## Search found 48 matches

Sat Mar 17, 2018 8:11 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Test #2 #7
Replies: 5
Views: 596

### Re: Test #2 #7

Should the overall n = 12, not 6?
Sat Mar 17, 2018 4:01 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Test #2 Question 6
Replies: 1
Views: 180

### Test #2 Question 6

The following redox couple forms a galvanic cell which generates a current under standard conditions

H+ / H2 and Ni2+/Ni

a) Identify the oxidizing agent
b) Identify the reducing agent

What method is used to solve this problem?
Sat Mar 17, 2018 3:06 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Overall Reaction
Replies: 1
Views: 168

### Overall Reaction

Do we have to include the phases when writing the overall reaction of a mechanism?
Sat Mar 17, 2018 1:17 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge vs. Porous Disk
Replies: 2
Views: 243

### Re: Salt Bridge vs. Porous Disk

I believe the question will tell you to when to use a salt bridge or porous disk.
Sat Mar 17, 2018 1:12 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic vs Concentration Cell
Replies: 2
Views: 182

### Re: Galvanic vs Concentration Cell

The E value of a concentration cell should always be 0, under standard conditions, because the concentration of the anode and cathode is equal.
Sat Mar 17, 2018 1:07 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Concentration cell
Replies: 1
Views: 153

### Re: Concentration cell

Is it possible for K to ever be zero?
Sat Mar 17, 2018 12:55 pm
Forum: Zero Order Reactions
Topic: Units of k
Replies: 12
Views: 999

### Re: Units of k

I highly doubt that we would be asked to find anything higher than the 3rd order. But we may be asked questions where the overall order is greater than 3.
Sat Mar 17, 2018 12:39 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Open, closed, or isolated test 1 question
Replies: 10
Views: 805

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

Why is the contents of an ideal cooler at 3 deg Celsius considered isolated and not closed?
Sat Mar 17, 2018 12:37 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: closed vs isolated
Replies: 11
Views: 757

### Re: closed vs isolated

Yes, heat transfer does happens because they system is doing work and losing energy. This energy is replaced by heat flow, q, into the system.
Sat Mar 17, 2018 12:32 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Bomb Calorimeter
Replies: 6
Views: 523

### Re: Bomb Calorimeter

So for Test #1 Question 3a:

Propane is burned in the presence in the oxygen inside a sealed bomb calorimeter in contact with a heat bath and the pressure increases inside the calorimeter from 1 atmosphere to 1.5 atmospheres.

How would you justify that there is no work being done?
Sat Mar 17, 2018 11:59 am
Forum: General Rate Laws
Topic: Test #3 Question 3
Replies: 1
Views: 360

### Test #3 Question 3

The rate of C2 gas consumption in this reaction is constant throughout and is given as 0.250 M/s. If your reaction vessel starts with 0.35M of ABC, how long will it take to get to 24.00M of ABC?

How would you solve this problem?
Sat Mar 17, 2018 1:46 am
Forum: *Electrophiles
Topic: what is going to be on the final? [ENDORSED]
Replies: 12
Views: 1231

### Re: what is going to be on the final?[ENDORSED]

During the Friday review session, it was mentioned that problems covering ochem topics should be relatively easy points since Lavelle only briefly went over the ochem topics!
Sat Mar 17, 2018 1:42 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Lyndon Review Test, Question 7a [ENDORSED]
Replies: 7
Views: 480

### Re: Lyndon Review Test, Question 7a[ENDORSED]

Sat Mar 17, 2018 12:19 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Bomb Calorimeter
Replies: 6
Views: 523

### Bomb Calorimeter

Are bomb calorimeters considered vacuums?
Sat Mar 17, 2018 12:10 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Transition State
Replies: 3
Views: 352

### Transition State

Can someone explain the concept of transition state? And is it always the peak of a free energy profile graph?
Sat Mar 17, 2018 12:02 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Lyndon Review Test, Question 7a [ENDORSED]
Replies: 7
Views: 480

### Re: Lyndon Review Test, Question 7a[ENDORSED]

How did you determine that there are no catalysts?
Sat Mar 17, 2018 12:00 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram: Porous Disk and Salt Bridge
Replies: 5
Views: 344

### Cell Diagram: Porous Disk and Salt Bridge

When drawing a cell diagram, do we use a double vertical line for both the porous disk and salt bridge?
Fri Mar 16, 2018 11:56 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Test #2 Question 5
Replies: 5
Views: 303

### Re: Test #2 Question 5

What's the correct answer for a and b?
Fri Mar 16, 2018 11:54 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: cell diagram
Replies: 4
Views: 259

### Re: cell diagram

Yes it is
Fri Mar 16, 2018 11:51 pm
Forum: *Nucleophiles
Topic: SN2 Reactions
Replies: 4
Views: 2616

### Re: SN2 Reactions

I am also confused about bimolecular nucleophile substitution. Can someone explain it?
Fri Mar 16, 2018 11:50 pm
Forum: *Nucleophiles
Topic: SN2 Reactions
Replies: 4
Views: 2616

### SN2 Reactions

Would we need to know how to identify SN2 reactions for the final?
Fri Mar 16, 2018 11:43 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Lyndon Review Test, Question 7a [ENDORSED]
Replies: 7
Views: 480

### Lyndon Review Test, Question 7a[ENDORSED]

Consider the following mechanism:

STEP 1 (FAST): 2A + B --> C
STEP 2 (SLOW): C + D --> 2E

a) Identify the intermediates and catalysts.

How do you identify what the catalysts are?
Fri Mar 16, 2018 11:34 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: A?
Replies: 6
Views: 615

### Re: A?

So is A affected by temperature or nearly independent of it?
Fri Mar 16, 2018 6:57 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Test #2 Question 5
Replies: 5
Views: 303

### Re: Test #2 Question 5

So the strongest reducing agent would have the greatest oxidizing power. Does that mean that the reducing agent with the greatest oxidizing power would have the most negative E?
Fri Mar 16, 2018 5:52 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.65 Part b
Replies: 2
Views: 207

### 15.65 Part b

15.65 For the reversible, one-step reaction 2 A ---> B + C, the forward rate constant for the formation of B is 265 L/(mol*min) and the rate constant for the reverse reaction is 392 L/(mol*min). The activation energy for the forward reaction is 39.7 kJ mol 1 and that of the reverse reaction is 25.4 ...
Fri Mar 16, 2018 5:24 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Test #2 Question 5
Replies: 5
Views: 303

### Test #2 Question 5

Rank the following in order of increasing oxidizing power:

a) Mn, Ag, Ti

b) Pb, Al, Cu

When it asks for increasing oxidizing power, does it mean to find the oxidizing agent or the reducing agent?
Fri Mar 16, 2018 12:38 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Steady-State Approximation vs. Pre-equilibrium Condition
Replies: 4
Views: 394

### Re: Steady-State Approximation vs. Pre-equilibrium Condition

Also my TA mentioned during discussion that we would not be tested on steady state approximation. Can anyone else confirm that?
Fri Mar 16, 2018 12:28 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Steady-State Approximation vs. Pre-equilibrium Condition
Replies: 4
Views: 394

### Re: Steady-State Approximation vs. Pre-equilibrium Condition

I am still a little fuzzy on the concept of pre-equilibrium condition. Can someone please explain?
Fri Mar 16, 2018 12:24 pm
Forum: *Electrophiles
Topic: what is going to be on the final? [ENDORSED]
Replies: 12
Views: 1231

### Re: what is going to be on the final?[ENDORSED]

So all we need to know about functional groups is being able to recognize and name them?
Fri Mar 16, 2018 12:24 pm
Forum: *Electrophiles
Topic: what is going to be on the final? [ENDORSED]
Replies: 12
Views: 1231

### Re: what is going to be on the final?[ENDORSED]

So all we need to know about functional groups is being able to recognize and name them?
Wed Feb 14, 2018 1:10 am
Forum: Calculating Work of Expansion
Topic: Leung Midterm Question 7 [ENDORSED]
Replies: 1
Views: 127

### Leung Midterm Question 7[ENDORSED]

Why is the w=0? To maintain a constant pressure, wouldn't you need a volume change, thus work is being done?
Sat Jan 13, 2018 11:55 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Delta values
Replies: 3
Views: 152

### Re: Delta values

For delta H, do label the units as KJ or KJ/mol?
Sat Jan 13, 2018 11:54 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Extensive vs Intensive Property
Replies: 3
Views: 148

### Extensive vs Intensive Property

Can someone explain the difference between intensive and extensive property?
Sat Jan 13, 2018 11:48 pm
Forum: Phase Changes & Related Calculations
Topic: Steam Burning
Replies: 7
Views: 484

### Re: Steam Burning

Steam burns a lot more because the enthalpy of condensation is high. The heating curve for water shows that as water goes through a phase stage into gas, it is dumping a large amount of energy at 100 deg Celsius of heat onto the skin.
Sat Dec 09, 2017 12:24 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Dentates
Replies: 4
Views: 345

### Re: Dentates

Is it valid to also look for O- when trying to identify what -dentate a ligand is?
Sat Dec 09, 2017 12:21 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligand Order
Replies: 2
Views: 255

### Ligand Order

Does the alphabetical order of the ligand matter when writing the chemical formula of a compound?
Fri Nov 10, 2017 11:39 am
Forum: Bond Lengths & Energies
Topic: Bond Length
Replies: 8
Views: 1815

### Re: Bond Length

The greater the bond strength the shorter the bond length. As there are more electrons, the pull force is greater which makes it stronger. For example a single bond has 2 electrons which gives it a weak bond strength and a long bong length. On the other hand, a triple bond has 6 electrons which give...
Fri Nov 10, 2017 11:31 am
Forum: Octet Exceptions
Topic: Beryllium exception
Replies: 4
Views: 719

### Re: Beryllium exception

There are also multiple exceptions to the octet rule including boron and aluminum
Sat Nov 04, 2017 4:02 pm
Forum: Photoelectric Effect
Topic: Exam Question Clarification [ENDORSED]
Replies: 3
Views: 273

### Re: Exam Question Clarification[ENDORSED]

Yes, I also agree with Miranda. You can't eject electrons by increasing the intensity of the radiation because in order to eject the electron.
Sat Nov 04, 2017 3:58 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Confused on Problem 1.57 (regarding the Balmer Series)
Replies: 9
Views: 2205

### Re: Confused on Problem 1.57 (regarding the Balmer Series)

The series of the wavelengths given will help you find the final energy level. Since this is a Balmer series, you already know that n1 =2, and by counting the numbers, you can see that n2 =7. So using the equation E = -hR/n^2 you can find the energy of both n1=2 and n2=2. Finally, you can use Ef - E...
Sat Oct 28, 2017 7:42 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Putting s orbital or p orbital first [ENDORSED]
Replies: 4
Views: 421

### Re: Putting s orbital or p orbital first[ENDORSED]

@804899546 Yes, you would still list the d-orbital before the s-orbital in chromium and copper since technically the s orbital was already filled with 2 electrons before the d orbital, making the d orbital now lower in energy. In the case of chromium, we are moving one electron from the s-orbital in...
Sat Oct 28, 2017 7:35 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Difference Between Orbitals and Subshells [ENDORSED]
Replies: 7
Views: 1139

### Re: Difference Between Orbitals and Subshells[ENDORSED]

@Humza_Khan_3F I believe that the three quantum numbers: principal (n), angular momentum (l), and magnetic (m) together describe the size, shape, and orientation in space of an orbital of an atom. So the orbital is not simply the l value, it is made up by n,l,and m.
Sat Oct 21, 2017 1:17 am
Forum: Einstein Equation
Topic: Lyman and Blamer series [ENDORSED]
Replies: 7
Views: 831

### Re: Lyman and Blamer series[ENDORSED]

Yes, the Lyman and Balmer series are specifically used to find the change in energy levels of hydrogen atoms.
Sat Oct 21, 2017 1:12 am
Forum: Photoelectric Effect
Topic: Energy emitted from an Electron [ENDORSED]
Replies: 4
Views: 457

### Re: Energy emitted from an Electron[ENDORSED]

You will get a negative energy because as it moves from n=5 to n=1, it loses energy. But remember that wavelength and frequency will always be positive!
Fri Oct 13, 2017 12:24 am
Forum: Photoelectric Effect
Topic: Photoelectric effect post-quiz 17-19 [ENDORSED]
Replies: 6
Views: 4174

### Re: Photoelectric effect post-quiz 17-19[ENDORSED]

@Helen
In order to get the work energy, 150.6 kJ/mol must be converted to Joules (1000 kJ= 1J) and then multiplied to Avogadro's number, 6.022 x 10^23, as a conversion factor to cancel out the mol in the denominator.
Fri Oct 13, 2017 12:07 am
Forum: Properties of Light
Topic: Balmer vs Lyman Series [ENDORSED]
Replies: 3
Views: 313

### Balmer vs Lyman Series[ENDORSED]

I was reading through one of the examples in the textbook about Balmer and Lyman series and it stated that because n1=2, the wavelength should match one of the lines in the Balmer series. How are you able to tell which region of the spectrum indicates which series to use? Also why is n1=2 Balmer ser...
Fri Oct 06, 2017 9:43 am
Forum: Molarity, Solutions, Dilutions
Topic: Homework E3
Replies: 2
Views: 263

### Re: Homework E3

You can also think of this as a ratio. For one astatine atom there are 3 gallium atoms. Since there are 9 gallium atoms 9/3=3, there would be 3 astatine atoms.
Fri Oct 06, 2017 9:39 am
Forum: Balancing Chemical Reactions
Topic: Fundamentals H.21
Replies: 2
Views: 975

### Re: Fundamentals H.21

It can be easier to make a list of all the elements on both sides of the equation and simply continue to add coefficients to the equation until the elements on both sides are equal.