Search found 96 matches

by Erik Buetow 1F
Sat Mar 14, 2020 8:10 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Units
Replies: 3
Views: 78

Units

Will units for k values given a trial chart always be M^-2.s^-1? Or will this unit change based on the reaction order?
by Erik Buetow 1F
Sat Mar 14, 2020 8:08 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Catalysts
Replies: 4
Views: 67

Catalysts

Will a catalyst always show up first in the reactants side and then on the product side in a reaction mechanism? In other words, will we be able to tell that it is a catalyst because it is the opposite of how an intermediate works?
by Erik Buetow 1F
Sat Mar 14, 2020 8:04 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Reaction order
Replies: 4
Views: 93

Reaction order

Can the Arrhenius equation be used for any reaction order? Or does reaction order not make a difference for this equation?
by Erik Buetow 1F
Sat Mar 14, 2020 6:53 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Final Review
Replies: 2
Views: 126

Final Review

For reaction mechanisms that have an intermediate in the rate law, I don't completely understand the concept behind multiplying rates 1 and 2 to determine whether or not that mechanism adheres to the determined rate law. Can someone explain how we multiply these rates?
by Erik Buetow 1F
Sat Mar 14, 2020 6:41 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: In Class Review Question
Replies: 1
Views: 84

In Class Review Question

In Dr. Lavelle's review, there is a question where he uses gibbs free energy and subtracts Gf and gets Gr. Does this "Gr" stand for Gibbs free energy of the entire reactant side or does it mean something different?
by Erik Buetow 1F
Fri Mar 13, 2020 5:40 am
Forum: First Order Reactions
Topic: HW 7B.3 Part C
Replies: 1
Views: 37

HW 7B.3 Part C

for this question on the homework, how would we set up the equation to solve for the rate constant if the reaction goes from 2A---->B+C if we are given A(o) and that after 115 seconds we are given the concentration of B?
by Erik Buetow 1F
Sun Mar 08, 2020 5:53 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Energy Barrier
Replies: 4
Views: 48

Energy Barrier

In a graph of a reaction, does the energy barrier that we see represent the "slow step" of the reaction, showing the bottleneck effect? Or does the energy barrier not have any correlation to the slow step?
by Erik Buetow 1F
Sun Mar 08, 2020 5:50 pm
Forum: Zero Order Reactions
Topic: Concept Behind 0 Order Reactions
Replies: 1
Views: 25

Concept Behind 0 Order Reactions

Conceptually, the way it was explained in class is that reaction order corresponds to the number of particles colliding simultaneously with one another in a particular order; with this being said, I don't totally understand the concept behind a zero order reaction because that would imply that no mo...
by Erik Buetow 1F
Sun Mar 08, 2020 5:48 pm
Forum: First Order Reactions
Topic: Half Life
Replies: 8
Views: 93

Half Life

In my notes I have written down that half life depends on initial concentration for a second order reaction, but for a first order reaction, it makes no difference for initial concentration regarding half life. Why is this?
by Erik Buetow 1F
Sun Mar 08, 2020 5:44 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Reaction Profile
Replies: 2
Views: 46

Reaction Profile

Will it be important to be able to analyze graphs for test questions based on determining reaction order, or are we only plotting them for conceptual understanding to see how the axis will change for zero, first, and second order reactions?
by Erik Buetow 1F
Sun Mar 08, 2020 5:40 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Forward and Reverse Rates
Replies: 1
Views: 36

Forward and Reverse Rates

In class we mentioned that when K>>1, products are favored and a forward reaction occurs. Is there a specific threshold value of K that we use to judge whether the reaction will be forward or not?
by Erik Buetow 1F
Tue Mar 03, 2020 4:44 pm
Forum: Balancing Redox Reactions
Topic: HW 6L.9
Replies: 3
Views: 88

HW 6L.9

For this question: “write and balance the redox reaction for potassium permanganate and iron (II) chloride” how do we set up the equation? How do we know what to put on the product side? Is it just assumed that we include the solid form of these compounds?
by Erik Buetow 1F
Sun Mar 01, 2020 9:28 pm
Forum: First Order Reactions
Topic: Slope form
Replies: 2
Views: 47

Slope form

In y=mx+b, is m (slope) representative to k in a first order reaction?
by Erik Buetow 1F
Sun Mar 01, 2020 9:26 pm
Forum: Zero Order Reactions
Topic: Reaction Order Number
Replies: 3
Views: 58

Reaction Order Number

Will reaction order always be a whole number, or are decimals acceptable?
by Erik Buetow 1F
Sun Mar 01, 2020 9:25 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Initial Rates
Replies: 3
Views: 94

Initial Rates

For the reaction to determine k or n, will we always be given initial concentrations and rates? Or will we need to solve for them?
by Erik Buetow 1F
Sun Mar 01, 2020 9:22 pm
Forum: General Rate Laws
Topic: Differential Rate Law
Replies: 2
Views: 52

Differential Rate Law

why is "k" in the differential rate law (kR^n) dependent on activation energy? And what does this mean?
by Erik Buetow 1F
Sun Mar 01, 2020 9:19 pm
Forum: General Rate Laws
Topic: Rate of Reactant
Replies: 3
Views: 55

Rate of Reactant

Will the rate of reaction for reactants always decrease over time? Or is this only true for favorable reactions?
by Erik Buetow 1F
Sun Mar 01, 2020 9:17 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Stablility
Replies: 3
Views: 63

Stablility

Does a lower gibbs free energy always mean that it is "more stable"? If so, why?
by Erik Buetow 1F
Sun Feb 23, 2020 12:39 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: max work
Replies: 1
Views: 41

max work

When we talk about the "maximum amount of work", does this occur when the Voltmeter or switch does not allow the current and electrons to flow through it? If so, is this because the electrical potential difference is at its highest at this point?
by Erik Buetow 1F
Sun Feb 23, 2020 12:36 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: 54

What does it mean if E is negative

If a positive E value corresponds to a spontaneous reaction meaning that the battery is working, and if the E value is zero when the battery is at equilibrium (dead), can E ever take a negative value? If so, what would a negative E value mean in context of electrochemistry?
by Erik Buetow 1F
Sun Feb 23, 2020 12:33 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Anode and Cathode
Replies: 4
Views: 54

Anode and Cathode

If we are given a cell diagram, can we always assume that the left side will be the anode (oxidation) side, and that the right will always be the cathode (reduction) side? Or will it sometimes be switched and we will need to recognize this?
by Erik Buetow 1F
Sun Feb 23, 2020 12:31 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams [ENDORSED]
Replies: 1
Views: 40

Cell Diagrams [ENDORSED]

Are the cell diagrams mainly drawn just to help understand the concept of how the redox reaction and battery works? Or will we be required to draw these (similar to how we needed to draw lewis structures) on the tests?
by Erik Buetow 1F
Sun Feb 23, 2020 12:24 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Inert Conductor
Replies: 1
Views: 21

Inert Conductor

Will we only need to add an inert conductor such as platinum on the galvanic cell diagram if both the reduction and oxidation reactions are aqueous?
by Erik Buetow 1F
Sun Feb 16, 2020 11:45 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: ΔS
Replies: 1
Views: 90

ΔS

Will we always solve for ΔS of the system or will we do equations to solve for the surroundings as well? If so, what is an example of when we would be given information to solve for the surrounding rather than the system?
by Erik Buetow 1F
Sun Feb 16, 2020 11:41 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: G vs G knot
Replies: 15
Views: 129

G vs G knot

Is there any difference between G and G knot or do they represent the same thing?
by Erik Buetow 1F
Sun Feb 16, 2020 11:40 pm
Forum: Van't Hoff Equation
Topic: When to Use Vant Hoff
Replies: 5
Views: 94

When to Use Vant Hoff

When exactly do we use this equation? Will it be helpful in determining the K value to then use in chemical equilibrium or does this give information about K in relationship to entropy and enthalpy?
by Erik Buetow 1F
Sun Feb 16, 2020 11:37 pm
Forum: Balancing Redox Reactions
Topic: redox reaction
Replies: 10
Views: 90

Re: redox reaction

Basically, you just have to look at the balanced equation to determine the oxidation number. Based on this, you can then use the LEO and OIL RIG rules to determine whether or not the element or compound has been oxidized or reduced in the reaction.
by Erik Buetow 1F
Sun Feb 16, 2020 11:36 pm
Forum: Balancing Redox Reactions
Topic: Reduction vs. oxidation
Replies: 29
Views: 335

Re: Reduction vs. oxidation

Basically oxidation means it will lose electrons. On the other side, reduction means it gains electrons in the reaction
by Erik Buetow 1F
Tue Feb 11, 2020 3:54 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Heat Capacity for Enthalpy
Replies: 2
Views: 45

Heat Capacity for Enthalpy

In the equation delta H = n*C*delta T is the "c" heat capacity or specific heat capacity?
by Erik Buetow 1F
Sun Feb 09, 2020 8:24 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Entropy units
Replies: 7
Views: 156

Re: Entropy units

Either one is fine, I think what you need to look out for is units during the calculations, especially regarding the constants that you are using. Also be sure to pay attention to what is being asked in the question as he might specify which one he wants the answer in.
by Erik Buetow 1F
Sun Feb 09, 2020 8:19 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Enthalpy versus heat
Replies: 11
Views: 126

Re: Enthalpy versus heat

Yes, in essence that is the only difference. A general rule of thumb is that enthalpy is always heat, but heat does not always equal enthalpy. This has to do with the fact that enthalpy is heat at a constant pressure, so if it is not a constant pressure then heat will not equal enthalpy.
by Erik Buetow 1F
Sun Feb 09, 2020 8:16 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: State Function
Replies: 7
Views: 79

State Function

Are we able to use Hess's law to help determine Gibbs free energy because they are both state functions or is there a separate reason?
by Erik Buetow 1F
Sun Feb 09, 2020 8:08 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Entropy Question
Replies: 3
Views: 47

Re: Entropy Question

yes, any time there is a change in structural position there will be a change in entropy due to Boltzmann's equation, which states that a change in degeneracy will result in a change in entropy
by Erik Buetow 1F
Sun Feb 09, 2020 8:05 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Degeneracy
Replies: 5
Views: 64

Degeneracy

Is the only time that we will use the equation S=Kb*ln(W) be when we are given degeneracy? Or will it be used other times as well?
by Erik Buetow 1F
Sun Feb 02, 2020 10:47 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Constant Volume and Pressure
Replies: 7
Views: 48

Re: Constant Volume and Pressure

The volume and pressure will remain constant or stay the same through the equation. This is significant because it will allow you to use q to serve for delta H in the equations.
by Erik Buetow 1F
Sun Feb 02, 2020 10:41 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Spontaneous
Replies: 4
Views: 60

Spontaneous

When we talk about a spontaneous reaction being favorable, what exactly does that mean?
by Erik Buetow 1F
Sun Feb 02, 2020 10:39 pm
Forum: Calculating Work of Expansion
Topic: Integrals
Replies: 4
Views: 41

Integrals

Will we actually be asked on a test to use integrals to solve a problem or is it more of just understanding what is going on conceptually?
by Erik Buetow 1F
Sun Feb 02, 2020 10:38 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Irreversible vs Reversible
Replies: 1
Views: 20

Irreversible vs Reversible

What is the main difference between reversible and irreversible expansion work?
by Erik Buetow 1F
Sun Feb 02, 2020 10:36 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Delta H
Replies: 2
Views: 34

Delta H

What is the difference between delta U and delta H?
by Erik Buetow 1F
Sun Jan 26, 2020 7:32 pm
Forum: Phase Changes & Related Calculations
Topic: Delta H
Replies: 3
Views: 26

Delta H

Will the delta H values always be given to us or will we need to know how to convert to find delta H separately?
by Erik Buetow 1F
Sun Jan 26, 2020 7:29 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard Enthalpy
Replies: 3
Views: 40

Standard Enthalpy

What is the difference between standard reaction enthalpy and standard enthalpy of formation?
by Erik Buetow 1F
Sun Jan 26, 2020 7:27 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 6
Views: 46

Re: Bond Enthalpies

We won't need to draw them, however it might help to give you a better understanding of what's going on
by Erik Buetow 1F
Sun Jan 26, 2020 7:26 pm
Forum: Phase Changes & Related Calculations
Topic: State Property
Replies: 3
Views: 21

State Property

What exactly does it mean for enthalpy to be a state property?
by Erik Buetow 1F
Sun Jan 26, 2020 7:25 pm
Forum: Phase Changes & Related Calculations
Topic: Phase Changes
Replies: 2
Views: 18

Re: Phase Changes

Yes, the reverse reactions of melting, vaporization, and sublimation are all exothermic reactions
by Erik Buetow 1F
Sun Jan 19, 2020 8:19 pm
Forum: Ideal Gases
Topic: Using PV=nRT
Replies: 7
Views: 71

Using PV=nRT

Will we need to use this equation for test 1? And if so, will we only use it to find pressure or concentration for the equilibrium equation?
by Erik Buetow 1F
Sun Jan 19, 2020 8:17 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Shift Of Reaction
Replies: 4
Views: 93

Re: Shift Of Reaction

You need to establish a ratio that is the same regardless of the amount of product or reactant, so the reaction will occur in whatever direction will achieve this ratio.
by Erik Buetow 1F
Sun Jan 19, 2020 8:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K vs Q
Replies: 14
Views: 89

K vs Q

When is it appropriate to use K and when should we use Q when doing an equilibrium problem?
by Erik Buetow 1F
Sun Jan 19, 2020 8:14 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Use of buffers
Replies: 2
Views: 23

Use of buffers

What exactly is a buffer and what do we need to know about them?
by Erik Buetow 1F
Sun Jan 19, 2020 8:14 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Not including solids and liquids
Replies: 7
Views: 85

Not including solids and liquids

Are solids and liquids always negated in calculations dealing with equilibrium constants? And if so, why?
by Erik Buetow 1F
Sun Jan 12, 2020 11:15 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE
Replies: 5
Views: 77

ICE

When should we use the ice table vs when do we just use the normal equilibrium concentration? Is the ICE table only used when a reaction is not in equilibrium and we need to find information from it?
by Erik Buetow 1F
Sun Jan 12, 2020 11:13 am
Forum: Ideal Gases
Topic: PV = nRT
Replies: 16
Views: 179

Re: PV = nRT

P= pressure V=volume n= moles of substance R= gas constant T= temperature in Kelvin
by Erik Buetow 1F
Sun Jan 12, 2020 11:11 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: When is the principle helpful?
Replies: 3
Views: 39

When is the principle helpful?

When is using Le Chatelier’s principle helpful when doing these equations and what exactly does it show us?
by Erik Buetow 1F
Sun Jan 12, 2020 11:09 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids and Liquids
Replies: 6
Views: 50

Solids and Liquids

I don’t totally understand why the solids and liquids in a reaction are not used in the calculations??
by Erik Buetow 1F
Sun Jan 12, 2020 11:08 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K vs Kc
Replies: 3
Views: 37

K vs Kc

In many of the problems that we are doing it will give us a “K” value that is often very large (say 400). What is the difference between this value, K, and the equilibrium constant, Kc and how do you convert between the two?
by Erik Buetow 1F
Sun Dec 01, 2019 10:55 pm
Forum: Conjugate Acids & Bases
Topic: Acids and Bases
Replies: 10
Views: 135

Re: Acids and Bases

You would use arrows for weak reactions because they are not completely dissociated.
by Erik Buetow 1F
Sun Dec 01, 2019 10:54 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Neutralization
Replies: 7
Views: 151

Re: Neutralization

Basically it is important to know that it is a reaction between an acid and a base which will produce water and salt and will end neutral (pH 7)
by Erik Buetow 1F
Sun Dec 01, 2019 10:51 pm
Forum: Industrial Examples
Topic: Coordination compounds as Chemotherapy drugs
Replies: 7
Views: 775

Re: Coordination compounds as Chemotherapy drugs

I believe the only one of these that we need to know would be about cisplatin which we talked about in class.
by Erik Buetow 1F
Sun Dec 01, 2019 10:50 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 12
Views: 161

Re: Cisplatin

Cisplatin prohibits cell division. I think the importance of it is that it can be used as a chemotherapy treatment and also the "trans" version of this drug would not effectively treat cancer in the same way due to the arrangement of the elements.
by Erik Buetow 1F
Sun Dec 01, 2019 10:48 pm
Forum: Naming
Topic: Brackets in Chem. Formula
Replies: 5
Views: 62

Re: Brackets in Chem. Formula

Transition metal and ligands are inside of the brackets. Everything else goes on the outside
by Erik Buetow 1F
Sun Nov 17, 2019 12:35 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Formula
Replies: 7
Views: 94

Re: VSEPR Formula

Yes, lone pairs still count as regions of electron density, however the shapes will be different names with lone pairs than it would be with strictly atom-atom bonding.
by Erik Buetow 1F
Sun Nov 17, 2019 12:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent
Replies: 3
Views: 77

Re: Bent

Yes, this would still be a bent structure however, the bond angles would be greater since there is less repulsion from the one lone pair as opposed to there being two lone pairs involved.
by Erik Buetow 1F
Sun Nov 17, 2019 12:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar Molecules
Replies: 4
Views: 63

Re: Polar Molecules

That's correct if I understand the question correctly. We talked about trans-molecules and cis-molecules during class and cis isomers are polar because the charges did not cancel. However, in a trans isomer, because the atoms are placed on opposite sides of the molecules, the partial charges cancel ...
by Erik Buetow 1F
Sun Nov 17, 2019 12:29 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Hydrogen Bonding
Replies: 6
Views: 80

Re: Hydrogen Bonding

It is a special type of dipole- dipole interaction, but it is a slightly stronger bond. Hydrogen bonds are around -15kJ/mol and normal dipole dipole interactions are about -2kJ/mol
by Erik Buetow 1F
Sun Nov 17, 2019 12:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: bond angles less than <109.5
Replies: 4
Views: 65

Re: bond angles less than <109.5

If there is a lone pair, it pushes the other atoms closer together, making the bond angles slightly less than 109.5
by Erik Buetow 1F
Sun Nov 10, 2019 7:40 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Showing Work
Replies: 6
Views: 108

Re: Showing Work

Writing your work out I feel like will always help, but is not specifically necessary to get full credit when it comes to formal charge.
by Erik Buetow 1F
Sun Nov 10, 2019 7:37 pm
Forum: Lewis Structures
Topic: Does the shape that I draw the Lewis structure matter?
Replies: 14
Views: 178

Re: Does the shape that I draw the Lewis structure matter?

I don't think it matters that much yet since we have not fully addressed shape, but I think this will change in the future.
by Erik Buetow 1F
Sun Nov 10, 2019 7:36 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability
Replies: 4
Views: 91

Re: Polarizability

Polarizability increases down and left, polarizing power increases up and right. This has to do with the trends of the atoms size and likelihood of accepting electrons
by Erik Buetow 1F
Sun Nov 10, 2019 7:34 pm
Forum: Bond Lengths & Energies
Topic: Resonance Bond Lengths
Replies: 3
Views: 41

Resonance Bond Lengths

If you have a resonance structure is it correct that the bond lengths would be in between the length of a single bond vs a double bond?
by Erik Buetow 1F
Sun Nov 10, 2019 7:33 pm
Forum: Electronegativity
Topic: electronegativity values
Replies: 6
Views: 57

Re: electronegativity values

You won't need to memorize these values, they will likely be given if needed but you should know the trend of electronegativity in general.
by Erik Buetow 1F
Sun Nov 03, 2019 1:10 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Purpose
Replies: 4
Views: 98

Formal Charge Purpose

Why do we want the formal charge to be as close to zero as possible? Does that just symbolize that it is the most stable structure that the compound can have?
by Erik Buetow 1F
Sun Nov 03, 2019 1:07 pm
Forum: Dipole Moments
Topic: Dipole Moment Significance
Replies: 1
Views: 31

Dipole Moment Significance

First, what does a dipole moment actually indicate? Second, do all bonds have a dipole moment or only specific ones?
by Erik Buetow 1F
Sun Nov 03, 2019 1:04 pm
Forum: Octet Exceptions
Topic: Covalent Bond
Replies: 4
Views: 65

Re: Covalent Bond

Coordinate covalent bonds are different from normal covalent bonds because one of the atoms provides all of the shared electrons rather than both atoms contributing.
by Erik Buetow 1F
Sun Nov 03, 2019 1:02 pm
Forum: Octet Exceptions
Topic: What are radicals
Replies: 7
Views: 88

What are radicals

What exactly is a radical and what is the significance of them?
by Erik Buetow 1F
Sun Nov 03, 2019 1:01 pm
Forum: Octet Exceptions
Topic: Expanded Valence Shells
Replies: 2
Views: 46

Expanded Valence Shells

I still don't understand why some elements are able to have expanded shells when drawing lewis structures?
by Erik Buetow 1F
Fri Oct 25, 2019 9:23 am
Forum: Ionic & Covalent Bonds
Topic: Bond length
Replies: 11
Views: 120

Bond length

In the example we did in class with the nitrate ion, he mentioned that the correct orientation was actually none of the Lewis structures but more likely a mix of all 3 due to the bond length being longer than a single but shorter than a double bond. What exactly is the significance of this and what ...
by Erik Buetow 1F
Fri Oct 25, 2019 9:20 am
Forum: Ionic & Covalent Bonds
Topic: Cation
Replies: 23
Views: 489

Re: Cation

Actions lose electrons and therefore have positive charge. Anions act in the opposite way, as they gain electrons and therefore have a negative charge. This is important because it gives insight into certain trends and properties of the atoms.
by Erik Buetow 1F
Fri Oct 25, 2019 9:17 am
Forum: Ionic & Covalent Bonds
Topic: Does the Octet Rule apply to Boron?
Replies: 14
Views: 154

Re: Does the Octet Rule apply to Boron?

H, He, Li, and Be all do not apply to the octet rule. Boron also does not apply because it acts as a more stable atom with 6 electrons rather than 8.
by Erik Buetow 1F
Fri Oct 25, 2019 9:15 am
Forum: Ionic & Covalent Bonds
Topic: Isoelectronic Atoms
Replies: 6
Views: 76

Re: Isoelectronic Atoms

Yes, basically isoelectronic atoms are atoms with the same amount of electrons, however, they still maintain different sizes and properties specific to that atom.
by Erik Buetow 1F
Fri Oct 25, 2019 9:12 am
Forum: Ionic & Covalent Bonds
Topic: Ionization Energy
Replies: 4
Views: 85

Ionization Energy

Why is it that in general elements with low ionization energy tend to form actions and conduct electricity in their solid state? Does it have to do with placement in the periodic table?
by Erik Buetow 1F
Fri Oct 18, 2019 9:47 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: What does the equation actually show?
Replies: 3
Views: 43

What does the equation actually show?

Does the Heisenberg Indeterminacy Equation represent a true answer to a problem or is it rather simply showing how varied your answers could be in relation to the actual answer of what you are trying to find?
by Erik Buetow 1F
Fri Oct 18, 2019 9:43 am
Forum: Properties of Electrons
Topic: Momentum
Replies: 11
Views: 95

Re: Momentum

Momentum is defined as p=mv (mass x velocity). The main difference between momentum and velocity is that momentum takes into account the mass of the object involved, where velocity does not.
by Erik Buetow 1F
Fri Oct 18, 2019 9:39 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Wave Properties of electrons
Replies: 1
Views: 46

Wave Properties of electrons

What exactly is the significance of the fact that electrons have wave properties? I understand what it means to have wave properties, but I do not fully understand the significance of this and why it is so important.
by Erik Buetow 1F
Fri Oct 18, 2019 9:34 am
Forum: *Shrodinger Equation
Topic: Math Function
Replies: 4
Views: 58

Math Function

We talk a lot in class about how all that the Shrodinger equation and all of the orbitals are just expressions of "math functions" but I don't exactly understand what the math function is that we are talking about to derive this statement and how it relates to the orbitals.
by Erik Buetow 1F
Fri Oct 18, 2019 9:30 am
Forum: DeBroglie Equation
Topic: Photon Equation
Replies: 4
Views: 93

Photon Equation

In class I took notes and I have that for a photon, you can use the equation E=pc. Yet when I think about this, I don't understand how a photon can have momentum if it has no resting mass? Maybe I just copied it wrong, but if not could someone explain to me how this works?
by Erik Buetow 1F
Fri Oct 11, 2019 9:23 am
Forum: Photoelectric Effect
Topic: Photoelectric Effect vs Atomic Spectrum
Replies: 2
Views: 54

Photoelectric Effect vs Atomic Spectrum

When we talk in class about emission or absorption of electrons changing energy and the corresponding "n" value, is this in reference to the photoelectric effect and that experiment or is that strictly dealing with the atomic spectrum? In other words, I don't totally understand the differe...
by Erik Buetow 1F
Fri Oct 11, 2019 9:18 am
Forum: Einstein Equation
Topic: Planack's constant
Replies: 8
Views: 203

Re: Planack's constant

Planack's constant can be used to help find the energy of a photon if you are using the equation E=hv, where E is energy, h is planack's constant, and v is the frequency.
by Erik Buetow 1F
Fri Oct 11, 2019 9:13 am
Forum: Photoelectric Effect
Topic: threshold energy
Replies: 4
Views: 59

Re: threshold energy

Threshold energy is basically the minimum energy of the incoming photon needed to remove an electron from the metal surface.
by Erik Buetow 1F
Fri Oct 11, 2019 9:09 am
Forum: Properties of Electrons
Topic: Multi-Electron Systems
Replies: 4
Views: 49

Multi-Electron Systems

In class it was mentioned that you need a more sophisticated model for multi-electron systems regarding the energy levels and corresponding visuals, can anyone briefly explain why this would require a more sophisticated model?
by Erik Buetow 1F
Fri Oct 11, 2019 9:05 am
Forum: Properties of Light
Topic: Electromagnetic Spectrum
Replies: 4
Views: 71

Re: Electromagnetic Spectrum

I don't know for sure, but I feel like it would be helpful to know both the lyman series (UV) and the balmer series (visible) and their corresponding energy levels and wavelengths.
by Erik Buetow 1F
Thu Oct 03, 2019 11:01 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Molar Mass
Replies: 10
Views: 151

Re: Molar Mass

The masses of the elements can always be found on the periodic table. If you are trying to find the molar mass of an entire molecule you can add up the individual molar masses of the elements in that molecule, but do not multiply by the stoichiometric coefficient in front.
by Erik Buetow 1F
Thu Oct 03, 2019 10:56 am
Forum: Significant Figures
Topic: Determining Sig Fig's
Replies: 5
Views: 108

Determining Sig Fig's

It's been a while since I've taken chem, so just a quick reminder... how do we determine how many sig fig's to round to in any given problem?
by Erik Buetow 1F
Thu Oct 03, 2019 10:54 am
Forum: Limiting Reactant Calculations
Topic: Ratios between Limiting Reactants and Products
Replies: 3
Views: 66

Re: Ratios between Limiting Reactants and Products

Yes, just the ratio in relation to the limiting reactant and whatever product is being analyzed.
by Erik Buetow 1F
Thu Oct 03, 2019 10:52 am
Forum: Balancing Chemical Reactions
Topic: Products of combustion reactions
Replies: 7
Views: 117

Products of combustion reactions

Are CO2 and H2O always products in a combustion reaction? If so, can there be any other products also or just those two?
by Erik Buetow 1F
Thu Oct 03, 2019 10:48 am
Forum: Balancing Chemical Reactions
Topic: Unequal coefficients
Replies: 7
Views: 104

Re: Unequal coefficients

They should all be able to be balanced, just use a fraction and then multiply (usually by 2) the whole equation to get rid of the fractions and then that should balance the equation assuming everything else has already been balanced and is correct.
by Erik Buetow 1F
Thu Oct 03, 2019 10:44 am
Forum: Molarity, Solutions, Dilutions
Topic: Empirical and Molecular Formulas
Replies: 13
Views: 296

Re: Empirical and Molecular Formulas

Empirical formulas can be the same as molecular formulas, but in general, an empirical formula gives the simplified ratio of the molecules present rather than the actual formula for a given compound.
by Erik Buetow 1F
Thu Oct 03, 2019 10:19 am
Forum: SI Units, Unit Conversions
Topic: mol, g.mol and g.mol-1
Replies: 12
Views: 218

Re: mol, g.mol and g.mol-1

mol are different than g.mol and g.mol-1, but I'm not totally sure what the difference is between g.mol and g.mol-1.

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