## Search found 104 matches

Sat Mar 14, 2020 9:11 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW 5.57
Replies: 3
Views: 88

### Re: HW 5.57

I see what you are saying. When it says "At equilibrium, So3 =0.245 moles ... The original number of moles of NO is set to x." is what I took as an implied ICE table where they take that input to q=equal it to the equilibrium constant to solve for the initial concentration of NO.
Sat Mar 14, 2020 9:04 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW 5.57
Replies: 3
Views: 88

### Re: HW 5.57

What formula are you referring to? I think for this problem you just use the given equilibrium and initial conditions to create an ice table which can be set equal to the equilibrium constant.
Sat Mar 14, 2020 8:59 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Activated Complex Model
Replies: 3
Views: 66

### Re: Activated Complex Model

The activation complex model shows us the activation energy (the height from the reactants line to the peak of the slope), if the reaction is endothermic (if reactants line is lower than the products line) or exothermic (if reactants line is higher than the products line), and the change in enthalpy...
Sun Mar 08, 2020 9:33 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Collision Theory and Transition State Theory
Replies: 2
Views: 51

### Collision Theory and Transition State Theory

Can someone please explain these two theories and do we need to know them mathematically?
Sun Mar 08, 2020 9:30 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Pre Equillibrium
Replies: 2
Views: 34

### Pre Equillibrium

I don't quite understand the concept of pre equilibrium; can someone expand on Lavelle's explanation: "the reaction before the rate limiting step at the equilibrium constant K"?
Sun Mar 08, 2020 3:50 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6.19
Replies: 1
Views: 30

### 6.19

How can I assume that lactic acid will be a bronsted acid that will interact with HbO2-?
Sun Mar 08, 2020 3:47 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5.35
Replies: 1
Views: 30

### 5.35

In the graph of this problem, I don't understand why A has a coefficient of 2. I understand why C has a coefficient of two (because its equilibrium concentration is double that of B), but would someone be able to explain to me why A has a coefficient of 2?
Sun Mar 01, 2020 11:17 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Direction of flow
Replies: 5
Views: 70

### Re: Direction of flow

When batteries are being "charged" you are forcing the flow of the electrons to go the non spontaneous way, towards the anode, by adding a force and leading to a higher Delta G as time proceeds. To "use" this battery, the electrons are allowed to flow the spontaneous way, towards...
Sun Mar 01, 2020 11:12 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.3
Replies: 3
Views: 30

### Re: 6L.3

The -.23 remains negative but it is subtracted, making it added to the Ecell.
Sun Mar 01, 2020 11:09 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Delta G and Electrochemistry
Replies: 2
Views: 38

### Re: Delta G and Electrochemistry

Delta G is related to electrochemistry through DeltaG(not)=-R*T*lnK, DeltaG = DeltaG(not) - R*T*lnK, and DeltaG = -nFE. All these can be combined in different ways and can be called the Nernst equation. This relates Delta G, concentration, and electrochemistry.
Sun Mar 01, 2020 7:12 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Current
Replies: 2
Views: 39

### Current

What should we know about current for test 2? I don't remember Dr. Lavelle talking about current in class, but it is mentioned in the reading. What should we know about it for test 2 and thee final ?
Tue Feb 25, 2020 7:43 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 5G.17
Replies: 2
Views: 60

### 5G.17

Can someone explain to me why the correct graph has I as the decreasing curve and why I2 is the increasing curve? I drew the same curved, but I thought I2 would be the decreasing curve and I would be the increasing curve since I2 had the higher pressure.
Sat Feb 22, 2020 11:21 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Clausius inequality
Replies: 1
Views: 87

### Clausius inequality

Can someone explain the Clausius inequality, Delta S is greater than or equal to q/T, and if I should even worry about it? I have never heard him explain it in class, but I read it in section 4I.2 and I was getting confused about it and its significance.
Sat Feb 22, 2020 10:29 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Problem 6L.3-b
Replies: 1
Views: 29

### Problem 6L.3-b

Can someone explain to me why the C(gr) and the Pt(s) are not expressed in the final balanced reaction when finding the balanced reaction of: C(gr)|H2(g)|H+(aq)|| Cl-(aq)| Cl2(g)|Pt (s) ?

Also where can the E cell of each half reaction be found?

Thank you!
Sat Feb 22, 2020 9:52 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: n in -nFE
Replies: 12
Views: 113

### n in -nFE

I know that he went over this in class, but can someone explain to me where the n comes from ? Thanks!
Mon Feb 17, 2020 8:11 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Boltzmann Formula
Replies: 11
Views: 193

### Boltzmann Formula

For the number of orientations in W in the Boltzmann equation, is it found by how many resonance structures there are ?
Sun Feb 16, 2020 10:27 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: isothermal reactions
Replies: 8
Views: 204

### Re: isothermal reactions

Internal energy is dependent on temperature; no change in temperature will lead to no change in internal energy.
Sun Feb 16, 2020 10:21 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: ΔS of Phase Changes
Replies: 5
Views: 140

### Re: ΔS of Phase Changes

We have to add all these changes in enthalpy because we cannot do q=n*C*deltaT because there is no delta T, since there us no change in temperature. We have to do the last step because this will give us the change in enthalpy at 85 degrees C. Since enthalpy is a state function, adding all these enth...
Sun Feb 16, 2020 10:10 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Types of Delta S
Replies: 3
Views: 128

### Re: Types of Delta S

Delta S total = Delta S system + Delta S surroundings.

Change in entropy can also arise from change of volume in a system.
Tue Feb 11, 2020 1:22 pm
Forum: Calculating Work of Expansion
Topic: Constant pressure in a calorimeter
Replies: 3
Views: 68

### Constant pressure in a calorimeter

Since pressure is always constant in a calorimeter, are all reactions in a calorimeter constant?
Mon Feb 10, 2020 10:54 am
Forum: Calculating Work of Expansion
Topic: Reversible and Isobaric
Replies: 4
Views: 68

### Reversible and Isobaric

Can I assume that an isobaric expansion is irreversible since the equation for irreversible expansion is Next*deltaV ?
Sun Feb 09, 2020 11:10 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy change
Replies: 3
Views: 41

### Re: Enthalpy change

When a reaction is reversed, enthalpy will become negative since enthalpy is a state function.
Sun Feb 09, 2020 11:09 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: specific heat v.s molar heat
Replies: 2
Views: 59

### Re: specific heat v.s molar heat

Molar heat capacity is heat needed to raise 1 mol of a substance by 1 kelvin. Specific heat capacity is the heat needed to raise 1 gram (or any unit mass) of a substance by 1 Kelvin.
Sun Feb 09, 2020 11:06 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Temp vs Vol
Replies: 3
Views: 50

### Re: Temp vs Vol

Equilibrium constants are dependent on the temperature of the reaction (if you have ever noticed it always says "K is ___ at ____ kelvin"). This is because heat can act as a reactant during reactions, shifting the K in a different direction.
Sun Feb 09, 2020 11:03 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Entropy calculations (rev and irrev)
Replies: 2
Views: 42

### Re: Entropy calculations (rev and irrev)

For reversible reactions there is no change in temperature therefore the nC(T2/T1) cannot be used for a reversible reaction, but I am not sure about nR(P1/P2).
Sun Feb 09, 2020 10:57 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: reversible reactions
Replies: 4
Views: 43

### Re: reversible reactions

Isobaric (no change in pressure) means it is an irreversible reaction. Work is found through W=P*deltaV or W=n*R*deltaT and q can be found from q=n*Cp*deltaT. Isothermal (no change in temperature) is reversible. DeltaU (internal energy) is equal to zero so w=-q or -w=q. Work is found from W=n*R*T*ln...
Sun Feb 09, 2020 10:50 pm
Forum: Calculating Work of Expansion
Topic: integration
Replies: 2
Views: 29

### Re: integration

We just use the derived version of the equation which is the equations with the ln in them. The integral version is still on the formula sheet though in case needed.
Sun Feb 02, 2020 11:24 pm
Forum: Calculating Work of Expansion
Topic: 4A.3 and 4A.5
Replies: 1
Views: 23

### 4A.3 and 4A.5

Can someone explain why in 4A.3, work is multiplied by a constant to convert it into joules while work in A4.5 was not converted and was just assumed to be joules ?
Sun Feb 02, 2020 6:45 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 4E.5
Replies: 1
Views: 28

### 4E.5

How do I find the composition of C6H6? Does it need to be a ring?
Sat Feb 01, 2020 2:11 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 4C.11 and 4C.13
Replies: 1
Views: 28

### 4C.11 and 4C.13

I am wondering why moles is used instead of grams when calculating the q for solid water while grams is used when calculating the q for liquid water and why the resulting number is multiplied by the constant 6.01*1^3 J/mol.
Mon Jan 27, 2020 9:33 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Work done BY vs work done ON
Replies: 9
Views: 84

### Work done BY vs work done ON

I am confused by the idea of work being done BY a system and work being done ON a system. Can someone explain this to me as well as its relation to the value (pos or neg) of work? Thanks!
Mon Jan 27, 2020 9:31 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 4B.5 and 4B.13 part a
Replies: 2
Views: 26

### 4B.5 and 4B.13 part a

In both of these problems I used w=-(Pext)(delta V) to find work but it is given in atm. In the solutions manual it is multiplied by a constant to convert it to joules. Can someone explain to me what constant should I use to convert my answer into joules? Thanks!
Sun Jan 26, 2020 11:13 pm
Forum: Calculating Work of Expansion
Topic: 4A 3
Replies: 5
Views: 94

### Re: 4A 3

That is indeed the correct equation that you are thinking of using! You need to use the dimensions (given in centimeters) to find the volume of the compression. with that you can find if the work is positive or negative and the change in internal energy.
Sun Jan 26, 2020 11:08 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Delta U
Replies: 2
Views: 21

### Re: Delta U

Delta U can also be expressed as: Delta U = work and heat.This would support the view of the first law of thermodynamics.
Sun Jan 26, 2020 10:56 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: State Functions
Replies: 4
Views: 42

### State Functions

Why is internal energy not a state function while heat and work are state functions? I thought initial energy would also be a state function since: State function = work + heat.
Sun Jan 26, 2020 12:20 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Negative Square Root solving an ICE box
Replies: 13
Views: 98

### Re: Negative Square Root solving an ICE box

When using the quadratic formula, you are supposed to get two terms from the equation. It is not just a negative square root, it is a plus or minus (+/-) meaning the square root value should be added and subtracted from the -B value, which gives you two different solutions. We always pick the soluti...
Sun Jan 26, 2020 12:12 am
Forum: Calculating Work of Expansion
Topic: Reversible Process - infinitesimal changes
Replies: 2
Views: 26

### Reversible Process - infinitesimal changes

In the section 4A.3, a reversible process is explained as a process that can be reversed by an infinitely small change in a variable. I do not understand what infinitely small variable means in this definition of reversible process.
Sun Jan 19, 2020 9:39 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Pressure & Le Chatelier's Principle
Replies: 6
Views: 53

### Re: Pressure & Le Chatelier's Principle

When pressure is increased (volume is decreased), the side with less moles is favored. When pressure is decreased (volume is increased), the side with more moles is favored. However, you need to remember that if an inert gas is used to increase pressure, it will not favor either side.
Sun Jan 19, 2020 11:11 am
Forum: Ideal Gases
Topic: inert gas
Replies: 5
Views: 34

### Re: inert gas

This is important to know for Le Chatleir. Adding any inert gas will NOT affect the the reaction.

They will also most probably explicitly say when a inert gas is being added. I hope this helps !
Sun Jan 19, 2020 11:05 am
Forum: Ideal Gases
Topic: PV=nRT
Replies: 13
Views: 141

### Re: PV=nRT

n/V is concentration, therefore this equation can also be seen as P=(concentration)RT or P/RT=(concentration). This allows us to convert from concentration to pressure or pressure to concentration in case a problem gives us some equilibrium information as pressure or some as concentration.
Sun Jan 19, 2020 11:02 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 5.29 calculating EQ concentration
Replies: 1
Views: 30

### Re: 5.29 calculating EQ concentration

Sun Jan 19, 2020 11:00 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Replies: 8
Views: 79

When we use an ICE table, we often account for the missing information as the variable of X. We are usually given the chemical equilibrium constant, so we need to solve for X. We input all the chemical equilibrium concentrations/partial pressures into the chemical equilibrium expression even though ...
Sun Jan 19, 2020 10:54 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K vs Kc
Replies: 3
Views: 27

### Re: K vs Kc

K stands for Chemical Equilibrium constant. If it is Kc, it is pertaining to the chemical equilibrium constant that is found through concentration. Kp is pertaining to the chemical equilibrium constant found through partial pressure.
Sun Jan 12, 2020 7:14 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 would create your chemical equilibrium expression with values that you can obtain from the equillibrium row of an equilibrium/I.C.E. table. ---In section 5I.3 in the book, they go into depth about equilibrium tables/I.C.E. tables; a summarized version is that in the initial row, y...
Sat Jan 11, 2020 11:04 am
Forum: Ideal Gases
Topic: Solids and liquids [ENDORSED]
Replies: 6
Views: 74

### Re: Solids and liquids[ENDORSED]

This is because the molar concentration of a pure substance (solid or liquid) does not change in a reaction. Dr. Lavelle also said that there is no such thing as a concentration of a pure solid or a liquid, therefore it is not included in the K expression.
Thu Jan 09, 2020 7:31 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Composite Equations
Replies: 2
Views: 33

### Re: 5H.3

If you go to page 411 5H.2 Composite Equations, it explains how the combined/composite K values must be multiplied. This section does not explain why it is multiplied, but it does give a good explanation of how calculating composite K is done. I hope this helps!
Thu Jan 09, 2020 7:15 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: How to calculate Q if not given concentrations
Replies: 3
Views: 34

### Re: How to calculate Q if not given concentrations

Do you have an example of a problem where this is the case?
Thu Jan 09, 2020 7:13 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Ratios of Pressure
Replies: 2
Views: 27

### Re: Ratios of Pressure

The stoichiometric coefficients must be taken into account as exponents when calculating K. If stoichiometric coefficients are taken into account, the K will be the same even if the concentration is changed.
Sat Dec 07, 2019 8:03 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: dien
Replies: 3
Views: 65

### Re: dien

Just to let you know, I saw Lavelle post here that we will only observe sulfato, carbonato, nitro/nitrito as monodentates for this course. I hope this helps.
Sat Dec 07, 2019 7:49 pm
Forum: Polyprotic Acids & Bases
Topic: HW 6C.17 Which is the stronger base?
Replies: 4
Views: 144

### Re: HW 6C.17 Which is the stronger base?

You can also look at the stability of the conjugate acid to see which one is stronger. The more stable one will be the stronger base.
Sat Dec 07, 2019 7:44 pm
Forum: Lewis Acids & Bases
Topic: acid base reactions
Replies: 2
Views: 51

### Re: acid base reactions

Pertaining to a strong acid, the first deprotonation will result in a H+ and a weaker acid. The second deprotonation will be weaker than the first.
Sat Dec 07, 2019 7:40 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: dien
Replies: 3
Views: 65

### Re: dien

Nitrate/nitrito is monodentate and Carbonato is bidentate.
Sat Dec 07, 2019 7:32 pm
Forum: Biological Examples
Topic: Hemoglobin
Replies: 4
Views: 94

### Re: Hemoglobin

The heme complex is the porphyrin ligand connected to a Fe2+. With a protein and an O2 attached Fe2+, this will become a myoglobin. Four myoglobin will create the whole hemoglobin. To help you remember it is heme complex > myoglobin > hemoglobin.
Sat Dec 07, 2019 7:23 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: H2O or OH2
Replies: 1
Views: 32

### H2O or OH2

Is there a difference between writing H2O and OH2 in the coordination compound? I know OH2 is just an indication that the O is bonding to the metal, but will the coordination compound be technically wrong if I write H2O?
Thu Dec 05, 2019 9:56 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Nitrosyl lewis structure
Replies: 1
Views: 41

### Nitrosyl lewis structure

How is the lewis structure of nitrosyl, NO, drawn to be a ligand with no charge ? I keep creating structures with a radical on N or a charge on one of them.
Wed Dec 04, 2019 7:56 am
Forum: Amphoteric Compounds
Topic: Amphoteric/acidic/basic
Replies: 5
Views: 72

### Re: Amphoteric/acidic/basic

Metalloids are on the diagonal band that Dr. Lavelle was talking about in lecture. It includes B, Si, Ge, As, Sb, Te, and Po.
Sun Dec 01, 2019 10:23 pm
Forum: Lewis Acids & Bases
Topic: Oxoacids
Replies: 3
Views: 49

### Re: Oxoacids

What is the difference between an oxoacid and a carboxyl acid?
Sun Dec 01, 2019 10:11 pm
Forum: Naming
Topic: Ligand Names
Replies: 1
Views: 37

### Re: Ligand Names

Yes we do need to know these names. Dr. Lavelle sent out an email with a chart that should help with the naming.I hope this helps !
Sun Dec 01, 2019 5:04 pm
Forum: Electronegativity
Topic: Problem 2.11 in Book
Replies: 1
Views: 100

### Problem 2.11 in Book

Would someone be able to explain to me what it means to draw a reduced product of (C6H4O2)2-? Thank you!
Sun Dec 01, 2019 4:23 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: How to tell if a ligand is polydenate?
Replies: 2
Views: 50

### Re: How to tell if a ligand is polydenate?

He mentioned that you can remember this by seeing if there is a lone pair, two spacers and another binding lone pair.
Sun Dec 01, 2019 4:21 pm
Forum: Naming
Topic: Roman numerals
Replies: 6
Views: 54

### Re: Roman numerals

The Roman numeral is the charge of the metal ion. You can find this number by finding the charge of the ligand, multiplying this charge by the number of ligands, and subtracting this number from the overall charge. for example: [Fe(CN)6]4- The overall charge is 4- and there are 6 CN. The formal char...
Sun Nov 24, 2019 11:18 pm
Forum: Bond Lengths & Energies
Topic: resonance bond length
Replies: 2
Views: 107

### Re: resonance bond length

The electron pair is shared in resonance, making it not as strong as the double bond.
Sun Nov 24, 2019 11:13 pm
Forum: Sigma & Pi Bonds
Topic: More complex practice problems
Replies: 2
Views: 103

### Re: More complex practice problems

I think just knowing the concepts of sigma and pi bonds will be sufficient for the final exam. There are not many problems you can make for sigma and pi bonds that need calculations.
Sun Nov 24, 2019 11:10 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination complexes
Replies: 3
Views: 55

### Re: Coordination complexes

Dont forget that the Lewis base is the electron pair donor!
Sat Nov 23, 2019 11:07 pm
Forum: Dipole Moments
Topic: Dipole Moment
Replies: 10
Views: 253

### Re: Dipole Moment

You can find the polarity of a molecule using the lewis structures and VSEPR models.
Sat Nov 23, 2019 11:04 pm
Forum: Bond Lengths & Energies
Topic: Boiling Points
Replies: 3
Views: 142

### Re: Boiling Points

Since NO2 has more electrons, there is a stronger LDF than in N2O which has a less electrons. I am not sure if this has to due with polarizability though. Hope this helps!
Sat Nov 23, 2019 10:52 pm
Forum: Hybridization
Topic: Sigma and Pi Bonds
Replies: 7
Views: 63

### Re: Sigma and Pi Bonds

Pi bonds interact by laying side by side whereas sigma bonds interact end to end. Sigma bonds look like a cylinder, having cylindrical symmetry around the internuclear axis while pi bonds look like two lobes on one side of the internuclear axis.
Sun Nov 17, 2019 10:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR shapes
Replies: 3
Views: 35

### Re: VSEPR shapes

There is also seesaw, bent, trigonal pyramidal, square pyramid, square planar, and t shape. I hope this helps!
Sun Nov 17, 2019 10:22 pm
Forum: Dipole Moments
Topic: Effects for boiling point
Replies: 5
Views: 65

### Re: Effects for boiling point

The strengths of the intermolecular forces are ion-ion > ion-dipole > hydrogen bonding > dipole-dipole > dipole-induced dipole > LDF/induced dipole-induced dipole
Sun Nov 17, 2019 10:16 pm
Forum: Dipole Moments
Topic: Dipole-Induced Dipole
Replies: 1
Views: 39

### Re: Dipole-Induced Dipole

dipole- induced dipole happens between a polar (HF) and a non polar (CH4) molecule. Basically the negative side of the polar molecule can have a force on a nonpolar molecule that makes one side of a usually nonpolar molecule positive (the side right next to the negative side of the polar molecule) a...
Sun Nov 17, 2019 10:09 pm
Forum: Sigma & Pi Bonds
Topic: Test 2 Sigma and Pi bonds
Replies: 5
Views: 64

### Re: Test 2 Sigma and Pi bonds

Another thing to add to that is sigma bonds are able to rotate while pi bonds cannot rotate due to the strength of the bond.
Sun Nov 17, 2019 10:08 pm
Forum: Hybridization
Topic: Normalized and Unnormalized
Replies: 1
Views: 58

### Normalized and Unnormalized

Can someone explain to me what normalized and unnormalized pertaining to hybridizations ?
Sun Nov 10, 2019 12:22 am
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Placement
Replies: 4
Views: 169

### Re: Formal Charge Placement

Usually it is put on the most electropositive atom, hence it usually being on the central atom. However, like the comment said before, it is not as important as where a spare electron is placed. Hope this helps!
Sun Nov 10, 2019 12:20 am
Forum: Bond Lengths & Energies
Topic: negative Ep
Replies: 5
Views: 83

### Re: negative Ep

Ep is always negative due to it being an attractive force; similarly gravity, is negative and an attractive force, so gravity can be seen as analogous too Ep.
Sun Nov 10, 2019 12:15 am
Forum: Bond Lengths & Energies
Topic: Shape of Molecules and bond strength
Replies: 5
Views: 56

### Re: Shape of Molecules and bond strength

The shape of the molecule can also affect the intermolecular forces like induced dipole - induced dipole because the dispersion of the negative side and the positive side of the molecule on a longer/ rod like molecule will create a stronger induced dipole - induced dipole compared to spherical molec...
Sun Nov 10, 2019 12:07 am
Forum: Resonance Structures
Topic: Resonance Structure for 2B.15
Replies: 3
Views: 64

### Re: Resonance Structure for 2B.15

Only one of the oxygens will have a double bond because the Nitrogen cannot exceed the octet rule. The formal charge of the Nitrogen and the Oxygen will just cancel out. It is better this way because Oxygen is more electronegative and this allows Nitrogen to stay within an octet. Hope this helped.
Sun Nov 10, 2019 12:00 am
Forum: Ionic & Covalent Bonds
Topic: covalent relationship to polarizability
Replies: 4
Views: 55

### Re: covalent relationship to polarizability

In other words, as the charge of an ion increases, the electrostatic attractions of the cation for the outer anion increases, creating a stronger covalent bond.
Sun Nov 03, 2019 7:57 pm
Forum: Ionic & Covalent Bonds
Topic: Carbon Bonding
Replies: 5
Views: 57

### Re: Carbon Bonding

Carbon does not typically take part in ionic bonds, so I guess you could say that carbon likes to gain electrons because it will make covalent bonds. I hope this helps!
Sun Nov 03, 2019 7:50 pm
Forum: Einstein Equation
Topic: De Broglie vs Einstein?
Replies: 2
Views: 163

### Re: De Broglie vs Einstein?

You should know how to derive De Broglie by using c = wavelength*frequency, momentum= mass*velocity, Energy=momentum*speed of light, and E=h*frequency. One of the equation s needed to derive De Broglie IS the Einstein equation. Hope this helps!
Sun Nov 03, 2019 7:45 pm
Forum: Properties of Light
Topic: Wave vs. Particle Model
Replies: 2
Views: 53

### Re: Wave vs. Particle Model

You should know that intensity pertaining to wave model is proportional to the amplitude of the wave. Contrastingly, in the particle model, intensity is proportional to the number of photons present at each instant. Another thing to remember is that in the particle model work function/threshold must...
Sun Nov 03, 2019 1:58 pm
Forum: *Shrodinger Equation
Topic: Concepts needed for midterm
Replies: 2
Views: 169

### Concepts needed for midterm

Hi! Can someone explain to me the concepts we need to know about the Schrodinger equation?
Sun Nov 03, 2019 1:55 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Atomic Orbitals in Terms of Probability
Replies: 6
Views: 191

### Atomic Orbitals in Terms of Probability

Hi! Can someone explain to me Atomic Orbitals in terms of probability? Thank you!
Sat Oct 26, 2019 10:15 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Shorthand Notation
Replies: 4
Views: 71

### Re: Shorthand Notation

I think he will ask of the whole thing from us since that is how my TA is having us practice writing the electron configurations.
Sat Oct 26, 2019 9:29 pm
Forum: Properties of Electrons
Topic: Mass of an Electron
Replies: 14
Views: 232

### Re: Mass of an Electron

It is on the formula sheet which holds many constant and equations that we will not need to memorize, but you do need to understand the uses of each and some even overlap.
Sat Oct 26, 2019 9:21 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration Shortcut
Replies: 3
Views: 66

### Re: Electron Configuration Shortcut

Don't forget about the exceptions to typical electron configuration: Chromium and Copper.
Sat Oct 26, 2019 9:15 pm
Forum: Resonance Structures
Topic: Resonance
Replies: 6
Views: 62

### Re: Resonance

Resonance does mean that a molecule is at a lower energy level because it is in a more stable form because the bonds are distributed more evenly.
Sat Oct 26, 2019 9:04 pm
Forum: Bond Lengths & Energies
Topic: Bond Lengths
Replies: 4
Views: 61

### Re: Bond Lengths

Yes, having a double bonds are shorter due to double bonds being stronger. More bonds leads to stronger energy between two atoms. Triple bonds therefore are even stronger.
Sat Oct 26, 2019 8:39 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals in relation to arrows
Replies: 10
Views: 215

### Re: Orbitals in relation to arrows

TimVintsDis3C, I think you are asking is why there are sub shells that have multiple arrows pointing up in several orbitals by itself rather than an up and a down in the same orbital. This is due to Hund's rule which claims that all electrons in a sub shell must first fill the parallel spin of the s...
Sat Oct 26, 2019 8:22 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: electron configuration
Replies: 4
Views: 82

### Re: electron configuration

Chromium and copper have this odd configuration because it is geometrically more symmetric for this atom which allows the atom to be more stable. Hope this helps!
Fri Oct 18, 2019 7:32 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: quantum number n, l, m
Replies: 13
Views: 155

### Re: quantum number n, l, m

To further add to the question, can someone explain n, l, and ml's relationship with one another? Thank you!
Fri Oct 18, 2019 7:30 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals in relation to arrows
Replies: 10
Views: 215

### Re: Orbitals in relation to arrows

To further explain why we fill in all the arrows in a parallel spin first is that the electrons must first fill in this lower energy state before having an opposite spinning electron which will be a higher energy level.
Fri Oct 18, 2019 7:28 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: electron configuration
Replies: 4
Views: 82

### Re: electron configuration

Also, don't forget that Chromium and Copper have an odd configuration; Chromium is [Ar] 3d5 4s1 and Copper is [Ar] 3d10 4s1. As you can see, the 4s1 orbital is not completely filled for both elements and some say the reasoning is that this has more symmetry. This is just a good thing to remember and...
Fri Oct 18, 2019 7:24 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: X,Y,and Z
Replies: 4
Views: 39

### Re: X,Y,and Z

Hi! This is not an answer, but I would like to add on to the question to ask for someone to explain the planes and the lobes, and how they are incorporated into the orbital notation which I am confused about. Thank you!
Fri Oct 18, 2019 7:20 pm
Forum: *Shrodinger Equation
Topic: Concepts of Schrodinger equation
Replies: 3
Views: 65

### Concepts of Schrodinger equation

Hi! I was wondering if anyone can explain to me the main concept of the Schrodinger equation because I am slightly confused about what I am supposed to know about it. Thank you!
Sat Oct 12, 2019 8:01 pm
Replies: 3
Views: 435

Intensity in respect to a wave is the amplitude of the peaks and the troughs as a wave whereas intensity in respect to a particle is the amount of photons. I hope this helps !
Sat Oct 12, 2019 7:55 pm
Forum: Einstein Equation
Topic: Cancelling out units
Replies: 2
Views: 61

### Re: Cancelling out units

A quick tip to understand how units cancel out is to just think of the units as numbers; 4/4 is 1 and meters over meters is just 1; if units do not cancel out they they look like a fraction (meters/second). Also, always put units next to numbers you are multiplying or dividing or adding or subtracti...
Sat Oct 12, 2019 7:47 pm
Forum: Photoelectric Effect
Topic: Wave-like Properties
Replies: 4
Views: 70

### Re: Wave-like Properties

Through De Broglies equation, we can see that inputting data from something on the larger scale will only have extremely small waves that are undetectable. Hope this helps!
Sat Oct 12, 2019 7:42 pm
Forum: Properties of Electrons
Topic: Electron Excitation
Replies: 6
Views: 82

### Re: Electron Excitation

Make sure to remember that an electron is not always in an excited state and always wants to return to its natural state on their original energy level.
Sat Oct 12, 2019 7:35 pm
Forum: Photoelectric Effect
Topic: Cathode ray and Photoelectric effect
Replies: 1
Views: 40

### Cathode ray and Photoelectric effect

Hi all! I am slightly confused between the Cathode ray and Photoelectric effect; I am wondering if they are in any way similar or related and if so how. Thank you!
Sat Oct 05, 2019 2:54 pm
Forum: Balancing Chemical Reactions
Topic: Combustion
Replies: 12
Views: 240

### Re: Combustion

Hi Aprice_1J, No you cannot have a combustion with any other products other than CO2 and H2O. Though combustion analysis is used to find empirical formulas, its only products are CO2 H2O. I hope this helps !