## Search found 20 matches

- Mon Mar 13, 2017 2:16 am
- Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
- Topic: Confusion about Z and E naming
- Replies:
**1** - Views:
**296**

### Confusion about Z and E naming

On page 103 in the course reader, there are examples of alkenes being named, but I'm not entirely sure how the priority of two different groups are determined. Can someone explain this to me? Without understanding how the priority is determined, it is impossible to name the molecule. Thanks.

- Mon Mar 06, 2017 12:45 am
- Forum: *Organic Reaction Mechanisms in General
- Topic: SN2 Reactions
- Replies:
**2** - Views:
**281**

### SN2 Reactions

Are SN2 reactions always for biomolecular molecules? When drawing the curved arrow diagrams, is it possible to show more than 1 bond breaking (the relocation of two pairs of electrons instead of just one?

- Mon Mar 06, 2017 12:39 am
- Forum: *Organic Reaction Mechanisms in General
- Topic: Diagram on Page 85
- Replies:
**1** - Views:
**201**

### Diagram on Page 85

On Page 85, there is a graph that displays the progress of an reaction with respect to the free energy that the reaction has. On the graph, it says that step 1 is slower because of the higher energy barrier, but I don't quite understand why there is a higher energy barrier at the beginning. Is this ...

- Mon Feb 20, 2017 11:52 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Arrhenius Equation
- Replies:
**1** - Views:
**285**

### Arrhenius Equation

I'm very confused about what the graphs on page 75 in the course reader represent. Arrhenius's Equation: k = A e^ (-E(a)/RT) >>> Produces a exponential curve. Simplification of the Arrhenius's Equation: ln k = -Ea/RT + ln A >>> Produces a linear slope. I'm not entirely sure what the graphs of these ...

- Sun Feb 12, 2017 10:18 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Confusion about intermediates
- Replies:
**4** - Views:
**386**

### Confusion about intermediates

On page 69 of the course reader, a proposed reaction mechanism is outlined in two steps: STEP 1: NO2(g) + NO2(g) --> NO3(g) + NO(g) STEP 2: NO3(g) + CO(g) --> NO2(g) + CO2(g) ______________________________________ OVERALL RXN: NO2(g) + CO(g) --> NO(g) + CO2(g) Before that, it says that the proposed ...

- Sun Feb 05, 2017 9:04 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Sensitivity of Cell Potential
- Replies:
**1** - Views:
**182**

### Sensitivity of Cell Potential

On page 53 of the course reader, it is claimed that the cell potential is sensitive to [R] and [P] (concentration of reactants and products. Discussed earlier in the quarter, the course reader refined an extensive property as something that depends on the number of substance. For example, heat capac...

- Sun Jan 29, 2017 5:29 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Confusion about K and Q and Equilibrium
- Replies:
**1** - Views:
**266**

### Confusion about K and Q and Equilibrium

From page 40 to 41 in the course reader, it seems like there are 2 equations for ΔG, one where K is used and another where Q is used: (1) ΔG = -RT ln (K) where K is the reaction quotient at equilibrium (ΔG = 0 and G(p) = G(r)) AND (2) ΔG = ΔG° + RT ln (Q) where Q is the reaction quotient when the sy...

- Sat Jan 21, 2017 8:19 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Application of Degeneracy [ENDORSED]
- Replies:
**1** - Views:
**256**

### Application of Degeneracy [ENDORSED]

On page 28, the course reader says that degeneracy (W) is defined as the number of ways of achieving a given energy state. The relationship between degeneracy (W) and entropy (S) is given by the Boltzmann Equation: S = k(b) ln(W). On page 31, there is another equation given by the change in entropy ...

- Sun Jan 15, 2017 5:32 pm
- Forum: Phase Changes & Related Calculations
- Topic: ΔH = ΔU Page 20 Confusion
- Replies:
**1** - Views:
**218**

### ΔH = ΔU Page 20 Confusion

On Page 20 in the Course Reader, an example is worked out where the concept is demonstrating that Q(system) = -Q(surroundings) and that Q(system) + Q(surrounding) = 0. I understand how the conclusion was deduced that ΔH(rxn) = -2.9 kJ at the end (because there was constant pressure, indicating that ...

- Fri Mar 11, 2016 10:11 pm
- Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
- Topic: Newman Projections for Cyclohexanes
- Replies:
**1** - Views:
**315**

### Newman Projections for Cyclohexanes

How do we draw the Newman Projection for cyclohexane?

- Fri Mar 11, 2016 10:10 pm
- Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
- Topic: Stable Conformation of Cyclopentane & Cyclohexane
- Replies:
**1** - Views:
**431**

### Stable Conformation of Cyclopentane & Cyclohexane

Can someone explain the envelope conformation of cyclopentane? Is there only one conformation?

Also for cyclohexanes, can someone explain why the equatorial and axial positions are switched?

Also for cyclohexanes, can someone explain why the equatorial and axial positions are switched?

- Fri Feb 26, 2016 9:36 pm
- Forum: *Alkanes
- Topic: Organic Chemistry Emergency
- Replies:
**1** - Views:
**268**

### Organic Chemistry Emergency

Hey fellow Chemistry peers. Please help me distinguish between tert-butyl and neopentane.

Thanks!

Thanks!

- Tue Feb 23, 2016 10:45 pm
- Forum: *Free Energy of Activation vs Activation Energy
- Topic: Section 4.3 HW number 4.30
- Replies:
**1** - Views:
**225**

### Section 4.3 HW number 4.30

If one has the activation energy, how do we determine whether it will occur at a specific temperature. I know we have to use:

delta(g) = delta(h) - (time)*(delta(s))

What do I need to solve it?

delta(g) = delta(h) - (time)*(delta(s))

What do I need to solve it?

- Tue Feb 16, 2016 11:41 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Equations for finding the Activation Energy
- Replies:
**1** - Views:
**284**

### Equations for finding the Activation Energy

When do we use each equation to find the activation energy? When would you chose one over the other?

k=A ^ -Ea/R*T

ln(k) = -Ea/R*T + ln(A)

k=A ^ -Ea/R*T

ln(k) = -Ea/R*T + ln(A)

- Tue Feb 16, 2016 11:29 pm
- Forum: General Rate Laws
- Topic: Units for K
- Replies:
**1** - Views:
**328**

### Units for K

Hi. Can anyone explain the difference between the units for k for a first order reaction, a second order one and a zero order one? I know they're different because the change of the rate needs to be in Molarity/Second.

- Fri Feb 05, 2016 5:38 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Platinum and Salt Bridges
- Replies:
**1** - Views:
**425**

### Platinum and Salt Bridges

In my discussion section, my TA told me that platinum was a strong reducing metal. Can anyone tell me why this is the case. Also what is the common makeup for a salt bridge?

- Sat Jan 30, 2016 1:47 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Dissolving a Gold Ring in 1M Nitric Acid
- Replies:
**1** - Views:
**421**

### Dissolving a Gold Ring in 1M Nitric Acid

On page 52 of the course reader, a question asks whether a gold ring would dissolve in 1M nitric acid and whether it would form a 1M Aluminum 3 Oxide solution. I understand the process of calculating the E and Delta G, but I don't understand how it is deduced that gold does not dissolve in 1M of nit...

- Fri Jan 22, 2016 5:01 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Degrees of Freedom
- Replies:
**1** - Views:
**293**

### Degrees of Freedom

What is the difference between transitional and rotational degrees of freedom? Also, how do you calculate it? Is there any connection between degrees of freedom and the Gibbs Free Energy equation?

- Fri Jan 15, 2016 4:21 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Clairifcation on when to use entropy equations.
- Replies:
**3** - Views:
**571**

### Clairifcation on when to use entropy equations.

In class today,

I wrote down the following two equations:

Change in entropy = Boltzmann's Constant * ln (w2/w1)

and

Change in entropy = number of moles * Ideal Gas Constant * ln (w2/w1)

When would each equation be used and how can these two equations possibly be used to calculate the same thing?

I wrote down the following two equations:

Change in entropy = Boltzmann's Constant * ln (w2/w1)

and

Change in entropy = number of moles * Ideal Gas Constant * ln (w2/w1)

When would each equation be used and how can these two equations possibly be used to calculate the same thing?

- Fri Jan 08, 2016 7:04 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Course Reader Page 19 and 20
- Replies:
**1** - Views:
**207**

### Course Reader Page 19 and 20

I understand that one can calculate standard reaction enthalpy by calculating standard enthalpy of formation of all products and subtract standard enthalpy of formation of all reactants. I am also aware that the standard enthalpy of formation of an element in its most stable form is zero. On page 20...