## Search found 21 matches

Fri Mar 11, 2016 9:21 pm
Forum: *Alkanes
Topic: cis vs trans
Replies: 2
Views: 356

### cis vs trans

How do you determine if a compound is cis or if it is trans?
Tue Mar 01, 2016 8:22 pm
Forum: *Nucleophiles
Topic: Ambident nucleophile
Replies: 1
Views: 334

### Ambident nucleophile

What does it mean for a nucleophile to be ambident?
Thu Feb 25, 2016 6:56 am
Forum: General Rate Laws
Topic: Rate Constant K
Replies: 2
Views: 450

### Re: Rate Constant K

K= [products]^n/[reactants]^m where n and m are the respective number of moles
Mon Feb 15, 2016 6:12 pm
Forum: First Order Reactions
Topic: Half-life
Replies: 2
Views: 413

### Half-life

When deriving the half-life equation for a 1st order reaction I am stuck on how ln 1[A]/2[A] becomes -.693. Can someone please explain how that number was reached?
Wed Feb 10, 2016 12:07 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Winter 2014 Midterm #8
Replies: 1
Views: 366

### Winter 2014 Midterm #8

Q8: Using the standard cell potentials: F2 (g) + 2 H+ (aq) + 2e --> 2HF (aq) E(not)= 3.03 V F2 (g) + 2e --> 2F- (aq) E (not)= 2.87 V For this question I wanted to flip the second reaction because 3.03-2.87 would leave the E cell a positive, but the answer flipped the first reaction and made the E ce...
Mon Feb 08, 2016 3:28 pm
Forum: Balancing Redox Reactions
Topic: Redox Reactions
Replies: 1
Views: 277

### Redox Reactions

How do we know if a reaction is acidic or basic, so how do we know when to add H+ or OH-?
Wed Feb 03, 2016 2:29 pm
Forum: Balancing Redox Reactions
Topic: Oxidation Numbers
Replies: 1
Views: 307

### Oxidation Numbers

Okay this may seem like a very basic question, but how do we know what the charges are for an element? When we are doing the acidic and basic medium equations that is the only part I am confused on, because sometimes it says +2 or -1, but what about when it doesn't say anything?
Tue Jan 26, 2016 11:35 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: Residual entropy
Replies: 1
Views: 382

### Residual entropy

Hi I need help calculating the residual entropy at T close to 0 K for 1 mil of bromobenzene (C6H5Br)
Wed Jan 20, 2016 11:02 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Entropy Practice Quiz 2014 #6
Replies: 3
Views: 473

### Entropy Practice Quiz 2014 #6

6. Which of the following statements is correct? a) C2H5OH (at 298 K) has higher molar entropy than CH4 (g), because C2H5OH is a larger molecule than CH4, and larger molecules have more chemical bonds and can store energy in more ways than smaller molecules. b) CH4 (g) has higher molar entropy than ...
Mon Jan 11, 2016 12:22 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Pistons
Replies: 1
Views: 236

### Pistons

What is a piston? Today we talked about if the piston goes in/out, but I didn't know what a piston was so I was confused.
Wed Jan 06, 2016 12:27 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy values
Replies: 2
Views: 470

### Enthalpy values

How do you find the enthrapy values when bonds are broken or formed?
Wed Nov 25, 2015 10:02 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Video Midterm Question #4
Replies: 1
Views: 319

### Video Midterm Question #4

Midterm review question #4.
Mon Nov 23, 2015 10:53 pm
Forum: Lewis Acids & Bases
Topic: Acids and Bases
Replies: 1
Views: 293

### Acids and Bases

How do we tell if a compound is an acid or a base in simplest terms?
Thu Nov 12, 2015 4:23 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Compression and photosynthesis. 11.115 hmwk
Replies: 4
Views: 567

### Re: Compression and photosynthesis. 11.115 hmwk

Why would you not include H2O?
Mon Nov 02, 2015 6:04 pm
Forum: Shape, Structure, Coordination Number, Ligands
Replies: 1
Views: 256

What is the concept of ligands? What are they and what are they used for? This section has really been confusing me.
Wed Oct 21, 2015 3:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarity and electronegativity
Replies: 2
Views: 302

### Polarity and electronegativity

Someone previously asked how we determine polarity and they said that it has to do with electronegativity and shape. But I don't understand how we determine the electronegativity? Can someone please explain this.
Tue Oct 13, 2015 9:39 pm
Forum: Quantum Numbers and The H-Atom
Topic: Spin State
Replies: 3
Views: 476

### Re: Spin State

So basically we determine the spin value? We just pick one?
Tue Oct 13, 2015 9:38 pm
Forum: Quantum Numbers and The H-Atom
Topic: quiz 1 preparation 2014
Replies: 2
Views: 424

### Re: quiz 1 preparation 2014

Thanks so much! That helped a ton!
Tue Oct 13, 2015 9:36 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Delta x
Replies: 4
Views: 1340

### Re: Delta x

If they give us delta x as a radius, do we have to multiply it by 2 to make it the diameter or do we use whatever they give us?
Thu Oct 08, 2015 4:36 pm
Forum: Quantum Numbers and The H-Atom
Topic: quiz 1 preparation 2014
Replies: 2
Views: 424

### quiz 1 preparation 2014

I am doing the quiz prep and do not understand how to do number 10. The question is:
An excited hydrogen atom emits light with a frequency of 1.14 x 10^14 Hz to reach the energy level for which n=4. In what principle quantum level did the electron begin?
Thanks so much for any help!
Wed Sep 30, 2015 3:07 pm
Forum: Significant Figures
Topic: All students read this sig fig post [ENDORSED]
Replies: 116
Views: 11251

### Re: All students read this sig fig post[ENDORSED]

Do you know if the problems will specifically tell us how many significant figures to use?