## Search found 13 matches

Mon Mar 13, 2017 5:18 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 2008 Final question 3B
Replies: 1
Views: 242

### 2008 Final question 3B

A chemist constructs two voltaic cells, each with a standard hydrogen electrode in one compartment. One cell also contains a Pb/Pb+ half-cell; the other contains a Cu/Cu2+ half-cell. Pb2+ + 2e- -> Pb E= -0.13 V Cu2+ + 2e- -> Cu E= 0.34V B. Which electrode in each cell is the anode? Can someone pleas...
Sun Mar 12, 2017 7:51 pm
Forum: *Alcohols
Topic: Priority in Cyclos [ENDORSED]
Replies: 2
Views: 898

### Re: Priority in Cyclos[ENDORSED]

Functional groups have priority over double/triple bonds and substituents, you would start numbering there.
Thu Mar 09, 2017 10:02 pm
Forum: *Electrophiles
Topic: nucleophile vs electrophile
Replies: 2
Views: 654

### Re: nucleophile vs electrophile

H2O is not an electrophile because it is has lone pairs on the central atom and is electron rich. The central atom oxygen is also much more electronegative than the two hydrogen atoms which makes it available to donate electrons- thus, making H2O an nucleophile. OH- is also a nucleophile.
Fri Mar 03, 2017 4:45 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Units for k
Replies: 1
Views: 213

### Units for k

For the formula K= k/k', when you are given K (equilibrium constant) and k' (rate constant of the reverse reaction) and you have to determine the the rate constant of the forward reaction, k, are you supposed to look at the rate law of the forward reaction to determine the order- which will therefor...
Fri Mar 03, 2017 4:36 pm
Forum: *Ketones
Topic: ketone placement
Replies: 1
Views: 557

### Re: ketone placement

A ketone can never be at the end of a carbon chain because it is bonded to two carbons or two groups- so it might be somewhere in the middle of a carbon chain. You can't end a carbon chain with a C because it has to have 4 bonds. On the other hand, an aldehyde is bonded to one or two hydrogens; this...
Sun Feb 19, 2017 7:56 pm
Forum: *Enzyme Kinetics
Topic: Quiz 2 Prep #9
Replies: 3
Views: 525

### Re: Quiz 2 Prep #9

Answers A, B, and C are correct. A substrate binds to the enzyme at its active site, and as the substrate concentration increases so does the reaction rate because there is more substrate for the enzyme react with. When there are enough substrates, the determining factor of the reaction rate depends...
Sun Feb 12, 2017 7:36 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Winter 2009 Midterm Question 8
Replies: 1
Views: 258

### Winter 2009 Midterm Question 8

Consider the cell Ag(z)|Ag+(aq, 5.0mmol/L)||Ag+(aq, 0.15 mol/L)| Ag(s). Can this cell do work at room temperature? If so, what is the maximum work in KJ that it can perform (per mole of Ag)? The solution says that Since [Ag+]anode < [Ag+]cathode, the ratio is less than 1 and E>0, so the cell can do ...
Sun Feb 05, 2017 12:50 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Charge for Anode and Cathode
Replies: 2
Views: 235

### Re: Charge for Anode and Cathode

Yes. The anode is considered negative and the cathode is considered positive in a galvanic cell. This makes sense because the anode is the source of electrons and the cathode is where the electrons flow to.
Sun Jan 29, 2017 4:00 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpy [ENDORSED]
Replies: 2
Views: 385

### Bond Enthalpy[ENDORSED]

When doing bond enthalpy problems, how do you know which bonds to break and which ones to form?
Sun Jan 22, 2017 7:25 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Measuring Heat Transfer
Replies: 3
Views: 353

### Measuring Heat Transfer

For the questions about measuring heat transfer, why is it that the equations for delta H are sometimes mC(delta T) and some are nC(delta T)? How would you know which equation to use?
Sun Jan 15, 2017 1:20 pm
Forum: Phase Changes & Related Calculations
Topic: Phase Change
Replies: 3
Views: 358

### Re: Phase Change

The equation for non-phase change (the sloped part of the graph) is Q= (m)(C)( delta T)
Fri Oct 28, 2016 12:56 pm
Forum: Lewis Structures
Topic: Lewis Structure of XeF2
Replies: 1
Views: 751

### Re: Lewis Structure of XeF2

Xe actually does not follow the octet rule; since it has a 4d sub-level, it can have more than 8 electrons. Since F cannot violate the octet rule, each fluorine atom can only form one bond with Xe to reach an octet. If two electrons of Xe are used, you are left with 3 lone pairs.
Fri Oct 14, 2016 5:38 pm
Forum: Significant Figures
Topic: Addition and subtraction of significant figures with scientific notation?
Replies: 4
Views: 882

### Re: Addition and subtraction of significant figures with scientific notation?

When adding and subtracting I believe you are supposed to round the answer to the smallest decimal place.