Search found 110 matches
- Wed Mar 10, 2021 7:13 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Adsorption
- Replies: 5
- Views: 263
Re: Adsorption
Adsorption is the adhesion of a liquid or a gas to the surface of a solid. The reactants are the adsorbate and the catalyst is the adsorbent.
- Wed Mar 10, 2021 7:11 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Frequency Factor, A
- Replies: 9
- Views: 410
Re: Frequency Factor, A
I think the frequency factor will always be given to us in any problem.
- Mon Mar 08, 2021 11:12 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: What is frequency factor
- Replies: 10
- Views: 751
Re: What is frequency factor
The frequency factor (pre-exponential factor) is the likelihood of collisions happening with the right orientation.
- Mon Mar 08, 2021 11:10 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Frequency Factor
- Replies: 3
- Views: 191
Re: Frequency Factor
There is not going to be a reaction if the collisions are not in the correct orientation.
- Mon Mar 08, 2021 11:09 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Activation energy
- Replies: 6
- Views: 376
Re: Activation energy
The activation energy problems will most of the time be given in kJ. However, the Arrhenius equation uses Joules, so make sure to convert from kj to Joules.
- Fri Mar 05, 2021 4:17 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Pseudo K
- Replies: 5
- Views: 230
Re: Pseudo K
Pseudo k is only for a specific reactant. It is used to calculate k if the order of the reaction is known, and the initial concentrations where k' is found.
- Fri Mar 05, 2021 4:13 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Determining the Slowest Step
- Replies: 4
- Views: 233
Re: Determining the Slowest Step
It is always given by experimental results, which is used to find the rate law of the reaction.
- Wed Mar 03, 2021 4:47 pm
- Forum: First Order Reactions
- Topic: Half Life caluclations
- Replies: 6
- Views: 327
Re: Half Life caluclations
It is just how many times you need to divide the larger concentration to get the second one.
- Wed Mar 03, 2021 4:45 pm
- Forum: Zero Order Reactions
- Topic: Half life
- Replies: 19
- Views: 851
Re: Half life
You just simply use the equation t1/2 = [A]0/2k
- Mon Mar 01, 2021 1:28 pm
- Forum: General Rate Laws
- Topic: Factors Affecting k
- Replies: 83
- Views: 4448
Re: Factors Affecting k
k can only change with temperature and the activation energy.
- Mon Mar 01, 2021 1:25 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: comparison
- Replies: 4
- Views: 400
Re: comparison
There is a direct relationship between the concentration of the reactants and the reaction rate through the differential rate law. The rate will be higher with a greater concentration because there is more to react.
- Fri Feb 26, 2021 5:34 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Kinetic stability
- Replies: 14
- Views: 624
Re: Kinetic stability
When reactants react very slowly, kinetic stability occurs. There is greater kinetic stability when the reaction is happening very slowly.
- Fri Feb 26, 2021 5:31 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Kinetics
- Replies: 9
- Views: 788
Re: Kinetics
Kinetic controlled is for short reactions. In contrast, thermodynamically is for long reactions.
- Wed Feb 24, 2021 3:15 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Concentrations
- Replies: 8
- Views: 597
Re: Concentrations
The voltage of the cell is connected to the concentrations, which is seen by the equation E = E* - (RT/Fn)lnQ. Both Q and E are concentration-dependent.
- Wed Feb 24, 2021 3:13 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Ion Selective Electrode
- Replies: 6
- Views: 545
Re: Ion Selective Electrode
An ion-selective electrode is a sensor that changes the activity of a specific ion dissolved in a solution into a electrical potential.
- Mon Feb 22, 2021 5:36 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Conceptual understandings
- Replies: 7
- Views: 428
Re: Conceptual understandings
The textbook is overall a great resource!
- Mon Feb 22, 2021 5:35 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Units for delta G
- Replies: 31
- Views: 1729
Re: Units for delta G
The units for delta G are just in kj.
- Sun Feb 21, 2021 7:08 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation States for TM
- Replies: 6
- Views: 318
Re: Oxidation States for TM
Yeah! You can figure out the oxidation states for TM's by figuring out the oxidation state of the atoms it is paired within the equation.
- Sun Feb 21, 2021 7:05 pm
- Forum: Balancing Redox Reactions
- Topic: salt bridge
- Replies: 19
- Views: 614
Re: salt bridge
The salt bridge is what keeps one side from not losing charge when electrons travel across, and it also removes charge from the other side to maintain a constant voltage.
- Sun Feb 21, 2021 7:03 pm
- Forum: Balancing Redox Reactions
- Topic: pneumonic for redox reactions
- Replies: 3
- Views: 221
Re: pneumonic for redox reactions
Thank you so much! This helps a lot.
- Sun Feb 21, 2021 7:02 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Spontaneous Reduction
- Replies: 9
- Views: 491
Re: Spontaneous Reduction
If your standard reduction potential value is positive, then the reaction is considered spontaneous.
- Wed Feb 17, 2021 12:48 pm
- Forum: Balancing Redox Reactions
- Topic: Change in potential as i -> 0
- Replies: 12
- Views: 552
Re: Change in potential as i -> 0
I think the i represents the current approaching zero, because the maximum potential difference is when there's very little current flowing.
- Wed Feb 17, 2021 12:46 pm
- Forum: Balancing Redox Reactions
- Topic: Cathode and Anode
- Replies: 24
- Views: 1437
Re: Cathode and Anode
A cell can do work when Ecell > 0, therefore the cathode > anode.
- Wed Feb 10, 2021 5:30 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: ΔG° vs ΔG
- Replies: 20
- Views: 672
Re: ΔG° vs ΔG
ΔG° is Gibbs free energy under standard conditions. ΔG is not under those standard conditions.
- Wed Feb 10, 2021 5:29 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs R constant
- Replies: 7
- Views: 258
Re: Gibbs R constant
You just use 8.314 J/mol*K
- Wed Feb 10, 2021 5:27 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy
- Replies: 5
- Views: 293
Re: Gibbs Free Energy
G is just simply Gibbs Free Energy. Delta G is the change in free energy. If delta G < 0, then it is a exergonic reaction. When delta G is > 0, then it is a endergonic reaction.
- Mon Feb 08, 2021 3:04 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Entropy
- Replies: 6
- Views: 301
Re: Entropy
It all depends on the information given on a question. Systems move towards entropy overall.
- Mon Feb 08, 2021 3:02 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Entropy and Phase Changes
- Replies: 5
- Views: 258
Re: Entropy and Phase Changes
There is increased thermal entropy because gases and liquids are at higher temperatures in comparison to solids. Hence, because of the different phases there is more movement and positions for molecules.
- Wed Feb 03, 2021 12:17 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: Degeneracy (W)
- Replies: 7
- Views: 216
Re: Degeneracy (W)
I don't think the term for degeneracy has any units.
- Wed Feb 03, 2021 12:16 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: Understanding Entropy
- Replies: 4
- Views: 414
Re: Understanding Entropy
As others have said, entropy can just be described as randomness in a system.
- Wed Feb 03, 2021 12:15 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: Microstates
- Replies: 16
- Views: 970
Re: Microstates
Degeneracy is connected to microstates by the equation W = X^n. Degeneracy describes all of the possible positions that a particle can exist at.
- Mon Feb 01, 2021 5:35 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Reversible Process
- Replies: 4
- Views: 126
Re: Reversible Process
Reversible processes are very slow but very efficient because it takes a long time and energy over a period of time to change the volume in an infinite number of small steps. Having a lower pressure inside the system and higher pressure outside and this releasing it is an example of a irreversible p...
- Mon Feb 01, 2021 5:32 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Constant Pressure in Open Systems
- Replies: 8
- Views: 237
Re: Constant Pressure in Open Systems
Yes, I think you can just assume that the pressure is at 1 atm because that's what the pressure is at STP.
- Wed Jan 27, 2021 5:54 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: endothermic/exothermic Q and K
- Replies: 16
- Views: 1935
Re: endothermic/exothermic Q and K
Delta H is basically the change in heat. Endothermic reactions absorb heat. In contrast, the exothermic reactions release heat.
- Wed Jan 27, 2021 5:53 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Open Systems
- Replies: 15
- Views: 784
Re: Open Systems
I think all of the equations should work.
- Mon Jan 25, 2021 12:08 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Enthalpy changes
- Replies: 6
- Views: 274
Re: Enthalpy changes
The reaction is endothermic when the products are higher than the reactant. The reaction is exothermic when the reactants are higher than the products.
- Mon Jan 25, 2021 12:04 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Calorimeters
- Replies: 3
- Views: 70
Re: Calorimeters
I think that a calorimeter under constant pressure measures the change in enthalpy of a reaction when it happens in a liquid solution. In contrast, a calorimeter under volume is constant, so there is no pressure and volume work.
- Mon Jan 25, 2021 12:00 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Rounding E Values in ICE charts
- Replies: 17
- Views: 575
Re: Rounding E Values in ICE charts
The x can be dropped if the K value is less than 1.0 x 10^-3.
- Mon Jan 25, 2021 11:58 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: 6D.15 and 6D.17
- Replies: 3
- Views: 198
6D.15 and 6D.17
For these two problems, I don't think the Ka was given in order to calculate the pH. Would we be given the Ka or Kb value for the midterm in order to solve these types of problems?
- Fri Jan 22, 2021 1:00 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess Law
- Replies: 10
- Views: 1558
Re: Hess Law
You would cancel out the reactants if those reactants are the same as the one's that are on the product side of another equation. The equations could be combined algebraically if the coefficients are different. Also, I think, if necessary you can flip the chemical equation, which you would also have...
- Fri Jan 22, 2021 12:56 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 3 methods for calculation change in enthalpy
- Replies: 5
- Views: 96
Re: 3 methods for calculation change in enthalpy
You have to choose the best method to use with the information given in a question. Although using bond enthalpies to calculate a reaction is not the most accurate method.
- Wed Jan 20, 2021 12:50 pm
- Forum: Phase Changes & Related Calculations
- Topic: Endothermic v. Exothermic
- Replies: 139
- Views: 9231
Re: Endothermic v. Exothermic
Endothermic reactions will have a positive delta H because the reaction requires heat. In contrast, exothermic reactions will have a negative delta H because the reaction gives a net release of heat.
- Wed Jan 20, 2021 12:46 pm
- Forum: Phase Changes & Related Calculations
- Topic: state functions
- Replies: 13
- Views: 1294
Re: state functions
State functions are for example, entropy, enthalpy, and Gibb's free energy, which they are dependent on the initial and final values.
- Wed Jan 20, 2021 12:44 pm
- Forum: Phase Changes & Related Calculations
- Topic: Vapor vs gas
- Replies: 121
- Views: 8302
Re: Vapor vs gas
Both vapor and gas are in the same phase, so they both mean the same thing.
- Fri Jan 15, 2021 3:49 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: pKA and pH
- Replies: 8
- Views: 202
Re: pKA and pH
The pH and pOH just states the concentration of H+ and OH-. In contrast, pKa & pKb states how strong a particular acid and base is.
- Wed Jan 13, 2021 5:34 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Weak & Strong Acids/Bases
- Replies: 6
- Views: 281
Re: Weak & Strong Acids/Bases
You should memorize the strong acids and bases. Also, know that strong acids and bases completely ionize in solution. In contrast, weak acids and bases only partially ionize in solution.
- Wed Jan 13, 2021 5:32 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Temperature
- Replies: 45
- Views: 1242
Re: Temperature
We need to know if the reaction is endothermic or exothermic, which is given by delta h.
- Wed Jan 13, 2021 5:31 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Left vs. Right
- Replies: 29
- Views: 917
Re: Left vs. Right
Both statements mean the same thing.
- Mon Jan 11, 2021 5:44 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: H2O
- Replies: 44
- Views: 1824
Re: H2O
H2O is only considered when it is a gas, and not a solid or a liquid.
- Mon Jan 11, 2021 5:42 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kw
- Replies: 7
- Views: 336
Re: Kw
Kw varies depending on the temperature, since temperature changes the equilibrium constant. Water is only considered neutral as said by others.
- Fri Jan 08, 2021 2:25 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Change in Pressure
- Replies: 4
- Views: 91
Re: Change in Pressure
You simply just have to look at the coefficients in order to see which side has more moles.
- Fri Jan 08, 2021 2:22 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Temperature Effect on the Direction of the Reaction
- Replies: 4
- Views: 159
Re: Temperature Effect on the Direction of the Reaction
When there is a change in temperature K does change. If a rxn is endothermic then the temperature or the K value will go to the reactants side, as if we were adding another species into the equation. Therefore, the reaction will favor the product's side. In contrast, if a rxn is exothermic then the ...
- Fri Jan 08, 2021 2:17 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Increasing Volume in Change of Pressure
- Replies: 7
- Views: 128
Re: Increasing Volume in Change of Pressure
The equilibrium will shift towards the products more when the volume increases and the pressure decreases, since there is more moles at the product's side.
- Tue Jan 05, 2021 6:27 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Qc vs Kc
- Replies: 15
- Views: 5115
Re: Qc vs Kc
Q<K = Reaction is going to the product side (right)- forward direction.
Q>K = Reaction is going in the reverse direction, when making too many products.
Q>K = Reaction is going in the reverse direction, when making too many products.
- Tue Jan 05, 2021 6:24 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: H2O
- Replies: 44
- Views: 1824
Re: H2O
Only include H2O when it is in gas form, but not when it is in solid or liquid form.
- Tue Jan 05, 2021 6:23 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: temperature change in reactions
- Replies: 11
- Views: 355
Re: temperature change in reactions
If a reaction is exothermic then the temperature goes to the product side, as if it was a chemical formula like CO2. Hence, if a reaction is endothermic then the temperature goes to the reactant side.
Re: Ferrate
You would use "-ate" when the overall charge of the complex ion is an anion. Such as ferrate and cobaltate.
- Fri Dec 11, 2020 6:18 pm
- Forum: Naming
- Topic: Polyatomic Ions
- Replies: 4
- Views: 363
Re: Polyatomic Ions
I think we should somewhat have memorized the common polyatomic ions. The more practice problems you do the better you'll get at memorizing them.
- Wed Dec 09, 2020 8:46 pm
- Forum: Identifying Acidic & Basic Salts
- Topic: Acidic, basic, or neutral?
- Replies: 10
- Views: 1509
Re: Acidic, basic, or neutral?
We determine whether the salt is acidic or basic by comparing the Ka and Kb values for the ion. Hence, if Ka > Kb, the ion is acidic. In contrast, if Kb > Ka, the ion is basic.
- Wed Dec 09, 2020 8:42 pm
- Forum: Polyprotic Acids & Bases
- Topic: CO2 + H2O
- Replies: 7
- Views: 869
Re: CO2 + H2O
H2O and CO2 combine to form H2CO3, a weak acid that dissociates into hydrogen ions and bicarbonate ions.
- Wed Dec 09, 2020 8:38 pm
- Forum: Polyprotic Acids & Bases
- Topic: Proton vs H+
- Replies: 14
- Views: 683
Re: Proton vs H+
The positive charge of H+ ions is basically represented as protons.
- Wed Dec 09, 2020 8:35 pm
- Forum: Polyprotic Acids & Bases
- Topic: polyprotic acids
- Replies: 5
- Views: 364
Re: polyprotic acids
The first proton to dissociate is the most strongly acidic, followed by the order in the next most strongly acidic proton.
- Fri Dec 04, 2020 7:31 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Equilibrium constant
- Replies: 5
- Views: 225
Re: Equilibrium constant
The equilibrium constant (K) represents the relationship between the products and reactants of a reaction when they are at equilibrium with respect to particular unit.
- Fri Dec 04, 2020 7:27 pm
- Forum: Conjugate Acids & Bases
- Topic: Definition of "Conjugate"
- Replies: 5
- Views: 227
Re: Definition of "Conjugate"
A conjugate acid-base pair has two substances that differs by the presence of hydrogen ions. Hence, a conjugate acid is formed when a hydrogen ion (proton) is added to a base, while a conjugate base is made when a proton is separated from an acid.
- Fri Dec 04, 2020 7:23 pm
- Forum: Amphoteric Compounds
- Topic: Amphoteric
- Replies: 11
- Views: 675
Re: Amphoteric
An amphiprotic substance is one that can donate and accept hydrogen ions. Amphoteric means that a substance reacts as both an acid and a base.
- Mon Nov 30, 2020 5:44 pm
- Forum: Biological Examples
- Topic: Hemoglobin
- Replies: 13
- Views: 704
Re: Hemoglobin
Both myoglobin and hemoglobin are hemeproteins, which their ability is to bind to molecular oxygen. Myoglobin helps with the transportation of oxygen in muscle cells as well.
- Mon Nov 30, 2020 5:41 pm
- Forum: Biological Examples
- Topic: Biological Functions of Transition Metals
- Replies: 6
- Views: 279
Re: Biological Functions of Transition Metals
I don't think their order of the TM in the periodic table is related to the characteristics for their biological function.
- Fri Nov 27, 2020 10:27 pm
- Forum: Hybridization
- Topic: Single Bonds and Sigma Bonds
- Replies: 23
- Views: 1046
Re: Single Bonds and Sigma Bonds
Yes. All single bonds consists of one sigma bond. Therefore, a double bond is made of one pi bond and one sigma bond. Similarly, a triple bond has two pi bonds and one sigma bond.
- Fri Nov 27, 2020 10:22 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Definition of diamagnetism and paramagnetism
- Replies: 4
- Views: 302
Re: Definition of diamagnetism and paramagnetism
Diamagnetism is when a substance has no unpaired electrons and is not attracted to a magnetic field. In contrast, paramagnetism is when a substance are attracted to a magnetic field.
- Fri Nov 27, 2020 10:18 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: What is bond order?
- Replies: 8
- Views: 464
Re: What is bond order?
Bond order is simply the number of covalent bonds that is shared within two atoms. For example, when the atoms share one pair of electrons, they have a single bond, therefore a bond order of 1. A bond order of 2 has two electrons pairs, while sharing three electron pairs results in having a bond ord...
- Fri Nov 27, 2020 10:13 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Ligands
- Replies: 9
- Views: 425
Re: Ligands
The number of ligands attached to central ion, which is actually the number of donor atoms is basically the coordination number.
- Fri Nov 27, 2020 10:07 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Sigma and Pi Bonds
- Replies: 33
- Views: 1489
Re: Sigma and Pi Bonds
Delocalized pi bonding is seen in resonance structure with varying locations of double and triple bond.
- Fri Nov 20, 2020 11:35 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Net Vector
- Replies: 4
- Views: 111
Re: Net Vector
Net vector is basically equal magnitude pointing down and equal magnitude pointing up, which makes a molecule non-polar because the dipole moments cancel.
- Fri Nov 20, 2020 11:30 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: T-shape
- Replies: 3
- Views: 178
Re: T-shape
T-shaped molecular geometry is basically where a central atom has three ligands. An example of this is ClF3, and it's bond angles are 90° and 180°
- Wed Nov 18, 2020 10:49 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Shape Names
- Replies: 50
- Views: 2236
Re: Shape Names
Angular molecules, which are also called bent or V-shaped have a non-linear shape. For example, a water molecule has two unshared lone pairs and two pairs of bonded electrons.
- Wed Nov 18, 2020 10:41 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pair E-
- Replies: 47
- Views: 1740
Re: Lone Pair E-
The lone pair electrons are also considered in the count of electron density, which that will affect the molecules shape. However, it doesn't count when figuring out the geometry of the molecule.
- Wed Nov 18, 2020 10:28 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 11/18/20 Lecture VSEPR Notation
- Replies: 4
- Views: 232
Re: 11/18/20 Lecture VSEPR Notation
What people of have said before is correct: X would represent the bond atom and E is the lone pair that surrounds the central atom.
- Fri Nov 13, 2020 11:11 pm
- Forum: Dipole Moments
- Topic: H-Bonds
- Replies: 14
- Views: 671
Re: H-Bonds
Only molecules with H attached to electronegative atoms, such as N, O, and F can hydrogen bond.
- Fri Nov 13, 2020 11:08 pm
- Forum: Dipole Moments
- Topic: Dipole-dipole vs. ion-dipole vs. ion-ion
- Replies: 4
- Views: 239
Re: Dipole-dipole vs. ion-dipole vs. ion-ion
Dipole-dipole forces are attractive forces between the positive end of a polar molecule and the negative end of a different polar molecule. Ion-Dipole force is an attractive force that comes from the attraction between a neutral molecule that has a dipole and an ion. Ion-Ion interactions are an attr...
- Wed Nov 11, 2020 11:40 pm
- Forum: Dipole Moments
- Topic: Polar covalent bonds
- Replies: 5
- Views: 186
Re: Polar covalent bonds
The polar covalent bond is much stronger than the dipole-dipole interaction.
- Wed Nov 11, 2020 11:25 pm
- Forum: Dipole Moments
- Topic: London Dispersion forces
- Replies: 7
- Views: 177
Re: London Dispersion forces
As other people have said, there are no exceptions. Hence, all molecules experience LDF as they all have a small moment in time where its electrons move to one side of the atom, which makes the atom become slightly more negative and little bit more positive on either sides.
- Wed Nov 11, 2020 11:22 pm
- Forum: Dipole Moments
- Topic: Dipole dipole vs LDF
- Replies: 10
- Views: 3285
Re: Dipole dipole vs LDF
LDF happens between nonpolar molecules, and they are extremely weak. Dipole-dipole forces happen between polar molecules, therefore they have a stronger bond, since it has a slight charge that are very similar to ions.
- Fri Nov 06, 2020 6:16 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic & Covalent Character
- Replies: 4
- Views: 95
Re: Ionic & Covalent Character
If electronegativity difference is greater than 2, then it is an ionic bond. If electronegativity difference less than 1.5, then it is a covalent bond.
- Fri Nov 06, 2020 6:12 pm
- Forum: Ionic & Covalent Bonds
- Topic: Homework due date
- Replies: 49
- Views: 1898
Re: Homework due date
The newest homework assignment is due 11/14, at the end of Week 6.
- Fri Nov 06, 2020 6:09 pm
- Forum: Ionic & Covalent Bonds
- Topic: Electron Affinity vs. Electronegativity
- Replies: 12
- Views: 1287
Re: Electron Affinity vs. Electronegativity
Electron affinity is the amount of energy released when a molecule or neutral atom obtain electron from outside. In contrast, electronegativity is a chemical property which decides the propensity of an atom to attract an electron.
- Tue Nov 03, 2020 11:29 am
- Forum: Resonance Structures
- Topic: Resonance and double bonds
- Replies: 4
- Views: 82
Re: Resonance and double bonds
This is also a double bond related question. How do we exactly know when there has to be a double bond when creating the Lewis Structure?
- Tue Nov 03, 2020 11:26 am
- Forum: Resonance Structures
- Topic: Why does d orbital have expanded octet?
- Replies: 3
- Views: 195
Re: Why does d orbital have expanded octet?
The additional d orbitals can serve more electrons. Hence, the d orbitals bond with other atoms, which produces an expanded octet.
- Fri Oct 30, 2020 1:03 pm
- Forum: Ionic & Covalent Bonds
- Topic: Nonpolar and polar
- Replies: 16
- Views: 1027
Re: Nonpolar and polar
Does electronegativity have any connection with a molecule being polar or nonpolar?
- Fri Oct 30, 2020 1:01 pm
- Forum: Ionic & Covalent Bonds
- Topic: intermolecular vs intramolecular
- Replies: 17
- Views: 1808
Re: intermolecular vs intramolecular
Intramolecular forces are forces that hold the atoms together between a molecule. In contrast, intermolecular forces are the forces that exist within the molecules.
- Thu Oct 29, 2020 3:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Step Up Sessions
- Replies: 71
- Views: 6437
Re: Step Up Sessions
Are the step-up sessions still going to mention "older material" such as fundamentals or will the UA's only talk about the new material that we're currently going over?
- Thu Oct 29, 2020 3:17 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbital vs. Subshell
- Replies: 13
- Views: 735
Re: Orbital vs. Subshell
A subshell is divided into orbitals. An orbital is basically an area of space where an electron can be found. Only two electrons are workable per orbital.
- Thu Oct 29, 2020 3:10 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Question 1D.25
- Replies: 6
- Views: 310
Question 1D.25
The question is: Which of the following subshells cannot exist in an atom: (a) 2d; (b) 4d; (c) 4g; (d) 6f?
I looked at the solution and it says that 2d and 4f cannot exist in an atom, and the rest do. Why exactly is that?
I looked at the solution and it says that 2d and 4f cannot exist in an atom, and the rest do. Why exactly is that?
- Thu Oct 22, 2020 4:26 pm
- Forum: Properties of Light
- Topic: Textbook Question 1.A.9
- Replies: 4
- Views: 213
Re: Textbook Question 1.A.9
Can someone please how do you match each type of radiation to the appropriate event? The activities were reading, getting a dental x-ray, making popcorn in a microwave oven, and acquiring a suntan.
- Thu Oct 22, 2020 4:22 pm
- Forum: Properties of Light
- Topic: Midterm
- Replies: 42
- Views: 1351
Re: Midterm
Maddie Turk Disc 2C wrote:How would there be opportunity for partial credit if it is multiple choice?
From what I understand if there's for example parts A and B, you don't need to do part A first in order to do part B, which helps you get as many points as possible.
- Thu Oct 22, 2020 4:19 pm
- Forum: Student Social/Study Group
- Topic: How are you studying?
- Replies: 204
- Views: 16950
Re: How are you studying?
I think one of the best ways to study is to redo all of the homework problems assigned, modules, and worksheets from workshops and step-up sessions. Don't forget to take breaks in between when studying. Hope this helps!
- Mon Oct 19, 2020 3:54 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Where can I buy a webcam for a reasonable price?
- Replies: 60
- Views: 3470
Re: Where can I buy a webcam for a reasonable price?
I bought a Webcam from Amazon that has to be connected to your laptop. I would get a webcam that's bluetooth instead.
- Mon Oct 19, 2020 3:31 pm
- Forum: DeBroglie Equation
- Topic: standing circular wave model
- Replies: 7
- Views: 445
Re: standing circular wave model
What exactly does it mean when an atom is "not a stable mathematical model/system?"
- Fri Oct 16, 2020 3:51 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Format
- Replies: 12
- Views: 415
Re: Midterm Format
Will the questions for the midterm be similar problems as the ones from the textbook?
- Fri Oct 16, 2020 3:49 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Quantum world syllabus problems
- Replies: 4
- Views: 127
Re: Quantum world syllabus problems
Does anyone know how to start problem 1B.5?
1B.5: The γ-ray photons emitted by the nuclear decay of a technetium-99 atom used in radiopharmaceuticals have an energy of 140.511 keV. Calculate the wavelength of these γ-rays.
1B.5: The γ-ray photons emitted by the nuclear decay of a technetium-99 atom used in radiopharmaceuticals have an energy of 140.511 keV. Calculate the wavelength of these γ-rays.
- Wed Oct 14, 2020 2:26 pm
- Forum: Properties of Light
- Topic: Rearranging Equations
- Replies: 4
- Views: 470
Rearranging Equations
Is there a way to figure out exactly how to rearrange the equation's E = hv and c = λv for a particular problem?