms. The reason it forms ...
- Thu Nov 15, 2018 5:47 pm
- Forum: Dipole Moments
- Topic: Dipole Moments
- Replies: 6
- Views: 634
Re: Dipole Moments
dipole is a concentration of charge, thus unbalancing the charge in an atom.
- Thu Nov 15, 2018 5:38 pm
- Forum: Bond Lengths & Energies
- Topic: bond energy clarification
- Replies: 4
- Views: 447
Re: bond energy clarification
I think energy of breaking the bonds
- Wed Nov 14, 2018 11:23 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Drawing structures
- Replies: 4
- Views: 387
Re: Drawing structures
Yes, because it has the same 3 Dimensional shape as a tetrahedral, however because of the lone pair, its shape is "Trigonal Pyramidal"
- Wed Nov 14, 2018 11:16 pm
- Forum: Electronegativity
- Topic: Homework Question 2D.11
- Replies: 1
- Views: 181
Re: Homework Question 2D.11
Sarah, you're right that N3- is bigger than O2-, which is why it has more polarizability, because there is more space for charge to concentrate in. You may be confusing the concept of polarizing power, which is question 2D9.
- Wed Nov 14, 2018 11:13 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: polar vs nonpolar
- Replies: 6
- Views: 761
Re: polar vs nonpolar
If charges favor a certain area more than any other area, it is polar. So usually if there is a lone pair hanging out polarity may occur because the lone pair pushes the bonds away more than a typical bond, thus the charges from the bonds are in a tighter local, thus not as equally spread out.
- Wed Nov 14, 2018 11:09 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape
- Replies: 4
- Views: 365
Re: Molecular Shape
Google it, Or Bing it ;), what an octahedron looks like. Outside atoms form the points of an octahedron.
- Wed Nov 14, 2018 11:05 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 3
- Views: 307
Re: Bond Angles
The wide balloon effect of Lone Pairs may help you visualize why it pushes the bonds closer, thus decreasing the angles.
- Sat Nov 10, 2018 8:48 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Lengths
- Replies: 6
- Views: 590
Re: Bond Lengths
Whip out your ruler and check.
We don't need to how to get bond lengths, just understand the relationship between strength, length, and single, double, triple, or james bonds.
We don't need to how to get bond lengths, just understand the relationship between strength, length, and single, double, triple, or james bonds.
- Sat Nov 10, 2018 8:42 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Drawing Lewis Structures with VSPER
- Replies: 5
- Views: 544
Re: Drawing Lewis Structures with VSPER
Lewis structures do not have to be drawn like its shape because in the complex shapes it would be difficult and pointless to try to replicate the 3D shape in 2D. That's why knowing the name and bond angle is important in order to specify.
- Sun Nov 04, 2018 1:32 pm
- Forum: Resonance Structures
- Topic: Resonance [ENDORSED]
- Replies: 2
- Views: 256
Re: Resonance [ENDORSED]
Resonance shows where the least concentration of charge will look like. But in reality, resonance structures are "averaged out". For example a thing with 2 single and 1 double bond is actually like 3 1.33 bonds.
- Mon Oct 22, 2018 11:02 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Frequency Condition
- Replies: 2
- Views: 410
Re: Frequency Condition
The second is a simplified version of the deltaE version of the first one. DeltaE being it is set up as final-initial. The first one shows how the energy is related to the concept, the second one does not.
- Mon Oct 22, 2018 11:00 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Bohr Frequency Condition
- Replies: 2
- Views: 210
Re: Bohr Frequency Condition
No, it the photon just passes right through. This can be understood through conservation of energy. The "input" photon which excites the electron must be the same value of the "output" photon when the electron drops. So it won't happen if it's 2.5, where 2 will input and the .5 w...