Search found 102 matches
- Thu Mar 11, 2021 11:36 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram order
- Replies: 6
- Views: 361
Re: Cell Diagram order
Yes, the cathode is written on the right side of a cell diagram whereas the anode lies on the left side.
- Thu Mar 11, 2021 11:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Stability/Favorable
- Replies: 5
- Views: 380
Re: Stability/Favorable
If the equilibrium constant K is greater than 1, then products are favored. When the equilibrium constant K is less than 1, reactants are favored.
- Thu Mar 11, 2021 11:32 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Calculating Reaction Quotient with Solids
- Replies: 8
- Views: 530
Re: Calculating Reaction Quotient with Solids
The denominator would be 1 if the reactants were solids or liquids.
- Thu Mar 11, 2021 11:30 pm
- Forum: Balancing Redox Reactions
- Topic: DeltaG = - n F E
- Replies: 3
- Views: 202
Re: DeltaG = - n F E
Delta G corresponds with E, and delta G naught corresponds with E naught.
- Thu Mar 11, 2021 11:29 pm
- Forum: Second Order Reactions
- Topic: Termolecular
- Replies: 43
- Views: 2399
Re: Termolecular
Termolecular is when the molecularity of a reaction is equal to 3, meaning that there are three reactants involved.
- Mon Mar 08, 2021 5:31 pm
- Forum: General Rate Laws
- Topic: Intermediates
- Replies: 17
- Views: 1507
Re: Intermediates
Intermediates are not included in the balanced chemical equation because they are both reactants and products, and they, therefore, get canceled in the balanced chemical equation
- Mon Mar 08, 2021 5:30 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Initial Rates = Maximum rates [ENDORSED]
- Replies: 9
- Views: 867
Re: Initial Rates = Maximum rates [ENDORSED]
The initial rate is the maximum rate because that is when there is little product, and since the reaction is trying to reach equilibrium, the rate at which the initial concentration of reactant that turns into the product will be the fastest, and thus maximum, rate.
- Mon Mar 08, 2021 5:28 pm
- Forum: General Rate Laws
- Topic: Rate determining step
- Replies: 38
- Views: 1600
Re: Rate determining step
The rate is only determined by the slowest step because it can only go as fast as that slow step. It can't go any faster than the slowest rate.
- Mon Mar 08, 2021 5:27 pm
- Forum: First Order Reactions
- Topic: Half Life Equation
- Replies: 5
- Views: 309
Re: Half Life Equation
The concentration of the reactant is not included in the half-life equation for a first-order reaction. Therefore, the half-life is independent of reactant concentration.
- Mon Mar 08, 2021 5:25 pm
- Forum: Zero Order Reactions
- Topic: Overall order of the reaction
- Replies: 45
- Views: 2083
Re: Overall order of the reaction
The overall order of the reaction is the sum of the orders of the individual reactants.
- Sun Feb 28, 2021 11:14 pm
- Forum: Balancing Redox Reactions
- Topic: Compounds as both reducing and oxidizing agents
- Replies: 2
- Views: 187
Re: Compounds as both reducing and oxidizing agents
A species can act as both an oxidizing and reducing agent when there is only one species on the left side of the chemical equation, for example.
- Sun Feb 28, 2021 11:12 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: n in ∆G = -nFE
- Replies: 80
- Views: 4514
Re: n in ∆G = -nFE
n refers to the number of moles of electrons transferred in the chemical reaction. In order to find the value of n, balance the half-reactions and determine how many electrons are needed when putting the two half-reactions together into one balanced chemical reaction.
- Sun Feb 28, 2021 11:09 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Instantaneous Rate
- Replies: 41
- Views: 2286
Re: Instantaneous Rate
The instantaneous rate is equal to 0 when the reaction is at equilibrium at constant K. It is negative on the left side of K and it is positive on the right side of K, forming a U-shaped graph.
- Sun Feb 28, 2021 11:06 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: cell potential (E) change affect overall
- Replies: 3
- Views: 233
Re: cell potential (E) change affect overall
the relationship is illustrated through the equation deltaG=-nfEcell. When E is negative, delta G is positive and the reaction is spontaneous in reverse. When E is positive, delta G is negative and the reaction is spontaneous as written
- Sun Feb 28, 2021 11:01 pm
- Forum: Balancing Redox Reactions
- Topic: Canceling Out Added Electrons in Half Reactions
- Replies: 10
- Views: 1420
Re: Canceling Out Added Electrons in Half Reactions
The net charges on each side of the equations is not the same. It needs to be matched in order for the chemical equation to be balanced. We add electrons to the side that is more positive in order to balance out the charge.
- Sun Feb 28, 2021 11:00 pm
- Forum: *Electrophiles
- Topic: Anode vs Cathode
- Replies: 16
- Views: 1489
Re: Anode vs Cathode
I think about the prefixes an- and cat-. Anions have a negative charge, and the anode is the electrode that releases electrons. The cathode is a positive charge and is the one that receives the electrons.
- Sun Feb 21, 2021 10:53 pm
- Forum: Phase Changes & Related Calculations
- Topic: State Property
- Replies: 71
- Views: 3287
Re: State Property
A state property does not take into account what path has been taken to get to the current condition. It only cares about the current condition.
- Sun Feb 21, 2021 10:52 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Spontaneity of a System
- Replies: 38
- Views: 2922
Re: Spontaneity of a System
Spontaneity relates to Gibbs Free energy, which helps explain why gas expands to a greater volume when given the opportunity, for example.
- Sun Feb 21, 2021 10:50 pm
- Forum: Calculating Work of Expansion
- Topic: adiabatic processes
- Replies: 18
- Views: 986
Re: adiabatic processes
Adiabatic processes are when q=0, meaning no heat is transferred
- Sun Feb 21, 2021 10:49 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Delta G and G naught
- Replies: 46
- Views: 4673
Re: Delta G and G naught
Delta G nought is fixed for a given reaction and temperature and so it does not change as the reaction proceeds. Delta G, on the other hand, depends on the composition of the reaction mixture and so it varies as the reaction proceeds.
- Sun Feb 21, 2021 10:46 pm
- Forum: Van't Hoff Equation
- Topic: Van't Hoff [ENDORSED]
- Replies: 6
- Views: 604
Re: Van't Hoff [ENDORSED]
The Van't Hoff equation can be used to find the enthalpy of a reaction when given two equilibrium constants and two temperature constants, I believe. Correct me if I am wrong.
- Mon Feb 15, 2021 7:10 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Internal Energy of a Closed System
- Replies: 5
- Views: 380
Re: Internal Energy of a Closed System
A closed system can do work because there can be a change in volume. One example of a closed system is a piston, since matter cannot be exchanged however energy in the form of both heat and work can be exchanged.
- Mon Feb 15, 2021 7:07 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Change in Enthalpy at Constant Volume
- Replies: 4
- Views: 259
Re: Change in Enthalpy at Constant Volume
the second term is derived from the ideal gas law PV=nRT
- Mon Feb 15, 2021 7:05 pm
- Forum: Calculating Work of Expansion
- Topic: Work and Equilbrium
- Replies: 5
- Views: 322
Re: Work and Equilbrium
At equilibrium, internal energy is at its minimum while entropy is at its maximum.
- Mon Feb 15, 2021 7:04 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: confusion on using Cp and Cv
- Replies: 24
- Views: 1159
Re: confusion on using Cp and Cv
Cp is the heat capacity at constant pressure while Cv is the heat capacity at constant volume.
- Mon Feb 15, 2021 7:02 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Isothermal Reactions
- Replies: 26
- Views: 1295
Re: Isothermal Reactions
Isothermal reactions are considered reversible because the temperature is constant
- Sat Feb 06, 2021 11:46 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Extensive vs intensive property for heat capacities
- Replies: 7
- Views: 345
Re: Extensive vs intensive property for heat capacities
An extensive property, like mass, depends on how much matter you have. An intensive property, like density, is something that is independent of the amount of matter you have. Likewise, heat capacity depends on how much of a substance you have that needs to be heated, while specific heat capacity is ...
- Sat Feb 06, 2021 11:43 am
- Forum: Calculating Work of Expansion
- Topic: Reversible Expansion
- Replies: 7
- Views: 307
Re: Reversible Expansion
That would just be considered an irreversible expansion. So you would use w = -P∆V .
- Sat Feb 06, 2021 11:42 am
- Forum: Student Social/Study Group
- Topic: Equations
- Replies: 7
- Views: 342
Re: Equations
It helps me when I know how the equations are derived, which also helps me memorize the equations because I fully understand what is happening within the equations. But you don't have to memorize the equations since they are given in the constants and equations worksheet that we can use during the e...
- Sat Feb 06, 2021 11:40 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy reactions
- Replies: 9
- Views: 461
Re: Enthalpy reactions
Bond enthalpies are not as accurate as the other methods when determining the enthalpy reaction. Reaction enthalpies have to do with Hess's law.
- Sat Feb 06, 2021 11:38 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Postive vs. negative work
- Replies: 18
- Views: 1049
Re: Postive vs. negative work
when work is done on the system, this means that there is compression. therefore, the internal energy is increasing, and the change in internal energy would be positive. When work is done by the system, there is expansion. Therefore, the internal energy is decreasing, and the change in internal ener...
- Sun Jan 31, 2021 11:36 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Clarification on pKw
- Replies: 15
- Views: 3918
Re: Clarification on pKw
Kw is the concentration of H3O+ multiplied by the concentration of OH-. pKw is when you take the negative logarithm of Kw.
- Sun Jan 31, 2021 11:34 pm
- Forum: Ideal Gases
- Topic: Reversing Reactions
- Replies: 68
- Views: 2548
Re: Reversing Reactions
When K represents the forward reaction, then 1/K represents the reverse reaction.
- Sun Jan 31, 2021 11:31 pm
- Forum: Phase Changes & Related Calculations
- Topic: Higher Enthalpy
- Replies: 6
- Views: 224
Re: Higher Enthalpy
When raising the temperature (adding heat) to an endothermic reaction, the products are favored. When raising the temperature of an exothermic reaction, however, the reactants are favored.
- Sun Jan 31, 2021 11:30 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess's Law
- Replies: 58
- Views: 3158
Re: Hess's Law
Hess's law reveals that enthalpy is a state function. Therefore, Hess's law shows that enthalpy can be added and subtracted.
- Sun Jan 31, 2021 11:29 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed system
- Replies: 43
- Views: 1644
Re: closed system
an open system can exchange both matter and energy with the surroundings. However, a closed system has a fixed amount of matter and can only exchange energy with the surroundings. the fixed amount of matter implies that the volume is constant.
- Sun Jan 24, 2021 10:03 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Inert Gases and Le Chatelier's Principle
- Replies: 6
- Views: 528
Re: Inert Gases and Le Chatelier's Principle
Inert gases do not change the equilibrium constant because they do not react with other substances. Therefore, the partial pressures of the reactants and the products do not change and thus the equilibrium constant does not change.
- Sun Jan 24, 2021 10:00 pm
- Forum: Phase Changes & Related Calculations
- Topic: State Property
- Replies: 71
- Views: 3287
Re: State Property
Enthalpy is a state property, which means that it is NOT dependent on the path taken to obtain that state. Only the initial state and the current state are taken into account, which means that enthalpy can be added and subtracted.
- Sun Jan 24, 2021 9:58 pm
- Forum: Phase Changes & Related Calculations
- Topic: Constant Temperature
- Replies: 20
- Views: 831
Re: Constant Temperature
Energy is for the breaking and the forming of bonds, but energy is not for changing the temperature. Therefore, the temperature of the sample is constant.
- Sun Jan 24, 2021 9:56 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: When to use ICE box
- Replies: 23
- Views: 952
Re: When to use ICE box
Equilibrium composition is just another way of saying equilibrium concentrations. You have to use ICE Box when the initial concentrations are given and you have to solve for equilibrium concentrations or vice versa.
- Sun Jan 24, 2021 9:55 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Strong Acids/Bases
- Replies: 12
- Views: 631
Re: Strong Acids/Bases
I just memorize some easy mnemonics . For strong acids, it's "So I Brought No Clean Clothes" (H2SO4, HI, HBr, HNO3, HCL, HCLO3, HCLO4". For strong bases, it's Lily and Nate RoBbed a Bank and Killed a Cessium of Strong Cats" (Li, Na, Rb, Ba, K, Cs, Sr, Ca)
- Sun Jan 17, 2021 4:51 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q > K, Q< K
- Replies: 25
- Views: 862
Re: Q > K, Q< K
When Q < K, the reaction will tend to favor the forward reaction and more products will be formed. When Q>K, the reaction will tend to favor the reverse reaction and more reactants will form. When Q = K, then equilibrium composition has been reached and there is no tendency to change in either direc...
- Sun Jan 17, 2021 4:47 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Endothermic/exothermic reactions and K
- Replies: 11
- Views: 585
Re: Endothermic/exothermic reactions and K
A change in temperature changes the equilibrium constant K. When increasing the heat and the reaction is endothermic, K will increase. When increasing the heat and the reaction is exothermic, K will decrease.
- Sun Jan 17, 2021 4:44 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: shifts left or right
- Replies: 23
- Views: 1174
Re: shifts left or right
When Q>K, then the reaction will favor the reactants (reverse reaction). If Q<K, then the reaction will favor the products (forwards reaction).
- Sun Jan 17, 2021 4:43 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle and Pressure
- Replies: 6
- Views: 340
Re: Le Chatelier's Principle and Pressure
An increase in pressure also means a decrease in volume. It is important to remember that when volume decreases and there are more moles of gas on the left, then the reaction will shift right. And when the volume decreases and there are more moles of gas on the right, then the reaction will shift le...
- Sun Jan 17, 2021 4:38 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Reaction shift
- Replies: 5
- Views: 273
Re: Reaction shift
When the problem is describing the reactants converting into products, then the reactants should have a negative change and the products should have a positive change in the ICE box. When the problem is describing the products turning into reactants, then the products will have a negative change and...
- Sun Jan 10, 2021 12:49 am
- Forum: Ideal Gases
- Topic: Inert Gas
- Replies: 20
- Views: 690
Re: Inert Gas
An inert gas does not affect the partial pressures of the components of a reaction at equilibrium (however, adding an inert gas may change the total pressure of a container). This is because the inert gas does not interact with any of the species of the reaction.
- Sun Jan 10, 2021 12:47 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Products and Equilibrium
- Replies: 5
- Views: 366
Re: Products and Equilibrium
When there are more products at equilibrium, it means that the reaction favors the products at equilibrium. This may be because the products have lower energy and are thus more stable than the respective reactants. When K>10^3 the reacting STRONGLY favors the products.
- Sun Jan 10, 2021 12:44 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatlier's Principle concerning change in temperature
- Replies: 2
- Views: 103
Re: Le Chatlier's Principle concerning change in temperature
Yes, Le Chatelier's Principle still applies when the change in temperature changes the value of K. When raising the temperature of an endothermic reaction, K will increase. When raising the temperature of an exothermic reaction, K will decrease.
- Sun Jan 10, 2021 12:41 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Q and K
- Replies: 13
- Views: 515
Re: Q and K
When Q<K, the reaction has a tendency to proceed toward products. When Q=K, the mixture has its equilibrium composition and has no tendency to change in either direction. When Q<K, the products tend to decompose into the reactants.
- Sun Jan 10, 2021 12:39 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Endothermic and Exothermic Concepts
- Replies: 12
- Views: 664
Re: Endothermic and Exothermic Concepts
Raising the temperature of an exothermic reaction lowers the value of K. Raising the temperature of an endothermic reaction increases the value of K.
- Tue Dec 15, 2020 9:46 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Strong Bases
- Replies: 4
- Views: 428
Re: Strong Bases
I learned a mnemonic my friend made up in order to memorize the strong bases more easily. Lily and Nate Robbed a Bank and Killed a Cesium of Strong Cats. (Li, Na, Rb, K, Cs, Sr, Ca).
- Tue Dec 15, 2020 9:44 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligands
- Replies: 8
- Views: 465
Re: Ligands
A coordination compound can have multiple ligands, it does not necessarily have to be just one type of ligand. Some examples we've seen are when we learned how to name coordination compounds with multiple ligands, in which we had to name each ligand in alphabetical order with its corresponding prefi...
- Tue Dec 15, 2020 9:42 pm
- Forum: Amphoteric Compounds
- Topic: Recognizing Amphoteric Compounds
- Replies: 9
- Views: 763
Re: Recognizing Amphoteric Compounds
An amphoteric compound is a compound that can act as both an acid or a base, depending on the situation. One example of an amphoteric compound is H2O (water). H2O can both donate a proton (H+) and change to OH-, but it can also accept a proton and form H3O+.
- Tue Dec 15, 2020 9:40 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: pka and acidity
- Replies: 6
- Views: 573
Re: pka and acidity
when the pKa of an acid is high, then the Ka is low. There is an inverse relationship between these two ideas.
- Tue Dec 15, 2020 9:38 pm
- Forum: Naming
- Topic: Ligand use -ate
- Replies: 18
- Views: 1105
Re: Ligand use -ate
you use the suffix -ate when the entire ligand has a negative charge (is an anion).
- Sat Dec 05, 2020 12:26 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Angular/Bent Shape
- Replies: 3
- Views: 178
Re: Angular/Bent Shape
Bent/Angular are names that describe the same shape of a molecule. A molecule with a bent/angular shape when the VSEPR formula is AX2E (2 atoms and 1 lone pair) and when the VSEPR formula is AX2E2 (2 atoms and 2 lone pairs).
- Sat Dec 05, 2020 12:21 am
- Forum: Hybridization
- Topic: Hybridization of Terminal Atoms
- Replies: 3
- Views: 137
Re: Hybridization of Terminal Atoms
I think that terminal atoms can also have hybridized orbitals. Consider that the terminal atoms bonds with the central atom. If the central atom has hybridized atoms, then the atoms that it bonds with will also have hybrid orbitals.
- Sat Dec 05, 2020 12:19 am
- Forum: Lewis Structures
- Topic: Most Stable Structure
- Replies: 23
- Views: 3629
Re: Most Stable Structure
The most stable structure is one that has the fewest number of, and smallest magnitude of, formal charges and with the negative formal charges on the more electronegative atoms.
- Sat Dec 05, 2020 12:17 am
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Stability based on Resonance
- Replies: 4
- Views: 179
Re: Stability based on Resonance
The resonance structures represent how electrons are delocalized in order to achieve a lower energy and therefore better stability. The representation of resonance structures just shows that the real structure of the molecule is a resonance hybrid structure in which the delocalization of electrons o...
- Sat Dec 05, 2020 12:13 am
- Forum: Hybridization
- Topic: Unhybridized orbitals
- Replies: 3
- Views: 424
Re: Unhybridized orbitals
In the a table in the textbook, it says that a molecule with an electron arrangement that is linear, the hybridization of the central atom is sp. If it is trigonal planar, it is sp^2. If the electron arrangement is tetrahedral, it is sp^3. If the electron arrangement is trigonal bipyramidal, it is s...
- Sun Nov 29, 2020 8:54 pm
- Forum: Hybridization
- Topic: How to find the hybridization
- Replies: 14
- Views: 764
How to find the hybridization
How do you figure out the number of hybrid orbitals of a molecule and the type of hybridation orbitals?
- Sun Nov 29, 2020 8:46 pm
- Forum: Electronegativity
- Topic: Does electronegativity cancel?
- Replies: 4
- Views: 460
Re: Does electronegativity cancel?
If a highly electronegative atom bonds with an atom that has low electronegativity, then the electrons are not shared equally and therefore the bond between the two atoms is polar. However, if polar bonds of equal polarity are evenly distributed in space, the molecule as a whole is considered nonpol...
- Sun Nov 29, 2020 8:42 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Polarity
- Replies: 16
- Views: 800
Re: Polarity
A molecule is considered polar when there is a difference in electronegativities between the atoms and when the polar bonds are NOT equally distributed in the space.
- Sun Nov 29, 2020 8:38 pm
- Forum: Coordinate Covalent Bonds
- Topic: OH
- Replies: 5
- Views: 465
Re: OH
A radical is a compound with unpaired electrons (does not fulfill octet rule). OH is a radical because it only has seven valence electrons, instead of eight.
- Sun Nov 29, 2020 8:35 pm
- Forum: Sigma & Pi Bonds
- Topic: Rotation
- Replies: 16
- Views: 949
Re: Rotation
A single bond is a sigma bond. A double bond is a sigma and a pi bond. A triple bond is a sigma and two pi bonds.
- Mon Nov 23, 2020 1:47 am
- Forum: Bronsted Acids & Bases
- Topic: Hydrogen Bonding
- Replies: 16
- Views: 1120
Re: Hydrogen Bonding
Lewis bases and Lewis acids deal with chemical reactions in which the Lewis base (in the reactant side of a reaction) donates the electrons to the Lewis acid (which is the product side of the reaction). Hydrogen bonding deals with intermolecular attractions in which a Hydrogen atom of one molecule i...
- Mon Nov 23, 2020 1:44 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Ionic Bond and Covalent Character
- Replies: 4
- Views: 350
Re: Ionic Bond and Covalent Character
Ionic bonds in general are when a nonmental bonds with a metal. Covalent bonds are when a nonmetal binds with another nonmetal, generally speaking. Ionic bonds have a covalent character in the sense that both neighboring atoms share the same electron density. Moreover, some covalent bonds have ionic...
- Mon Nov 23, 2020 1:40 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Determining Non-Polarity
- Replies: 5
- Views: 328
Re: Determining Non-Polarity
There are various factors that determine whether a molecule is polar or non-polar. One factor that should be taken into account is the shape of the molecule since shape affects polarity. Polar bonds can also be viewed as vectors. If the vectors are equal in magnitude and opposite in direction, they ...
- Mon Nov 23, 2020 1:36 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Polarizablity
- Replies: 10
- Views: 536
Re: Polarizablity
Polarizability is concerned with how easily an atom's or molecule's electrons can be distorted. Highly polarizable molecules/atoms are those in which the nuclear charges have little control over the surrounding electrons. Electrons tend to be easily distorted when the atom is large, in which the dis...
- Mon Nov 23, 2020 1:32 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Instantaneous Dipoles
- Replies: 5
- Views: 229
Re: Instantaneous Dipoles
Rod-shaped molecules have a greater surface area than spherical molecules, even though both molecules have the same chemical formula. Because of this characteristic, there are more opportunities for a rod-shaped molecule to have induced dipole-induce dipole interactions than spherical-shaped molecul...
- Sun Nov 15, 2020 7:14 pm
- Forum: Ionic & Covalent Bonds
- Topic: Dipole- Induced Dipole vs Induced Dipole - Induced Dipole
- Replies: 1
- Views: 72
Dipole- Induced Dipole vs Induced Dipole - Induced Dipole
What is the difference between Dipole-Induced Dipole versus Induced Dipole-Induced Dipole in terms of intermolecular bonding? Is one attraction stronger than the other one or are they relatively the same?
- Sun Nov 15, 2020 7:07 pm
- Forum: Bond Lengths & Energies
- Topic: Hydrogen Bonds
- Replies: 17
- Views: 901
Re: Hydrogen Bonds
An H-atom must be attracted to N, O, or F in order to call it a hydrogen bond. If an H-atom of a molecule is attracted to an H-atom of another molecule, then it is not considered an H-bond. In fact, hydrogens generally are not attracted to each other since usually H atoms are both partially positive...
- Sun Nov 15, 2020 7:04 pm
- Forum: Octet Exceptions
- Topic: Identifying Radicals
- Replies: 24
- Views: 1254
Re: Identifying Radicals
Radicals are species that have electrons with unpaired spins, which means that they are not a part of a pair. This can be seen using a lewis structure. Radicals are also highly reactive and have a fleeting existence. Radicals also do not fulfill the octet rule because they do not have enough valence...
- Sun Nov 15, 2020 7:00 pm
- Forum: Dipole Moments
- Topic: Dipole or Ion
- Replies: 4
- Views: 261
Re: Dipole or Ion
Ionic attractions are a lot stronger than Dipole attractions because Dipoles have only partial charges since they are a part of covalent bonds.
- Sun Nov 15, 2020 6:53 pm
- Forum: Resonance Structures
- Topic: Resonance
- Replies: 19
- Views: 787
Re: Resonance
The most stable resonance structure minimizes formal charges, meaning that it has the fewest number of and smallest magnitude of formal charges. And the negative formal charges are on the more electronegative atoms. Resonance structures are multiple Lewis structures that collectively represent a mol...
- Sun Nov 08, 2020 6:53 pm
- Forum: Ionic & Covalent Bonds
- Topic: Identifying Ionic and Covalent Bonds
- Replies: 10
- Views: 273
Re: Identifying Ionic and Covalent Bonds
There is a rough guideline to differentiate between what is covalent and what is ionic. In his lecture, Lavelle said to follow the guideline that if the electronegativity difference between two atoms is over 2, then the bond between the two atoms is ionic. If the electronegativity difference between...
- Sun Nov 08, 2020 6:50 pm
- Forum: Trends in The Periodic Table
- Topic: Octet Rule
- Replies: 6
- Views: 305
Re: Octet Rule
H, He, Li, and Be are exceptions to the octet rule because their electron configurations do not reach the 2p orbitals. This means that they only have the 1s and 2s orbitals and do not have the capacity to have 8 electrons in their valence shells.
- Sun Nov 08, 2020 6:47 pm
- Forum: Ionic & Covalent Bonds
- Topic: Chemical Bonds
- Replies: 12
- Views: 575
Re: Chemical Bonds
Double bonds are shorter in length than single bonds because double bonds are stronger than single bonds. Likewise, triple bonds are stronger than double bonds, which means that the length of the triple bond would be shorter.
- Sun Nov 08, 2020 6:44 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Cations and Anions
- Replies: 4
- Views: 196
Re: Cations and Anions
One way to think about why this occurs is the differences between ionization energies of groups on the left side of the periodic table versus the right side. The ionization energies increase as you go across a period, which means that it requires more energy/it is harder to remove a valence electron...
- Sun Nov 08, 2020 6:40 pm
- Forum: Electronegativity
- Topic: Electron Affinity vs. Electronegativity vs. Ionization Energy
- Replies: 4
- Views: 250
Electron Affinity vs. Electronegativity vs. Ionization Energy
Hi, can someone explain to me the difference between the electron affinity, electronegativity, and ionization energy of an element? Also, can someone explain the differences in trends on the periodic table as well?
- Sat Oct 31, 2020 12:02 pm
- Forum: SI Units, Unit Conversions
- Topic: eV to Joules (Defining these Units) Question
- Replies: 12
- Views: 1552
Re: eV to Joules (Defining these Units) Question
You are not expected to memorizes the eV to Joule conversions because it is given on the constants and equations worksheets, the conversion given on Lavelle's constants and equations paper is 1 eV = 1.674927*10^-19 J (be aware that it is the conversion for J, not kJ)
- Sat Oct 31, 2020 11:44 am
- Forum: Lewis Structures
- Topic: Octet Rule
- Replies: 12
- Views: 498
Re: Octet Rule
H, He, Li, and Be are exceptions because H and He only have 1s orbitals and Li and Be only have 1s 2s orbitals
- Sat Oct 31, 2020 11:42 am
- Forum: Lewis Structures
- Topic: Lewis Structures
- Replies: 7
- Views: 567
Re: Lewis Structures
In his lecture, Lavelle said to choose the atom with the lowest ionization energy as the central atom. Two trends of ionization energies seen on the periodic table are that the ionization energies decrease as you go down a group and increase as you go across the group. Hope that helps!
- Sat Oct 31, 2020 11:30 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Shape of Orbitals
- Replies: 8
- Views: 363
Re: Shape of Orbitals
The shapes of the orbitals are determined by Schrodinger's Equation. Schrodinger's Equation uses the idea that the electron has wave-like properties and uses the indeterminacy in momentum and position. When squaring the wavefunction, that value will give you the probability of an electron being there.
- Sat Oct 31, 2020 11:23 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Atomic and Ionic Radius
- Replies: 6
- Views: 212
Re: Atomic and Ionic Radius
Like the radius of a circle, the atomic radius is just taking the radius of an atom (the distance from the nucleus to the normal valence electrons of an atom)... in the lecture, it is explained as half the distance between centers of neighboring atoms. One trend on the periodic table is that the ato...
- Sun Oct 25, 2020 8:21 pm
- Forum: Properties of Electrons
- Topic: rydberg equation
- Replies: 8
- Views: 390
Re: rydberg equation
n1 represents the lower energy level and the n2 value represents the higher energy level.
- Sun Oct 25, 2020 7:12 pm
- Forum: Photoelectric Effect
- Topic: Frequency and energy
- Replies: 15
- Views: 573
Re: Frequency and energy
Yes, the energy of a photon is proportional to its frequency with the constant h (Planck's constant: 6.626*10^-34). As the frequency of light increases, the energy of light also increases. You can also see this positive correlation on the electromagnetic spectrum, where gamma rays have a higher freq...
- Sun Oct 25, 2020 7:04 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: When n= infinity, the energy required = 0
- Replies: 4
- Views: 657
Re: When n= infinity, the energy required = 0
Since n is in the denominator, when n is a super large value (like infinity) the fraction would be so small that it would be super close to 0. Therefore as n approaches infinity, E would also be approaching 0. As the electron gets closer to the nucleus, the energy becomes more negative. And vice ver...
- Sun Oct 25, 2020 1:50 pm
- Forum: Student Social/Study Group
- Topic: Fundamental Topics for Midterm
- Replies: 3
- Views: 220
Re: Fundamental Topics for Midterm
I think the fundamentals that will be covered are everything that was on the syllabus. The essential readings that he wants us to read are sections Fundamentals E, F, G, H, L 1-2, and M... I assume that these are the topics that he will be testing us on in the Midterm.
- Sat Oct 24, 2020 4:26 pm
- Forum: Properties of Electrons
- Topic: Electron Wave-Particle Duality
- Replies: 10
- Views: 370
Re: Electron Wave-Particle Duality
I think that light behaves as both a wave and as a particle, no matter the length of the wavelength. I think the wave-particle duality just means that there are two ways to think about how light behaves. The first way is through waves and the second is through particles. When you increase the intens...
- Sat Oct 24, 2020 4:18 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Heisenberg Uncertainty Equation Answers
- Replies: 1
- Views: 128
Re: Heisenberg Uncertainty Equation Answers
The Heisenberg Uncertainty Equation expresses complementarity. If delta p is known than delta x must be unknown. Complementarity means you never know both of the values, and if you know the precise value of one, then you cannot know the precise value of the other variable.
- Sun Oct 18, 2020 8:31 pm
- Forum: Properties of Light
- Topic: Photons
- Replies: 9
- Views: 247
Re: Photons
A photon helps explain the particle-like characteristic that light possesses. When you think of light as a particle, that particle is called a photon. A photon is a "packet of energy" according to the textbook. And to measure the energy of the photon is E=hv (energy = plank's constant mult...
- Sun Oct 18, 2020 8:26 pm
- Forum: SI Units, Unit Conversions
- Topic: studying tactics
- Replies: 8
- Views: 206
Re: studying tactics
I definitely recommend studying your notes from lectures and maybe even reading how the textbook explains concepts covered over lectures. The textbook problems will also be very helpful as Dr. Lavelle explained that he will be using some of those questions on our tests. Even when the exam is not in ...
- Sun Oct 18, 2020 8:21 pm
- Forum: Significant Figures
- Topic: sig fig
- Replies: 20
- Views: 1200
Re: sig fig
I agree with all of the other responses. I definitely recommend waiting until your final answer to round based on significant figures just to make your answer more accurate. Just keep in mind that if you do end up rounding throughout your calculations that there are different rules for rounding when...
- Sun Oct 18, 2020 8:14 pm
- Forum: Properties of Electrons
- Topic: Electron Wave-Particle Duality
- Replies: 10
- Views: 370
Re: Electron Wave-Particle Duality
Light behaves like both a wave and a particle regardless of the light's wavelength/frequency. Light acting as a particle helps explain why light with a low-frequency/long-wavelength (even with high intensity) is unable to emit an electron from the metal surface in the photoelectric effect. Under the...
- Sun Oct 18, 2020 8:05 pm
- Forum: Properties of Electrons
- Topic: The Quantum World
- Replies: 7
- Views: 179
Re: The Quantum World
The electron still gets emitted if the energy of the light matches the energy of the work function. The kinetic energy would just be zero.
- Sun Oct 18, 2020 7:58 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Equation
- Replies: 1
- Views: 47
Re: Rydberg Equation
Hi! For the Rydberg equation, n1 represents the lower energy level and n2 represents the higher energy level. Hope this was helpful
- Thu Oct 08, 2020 12:10 am
- Forum: Molarity, Solutions, Dilutions
- Topic: Molarity Calculation
- Replies: 5
- Views: 354
Re: Molarity Calculation
The question is asking for the Molarity of the solution KCl mixed with water. First, I converted 55.1 g KCl using the molar mass ratio (74.548 g/ mol). After this calculation, I got 0.739 moles of KCl. Then I converted 125 mL to 0.125 L. My final answer (after using the Molarity formula M=n/V) is 5....
- Wed Oct 07, 2020 11:56 pm
- Forum: Significant Figures
- Topic: Which number determines sig figs of the answer?
- Replies: 26
- Views: 1022
Re: Which number determines sig figs of the answer?
For addition/subtraction problems, your final answer may have no more significant figures to the right of the decimal than the LEAST number of significant figures in any decimal portion of any number in the problem. For multiplication/division, the LEAST number of significant figures in any number o...