Search found 99 matches
- Sat Mar 14, 2020 9:06 pm
- Forum: Balancing Redox Reactions
- Topic: flipping equations
- Replies: 7
- Views: 563
Re: flipping equations
This would depend on the situation given, but generally, you would want to manipulate the equations so that you end up with the standard potential of the cell being positive (the reaction is spontaneous). Use the equation E(cell)=E(electrode on right of cell diagram)-E(electrode on left of cell diag...
- Sat Mar 14, 2020 9:01 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Finding enthalpy
- Replies: 2
- Views: 273
Re: Finding enthalpy
Enthalpy can be found using the equation H=U+PV, or deltaH=deltaU+deltan(gas)RT
- Sat Mar 14, 2020 3:31 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Delta S
- Replies: 8
- Views: 693
Re: Delta S
Delta S total is the entropy of both the system and its surroundings, while delta S surroundings is just the entropy of the surroundings and not the system.
- Fri Mar 13, 2020 8:34 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Order reaction
- Replies: 4
- Views: 371
Re: Order reaction
The order of a reaction depends on the number of reactants in the reaction. For example, if a reaction has O2 with a coefficient of 2 that are reactants, then the order of the reaction is second order. If a reaction has CO2 with a coefficient of 1 and H2O with a coefficient of 1 in the reactants, th...
- Fri Mar 13, 2020 8:14 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic vs Electrolytic cells
- Replies: 6
- Views: 538
Re: Galvanic vs Electrolytic cells
An electrolytic cell converts electrical energy into chemical energy, while a galvanic cell converts chemical energy into electrical energy.
- Sun Mar 08, 2020 10:06 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Arrhenius Equation Variables
- Replies: 4
- Views: 396
Re: Arrhenius Equation Variables
In the Arrhenius equation k=Ae^-Ea/RT, A is the "pre-exponential factor" or frequency factor, the frequency of collisions and their orientation, Ea is the activation energy, T is temperature, and R is the universal gas constant.
- Sun Mar 08, 2020 9:51 pm
- Forum: General Rate Laws
- Topic: Rate Law equations
- Replies: 1
- Views: 170
Re: Rate Law equations
The rate law equations can be used to predict a rate concentration, the concentration of reactants, or the rate of a reaction.
- Sun Mar 08, 2020 9:49 pm
- Forum: First Order Reactions
- Topic: first order reaction vs second order reaction
- Replies: 2
- Views: 225
Re: first order reaction vs second order reaction
First order means that the concentration of a single reactant is raised to the first power. For a second order reaction, the concentration of 2 reactants is raised to the first power or the concentration of a single reactant is raised to the second power. The order of a reaction is determined by the...
- Sun Mar 08, 2020 9:45 pm
- Forum: Zero Order Reactions
- Topic: Concentration of Reactants in a Zero-Order Reaction
- Replies: 2
- Views: 252
Re: Concentration of Reactants in a Zero-Order Reaction
Because zero order reactions are equal to the rate constant, k. In different order reactions, the concentrations are put to the power of the reaction's order, and in the case of zero order reactions, the concentration is put to the power of 0, and anything to the power of 0 is equal to one, so the c...
- Sun Mar 08, 2020 9:43 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Collision Theory and Transition State Theory
- Replies: 2
- Views: 369
Re: Collision Theory and Transition State Theory
Collision theory states that in order for a reaction to occur, the molecules participating must collide with each other. The rate of the reaction depends on the frequency of the collisions. Transition state theory regards chemical reactions as a continuous change in the relative positions of molecul...
- Sun Mar 01, 2020 9:25 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic Cells
- Replies: 10
- Views: 541
Re: Galvanic Cells
Yes, I'm also pretty sure a galvanic cell can never have a negative E cell
- Sun Mar 01, 2020 9:21 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: first order
- Replies: 8
- Views: 612
Re: first order
First order reactions have a graph that looks linear and the slope of the graph is -k
- Sun Mar 01, 2020 9:20 pm
- Forum: Balancing Redox Reactions
- Topic: oxidizing agents
- Replies: 11
- Views: 592
Re: oxidizing agents
The oxidation agent causes another substance to be oxidized, which is why the oxidizing agent is different from what's being oxidized
- Sun Mar 01, 2020 6:34 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Electromotive force
- Replies: 2
- Views: 200
Re: Electromotive force
Electromotive force is the electrical potential generated from a system (like a galvanic cell)
- Sun Mar 01, 2020 6:22 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Diamond
- Replies: 6
- Views: 433
Re: Diamond
Diamond is kinetically stable with respect to graphite because the path for diamond becoming graphite has a larger activation energy barrier that makes the diamond less ready to transition to graphite, so diamond is kinetically stable.
- Sun Feb 23, 2020 6:41 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: F
- Replies: 7
- Views: 430
Re: F
Amount of electrical charge carried by one mole
- Sun Feb 23, 2020 6:38 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6L.5 part b)
- Replies: 2
- Views: 178
Re: 6L.5 part b)
Both of the Ce molecules are in the aqueous phase, so they both need an inert electrode.
- Sun Feb 23, 2020 6:35 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6L. 3
- Replies: 4
- Views: 307
Re: 6L. 3
The anode is always placed on the left side and the cathode is always on the right side.
- Sun Feb 23, 2020 12:51 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: What does it mean if E is negative
- Replies: 3
- Views: 636
Re: What does it mean if E is negative
If the value of E is negative, then it means that the reaction in the forward direction is not spontaneous, while the reverse reaction is spontaneous.
- Sun Feb 23, 2020 11:29 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: adding/subtracting half-redox rxns
- Replies: 4
- Views: 309
Re: adding/subtracting half-redox rxns
This is because delta H is a state function while E is not. So delta H doesn't depend on anything but the initial and final state, which is why we can use Hess's law.
- Sun Feb 16, 2020 11:37 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Signs for Gibbs Free Energy
- Replies: 11
- Views: 649
Re: Signs for Gibbs Free Energy
If Gibbs free energy is negative, then the process is spontaneous in the forward direction. If the Gibbs free energy is positive, then the process is nonspontaneous in the forward direction and spontaneous in the reverse direction.
- Sun Feb 16, 2020 11:33 pm
- Forum: Van't Hoff Equation
- Topic: Constant delta H
- Replies: 4
- Views: 286
Re: Constant delta H
Delta H remains constant in the Van't Hoff Equation, since its under the assumption that temperature changes little enough that delta H can be considered constant throughout the reaction.
- Sun Feb 16, 2020 11:24 pm
- Forum: Van't Hoff Equation
- Topic: finding K
- Replies: 1
- Views: 112
Re: finding K
You would use the equation to figure out how the value of K would change if the temp. of the reaction increased, and you are trying to find the K value given the 2 temperatures.
- Sun Feb 16, 2020 11:18 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: gibbs free energy -RTlnk
- Replies: 2
- Views: 169
Re: gibbs free energy -RTlnk
That equation is used when the system is at equilibrium.
- Sun Feb 16, 2020 11:10 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Spectator Ions
- Replies: 3
- Views: 177
Re: Spectator Ions
No, we don't include spectator ions in the equilibrium constant
- Sun Feb 09, 2020 9:42 pm
- Forum: Calculating Work of Expansion
- Topic: Ideal Gas Internal Energy
- Replies: 4
- Views: 156
Re: Ideal Gas Internal Energy
I found this in a helpful table in section 4C.3 of the textbook. It is part of a set of values that correspond to what the values of Cv,m and Cp,m would be depending on if the question asks about an atom, linear molecule, or nonlinear molecule.
- Sun Feb 09, 2020 9:38 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: Second and Third Law of Thermodynamics
- Replies: 2
- Views: 115
Re: Second and Third Law of Thermodynamics
The second law of thermodynamics states that the entropy of an isolated system increases from any spontaneous change. An example of this would be how the spontaneous cooling of hot metal in a cold environment causes an increase in entropy since the heat spreads to the surroundings. The third law of ...
- Sun Feb 09, 2020 8:53 pm
- Forum: Phase Changes & Related Calculations
- Topic: reversible
- Replies: 4
- Views: 199
Re: reversible
A irreversible process is where the system will not go back to its initial state, no matter what factors are changed.
- Sun Feb 09, 2020 8:47 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Intensive vs. Extensive
- Replies: 15
- Views: 1297
Re: Intensive vs. Extensive
Intensive properties don't depend on the quantity of matter that's being measured, while extensive properties do depend on the quantity being measured. An intensive property would be density while an extensive property would be volume.
- Wed Feb 05, 2020 12:21 am
- Forum: Phase Changes & Related Calculations
- Topic: about system and surroundings
- Replies: 8
- Views: 355
Re: about system and surroundings
The system is what we're interested in, and the surroundings are everything else around the system
- Wed Feb 05, 2020 12:19 am
- 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: Calculating W
- Replies: 3
- Views: 162
Re: Calculating W
R is the universal gas constant, which is equal to 8.314 J/mol.K
- Wed Feb 05, 2020 12:15 am
- 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: Entropy in an isolated system
- Replies: 3
- Views: 184
Re: Entropy in an isolated system
Since degeneracy is the number of ways to achieve a particular energy state and entropy is the likelihood that the system will be in a particular state, degeneracy (W) being at a maximum probably means that the number of ways to achieve a particular energy state is the highest.
- Wed Feb 05, 2020 12:12 am
- 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: Boltzmann Equation
- Replies: 2
- Views: 133
Re: Boltzmann Equation
Yes, since the equation is s=Kb(lnW), it relates degeneracy and entropy
- Tue Feb 04, 2020 9:08 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed vs isolated
- Replies: 14
- Views: 445
Re: closed vs isolated
In an isolated system, no exchange of any kind can happen between the system and the surroundings, while in a closed system, energy can be exchanged between the system and the surroundings. The examples given in class were the bomb calorimeter being a isolated system while a sealed beaker is a close...
- Sun Jan 26, 2020 7:30 pm
- Forum: Phase Changes & Related Calculations
- Topic: State Property
- Replies: 3
- Views: 111
Re: State Property
Enthalpy is a state property because its value isn't dependent on the path taken to obtain that state
- Sun Jan 26, 2020 7:07 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kp to Kc
- Replies: 11
- Views: 543
Re: Kp to Kc
Yes, because in this case water isn't in the pure liquid form.
- Sun Jan 26, 2020 6:56 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Standard enthalpy of formation of O2
- Replies: 4
- Views: 211
Re: Standard enthalpy of formation of O2
The standard enthalpy of O2 is 0 since the reaction goes from O2-->O2, the O2 is already in its most stable form
- Sun Jan 26, 2020 6:46 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Gas Constant
- Replies: 13
- Views: 521
Re: Gas Constant
0.08206 L.atm.mol.K
- Sun Jan 26, 2020 4:16 pm
- Forum: Phase Changes & Related Calculations
- Topic: State Properties
- Replies: 4
- Views: 132
Re: State Properties
A state property is a property where its value does not depend on the path taken to get to its current state. In class Lavelle explained how the properties can be added or subtracted, since the value only depends on the first state and the last state.
- Sun Jan 19, 2020 9:11 pm
- Forum: Ideal Gases
- Topic: When to use PV=nRT
- Replies: 5
- Views: 143
Re: When to use PV=nRT
Since PV=nRT can be converted into the equation P=(n/V)RT and R is a constant, we can convert from partial pressures to concentration to find K and vice versa
- Sun Jan 19, 2020 9:08 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle
- Replies: 7
- Views: 164
Re: Le Chatelier's Principle
Le Chatelier's principle explains how chemical reactions adapt to a change in physical parameters like temperature, pressure, or volume.
- Sun Jan 19, 2020 12:00 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Solids and Liquids
- Replies: 6
- Views: 244
Re: Solids and Liquids
The change in solvent concentration is insignificant, which is why pure liquids are eliminated from the equilibrium expression.
- Sun Jan 19, 2020 11:56 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Change in Temperature
- Replies: 2
- Views: 90
Re: Change in Temperature
If the reaction is endothermic, then heating higher than 25 C favors the forward reaction and creates more product. If the reaction is exothermic, then cooling to less than 25 C favors product formation, while heating will favor reactant formation.
- Sun Jan 19, 2020 11:53 am
- Forum: Ideal Gases
- Topic: R Constant
- Replies: 7
- Views: 234
Re: R Constant
R is the universal gas constant, which is 0.082 L.atm/mol.K
- Sun Jan 12, 2020 8:44 pm
- Forum: Ideal Gases
- Topic: ICE Table
- Replies: 9
- Views: 456
Re: ICE Table
Usually the products have a positive change since there are more products being created and the reactants have a negative change since reactants are being used to make products.
- Sun Jan 12, 2020 7:10 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Equilibrium Concentrations using I and K
- Replies: 3
- Views: 165
Re: Equilibrium Concentrations using I and K
To solve this, you use the ICEbox method. ICE stands for initial concentration, change in concentration, and equilibrium concentration. This method tries to create a quadratic equation where you can solve for the variable x. You would use the balanced chemical equation to represent the unknown chang...
- Sun Jan 12, 2020 7:03 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: increasing yield of NH3
- Replies: 3
- Views: 132
Re: increasing yield of NH3
Removing some of the NH3 makes the reaction form more products to reach equilibrium, so more NH3 would be produced
- Sun Jan 12, 2020 11:43 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q
- Replies: 6
- Views: 291
Re: Q
Comparing the reaction quotient to K tells us which direction of the reaction is favored. So if Q>K then the reverse reaction is favored since this means that there are more products than reactants in the nonequilibrium concentration Q. If Q<K, then the forward reaction is favored since this means t...
- Sun Jan 12, 2020 11:40 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: solids and liquids
- Replies: 3
- Views: 101
Re: solids and liquids
Solids and liquids are not included in the equilibrium constant because their concentrations stay constant throughout the entire reaction
- Sun Dec 08, 2019 10:02 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: -ido vs -o
- Replies: 5
- Views: 595
Re: -ido vs -o
-ido and -o are a part of different naming guidelines, but Lavelle said it was fine to use either
- Sun Dec 08, 2019 9:59 pm
- Forum: Lewis Acids & Bases
- Topic: Lewis Acids.
- Replies: 4
- Views: 1398
Re: Lewis Acids.
Lewis acids are able to accept electrons, so they are normally electron deficient molecules
- Sun Dec 08, 2019 9:58 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: 9
- Views: 899
Re: boiling point
When something has stronger intermolecular forces, the boiling point is generally higher. For example, if a molecule has H-bonds, it'll have a higher boiling point than a molecule with only London Dispersion Forces, as LDF are weaker than H-bonds.
- Sun Dec 08, 2019 9:56 pm
- Forum: Biological Examples
- Topic: Cisplatin [ENDORSED]
- Replies: 19
- Views: 1252
Re: Cisplatin [ENDORSED]
Cisplatin is able to attach to DNA and stop cell division, which is why it is used in treating cancer
- Sun Dec 08, 2019 9:54 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: pka and ka
- Replies: 4
- Views: 410
Re: pka and ka
Both pKa and Ka are used for determining how acidic a molecule is
- Sun Dec 01, 2019 9:35 pm
- Forum: Lewis Acids & Bases
- Topic: Protons in Acids
- Replies: 6
- Views: 277
Re: Protons in Acids
Strong acids when reacting with water have a higher concentration of H3O+, and when acids are broken in water, protons (H molecules) are transferred to a water molecule to produce H3O+.
- Sun Dec 01, 2019 9:29 pm
- Forum: Lewis Acids & Bases
- Topic: Oxoacids
- Replies: 3
- Views: 256
Re: Oxoacids
An oxoacid is an acid that contains oxygen
- Sun Dec 01, 2019 9:24 pm
- Forum: Lewis Acids & Bases
- Topic: Properties of Bases
- Replies: 3
- Views: 227
Re: Properties of Bases
I googled this and found that bases feel soapy when we touch them because our skin has fatty acids, and the bases react with these fatty acids to actually create some soap on our skin, leading to the soapy feeling.
- Sun Dec 01, 2019 9:21 pm
- Forum: *Molecular Orbital Theory Applied To Transition Metals
- Topic: Transition metals
- Replies: 11
- Views: 1026
Re: Transition metals
Transition metals are in the d-block, groups 3-12. Examples of transition metals are copper and chromium
- Sun Dec 01, 2019 9:04 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: D-block
- Replies: 4
- Views: 373
Re: D-block
The transition metals in the d-block are more electronegative than the metals in other groups.
- Sun Nov 24, 2019 6:47 pm
- Forum: Hybridization
- Topic: Hybrid Orbitals
- Replies: 2
- Views: 131
Re: Hybrid Orbitals
You count the numbers of bonds and lone pairs (regions of electron density) around the atom and then match this number to the matching hybridization. Sp has 2 regions of electron density, sp2 has 3 regions of electron density, sp4 has 4 regions of electron density, etc.
- Sun Nov 24, 2019 6:38 pm
- Forum: Hybridization
- Topic: How to Determine Hybridization
- Replies: 2
- Views: 315
Re: How to Determine Hybridization
Usually if a central atom is surrounded by more than one outer atom, then it has to hybridize.
- Sun Nov 24, 2019 6:29 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordinate Covalent Bonds
- Replies: 1
- Views: 49
Re: Coordinate Covalent Bonds
A coordinate covalent bond is a bond where both electrons come from only one of the atoms in the bond. An example of this would be BF4-
- Sun Nov 24, 2019 5:59 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polarity
- Replies: 5
- Views: 312
Re: Polarity
In terms of making actual calculations, a bond is considered polar if the difference in electronegativity of the atoms in a bond is larger than 0.4. If the difference is less than 0.4 than the bond is nonpolar.
- Sun Nov 24, 2019 5:34 pm
- Forum: Bronsted Acids & Bases
- Topic: Weak vs Strong Acids
- Replies: 3
- Views: 253
Re: Weak vs Strong Acids
Most acids are weak, but an acid that fully dissolves into ions is a strong acid while an acid that doesn't fully dissolve into ions is a weak acid.
- Sun Nov 17, 2019 2:49 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: 251
Re: Hydrogen Bonding
Hydrogen bonding occurs when a H is bonded to a small atom that's very electronegative, like N, O, or F. So NH3 can form hydrogen bonds
- Sat Nov 16, 2019 9:12 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Ions
- Replies: 3
- Views: 319
Re: Ions
Ions are different from regular atoms because they are charged, either from taking away an electron or adding one. Their electron configuration differs because it will have a greater or smaller number of electrons in the configuration, depending on if the atom becomes a cation or anion
- Sat Nov 16, 2019 9:03 pm
- Forum: Bond Lengths & Energies
- Topic: Lone pairs
- Replies: 7
- Views: 606
Re: Lone pairs
Lone pairs occupy more space around the central atom than bonding pairs and lone pairs are also more impacted by electrostatic repulsion between like charges
- Sat Nov 16, 2019 8:51 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: What is VSPER
- Replies: 14
- Views: 950
Re: What is VSPER
VSEPR assumes that each molecule in an atom will have a shape that minimizes the repulsion between valence electrons. This model helps us determine the shape of molecules and their bond angles.
- Sat Nov 16, 2019 3:53 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: Bond Strengths in order?
- Replies: 2
- Views: 126
Re: Bond Strengths in order?
Hydrogen bonding is the strongest, followed by ion-dipole interactions, then dipole-dipole interactions, and then London forces
- Sun Nov 10, 2019 7:37 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: molar mass and attractive interactions
- Replies: 3
- Views: 141
Re: molar mass and attractive interactions
When molecules are larger and have a higher molar mass, then they have more electrons, which means that they have more attractive interactions.
- Sun Nov 10, 2019 7:30 pm
- Forum: Dipole Moments
- Topic: Dipole moment units
- Replies: 4
- Views: 229
Re: Dipole moment units
The calculation for the dipole moment actually tells you the measurement for the separation of two opposite charges of molecules.
- Sun Nov 10, 2019 7:11 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: interactions
- Replies: 2
- Views: 97
Re: interactions
The dipole dipole interaction happens between a fully charged ion and a partially charged dipole. The induced dipole interaction happens between a fully charged ion and a temporarily charged dipole.
- Sat Nov 09, 2019 7:50 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: Ion-Dipole Forces
- Replies: 4
- Views: 213
Re: Ion-Dipole Forces
Ion-dipole forces result from attraction between a neutral molecule with a dipole and an ion. These forces become stronger as the charge on the ion increases.
- Sat Nov 09, 2019 7:44 pm
- Forum: Electronegativity
- Topic: Differences
- Replies: 3
- Views: 258
Re: Differences
Ionization energy is the amount of energy needed to remove an electron from a neutral atom. Electron affinity is the change in energy from a neutron attracting an electron, that when present, causes a negative charge on the ion. Electronegativity is the ability of an atom within a molecule to attrac...
- Sun Nov 03, 2019 10:53 pm
- Forum: *Shrodinger Equation
- Topic: Schrodinger relationships
- Replies: 4
- Views: 295
Re: Schrodinger relationships
Schrodinger's equation uses a wave function to describe the electrons in an atom since electrons have wavelike properties.
- Sun Nov 03, 2019 10:04 pm
- Forum: Properties of Light
- Topic: Solving for energy of a photon
- Replies: 3
- Views: 186
Re: Solving for energy of a photon
That should be correct since the Bohr frequency condition says that hv=E upper-E lower
- Sun Nov 03, 2019 1:26 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Bohr Frequency Condition
- Replies: 1
- Views: 116
Re: Bohr Frequency Condition
Bohr's frequency condition is that hv=energy of the upper state-energy of the lower state. So Planck's constant (6.626x10^-34) multiplied by velocity is equal to the difference in energy between the upper energy state and the lower energy state
- Sun Nov 03, 2019 1:21 pm
- Forum: Dipole Moments
- Topic: Hydrogen Bond
- Replies: 7
- Views: 391
Re: Hydrogen Bond
Hydrogen bonding is a type of dipole-dipole interaction. The hydrogen bonds are more commonly found in water molecules and are usually stronger.
- Sun Nov 03, 2019 1:18 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 1D.23
- Replies: 1
- Views: 101
1D.23
The question asks, how many orbitals can have the following quantum numbers in an atom? a) n=3, l=1, b) n=5, l=3, ml=-1, c) n=2, l=1, ml=0, d) n=7. I'm not sure how to find these answers, could someone please explain? Thank you!
- Sun Oct 27, 2019 5:55 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: 1B.25
- Replies: 4
- Views: 286
1B.25
I don't get how to solve this problem. It states that, "What is the minimum uncertainty in the speed of an electron confined within a lead atom of diameter 350. pm? Model the atom as a one dimensional box with a length equal to the diameter of the actual atom". Thank you
- Sun Oct 27, 2019 5:15 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge Vs. Oxidation Number
- Replies: 4
- Views: 260
Re: Formal Charge Vs. Oxidation Number
Oxidation numbers are found by assigning the electrons in the covalent bond to the more electronegative atom in the bond. The formal charge is different because the number isn't determined by which atom is more electronegative.
- Sun Oct 27, 2019 3:48 pm
- Forum: Resonance Structures
- Topic: Resonance hybrids
- Replies: 3
- Views: 93
Re: Resonance hybrids
A resonance hybrid is a molecule that has resonance and its structure is represented by a combination/average of multiple structural formulas. The formulas are separated from each other by arrows.
- Sun Oct 27, 2019 2:39 pm
- Forum: Trends in The Periodic Table
- Topic: Cations
- Replies: 8
- Views: 341
Re: Cations
Cations are smaller than their parent atoms because they are formed by a loss of electrons from the parent atom, while their nuclear charge stays the same. This makes the electrons stay closer to the nucleus, and therefore make the cation smaller than the parent atom.
- Sun Oct 27, 2019 1:05 pm
- Forum: Lewis Structures
- Topic: Resonance
- Replies: 1
- Views: 73
Re: Resonance
Molecules that have resonance are known to be more stable since the double bonds can be placed in more different positions. So a molecule that can form 2 different structures is less stable than a molecule that can form 4 different structures, but is more stable than a molecule that doesn't have res...
- Sun Oct 20, 2019 3:36 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: h bar
- Replies: 3
- Views: 289
Re: h bar
h bar is also good for calculations that have precise measurements dealing with subatomic particles
- Sun Oct 20, 2019 3:31 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: 1D. 25
- Replies: 4
- Views: 175
Re: 1D. 25
Option a, 2d, does not exist because d orbitals don't exist until the third energy level. 4d can exist because this indicates 5th row transition metals in the periodic table. 4g does not exist because g orbitals only exist in energy levels 5 or greater. 6f can exist because it is in the lanthanoids/...
- Sun Oct 20, 2019 12:43 pm
- Forum: Properties of Light
- Topic: Baler v. Lyman Series
- Replies: 10
- Views: 510
Re: Baler v. Lyman Series
The Lyman series is the ultraviolet region of light while the Balmer series is the visible region of light. The Lyman series drops to n=1 while the Balmer series drops to n=2
- Sun Oct 20, 2019 12:35 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: complementarity in the uncertainty principle
- Replies: 1
- Views: 111
complementarity in the uncertainty principle
Hi, I was reading the textbook and it says that complementarity if the impossibility of knowing the precise position of a particle even if the linear momentum is known since momentum and location can't be known at the same time. I'm still a bit confused on why momentum and location can't be known at...
- Sun Oct 20, 2019 11:40 am
- Forum: Properties of Light
- Topic: Question 1A.15
- Replies: 5
- Views: 226
Question 1A.15
Hi, could someone explain how to do question 1A.15 to me? The question says, in the ultraviolet spectrum of atomic hydrogen, a line is observed at 102.6 nm. Determine the values of n for the initial and final energy levels of the electron during the emission of energy that leads to this spectral lin...
- Sun Oct 13, 2019 2:10 pm
- Forum: Properties of Light
- Topic: speed of light
- Replies: 10
- Views: 294
Re: speed of light
No the speed of does not remain constant, a case where it changes is when it goes through multiple different mediums.
- Sun Oct 13, 2019 2:09 pm
- Forum: Properties of Light
- Topic: frequency of light
- Replies: 2
- Views: 130
frequency of light
Why does the frequency of light remain constant when the light travels through different mediums even if the wavelength and speed change?
- Sun Oct 13, 2019 1:44 pm
- Forum: Properties of Light
- Topic: wavelike properties
- Replies: 4
- Views: 228
wavelike properties
In my lecture notes, I had written a lot about particles having "wavelike properties" and "measurable wavelike properties" and how a particle must have wavelike properties to work in DeBroglie's wave equation. Can someone expain exactly what these "wavelike properties" ...
- Sun Oct 13, 2019 12:24 pm
- Forum: Properties of Light
- Topic: Problem 1A.9
- Replies: 2
- Views: 162
Problem 1A.9
Problem 1A.9 gives a situation where throughout the day, a student does 4 different activities involving radiation from different parts of the electromagnetic spectrum (reading, getting a dental x-ray, microwaving popcorn, and getting a tan). Then it asks you to complete a table with frequency, wave...
- Sat Oct 12, 2019 1:23 pm
- Forum: Photoelectric Effect
- Topic: What is high light frequency?
- Replies: 3
- Views: 101
Re: What is high light frequency?
Since each photon interacts with an electron (1 photon interacts with 1 electron), the frequency is considered high enough when the energy per photon is greater than or equal to the energy needed to remove an electron. The energy needed to remove an electron usually depends on the situation in the p...
- Sun Oct 06, 2019 12:49 pm
- Forum: Administrative Questions and Class Announcements
- Topic: powers of 10 in answers
- Replies: 2
- Views: 105
powers of 10 in answers
Hi, on tests will we lose points in our answer if we don't use the "multiple powers of 10" in our calculations and answers? (like how an answer could be written as 0.002 or 2 x 10^-3). Thank you!
- Sun Oct 06, 2019 2:19 am
- Forum: SI Units, Unit Conversions
- Topic: Negative and Non-Negative powers
- Replies: 2
- Views: 181
Re: Negative and Non-Negative powers
Positive powers will indicate that the number is larger/higher while negative powers usually indicate that the number is smaller/lower. For example something that is 10^4 would equal 10,000 while something that is 10^-4 would equal 0.0001.
- Sun Oct 06, 2019 2:14 am
- Forum: Limiting Reactant Calculations
- Topic: % yield
- Replies: 5
- Views: 248
Re: % yield
I think you can never get an exact actual yield just using a theoretical yield since an actual yield is what comes from the lab and generally will vary depending on who does the experiment and the outside conditions.
- Fri Oct 04, 2019 10:53 am
- Forum: SI Units, Unit Conversions
- Topic: What is a t
- Replies: 2
- Views: 169
Re: What is a t
t probably means ton. The conversion would be 1 ton=1,000,000 grams. Hope this is helpful!
- Thu Oct 03, 2019 7:42 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: E15
- Replies: 3
- Views: 934
E15
Question E15 says that the molar mass of metal hydroxide M(OH)2 is 74 g.mol^-1 and then asks for the molar mass of the chloride of this metal. I did not see any chloride in the molecular formula so then I checked the answer key and they solved for the molar mass of another different substance, calci...