Search found 21 matches
- Fri Mar 11, 2016 9:21 pm
- Forum: *Alkanes
- Topic: cis vs trans
- Replies: 2
- Views: 574
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: 506
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: 673
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: 745
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: 543
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: 470
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: 429
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: 540
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: 793
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: 330
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: 703
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: 450
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: 504
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: 847
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
- Topic: General info about ligands
- Replies: 1
- Views: 378
General info about ligands
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: 590
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: 714
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: 616
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: 2602
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: 616
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!
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: 170
- Views: 33495
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?