Search found 22 matches
- Sat Mar 12, 2016 3:06 am
- Forum: *Cycloalkanes
- Topic: Atomic number vs Alphabetizing
- Replies: 1
- Views: 450
Atomic number vs Alphabetizing
When naming a cyclohexane with the substituents of Iodine and Bromine for example, would you give the lower number to the Bromine because of alphabetizing or would you give it to the Iodine because it has a higher atomic number?
- Fri Mar 11, 2016 4:18 pm
- Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
- Topic: Equatorial Priority
- Replies: 1
- Views: 1162
Equatorial Priority
Do you determine which element substituent is prioritized to get the equatorial position in a chair conformation based on higher atomic number or higher atomic radius? For example with Br and Cl as substituents.
- Wed Mar 02, 2016 10:45 pm
- Forum: *Alkenes
- Topic: Bond Angle of Alkene
- Replies: 1
- Views: 641
Bond Angle of Alkene
What are the bond angles of the carbons in alkenes? For example C3H6?
- Wed Feb 24, 2016 6:13 pm
- Forum: *Electrophilic Addition
- Topic: Single Headed Arrow
- Replies: 1
- Views: 569
Single Headed Arrow
When drawing the arrow from nucleophiles to electrophile, what is an example of when only one electron moves from nucleophile to electrophile? It seems like all the examples are normally with double headed arrows.
- Fri Feb 19, 2016 7:34 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Spontaneous Rxn vs Energetically Favorable
- Replies: 1
- Views: 1127
Spontaneous Rxn vs Energetically Favorable
What is the difference between a spontaneous reaction and an energetically favorable reaction in terms of the graph of the reactants to products?
- Mon Feb 08, 2016 10:40 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Winter 2015 Midterm 4B
- Replies: 1
- Views: 499
Winter 2015 Midterm 4B
In the problem, the volume is expanding from 3.3L to 9.2*10^5 L. However, when calculating the heat capacity for step 2, the solution says that volume is constant and C= 3/2(R). Shouldn't it be 5/2(R) because the pressure is constant?
- Mon Feb 08, 2016 12:18 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Determining Overall Reaction
- Replies: 1
- Views: 444
Determining Overall Reaction
If you are given two half reactions (both written as reductions) and are asked to write the overall reaction, how do you determine which half reaction is the oxidized reaction and should be flipped? For example, 7A in the 2011 Midterm.
- Fri Feb 05, 2016 11:37 am
- Forum: Calculating Work of Expansion
- Topic: Expanding Freely
- Replies: 1
- Views: 420
Expanding Freely
Why is a system that is expanding freely considered to be doing zero work?
- Mon Jan 25, 2016 4:59 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Isothermal
- Replies: 3
- Views: 651
Isothermal
When a system is isothermal, isn't q (enthalpy) always 0 because delta T is 0? In our practice quizzes, it showed q to equal -w. Is this because it was reversible? If it was irreversible, would q then be equal to 0?
- Wed Jan 20, 2016 12:13 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Calculating q (Enthalpy)
- Replies: 2
- Views: 535
Calculating q (Enthalpy)
In homework problem 8.53, the answer key uses the equation q= -C x T. Why is moles or grams not taken into account for this problem? Why is it necessary to use this equation rather than q= n x C x T?
- Tue Jan 12, 2016 5:33 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Enthalpy Calculation
- Replies: 1
- Views: 451
Enthalpy Calculation
When calculating enthalpy, how do you know when to use grams in the equation (grams x specific heat x change in temperature) or moles in the equation (moles x molar heat capacity x change in temperature) ? How do the two equations differ?
- Wed Jan 06, 2016 6:07 pm
- Forum: Phase Changes & Related Calculations
- Topic: Steam
- Replies: 2
- Views: 575
Steam
When steam touches the skin, Dr. Lavelle explained how first it would phase change to water (40.7 kJ/mol) and then would decrease in temperature, still in the liquid phase. Could you predict how much the temperature of the water will actually decrease by taking the average of the temperature of the ...
- Thu Dec 03, 2015 1:10 am
- Forum: Conjugate Acids & Bases
- Topic: Autoprotolysis
- Replies: 1
- Views: 504
Autoprotolysis
In the course reader, the definition of an autoprotolysis reaction is when one molecule transfers a proton to another molecule of the same type. What does it mean when it says "same type"? Does this mean an acid/base with its conjugate?
- Wed Nov 25, 2015 11:30 pm
- Forum: Conjugate Acids & Bases
- Topic: Protonating the Carboxyl Group
- Replies: 1
- Views: 440
Protonating the Carboxyl Group
For a compound with COO- attached, one of the O's has three lone pairs and therefore has a high affinity for protons and can pull off a hydrogen from water so that the formal charge becomes zero. However, once this occurs, the oxygen in water molecule has three lone pairs. Does this mean that the pr...
- Tue Nov 17, 2015 4:02 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Dentates
- Replies: 1
- Views: 495
Dentates
When determining if a molecule is monodentate or polydentate, do you simply look at the number of lone electron pairs? Or should you also take formal charge into account? For example oxygen with 2 lone pairs and 2 bonds has a formal charge of 0 but 2 lone pairs. Does that mean it is polydentate or m...
- Thu Nov 12, 2015 6:54 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Effects of Changing Volume
- Replies: 1
- Views: 381
Effects of Changing Volume
During lecture, Dr. Lavelle mentioned that a quick way to determine if a reaction follows a forward or reverse reaction by decreasing volume could be comparing the number of moles of both product(s) and reactant(s). How would you apply this if the moles were equal for both products and reactants? Wo...
- Tue Nov 03, 2015 10:29 pm
- Forum: Dipole Moments
- Topic: Polarity of Double Bonds
- Replies: 1
- Views: 3536
Polarity of Double Bonds
Is an anion such as PO4 3- , which has 3 single bonds and 1 double bond, considered polar? Would the double bond of one of the oxygens cause that oxygen to pull more electrons because it has a shorter distance from the central atom, causing a dipole moment?
- Tue Oct 27, 2015 9:44 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Linear Molecular Geometry
- Replies: 2
- Views: 797
Linear Molecular Geometry
If the shape of a molecule is linear with lone pairs, is the bond angle always still 180 degrees or can it be less than that as a result of lone pair repulsion?
- Wed Oct 21, 2015 3:33 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pair Repulsion for T-shape
- Replies: 1
- Views: 589
Lone Pair Repulsion for T-shape
Dr. Lavelle mentioned that when creating a Lewis diagram, lone pairs must be placed as far as possible from each other. However, with the Lewis structure of IF3, for example, the two sets of lone pairs for Iodine are right next to each other as the molecule forms a T-shape structure. Why aren't the ...
- Wed Oct 14, 2015 9:32 pm
- Forum: Trends in The Periodic Table
- Topic: 2nd Ionization Energy
- Replies: 2
- Views: 724
2nd Ionization Energy
During lecture, Dr. Lavelle mentioned that the 2nd ionization energy of an element is always higher. What about an element like magnesium when you have already removed an electron and the electron configuration is now [Ne]3s1? Wouldn't the element be more "willing" to give up another elect...
- Mon Oct 05, 2015 11:54 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Angular Momentum
- Replies: 1
- Views: 394
Angular Momentum
In the course reader, it explains that angular momentum can have the values l=0,1,2,...,n-1. Since n can go all the way to 7, can the angular momentum go beyond 3? If so, what orbital does the angular momentum correspond to once it exceeds 3 with the f-orbital?
- Tue Sep 29, 2015 10:07 am
- Forum: Properties of Light
- Topic: Increasing Intensity of Light
- Replies: 2
- Views: 697
Increasing Intensity of Light
During lecture, Dr. Lavelle mentioned that an increase in light intensity does not mean an increase in energy, but rather just an increase in number of photons emitted. However, by increasing the number of photons, which are packets of energy, isn't energy also increased as a result? Therefore, is i...