Search found 17 matches

Wed Mar 09, 2016 9:03 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Winter Final 2012 2C
Replies: 1
Views: 346

Re: Winter Final 2012 2C

According to the problem, the Helium gas is heated up in the non-expandable case up to 100 degrees before it is allowed to leak out. Since the case is non-expandable, the volume is constant and you thus use Cv instead of Cp. During the heating process, since the volume is constant, the pressure is g...
Sun Mar 06, 2016 11:23 pm
Forum: *Ethers
Topic: Self-Test 2.10A
Replies: 1
Views: 360

Re: Self-Test 2.10A

I also noticed this mistake and do believe the textbook has a mistake. The functional group should get the lowest number, so I think it should get the 2.
Sun Feb 28, 2016 9:28 pm
Forum: *Alkanes
Topic: Numbering and Alphabetizing
Replies: 1
Views: 345

Re: Numbering and Alphabetizing

According to IUPAC, the number of the substituent goes first in order to have the lowest numbering for them. If we alphabetized first, we might not get the lowest possible number combinations. So yes, we always number substituents first.
Sun Feb 21, 2016 10:24 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8017
Views: 1403391

Re: Chemistry Jokes

When one physicist asks another, "What's new?" The physicist says?

C over lambda.
Sun Feb 14, 2016 11:25 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Rate Constant (k) and order (n)
Replies: 1
Views: 412

Re: Rate Constant (k) and order (n)

The rate constant K represents the change in molarity over a given period of time for a particular reaction. For example, mols/(L x seconds) are common units for a rate constant The n represents the exponent of a given substance in a reactant which its concentration term in the reaction rate is rais...
Sat Feb 06, 2016 8:00 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: K value
Replies: 2
Views: 520

K value

When given a redox reaction, how can someone determine whether or not the K value is greater than one? If the K value is greater than one, is the going to go forward?
Thu Jan 28, 2016 12:42 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Multiple Cell Bridges and Galvanic Cells?
Replies: 2
Views: 321

Re: Multiple Cell Bridges and Galvanic Cells?

In terms of multiple salt and voltaic bridges, I don't believe there would ever be a case in which you would need more than one. I believe adding another set of bridges would split the current being sent through them by half. If you have a solution with two or more anodes or cathodes, if they aren't...
Fri Jan 22, 2016 6:37 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Spontaneity of a reaction
Replies: 1
Views: 285

Re: Spontaneity of a reaction

Gibb's free energy is equal to the maximum useful work which can be accomplished by the reaction. Therefore, if a reaction has a negative delta G, it means that work was done by the system as opposed to the surroundings, making the reaction favorable and thus will occur spontaneously. A reaction tha...
Sun Jan 17, 2016 9:21 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: State functions
Replies: 2
Views: 419

Re: State functions

Since the path taken to reach the final state does not affect the property, the state function is independent of the path function. Therefore, if we are only concerned with state functions, they can be added and subtracted because we're only working with the one given state of the enthalpies.
Sun Jan 10, 2016 8:45 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard Reaction Enthalpy
Replies: 1
Views: 337

Re: Standard Reaction Enthalpy

If the reaction is not occurring in a standard state, then the given experimental values for the enthalpies of the reaction will not be true for that reaction. The temperature and pressure effect the amount of energy released or absorbed.
Mon Nov 30, 2015 2:42 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect Video
Replies: 3
Views: 548

Re: Photoelectric Effect Video

Sorry, Just now posting in .wmv format. I could not figure out how to change the format.
Sat Nov 28, 2015 3:39 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Stronger Acid
Replies: 1
Views: 438

Stronger Acid

HW Question 12.50- How would you determine which is a stronger acid, HCN or NH4+? Would the fact that NH4+ is a positive ion make it easier to remove the protons due to repulsion from the nucleus?
Fri Nov 13, 2015 4:32 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 2013 Quiz 3 Preparation #10
Replies: 10
Views: 1194

Re: 2013 Quiz 3 Preparation #10

When making the ICE table, does the change in equilibrium become (.54 + 2x) due to the initial balanced equation. Also, how would one go about solving for the new equilibrium pressure?
Mon Nov 02, 2015 2:04 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Molecular Orbital Between Heterogenous Molecules
Replies: 1
Views: 275

Molecular Orbital Between Heterogenous Molecules

In a heterogenous molecule with one atom of Nuclear charge of Z>8 and another atom of Z<8, which Molecular orbital combination is used? The one for Z<8 or Z>8?
Mon Oct 26, 2015 2:13 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles for BH3-
Replies: 1
Views: 5065

Bond Angles for BH3-

Question 4.19 asks for the bond angles between the atoms in BH2-. There be a lone electron pair on the Boron atom and how would that affect the bond angles?
Wed Oct 21, 2015 11:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Square Planar Angles
Replies: 4
Views: 1304

Square Planar Angles

I know that when there is an unpaired set of electrons, the bonded pairs get pushed away due to the electrostatic repulsion. In a molecule with a square planar VSEPR Structure, will the angles between the remaining 4 bonded atoms remain 90 degrees , or will the repulsion push them closer together?
Tue Oct 06, 2015 7:21 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals, value of l
Replies: 5
Views: 761

Re: Orbitals, value of l

Hi Marvin, I'm pretty sure that there are no orbitals beyond the f-orbitals. The positive nuclear charge of the nucleus is shielded by too many core electrons to keep the valence electrons from leaving. The effective nuclear charge is also a lot less, therefore the attraction between the valence ele...