## Search found 58 matches

Sat Mar 17, 2018 5:31 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Cp & Cv?
Replies: 3
Views: 300

### Cp & Cv?

I know that in a bomb calorimeter deltaV= 0 is pressure also 0?
Fri Mar 16, 2018 12:13 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Finding E
Replies: 3
Views: 201

### Finding E

Are there instances when you can only use cathode-anode or any when you can only flip the value? Or can we always use either?
Mon Mar 12, 2018 1:31 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Open, closed, or isolated test 1 question
Replies: 10
Views: 631

### Re: Open, closed, or isolated test 1 question

Open. The way I remember it is, if it is open, it can be knocked over and matter can leave it.
Mon Mar 12, 2018 1:27 pm
Forum: *Alcohols
Topic: Functional group in final [ENDORSED]
Replies: 1
Views: 328

### Functional group in final[ENDORSED]

Will we only have to identify the examples given in class or is there more?
Tue Mar 06, 2018 3:38 pm
Forum: First Order Reactions
Topic: Order Reactions
Replies: 3
Views: 186

### Re: Order Reactions

No they are all on the constants sheet.
Tue Mar 06, 2018 3:35 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Straight line
Replies: 7
Views: 362

### Re: Straight line

If you were given three graphs and were asked what order it is, you'd have to look at the one with a straight line to tell.
Mon Mar 05, 2018 8:19 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Method of initial rate vs more than one reactant
Replies: 2
Views: 149

### Method of initial rate vs more than one reactant

How do we find the reaction rate/law using method of initial rates vs for more than one reactant? What is the difference?
Tue Feb 27, 2018 4:15 pm
Forum: General Rate Laws
Topic: Writing a rate equation
Replies: 3
Views: 157

### Re: Writing a rate equation

I believe it is because you won't always know how much product will be made.
Tue Feb 27, 2018 4:10 pm
Forum: General Rate Laws
Topic: initial rate law
Replies: 5
Views: 189

### Re: initial rate law

Yes because you won't always know how much product is made.
Tue Feb 27, 2018 4:08 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Half-life
Replies: 4
Views: 216

### Half-life

Is T always equal to 1/2 or what does it depend on?
Tue Feb 20, 2018 7:36 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell diagram/equation
Replies: 2
Views: 108

### Cell diagram/equation

Since the anode and the cathode on the cell diagram can be switched (i.e cathode on the left & anode on the right) does that also apply to the equation that represents it?
Tue Feb 20, 2018 7:20 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Q & K?
Replies: 4
Views: 192

### Q & K?

I know when products/reactants are favored in terms of K>1 etc, but what are the rules when Q>K or Q<K?
Tue Feb 20, 2018 7:18 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Equilibrium constant
Replies: 3
Views: 195

### Re: Equilibrium constant

Are Q and K interchangeable?
Mon Feb 12, 2018 11:27 pm
Forum: Phase Changes & Related Calculations
Topic: Phase changes with entropy?
Replies: 6
Views: 242

### Re: Phase changes with entropy?

You can also use the equation deltaS= n x delta H / T when there is vaporization/ fusion and deltaS= nCpln(T2/T1) for phase changes.
Mon Feb 12, 2018 11:22 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: K_b
Replies: 2
Views: 169

### K_b

What does the Kb stand for/ what is its purpose?
Mon Feb 12, 2018 11:18 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Derivation of Formulas
Replies: 5
Views: 358

### Re: Derivation of Formulas

Nope but it is helpful in case we need to manipulate one to get another.
Mon Feb 05, 2018 6:34 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Cv vs. Cp [ENDORSED]
Replies: 13
Views: 1352

### Re: Cv vs. Cp[ENDORSED]

The problem usually states when there is constant pressure/volume
Mon Feb 05, 2018 6:28 pm
Forum: Balancing Redox Reactions
Topic: acronym for reduction
Replies: 5
Views: 315

### Re: acronym for reduction

You can also use "OIL RIG"
Oxidation Is Losing (e-)
Reduction Is Gaining (e-)
Mon Feb 05, 2018 6:26 pm
Forum: Balancing Redox Reactions
Topic: Salt Bridges?
Replies: 6
Views: 177

### Salt Bridges?

I know what they are used for, but how do they work?
Mon Jan 29, 2018 5:41 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Utotal of Ideal Gas
Replies: 3
Views: 160

### Re: Utotal of Ideal Gas

When you have constant volume and you have to use the equation: change in S=nRln(v2/v1) the R(8.314) has to be multiplied by 3/2.
Mon Jan 29, 2018 5:37 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Replies: 2
Views: 136

Since adiabatic means that no heat is transferred, and enthalpy is the study of heat released or absorbed, does that mean that they are not related at all?
Mon Jan 29, 2018 5:34 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: CV or CP
Replies: 5
Views: 222

### Re: CV or CP

The question will usually state that it is at constant volume or constant pressure.
Tue Jan 23, 2018 7:56 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Reaction Enthalpies vs other methods
Replies: 2
Views: 111

### Reaction Enthalpies vs other methods

Is there a difference between reaction enthalpies and the three methods?
Tue Jan 23, 2018 6:35 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law Details
Replies: 2
Views: 118

### Re: Hess's Law Details

Yes to both questions. You will need to manipulate the other reactants/products in order to get to the original equation.
Mon Jan 22, 2018 7:28 pm
Forum: Phase Changes & Related Calculations
Topic: Test 1 [ENDORSED]
Replies: 7
Views: 358

### Re: Test 1[ENDORSED]

Josh Moy 1H wrote:will all the equations be on a formula sheet?

Yes. The formula sheet is separate and has many other different formulas we won't need for this test but for future ones too.
Thu Jan 18, 2018 6:12 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Specific Heat Capacity vs Heat Capacity
Replies: 5
Views: 267

### Re: Specific Heat Capacity vs Heat Capacity

The way I understand it is that specific heat is to change the temperature of the substance by 1 degrees and specific heat capacity is to change 1 gram of the substance by 1 degrees.
Thu Jan 18, 2018 6:07 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Energy and matter?
Replies: 6
Views: 307

### Energy and matter?

Are both matter and energy taken into account to identify open/closed/isolated systems?
Thu Jan 18, 2018 6:05 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 3 Methods
Replies: 2
Views: 87

### 3 Methods

I know we use three methods, but what exactly are they used for? What are we trying to find?
Thu Jan 18, 2018 6:03 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Constant pressure/volume
Replies: 2
Views: 124

### Constant pressure/volume

What exactly does Cp=5/2*R and Cv= 3/2*R mean? When would we use it?
Thu Jan 18, 2018 5:59 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Most Stable Form
Replies: 3
Views: 126

### Re: Most Stable Form

I was told we should know that Br2, and Hg are liquid, H2, N2, O2, F2, I2, and Cl2 are gases and their standard enthalpy of formation is 0. Besides the ones I named, any other ones should be given to us.
Sun Jan 14, 2018 9:57 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: standard reaction enthalpy
Replies: 1
Views: 99

### standard reaction enthalpy

On Friday Lavelle went over three methods. If I understood right, he provided examples for the the 2nd and 3rd, but I am not sure how to use the first. Can someone explain how or when we'd use standard reaction enthalpy?
Sat Dec 09, 2017 10:39 pm
Forum: Lewis Acids & Bases
Topic: Lewis acids and bases
Replies: 2
Views: 180

### Re: Lewis acids and bases

We might be asked to identify the lewis base/acid in a compound that has ligands. The metal is always the lewis acid and the ligand is always the lewis base.
Sat Dec 09, 2017 10:32 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE table
Replies: 7
Views: 479

### Re: ICE table

Clarissa Molina 1C wrote:Can somebody explain the 5% rule when approximating x please? Is K being less than 10^-3 enough to be able to approximate or does it also have to follow the 5% rule?

It was mentioned that 10^-3 should be enough to use approximation but you can be asked to prove that it follows the 5% rule.
Sat Dec 09, 2017 10:28 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium partial pressures
Replies: 2
Views: 342

### Re: Equilibrium partial pressures

Dr Lavelle mentioned that you can use partial pressure in ice boxes, so you do not have to convert unless it asks.
Sat Dec 09, 2017 10:16 pm
Forum: Photoelectric Effect
Topic: nm to m
Replies: 4
Views: 258

### nm to m

When given the wavelength in nm, how do we convert it to m?
Sat Dec 09, 2017 10:13 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: titration
Replies: 3
Views: 190

### Re: titration

No I believe this topic will be covered in 14B.
Thu Dec 07, 2017 9:15 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Reaction shift
Replies: 3
Views: 157

### Reaction shift

If you increase the products of a reaction, which way will the reaction shift?
Wed Dec 06, 2017 7:06 pm
Forum: Dipole Moments
Topic: Dipoles: Polar or nonpolar?
Replies: 2
Views: 193

### Dipoles: Polar or nonpolar?

How are dipole moments and polarity related to each other?
Wed Dec 06, 2017 9:21 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: ICE Chart [ENDORSED]
Replies: 9
Views: 431

### Re: ICE Chart[ENDORSED]

When there are problems where we have to use ice boxes, are the acids and bases automatically weak?
Tue Dec 05, 2017 9:42 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: partial pressure in ice boxes? [ENDORSED]
Replies: 2
Views: 313

### partial pressure in ice boxes?[ENDORSED]

Can you use partial pressure in ice boxes or does it have to be in concentration?
Tue Dec 05, 2017 9:40 am
Forum: Electronegativity
Topic: Trends? [ENDORSED]
Replies: 10
Views: 644

### Trends?[ENDORSED]

What are the trends we have gone over in class? I know for sure there is atomic size and electronegativity.
Tue Dec 05, 2017 9:36 am
Forum: Molarity, Solutions, Dilutions
Topic: Molarity and Dilution [ENDORSED]
Replies: 7
Views: 1017

### Re: Molarity and Dilution[ENDORSED]

I have a hard time identifying what is what in wordy questions. For instance I often mix up what is the Molarity, number of moles of solute, or the volume. And I have a hard time with excluding unnecessary givens in the equation. Does anyone have any advice? Molarity is moles/Liters and is sometime...
Tue Dec 05, 2017 9:32 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Are pH and pOH opposites?
Replies: 2
Views: 205

### Re: Are pH and pOH opposites?

pH is for acids and pOH are for bases, so I guess you can say they are opposites. If you have one you should always be able to find the other.
Mon Dec 04, 2017 9:16 am
Forum: Bronsted Acids & Bases
Topic: Proton donor/acceptor [ENDORSED]
Replies: 1
Views: 161

### Proton donor/acceptor[ENDORSED]

Can someone please explain how an element can be a proton donor or acceptor or how to identify one? I am having trouble understanding this concept.
Mon Nov 27, 2017 5:25 pm
Forum: Biological Examples
Topic: Lewis Acid/Base?
Replies: 2
Views: 279

### Lewis Acid/Base?

I am having trouble understanding the how something is a lewis base/acid. I know that a Lewis base is an electron pair donor and a Lewis acid accepts an electron pair. How do they "donate" or "accept" electrons?
Mon Nov 27, 2017 5:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Writing reaction quotient or equilibrium expression
Replies: 5
Views: 209

### Re: Writing reaction quotient or equilibrium expression

I have a question regarding this, do we use the ideal gas law to convert between the partial pressure and concentration?
Mon Nov 27, 2017 5:15 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Writing reaction quotient or equilibrium expression
Replies: 5
Views: 209

### Re: Writing reaction quotient or equilibrium expression

Yes, it depends on what the question is asking for, concentration of partial pressure.
Sun Nov 26, 2017 5:25 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: partial pressure
Replies: 3
Views: 177

### Re: partial pressure

so are partial pressure and concentrations two different things?
Sun Nov 26, 2017 2:20 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: partial pressure
Replies: 3
Views: 177

### partial pressure

In lecture, the first example Lavelle went over for finding K was about a reaction that had gases but he went on to explain partial pressure. My question is, when asked for equilibrium for a reaction of gases is it in partial pressure or does it depend on what is being asked?
Mon Nov 13, 2017 7:40 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AXE
Replies: 3
Views: 182

### AXE

When doing the VSEPR formula I know how to find AX_n but how would you identify E or the subscript for it?
Mon Nov 13, 2017 6:06 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.5 Shape
Replies: 2
Views: 227

### Re: 4.5 Shape

Is regional planar the same as angular? The solutions manual says it is angular, I'm confused.
Wed Nov 01, 2017 6:29 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 2.29
Replies: 2
Views: 149

### Re: 2.29

For a) the alphabetical letter for l=1 is p. Also the quantum/group number is given (4) So it is 4p. The most # of electrons 4p can have is six. For c, the group number is given 2. The most number of electrons that group 2 can have is 8. (2s2 4p6) 2+6=8 I am not sure how to find the others because i...
Tue Oct 31, 2017 5:25 pm
Forum: *Shrodinger Equation
Topic:
Replies: 4
Views: 386

### Re: Hψ

I was told that all we really need to know is that Ψ is the wave property of an electron.
Tue Oct 24, 2017 5:44 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: P_xyz axis
Replies: 3
Views: 191

### P_xyz axis

I am having trouble understanding how the lobes of Px,y,z orient along their respective axes. Are the axes similar to x & y axis of a graph? If so, where would the axis Pz be?
Sat Oct 21, 2017 9:35 pm
Forum: Quantum Numbers and The H-Atom
Topic: The 4 Quantum Numbers [ENDORSED]
Replies: 5
Views: 600

### Re: The 4 Quantum Numbers[ENDORSED]

Is there a specific orientation for the quantum numbesr in m sub l?
Wed Oct 18, 2017 5:00 pm
Forum: Properties of Electrons
Topic: Problem 1.38 [ENDORSED]
Replies: 3
Views: 283

### Re: Problem 1.38[ENDORSED]

I have a question regarding the response to the question. Are velocity and the light constant the same? Because I know that c= wavelength x frequency. I did not know that wavelength x frequency=velocity?
Fri Oct 06, 2017 9:59 am
Forum: Limiting Reactant Calculations
Topic: Theoretical Yield [ENDORSED]
Replies: 6
Views: 425

### Theoretical Yield[ENDORSED]

In the Limiting Reactants module, Dr Lavelle mentioned how to get to the theoretical yield but there was no example on how to. I am not quite sure how to find it. If someone could show me with an example I would greatly appreciate it. Thanks!
Fri Oct 06, 2017 9:45 am
Forum: Molarity, Solutions, Dilutions
Topic: Molarity and Dilution [ENDORSED]
Replies: 7
Views: 1017

### Re: Molarity and Dilution[ENDORSED]

You do not have to do M1xV1=M2V2 because the question is asking for molarity and not dilution. You still can but it will take you longer.