Search found 99 matches

by Kimberly Koo 2I
Sat Mar 14, 2020 9:06 pm
Forum: Balancing Redox Reactions
Topic: flipping equations
Replies: 7
Views: 125

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...
by Kimberly Koo 2I
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: 77

Re: Finding enthalpy

Enthalpy can be found using the equation H=U+PV, or deltaH=deltaU+deltan(gas)RT
by Kimberly Koo 2I
Sat Mar 14, 2020 3:31 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Delta S
Replies: 8
Views: 122

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.
by Kimberly Koo 2I
Fri Mar 13, 2020 8:34 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Order reaction
Replies: 4
Views: 87

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...
by Kimberly Koo 2I
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: 75

Re: Galvanic vs Electrolytic cells

An electrolytic cell converts electrical energy into chemical energy, while a galvanic cell converts chemical energy into electrical energy.
by Kimberly Koo 2I
Sun Mar 08, 2020 10:06 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Arrhenius Equation Variables
Replies: 4
Views: 58

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.
by Kimberly Koo 2I
Sun Mar 08, 2020 9:51 pm
Forum: General Rate Laws
Topic: Rate Law equations
Replies: 1
Views: 31

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.
by Kimberly Koo 2I
Sun Mar 08, 2020 9:49 pm
Forum: First Order Reactions
Topic: first order reaction vs second order reaction
Replies: 2
Views: 17

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...
by Kimberly Koo 2I
Sun Mar 08, 2020 9:45 pm
Forum: Zero Order Reactions
Topic: Concentration of Reactants in a Zero-Order Reaction
Replies: 2
Views: 30

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...
by Kimberly Koo 2I
Sun Mar 08, 2020 9:43 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Collision Theory and Transition State Theory
Replies: 2
Views: 49

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...
by Kimberly Koo 2I
Sun Mar 01, 2020 9:25 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic Cells
Replies: 10
Views: 79

Re: Galvanic Cells

Yes, I'm also pretty sure a galvanic cell can never have a negative E cell
by Kimberly Koo 2I
Sun Mar 01, 2020 9:21 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: first order
Replies: 8
Views: 111

Re: first order

First order reactions have a graph that looks linear and the slope of the graph is -k
by Kimberly Koo 2I
Sun Mar 01, 2020 9:20 pm
Forum: Balancing Redox Reactions
Topic: oxidizing agents
Replies: 11
Views: 117

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
by Kimberly Koo 2I
Sun Mar 01, 2020 6:34 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Electromotive force
Replies: 2
Views: 24

Re: Electromotive force

Electromotive force is the electrical potential generated from a system (like a galvanic cell)
by Kimberly Koo 2I
Sun Mar 01, 2020 6:22 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Diamond
Replies: 6
Views: 110

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.
by Kimberly Koo 2I
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: 74

Re: F

Amount of electrical charge carried by one mole
by Kimberly Koo 2I
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: 33

Re: 6L.5 part b)

Both of the Ce molecules are in the aqueous phase, so they both need an inert electrode.
by Kimberly Koo 2I
Sun Feb 23, 2020 6:35 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L. 3
Replies: 4
Views: 51

Re: 6L. 3

The anode is always placed on the left side and the cathode is always on the right side.
by Kimberly Koo 2I
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: 43

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.
by Kimberly Koo 2I
Sun Feb 23, 2020 11:29 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: adding/subtracting half-redox rxns
Replies: 4
Views: 58

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.
by Kimberly Koo 2I
Sun Feb 16, 2020 11:37 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Signs for Gibbs Free Energy
Replies: 11
Views: 137

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.
by Kimberly Koo 2I
Sun Feb 16, 2020 11:33 pm
Forum: Van't Hoff Equation
Topic: Constant delta H
Replies: 4
Views: 42

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.
by Kimberly Koo 2I
Sun Feb 16, 2020 11:24 pm
Forum: Van't Hoff Equation
Topic: finding K
Replies: 1
Views: 27

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.
by Kimberly Koo 2I
Sun Feb 16, 2020 11:18 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: gibbs free energy -RTlnk
Replies: 2
Views: 29

Re: gibbs free energy -RTlnk

That equation is used when the system is at equilibrium.
by Kimberly Koo 2I
Sun Feb 16, 2020 11:10 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Spectator Ions
Replies: 3
Views: 42

Re: Spectator Ions

No, we don't include spectator ions in the equilibrium constant
by Kimberly Koo 2I
Sun Feb 09, 2020 9:42 pm
Forum: Calculating Work of Expansion
Topic: Ideal Gas Internal Energy
Replies: 4
Views: 38

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.
by Kimberly Koo 2I
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: 38

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 ...
by Kimberly Koo 2I
Sun Feb 09, 2020 8:53 pm
Forum: Phase Changes & Related Calculations
Topic: reversible
Replies: 4
Views: 53

Re: reversible

A irreversible process is where the system will not go back to its initial state, no matter what factors are changed.
by Kimberly Koo 2I
Sun Feb 09, 2020 8:47 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Intensive vs. Extensive
Replies: 15
Views: 310

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.
by Kimberly Koo 2I
Wed Feb 05, 2020 12:21 am
Forum: Phase Changes & Related Calculations
Topic: about system and surroundings
Replies: 8
Views: 75

Re: about system and surroundings

The system is what we're interested in, and the surroundings are everything else around the system
by Kimberly Koo 2I
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: 32

Re: Calculating W

R is the universal gas constant, which is equal to 8.314 J/mol.K
by Kimberly Koo 2I
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: 49

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.
by Kimberly Koo 2I
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: 30

Re: Boltzmann Equation

Yes, since the equation is s=Kb(lnW), it relates degeneracy and entropy
by Kimberly Koo 2I
Tue Feb 04, 2020 9:08 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: closed vs isolated
Replies: 14
Views: 119

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...
by Kimberly Koo 2I
Sun Jan 26, 2020 7:30 pm
Forum: Phase Changes & Related Calculations
Topic: State Property
Replies: 3
Views: 18

Re: State Property

Enthalpy is a state property because its value isn't dependent on the path taken to obtain that state
by Kimberly Koo 2I
Sun Jan 26, 2020 7:07 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kp to Kc
Replies: 11
Views: 81

Re: Kp to Kc

Yes, because in this case water isn't in the pure liquid form.
by Kimberly Koo 2I
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: 33

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
by Kimberly Koo 2I
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: 82

Re: Gas Constant

0.08206 L.atm.mol.K
by Kimberly Koo 2I
Sun Jan 26, 2020 4:16 pm
Forum: Phase Changes & Related Calculations
Topic: State Properties
Replies: 4
Views: 43

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.
by Kimberly Koo 2I
Sun Jan 19, 2020 9:11 pm
Forum: Ideal Gases
Topic: When to use PV=nRT
Replies: 5
Views: 48

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
by Kimberly Koo 2I
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: 56

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.
by Kimberly Koo 2I
Sun Jan 19, 2020 12:00 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Solids and Liquids
Replies: 6
Views: 57

Re: Solids and Liquids

The change in solvent concentration is insignificant, which is why pure liquids are eliminated from the equilibrium expression.
by Kimberly Koo 2I
Sun Jan 19, 2020 11:56 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Change in Temperature
Replies: 2
Views: 27

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.
by Kimberly Koo 2I
Sun Jan 19, 2020 11:53 am
Forum: Ideal Gases
Topic: R Constant
Replies: 7
Views: 52

Re: R Constant

R is the universal gas constant, which is 0.082 L.atm/mol.K
by Kimberly Koo 2I
Sun Jan 12, 2020 8:44 pm
Forum: Ideal Gases
Topic: ICE Table
Replies: 9
Views: 100

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.
by Kimberly Koo 2I
Sun Jan 12, 2020 7:10 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Equilibrium Concentrations using I and K
Replies: 3
Views: 35

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...
by Kimberly Koo 2I
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: 51

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
by Kimberly Koo 2I
Sun Jan 12, 2020 11:43 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q
Replies: 6
Views: 81

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...
by Kimberly Koo 2I
Sun Jan 12, 2020 11:40 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: solids and liquids
Replies: 3
Views: 25

Re: solids and liquids

Solids and liquids are not included in the equilibrium constant because their concentrations stay constant throughout the entire reaction
by Kimberly Koo 2I
Sun Dec 08, 2019 10:02 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: -ido vs -o
Replies: 5
Views: 199

Re: -ido vs -o

-ido and -o are a part of different naming guidelines, but Lavelle said it was fine to use either
by Kimberly Koo 2I
Sun Dec 08, 2019 9:59 pm
Forum: Lewis Acids & Bases
Topic: Lewis Acids.
Replies: 4
Views: 122

Re: Lewis Acids.

Lewis acids are able to accept electrons, so they are normally electron deficient molecules
by Kimberly Koo 2I
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: 336

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.
by Kimberly Koo 2I
Sun Dec 08, 2019 9:56 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 17
Views: 365

Re: Cisplatin

Cisplatin is able to attach to DNA and stop cell division, which is why it is used in treating cancer
by Kimberly Koo 2I
Sun Dec 08, 2019 9:54 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pka and ka
Replies: 4
Views: 153

Re: pka and ka

Both pKa and Ka are used for determining how acidic a molecule is
by Kimberly Koo 2I
Sun Dec 01, 2019 9:35 pm
Forum: Lewis Acids & Bases
Topic: Protons in Acids
Replies: 6
Views: 57

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+.
by Kimberly Koo 2I
Sun Dec 01, 2019 9:29 pm
Forum: Lewis Acids & Bases
Topic: Oxoacids
Replies: 3
Views: 49

Re: Oxoacids

An oxoacid is an acid that contains oxygen
by Kimberly Koo 2I
Sun Dec 01, 2019 9:24 pm
Forum: Lewis Acids & Bases
Topic: Properties of Bases
Replies: 3
Views: 38

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.
by Kimberly Koo 2I
Sun Dec 01, 2019 9:21 pm
Forum: *Molecular Orbital Theory Applied To Transition Metals
Topic: Transition metals
Replies: 4
Views: 120

Re: Transition metals

Transition metals are in the d-block, groups 3-12. Examples of transition metals are copper and chromium
by Kimberly Koo 2I
Sun Dec 01, 2019 9:04 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: D-block
Replies: 4
Views: 99

Re: D-block

The transition metals in the d-block are more electronegative than the metals in other groups.
by Kimberly Koo 2I
Sun Nov 24, 2019 6:47 pm
Forum: Hybridization
Topic: Hybrid Orbitals
Replies: 2
Views: 29

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.
by Kimberly Koo 2I
Sun Nov 24, 2019 6:38 pm
Forum: Hybridization
Topic: How to Determine Hybridization
Replies: 2
Views: 31

Re: How to Determine Hybridization

Usually if a central atom is surrounded by more than one outer atom, then it has to hybridize.
by Kimberly Koo 2I
Sun Nov 24, 2019 6:29 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordinate Covalent Bonds
Replies: 1
Views: 23

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-
by Kimberly Koo 2I
Sun Nov 24, 2019 5:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarity
Replies: 5
Views: 53

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.
by Kimberly Koo 2I
Sun Nov 24, 2019 5:34 pm
Forum: Bronsted Acids & Bases
Topic: Weak vs Strong Acids
Replies: 3
Views: 43

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.
by Kimberly Koo 2I
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: 72

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
by Kimberly Koo 2I
Sat Nov 16, 2019 9:12 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Ions
Replies: 3
Views: 143

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
by Kimberly Koo 2I
Sat Nov 16, 2019 9:03 pm
Forum: Bond Lengths & Energies
Topic: Lone pairs
Replies: 7
Views: 223

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
by Kimberly Koo 2I
Sat Nov 16, 2019 8:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: What is VSPER
Replies: 14
Views: 355

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.
by Kimberly Koo 2I
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: 34

Re: Bond Strengths in order?

Hydrogen bonding is the strongest, followed by ion-dipole interactions, then dipole-dipole interactions, and then London forces
by Kimberly Koo 2I
Sun Nov 10, 2019 7:37 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: molar mass and attractive interactions
Replies: 3
Views: 45

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.
by Kimberly Koo 2I
Sun Nov 10, 2019 7:30 pm
Forum: Dipole Moments
Topic: Dipole moment units
Replies: 4
Views: 41

Re: Dipole moment units

The calculation for the dipole moment actually tells you the measurement for the separation of two opposite charges of molecules.
by Kimberly Koo 2I
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: 50

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.
by Kimberly Koo 2I
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: 46

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.
by Kimberly Koo 2I
Sat Nov 09, 2019 7:44 pm
Forum: Electronegativity
Topic: Differences
Replies: 2
Views: 39

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...
by Kimberly Koo 2I
Sun Nov 03, 2019 10:53 pm
Forum: *Shrodinger Equation
Topic: Schrodinger relationships
Replies: 4
Views: 197

Re: Schrodinger relationships

Schrodinger's equation uses a wave function to describe the electrons in an atom since electrons have wavelike properties.
by Kimberly Koo 2I
Sun Nov 03, 2019 10:04 pm
Forum: Properties of Light
Topic: Solving for energy of a photon
Replies: 3
Views: 90

Re: Solving for energy of a photon

That should be correct since the Bohr frequency condition says that hv=E upper-E lower
by Kimberly Koo 2I
Sun Nov 03, 2019 1:26 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Bohr Frequency Condition
Replies: 1
Views: 55

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
by Kimberly Koo 2I
Sun Nov 03, 2019 1:21 pm
Forum: Dipole Moments
Topic: Hydrogen Bond
Replies: 7
Views: 154

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.
by Kimberly Koo 2I
Sun Nov 03, 2019 1:18 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 1D.23
Replies: 1
Views: 41

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!
by Kimberly Koo 2I
Sun Oct 27, 2019 5:55 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: 1B.25
Replies: 2
Views: 55

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
by Kimberly Koo 2I
Sun Oct 27, 2019 5:15 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Vs. Oxidation Number
Replies: 4
Views: 77

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.
by Kimberly Koo 2I
Sun Oct 27, 2019 3:48 pm
Forum: Resonance Structures
Topic: Resonance hybrids
Replies: 3
Views: 45

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.
by Kimberly Koo 2I
Sun Oct 27, 2019 2:39 pm
Forum: Trends in The Periodic Table
Topic: Cations
Replies: 8
Views: 119

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.
by Kimberly Koo 2I
Sun Oct 27, 2019 1:05 pm
Forum: Lewis Structures
Topic: Resonance
Replies: 1
Views: 31

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...
by Kimberly Koo 2I
Sun Oct 20, 2019 3:36 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: h bar
Replies: 3
Views: 70

Re: h bar

h bar is also good for calculations that have precise measurements dealing with subatomic particles
by Kimberly Koo 2I
Sun Oct 20, 2019 3:31 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: 1D. 25
Replies: 4
Views: 51

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/...
by Kimberly Koo 2I
Sun Oct 20, 2019 12:43 pm
Forum: Properties of Light
Topic: Baler v. Lyman Series
Replies: 10
Views: 155

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
by Kimberly Koo 2I
Sun Oct 20, 2019 12:35 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: complementarity in the uncertainty principle
Replies: 1
Views: 44

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...
by Kimberly Koo 2I
Sun Oct 20, 2019 11:40 am
Forum: Properties of Light
Topic: Question 1A.15
Replies: 5
Views: 85

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...
by Kimberly Koo 2I
Sun Oct 13, 2019 2:10 pm
Forum: Properties of Light
Topic: speed of light
Replies: 10
Views: 97

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.
by Kimberly Koo 2I
Sun Oct 13, 2019 2:09 pm
Forum: Properties of Light
Topic: frequency of light
Replies: 2
Views: 47

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?
by Kimberly Koo 2I
Sun Oct 13, 2019 1:44 pm
Forum: Properties of Light
Topic: wavelike properties
Replies: 4
Views: 78

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" ...
by Kimberly Koo 2I
Sun Oct 13, 2019 12:24 pm
Forum: Properties of Light
Topic: Problem 1A.9
Replies: 2
Views: 44

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...
by Kimberly Koo 2I
Sat Oct 12, 2019 1:23 pm
Forum: Photoelectric Effect
Topic: What is high light frequency?
Replies: 3
Views: 38

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...
by Kimberly Koo 2I
Sun Oct 06, 2019 12:49 pm
Forum: Administrative Questions and Class Announcements
Topic: powers of 10 in answers
Replies: 2
Views: 55

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!
by Kimberly Koo 2I
Sun Oct 06, 2019 2:19 am
Forum: SI Units, Unit Conversions
Topic: Negative and Non-Negative powers
Replies: 2
Views: 67

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.
by Kimberly Koo 2I
Sun Oct 06, 2019 2:14 am
Forum: Limiting Reactant Calculations
Topic: % yield
Replies: 5
Views: 80

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.
by Kimberly Koo 2I
Fri Oct 04, 2019 10:53 am
Forum: SI Units, Unit Conversions
Topic: What is a t
Replies: 2
Views: 83

Re: What is a t

t probably means ton. The conversion would be 1 ton=1,000,000 grams. Hope this is helpful!
by Kimberly Koo 2I
Thu Oct 03, 2019 7:42 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: E15
Replies: 3
Views: 113

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...

Go to advanced search