## Search found 111 matches

Sat Mar 14, 2020 11:42 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: pre equilibrium approach
Replies: 2
Views: 38

### pre equilibrium approach

When using the pre equilibrium approach, how do we know which step we need to use to find Kc or the equilibrium constant? Is it always the first step?
Sat Mar 14, 2020 8:32 am
Forum: First Order Reactions
Topic: k versus k prime
Replies: 6
Views: 93

### k versus k prime

I dont conceptually understand the difference between k and k prime. Why does k eq equal k divided by k prime? Is it products over reactants?
Fri Mar 13, 2020 8:39 am
Forum: Phase Changes & Related Calculations
Topic: phase change
Replies: 6
Views: 126

### Re: phase change

Like the diagram in class, you can tell that there is a phase change when the heat or enthalpy is increasing, but the temperature is not increasing, or delta T is zero.
Fri Mar 13, 2020 8:37 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

A galvanic cell is essentially where chemical energy drives electrical energy, so in this case E is positive and the reaction is favored. In a electrolytic cell, E is negative, which means the reaction is not favored and an electric current must be supplied in order for it to happen. In this case, e...
Fri Mar 06, 2020 12:34 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Concentration Cells
Replies: 5
Views: 92

### Re: Concentration Cells

Since the composition of the cells is the same molecule, there would be no difference between E cathode and E anode, making the overall cell potential zero.
Fri Mar 06, 2020 12:27 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Favoring reactions
Replies: 7
Views: 108

### Re: Favoring reactions

Using the equation deltaG=-nfE(naught), if E(naught) is calculated using E(cathode)-E(anode), and E anode is bigger, this means that the total cell potential will be negative. Since negative times negative is positive, delta G is positive, which tells us that the forward reaction is not favored, but...
Fri Mar 06, 2020 12:14 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: non ideal gases
Replies: 6
Views: 98

### Re: non ideal gases

Yes, n is the amount of electrons transferred. When you add the half reactions to get the total reactions these number of electrons should cancel out
Fri Mar 06, 2020 12:13 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Finding Q
Replies: 7
Views: 121

### Re: Finding Q

Since you flip the equation for the anode when writing out the total equation for a cell, it makes sense that Q would be anode/cathode because this way the anode becomes the product.
Fri Mar 06, 2020 12:10 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Cell potential
Replies: 6
Views: 79

### Re: Cell potential

Adding water will dilute a solution, and depending on whether it is added to the anode or cathode, delta G, or work, may also go up or down.
Thu Mar 05, 2020 10:26 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Electromotive force (emf)
Replies: 9
Views: 101

### Re: Electromotive force (emf)

I think all we need to know is that EMF is the same thing as the cell potential, or the variable E, so if a problem refers to emf it is just referring to E.
Thu Mar 05, 2020 10:25 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs free energy of formation
Replies: 2
Views: 83

### Gibbs free energy of formation

I dont understand conceptually how the standard Gibbs free energy for pure substances is also zero, like delta H standard. Since the equation for Delta G is H-TdeltaS, why doesnt the TdeltaS part factor in? Why is it still zero?
Sun Mar 01, 2020 11:01 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Cell doing work
Replies: 1
Views: 70

### Cell doing work

Can someone explain the conceptual reasoning behind why a concentration cell is available to do work if the concentration of ion in the anode is lower than the concentration of ion in the cathode? Is it because then electron flow will go from anode to cathode to balance out charges?
Fri Feb 28, 2020 3:21 pm
Forum: Balancing Redox Reactions
Topic: Writing half reactions
Replies: 9
Views: 107

### Re: Writing half reactions

Yes, usually in cell diagrams you write the anode then the cathode from left to right, so to keep it consistent it makes sense to do this.
Fri Feb 28, 2020 2:40 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: diamond
Replies: 4
Views: 70

### Re: diamond

Diamond is thermodynamically unstable because the delta G to go from Diamond to graphite is negative, which means the reaction for that to happen is favorable. However, it is kinetically stable, at least at standard temperature and pressure, because the rate of the reaction would be so slow that ess...
Fri Feb 28, 2020 2:39 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: finding top of your series
Replies: 3
Views: 36

### Re: finding top of your series

Yes, the E value corresponds to the element with the highest oxidation.
Fri Feb 28, 2020 10:46 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge
Replies: 4
Views: 69

### Re: Salt Bridge

If there was no salt bridge, the reaction would stop due to overly high concentration of negative or positive ions in the anode/cathode. By balancing out these charges with the anion or cation, the salt bridge helps the reaction to proceed.
Fri Feb 28, 2020 10:44 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Why is E Standard=0 in a concentration cell?
Replies: 4
Views: 70

### Re: Why is E Standard=0 in a concentration cell?

In a concentration cell, essentially the reduction half reaction and oxidation half reaction cancel each other out because the same type of solution is used in both compartments of the cell.
Fri Feb 21, 2020 6:44 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2 Material
Replies: 16
Views: 266

### Re: Test 2 Material

The test will only cover the part of thermodynamics that we learned after the midterm (ie the rest of the Gibbs free energy equations) and the electrochemistry applications outline. Anything after that will not be tested, even if it is lectured on.
Fri Feb 21, 2020 6:37 pm
Forum: Balancing Redox Reactions
Topic: Charge of oxygen
Replies: 15
Views: 126

### Re: Charge of oxygen

Yeah, my TA also said that you can assume that the charge of Oxygen is -2. Using this known value we can use it to find the oxidation numbers of other elements.
Fri Feb 21, 2020 6:34 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: sign of Ecell
Replies: 2
Views: 24

### Re: sign of Ecell

As Dr. Lavelle explained in class today, the reaction is favorable if Ecell is positive, because that means that delta G is negative. When delta G or Gibb's free energy is negative, that means the reaction is favorable.
Fri Feb 21, 2020 6:25 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Calculating Standard Cell Potentials
Replies: 2
Views: 32

### Re: Calculating Standard Cell Potentials

Since standard cell potential is calculated using standard conditions, the stoichiometric coefficients do not affect it.
Wed Feb 12, 2020 3:29 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: pizza rolls 5c
Replies: 2
Views: 48

### pizza rolls 5c

For 5C on the pizza rolls, it is false that one cannot calculate the entropy of vaporization for water at room temp because water has a boiling point of 373K. How would you calculate entropy of vaporization without raising the temperature? I dont understand how it is false.
Wed Feb 12, 2020 11:02 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Entropy in different phases
Replies: 3
Views: 44

### Re: Entropy in different phases

Tue Feb 11, 2020 10:00 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Entropy in different phases
Replies: 3
Views: 44

### Entropy in different phases

How does entropy of a substance in aqueous phase relate to entropy in the gas, liquid, solid, etc. phase?
Tue Feb 11, 2020 9:49 pm
Forum: Calculating Work of Expansion
Topic: A system doing no work
Replies: 4
Views: 50

### A system doing no work

How do we know that a system is not doing work on the surroundings? Would the only case for this be that the system is not expanding?
Tue Feb 11, 2020 9:48 pm
Forum: Calculating Work of Expansion
Topic: Work for an isothermal reversible expansion
Replies: 3
Views: 78

### Work for an isothermal reversible expansion

For the equation for isothermal reversible expansion, w=-nrTln(V2/V1), are the final temperature, moles, pressure used always?
Tue Feb 11, 2020 11:41 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Replies: 19
Views: 292

Yes, in an adiabatic process q equals to zero because there is no transfer or heat between a system and its surroundings.
Tue Feb 11, 2020 10:15 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Cp and Cv in a not ideal gas
Replies: 1
Views: 33

### Cp and Cv in a not ideal gas

If we are given a problem that involves a substance that is not an ideal gas, Cp and/or Cv will probably be given in the problem right?
Sun Feb 09, 2020 10:32 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Calculating Bond Enthalpies
Replies: 5
Views: 68

### Re: Calculating Bond Enthalpies

Bond enthalpies should be given. The only type of problem that we would need bond enthalpy for is for calculating delta H, and subtracting the bonds formed from the bonds broken. In this case its usually helpful to draw out the structure.
Thu Feb 06, 2020 3:41 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Enthalpy versus heat
Replies: 11
Views: 114

### Enthalpy versus heat

For enthalpy and heat, the only differences between them (q and H) is that enthalpy is a state property and the heat is not, correct? When are we supposed to assume that they equal each other?
Thu Feb 06, 2020 3:04 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Adiabatic vs isothermal
Replies: 2
Views: 41

### Adiabatic vs isothermal

I'm a little confused with the difference between an adiabatic and isothermal system. For isothermal since delta T is 0 and for for adiabatic system q is 0 does it mean that all isothermal systems are adiabatic and vice versa? since q=ncdeltaT?
Wed Feb 05, 2020 2:20 pm
Forum: Calculating Work of Expansion
Topic: Kelvin vs Celsius
Replies: 5
Views: 44

### Re: Kelvin vs Celsius

Usually for thermodynamics problems Kelvin is used, but for many equations it doesn't really matter because the difference in one degree of Kelvin is the same as that of Celsius.
Wed Feb 05, 2020 2:17 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Cp and Cv
Replies: 10
Views: 77

### Re: Cp and Cv

I don't think we need to memorize them.
Fri Jan 31, 2020 9:39 pm
Forum: Ideal Gases
Topic: Temperature
Replies: 17
Views: 154

### Re: Temperature

It does not matter for the most part because the change in temperature in one degree of Celsius is the same as the change in temperature in one degree of Kelvin.
Fri Jan 31, 2020 9:39 pm
Forum: Phase Changes & Related Calculations
Topic: Phase Changes
Replies: 17
Views: 141

### Re: Phase Changes

Phase Changes occur when temperature is constant, and the temperature goes up as the entropy of the solution goes up; however it doesn't undergo a phase change at this time.
Fri Jan 31, 2020 9:32 pm
Forum: Phase Changes & Related Calculations
Topic: DELTA H Vs Q
Replies: 7
Views: 64

### Re: DELTA H Vs Q

Delta H is measured in heat, whereas Q means enthalpy. Enthalpy is a state property, whereas heat is not.
Fri Jan 31, 2020 9:17 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Equilibrium shift by pressure
Replies: 7
Views: 79

### Re: Equilibrium shift by pressure

The equilibrium constant does not change with pressure.
Fri Jan 31, 2020 9:14 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Strong/weak acids & bases
Replies: 14
Views: 209

### Re: Strong/weak acids & bases

Strong acids are usually ones that give off protons easily, such as HF or HCl. Strong bases will give off OH- easily, such as NaOH.
Fri Jan 24, 2020 3:41 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpy Accuracy
Replies: 6
Views: 33

### Re: Bond Enthalpy Accuracy

Bond enthalpies are only accurate with diatomic molecules with atoms of the same type, otherwise it is not so accurate since the enthalpy is calculated using averages.
Fri Jan 24, 2020 3:36 pm
Forum: General Science Questions
Topic: Fall 2019 final
Replies: 7
Views: 95

### Re: Fall 2019 final

I believe it was anytime this week after 11 but they should be handing them out next week too.
Thu Jan 23, 2020 5:16 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Kw = (Ka)(Kb)
Replies: 4
Views: 58

### Re: Kw = (Ka)(Kb)

Yes, you can assume that the temperature is 25 degrees and you can use the equation.
Thu Jan 23, 2020 12:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Converting from Kp to Kc
Replies: 4
Views: 50

### Re: Converting from Kp to Kc

Kp is the constant given by the partial pressures of the gases, and Kc is the equilibrium constant given by the concentrations of gases. They are both calculated the same way but will result in different numbers. I'm pretty sure that if we need to know them then the conversion constants will be give...
Thu Jan 23, 2020 10:16 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Water in K constant
Replies: 6
Views: 52

### Water in K constant

Is water included in the K constant expression if it is a gas? Is it only not included when it is a solvent?
Sat Jan 18, 2020 3:22 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q < K
Replies: 16
Views: 132

### Re: Q < K

If Q is less than K, then it means that there are more reactants than products when compared to equilibrium, so more products need to be formed.
Sat Jan 18, 2020 3:20 pm
Forum: Administrative Questions and Class Announcements
Topic: Study Guide Test One
Replies: 17
Views: 195

### Re: Study Guide Test One

Your best resources are probably the 2 Outlines as well as the Peer Learning and Step Up sessions.
Sat Jan 18, 2020 3:09 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE and quadratic formula
Replies: 11
Views: 94

### Re: ICE and quadratic formula

If the initial concentration (such as 0.1-x) is small enough, then you can "take away" the x from the bottom ONLY since it is probably a small number, but this is just to make calculations easier. Technically it's not mathematically correct but the difference if you used the quadratic form...
Sat Jan 18, 2020 3:06 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE Tables
Replies: 3
Views: 48

### Re: ICE Tables

Yes, generally an ice table is used if you know initial concentrations, and the K value. I dont think we have seen many other variations of this.
Sat Jan 18, 2020 3:03 pm
Forum: Ideal Gases
Topic: Solids and Liquids [ENDORSED]
Replies: 10
Views: 109

### Re: Solids and Liquids[ENDORSED]

Also for solids and liquids, pressure does not affect them, in other words they can't be compressed further, whereas gases can.
Sun Jan 12, 2020 6:25 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K and Q
Replies: 10
Views: 70

### Re: K and Q

If you compare Q to K, you can determine whether the reaction is going go to in the forward or reverse reaction to reach equilibrium.
Sun Jan 12, 2020 6:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: memorization
Replies: 12
Views: 126

### Re: memorization

Im not sure but I believe we might have to, since an equation sheet and periodic table is all we get.
Sun Jan 12, 2020 2:12 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J:5d
Replies: 2
Views: 36

### Re: 5J:1d

As we learned in class, change in pressure generally does not change state of equlibrium.
Sun Jan 12, 2020 2:10 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homework 5G.1 Help
Replies: 4
Views: 129

### Re: Homework 5G.1 Help

Essentially, because the reaction wants to reach equilibrium again after you add more reactant, that reactant will go through the reaction to form the product and the reaction will move forward, causing more product to form till it reaches equilibrium again.
Sun Jan 12, 2020 2:08 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc vs Kp
Replies: 10
Views: 73

### Re: Kc vs Kp

Kc and Kp eventually lead to the same conclusion, it's just that Kc uses concentration and Kp uses pressure.
Sat Dec 07, 2019 1:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: polarity of dichloromethane
Replies: 3
Views: 118

### Re: polarity of dichloromethane

Unless all four surrounding molecules are the same, all tetrahedral molecules are polar.
Sat Dec 07, 2019 12:28 pm
Forum: Lewis Acids & Bases
Topic: Problem 6.13 Textbook, boric acid
Replies: 1
Views: 43

### Problem 6.13 Textbook, boric acid

Can someone explain why boric acid is a Lewis acid and an electron pair acceptor? Also does this mean that the conjugate base of boric acid is not stable since boric acid is a weak acid?
Sat Dec 07, 2019 9:56 am
Forum: Determining Molecular Shape (VSEPR)
Topic: polarity of dichloromethane
Replies: 3
Views: 118

### Re: polarity of dichloromethane

Since the structure of this molecule is tetrahedral, it is not the same that it looks when drawn as a 2 d Lewis structure. Essentially a tetrahedral structure can be rotated in different ways that is not accurately depicted in a 2 d structure, so if the H's and Cl's were opposite each other the mole...
Sat Dec 07, 2019 9:53 am
Forum: Naming
Topic: "Cyano" vs. "Cyanido"
Replies: 1
Views: 37

### Re: "Cyano" vs. "Cyanido"

"Cyano" is the conventional way of naming whereas "cyanido" is the new IUPAC way of naming. I believe that Lavelle accepts both, but uses the conventional way in all his examples. They both mean the same thing and either one is acceptable.
Fri Dec 06, 2019 5:37 pm
Forum: Naming
Topic: cyano v. cyanido
Replies: 4
Views: 87

### Re: cyano v. cyanido

cyano and cynanido essentially mean the same thing; I believe Lavelle accepts both on his tests, but uses the cyano. For more information refer to the Coordination Compounds pdf on his Chem 14A website.
Fri Dec 06, 2019 2:04 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: polarizability
Replies: 4
Views: 154

### Re: polarizability

Molecules with just London Dispersion forces do not have polarizability, as they are nonpolar. These forces are present in all molecules, even nonpolar ones.
Fri Dec 06, 2019 11:36 am
Forum: Lewis Structures
Topic: Cl as a central atom
Replies: 5
Views: 256

### Cl as a central atom

If Cl were to be a central atom in a molecule and there four surrounding atoms, would it be wrong to have 3 double bonds and a single bond in the molecule? Since in that case the formal charge of Cl is zero and it can expand its octet, would this technically be correct or 14 electrons too much?
Fri Dec 06, 2019 11:34 am
Forum: Properties & Structures of Inorganic & Organic Bases
Topic: Identifying electron donors vs electron withdrawers (6C 21)
Replies: 1
Views: 119

### Re: Identifying electron donors vs electron withdrawers (6C 21)

Basically electronegativity determines the electron withdrawing ability of atoms in a molecule, and therefore its acidity. So for the CH3 vs CCl3 example, since Cl is more electronegative, the Cl atoms pull the e- density closer to themselves, making the H easier to detach.
Fri Dec 06, 2019 11:18 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligand Definition
Replies: 4
Views: 58

### Re: Ligand Definition

A ligand is a molecule that attaches to a metal cation to form a coordination compound. A ligand can be a mono or poly dentate, which means it "bites" to the metal in one place or in multiple places. This depends on the structure and flexibility of the ligand.
Fri Dec 06, 2019 11:17 am
Forum: Administrative Questions and Class Announcements
Topic: Curving in Chem 14A
Replies: 7
Views: 238

### Re: Curving in Chem 14A

Nothing has been curved yet, but I believe that in the past Dr. Lavelle has curved the final grades of the class.
Fri Dec 06, 2019 11:15 am
Forum: Bronsted Acids & Bases
Topic: Lewis vs Bronsted
Replies: 3
Views: 68

### Re: Lewis vs Bronsted

The general trend is that acids like to become more negative and bases like to become more positive. Therefore, an acid in the Lewis definition is an electron pair acceptor and in a Bronsted definition a proton donor, and a base in the Lewis definition is an e- pair donor and a proton acceptor in th...
Fri Dec 06, 2019 11:13 am
Forum: Biological Examples
Topic: Cisplatin H2O
Replies: 2
Views: 50

### Re: Cisplatin H2O

I think the most we will have to know about cisplatin is how to draw it and why it is used as a chemotherapy drug whereas trans platin is not.
Thu Dec 05, 2019 4:17 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: EDTA
Replies: 3
Views: 86

### Re: EDTA

Also I believe that the singly bonded oxygens and the nitrogens have electron lone pairs that can form coordinate covalent bonds with said metal, so it chelates and binds to metals.
Thu Dec 05, 2019 4:12 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Content of the final
Replies: 10
Views: 468

### Re: Content of the final

We do not need to know about bond order; it helps to refer to the outline to see what exactly in the book we covered.
Wed Dec 04, 2019 9:37 pm
Forum: Lewis Acids & Bases
Topic: HCl and HI
Replies: 10
Views: 111

### Re: HCl and HI

Is there a periodic trend in terms of this? Does this mean that HF is the weakest acid, then HCl, then HBr, then HI?
Wed Dec 04, 2019 9:36 pm
Forum: Polyprotic Acids & Bases
Topic: Ka value
Replies: 5
Views: 91

### Re: Ka value

Does Ka 3 mean Ka1 plus Ka2? Is is the overall Ka for the reaction?
Wed Dec 04, 2019 8:49 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelate
Replies: 5
Views: 95

### Re: Chelate

I thought we use bis tris etc when naming multiple of the same polydentate? or is this the same thing?
Wed Dec 04, 2019 8:47 pm
Forum: Identifying Acidic & Basic Salts
Topic: Lecture
Replies: 3
Views: 52

### Re: Lecture

Since Cl- has a octet, it will not have an affinity to other ions or water so it won't affect the pH
Wed Dec 04, 2019 8:46 pm
Forum: Naming
Topic: "Ferrate"
Replies: 14
Views: 787

### Re: "Ferrate"

I think the one other exception we would need to know is for copper; it has a latin prefix of "cupr"
Wed Dec 04, 2019 8:44 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordinate Compounds
Replies: 3
Views: 44

### Re: Coordinate Compounds

I think we also need to know how to name them, as discussed in class.
Wed Dec 04, 2019 2:45 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 6
Views: 89

### Re: Cisplatin

I think we do, because he talked about the different structures that coordination compounds can have, like tetrahedral, octahedral, square planar.
Wed Dec 04, 2019 2:41 pm
Forum: Naming
Topic: Naming for Hydrocarbons
Replies: 2
Views: 50

### Re: Naming for Hydrocarbons

I believe we also need to know what a carboxyl group looks like, as well as other structurs we learned such as benzene or ethene.
Wed Dec 04, 2019 2:41 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: coordination number
Replies: 3
Views: 39

### Re: coordination number

Coordination number is simply the number of bonds formed.
Wed Dec 04, 2019 2:39 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 6
Views: 89

### Re: Cisplatin

Why is ciplatin square planar and not tetrahedral?
Wed Dec 04, 2019 2:37 pm
Forum: Naming
Topic: Naming Acids/ Bases
Replies: 4
Views: 75

### Re: Naming Acids/ Bases

I believe the -ic vs -ous depends on the composition of the anion. For nitric acid it is produced when a H+ bonds to the nitrate anion, and for nitrous acid it is produced when an H+ bonds to a nitrite anion. In general, an "ate" anion corresponds to an "ic" acid, and an "it...
Sun Dec 01, 2019 9:33 pm
Forum: Lewis Acids & Bases
Topic: Final
Replies: 4
Views: 71

### Re: Final

I'm not sure, but I'm guessing so; we have already been tested on everything else. This would be a good question for Dr. Lavelle or any of the TAs
Sun Dec 01, 2019 9:31 pm
Forum: Conjugate Acids & Bases
Topic: the conjugate seesaw
Replies: 5
Views: 76

### Re: the conjugate seesaw

In more detail, a conjugate base is produced when an acid donates a proton, and a conjugate acid is produced when a base accepts a proton.
Sun Dec 01, 2019 9:30 pm
Forum: Student Social/Study Group
Topic: Final
Replies: 3
Views: 73

### Re: Final

i think the final will have two more questions than the midterm, i believe it is similarly structured.
Sun Dec 01, 2019 9:28 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Notes
Replies: 3
Views: 51

### Re: Notes

Does this mean that we will be covering all new material up until Friday?
Sun Dec 01, 2019 9:27 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: AXE formula
Replies: 32
Views: 4755

### Re: AXE formula

The best way is to know the chart and which shape corresponds with which AXE formula.
Sun Nov 24, 2019 5:17 pm
Forum: Naming
Topic: using brackets
Replies: 5
Views: 54

### Re: using brackets

The brackets are what is inside the coordination sphere, which can be determined by the shape of the molecule.
Sun Nov 24, 2019 5:14 pm
Forum: Electronegativity
Topic: Electronegativity
Replies: 15
Views: 312

### Re: Electronegativity

If a atom has a very high electronegativity, it will pull on the electrons more and therefore form a stronger bond.
Sun Nov 24, 2019 5:13 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Dipole Moment?
Replies: 4
Views: 72

### Re: Dipole Moment?

So the shape of an atom will help you determine whether the dipole moments cancel out, and therefore whether the molecule is polar or nonpolar. You need to know the 3D geometry because there are some molecules that can be drawn in a Lewis structure to look "symetrical" but are actually not...
Sun Nov 24, 2019 5:10 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AXE Format
Replies: 34
Views: 280

### Re: AXE Format

You do not have to write a subscript if it is just 1, it's like math.
Sun Nov 24, 2019 5:09 pm
Forum: Lewis Acids & Bases
Topic: Lewis and Bronsted
Replies: 5
Views: 66

### Re: Lewis and Bronsted

A lewis acid is an electron pair acceptor and a Lewis base lends an electron pair. The bronsted definition is that an acid is a proton donor and a base is a proton acceptor.
Sun Nov 24, 2019 5:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw
Replies: 23
Views: 210

### Re: Seesaw

Since there is a lone pair that replaces the atom in a trigonal bipyramidal, it "pushes" on the other atoms and causes their bond angles to decrease.
Mon Nov 11, 2019 6:40 pm
Forum: Sigma & Pi Bonds
Topic: Sigma & Pi Bonds
Replies: 4
Views: 84

### Re: Sigma & Pi Bonds

I believe they will be covered after the midterm.
Mon Nov 11, 2019 6:39 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal charge
Replies: 16
Views: 221

### Re: Formal charge

The second best option is to make sure that the more electronegative atom has a negative charge, and vice versa. this is considered the correct lewis structure.
Sun Oct 27, 2019 8:33 pm
Forum: Octet Exceptions
Topic: Exceptions
Replies: 10
Views: 733

### Re: Exceptions

Not only are some elements in the d block exceptions to the octet rule, so are the first four elements (hydrogen, Beryllium, Helium, and Lithium.
Sun Oct 27, 2019 8:32 pm
Forum: Ionic & Covalent Bonds
Topic: Metalloids
Replies: 5
Views: 66

### Re: Metalloids

Adding on to that, since metalloids neither have "too many" or "too little" valence electrons as can be seen by where they are placed in the periodic table, they can go either way and lose electrons or gain electrons. Hence, they are called metalloids.
Sun Oct 27, 2019 8:30 pm
Forum: Resonance Structures
Topic: Formal Charge
Replies: 5
Views: 80

### Re: Formal Charge

No, I believe not. Informal charges do not exist.
Sun Oct 27, 2019 8:29 pm
Forum: Ionic & Covalent Bonds
Topic: Double bond placement
Replies: 15
Views: 180

### Re: Double bond placement

Due to the concept of resonance, technically double and triple bonds can be anywhere as long as the satisfy the octet rule. Just make sure to count up all the electrons before you place the double and triple bonds in a certain location
Sun Oct 27, 2019 8:26 pm
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 3
Views: 39

### Re: Drawing Lewis Structures

For me it really helps to count up all the total electrons in the structure and see if it matches my Lewis structure to check my work. It also helps for me to draw the atom in the center, which is the one with the least ionization energy, first so that I can draw everything around it after.
Sat Oct 19, 2019 12:33 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Same spin
Replies: 10
Views: 138

### Re: Same spin

Same spin means that the electrons spin in the same direction (parallel to each other) and have the same quantum number (1/2 or -1/2). According to Hund's rule all electrons that are unpaired in an orbital will have the same, or parallel spin, but if there is more electrons and it requires pairing u...
Sat Oct 19, 2019 12:30 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: how to prepare
Replies: 22
Views: 240

### Re: how to prepare

It would probably be really helpful to go to the step up sessions, since those start from the beginning and once you feel more comfortable you can go to the drop in ones. I also wouldnt stress about memorizing formulas because many will be provided but its important to know units (eg use kg and not ...
Sat Oct 19, 2019 12:27 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Spin State
Replies: 6
Views: 94

### Re: Spin State

I am not sure why the 1/2 is there for the spin quantum number but it may be because the other quantum numbers are integers
Thu Oct 17, 2019 12:31 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals
Replies: 4
Views: 67

### Re: Orbitals

if n is 2, l is 1, and ml is -1 then the electron is in -2px state because the n number corresponds to number of orbital and l corresponds to the fact that its a p orbital, and as mentioned above the -1 corresponds to the x axis. It is true that the orientation is arbitrary but the ml number tells u...

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