Search found 25 matches
- Thu Mar 10, 2016 4:12 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Cell potential
- Replies: 1
- Views: 387
Cell potential
Does increasing the amount of solid in a galvanic cell change the cell potential? Such as in the equation Na2S(s)+Cd[2+](aq)=CdS(aq)+2Na[+](aq) I would assume that, because of the Nernst Equation, the cell potential should not change because changing the amount of solid would not change Q, is this r...
- Wed Mar 09, 2016 2:26 am
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Residual Entropy
- Replies: 1
- Views: 447
Residual Entropy
Why does NO have a greater residual entropy than BF3 @ 0K?
- Thu Mar 03, 2016 6:20 pm
- Forum: *Alkenes
- Topic: Priority In Numbering
- Replies: 2
- Views: 711
Priority In Numbering
When there is both a functional group as well as a double bond in a Carbon structure, which is given priority?
- Mon Feb 29, 2016 5:19 pm
- Forum: *Alkanes
- Topic: Order of substituents
- Replies: 1
- Views: 409
Order of substituents
let's say that instead of isopropyl, I decided to name my substituent using IUPAC naming rules and named it 1-methylethyl. If I was sorting this in alphabetical order amongst other substituents, would I base it off of the "M" in methyl or "E" in ethyl since ethyl is the parent (s...
- Mon Feb 29, 2016 1:46 pm
- Forum: *Organic Reaction Mechanisms in General
- Topic: SN2 vs Friedal-Crafts Alkylation
- Replies: 1
- Views: 599
SN2 vs Friedal-Crafts Alkylation
What is the difference between an SN2 reaction and a Friedal-Crafts alkylation if they both involve the addition of a nucleophile onto an organic compound?
- Sun Feb 28, 2016 10:12 pm
- Forum: *Electrophiles
- Topic: Ambident Nucleophile
- Replies: 1
- Views: 510
Ambident Nucleophile
Why are SCN- and CN- Ambident Nucleophiles?
- Sun Feb 21, 2016 10:26 pm
- Forum: *Electrophiles
- Topic: Electrophiles and Nucleophiles
- Replies: 1
- Views: 447
Electrophiles and Nucleophiles
After a reaction where a nucleophile "donates" electrons to a electrophile, can the nucleophile then become an electrophile? can something be a nucleophile and an electrophile?
- Tue Feb 09, 2016 12:55 am
- Forum: Balancing Redox Reactions
- Topic: Q7 2013 Midterm
- Replies: 1
- Views: 460
Q7 2013 Midterm
On Question 7 of the 2013 Midterm we are asked to balance a redox reaction. When balancing however it is required we use H+ to balance out the water molecules, but it is not stated explicitly whether the reaction is occurring under acidic or basic conditions. Are we to assume that it is always under...
- Sat Feb 06, 2016 7:03 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 1
- Views: 418
Cell Diagrams
When creating a cell diagram where the reactants and products are not solid, how do I know whether to use Pt or Graphite?
- Sat Feb 06, 2016 3:50 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst Equation Concentrations.
- Replies: 1
- Views: 432
Nernst Equation Concentrations.
When using the Nernst equation, if I have some reactants and products that involve concentrations using molarity and others that use partial pressures, is there any conversions I need to make?
- Mon Jan 25, 2016 10:01 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Calculating final temperature of a system
- Replies: 3
- Views: 700
Calculating final temperature of a system
When calculating the final temperature of a system using initial temperatures of the objects involved, heat capacities, and masses, must we always convert the temperature from Celsius to Kelvin from the start?
- Sun Jan 24, 2016 5:42 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Change in Entropy for reversible vs irreversible expansion
- Replies: 1
- Views: 383
Change in Entropy for reversible vs irreversible expansion
Is any work done in free expansion? And if not, because there is no change in internal energy, would it mean that there is no heat and therefore q=0 for the surroundings, so there is no entropy change due to delta S= q/T? Also would the change in entropy of the system be the same in a reversible pat...
- Sun Jan 17, 2016 3:05 pm
- Forum: Phase Changes & Related Calculations
- Topic: Systems at constant pressure
- Replies: 1
- Views: 563
Systems at constant pressure
If a questions says a system is at constant pressure, that would mean that volume is changing, would that mean that we can assume internal pressure = external pressure?
- Sun Jan 10, 2016 6:01 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: When to use each method
- Replies: 3
- Views: 711
When to use each method
Would Hess's Law, Bond Enthalpies, and Standard Enthalpies of Formation all be appropriate ways of finding Reaction Enthalpies, but we use one based on the information provided to us in the question?
- Sun Dec 06, 2015 10:41 am
- Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
- Topic: When to use the Henderson-Hasselbalch Equation
- Replies: 4
- Views: 2930
When to use the Henderson-Hasselbalch Equation
Can I use the Henderson-Hasselbalch equation when I have a weak acid that is being titrated by a strong base, but not all the way to the stoichiometric point? I guess my real question would be, is the HH equation valid when the volume (and thus molarity) of a system is changing (if I were to calcula...
- Sat Dec 05, 2015 11:05 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: LUMO and HOMO
- Replies: 2
- Views: 4286
LUMO and HOMO
If I were filling out the Molecular Orbital Diagram for B2- (Two Borons with a -1 charge) I would have 7 valence electrons. The Homo would be one of the pi2p orbitals since one (either the pi2px or pi2py) contains an unpaired electron. However, I was wondering would the LUMO be considered the other ...
- Thu Dec 03, 2015 1:05 pm
- Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
- Topic: Amphiprotic Molecules
- Replies: 1
- Views: 554
Amphiprotic Molecules
Could an aqueous solution of an amphiprotic molecule act as a buffer?
- Thu Nov 26, 2015 10:33 pm
- Forum: Conjugate Acids & Bases
- Topic: Conjugate acids and bases
- Replies: 1
- Views: 580
Conjugate acids and bases
I just wanted to make sure, once an acid loses its proton, it becomes its conjugate base, and once a base accepts a proton it becomes its conjugate acid?
- Wed Nov 18, 2015 12:34 pm
- Forum: Ideal Gases
- Topic: Total Pressure of a System
- Replies: 1
- Views: 516
Total Pressure of a System
When trying to figure out the pressure of an entire system as a whole, do you simply add partial pressures? if you do, do you multiply the partial pressures of each compound by the amount of moles first?
- Wed Nov 18, 2015 9:36 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Shape when dealing with polydentates
- Replies: 2
- Views: 625
Shape when dealing with polydentates
Would the shape of a coordination compound only be dependent on regions of electron density? For example if there were two bidentates bound to TM, would its shape still be tetrahedral and would everything else (coordination number, shape, # of ligands, etc.) be the same as if I had 4 monodentates bo...
- Sun Nov 08, 2015 10:03 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Equilibrium
- Replies: 1
- Views: 353
Equilibrium
So when a chemical reaction is at equilibrium, that just means k remains constant? So if you were to measure "Q" it would equal K?
- Wed Oct 28, 2015 10:06 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polarization of a molecule with loose electrons
- Replies: 1
- Views: 566
Polarization of a molecule with loose electrons
I know how polarization works in molecules when they have certain shapes and molecular structures in terms of the electronegativity differences between atoms, but I was wondering what the rule is for molecules that have a pair of electrons that are not bonded (loose electrons)? For example, in ozone...
- Fri Oct 23, 2015 7:39 pm
- Forum: Hybridization
- Topic: Hybridization
- Replies: 1
- Views: 382
Hybridization
Does hybridization happen to all p-block elements, and if so, what would it look like in an oxygen atom with two sigma bonds and 2 lone pairs of electrons?
- Sun Oct 11, 2015 4:52 pm
- Forum: Trends in The Periodic Table
- Topic: Effective Nuclear Charge
- Replies: 1
- Views: 783
Effective Nuclear Charge
What is the Effective Nuclear Charge and what does it depend on?
- Thu Oct 01, 2015 4:54 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Lecture Question
- Replies: 1
- Views: 412
Re: Lecture Question
The negative result simply means that the electron went from a higher energy level, to a lower energy level, releasing radiation. However, you should view the energy itself as a positive value.