Search found 26 matches

by amyjunus1A
Mon Mar 07, 2016 10:48 am
Forum: *Nucleophiles
Topic: Double Bonds
Replies: 3
Views: 512

Re: Double Bonds

It is helpful to think of anywhere where there is a lot of electrons (double/triple bonds or lone pairs being the most prominent) as an electron-rich area that will contribute to making a nucleophile.
by amyjunus1A
Tue Mar 01, 2016 7:43 pm
Forum: *Alkenes
Topic: Naming Alkene
Replies: 5
Views: 771

Re: Naming Alkene

I have not seen the number placed after the "pentene" or final name at all, so I would not suggest doing that (it most likely is wrong).
by amyjunus1A
Tue Feb 23, 2016 9:37 am
Forum: *Electrophiles
Topic: Deciding where electrophile goes
Replies: 2
Views: 417

Re: Deciding where electrophile goes

Depending on what the compounds are, the location of the added electrophile will attach to certain spots. This ultimately depends on the stability of the compounds formed. One example where location of added electrophiles doesn't matter is attaching a Br from Br2 to C2H4. One example where location ...
by amyjunus1A
Wed Feb 17, 2016 2:04 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Quiz 2 2015 #5
Replies: 1
Views: 343

Re: Quiz 2 2015 #5

I believe this question is best answered by using mathematical, linear graphs of lnk v 1/T. We know from the linear version of the Arrhenius Equation that the slope of the line is -Ea/R given that the x axis is 1/T and the y axis is lnk. Therefore we know that the smaller the Ea, then the less steep...
by amyjunus1A
Wed Feb 10, 2016 11:31 am
Forum: Balancing Redox Reactions
Topic: pairs of redox couples
Replies: 3
Views: 615

Re: pairs of redox couples

The important thing to remember is the cathode is the better oxidizing agent (gains electrons), thus the reduction number (which is given) must be more positive. Hopefully that helps a little.
by amyjunus1A
Wed Feb 03, 2016 12:13 am
Forum: Balancing Redox Reactions
Topic: 14.7
Replies: 1
Views: 2254

Re: 14.7

The way that first comes to my mind is to look in the Appendix 2 for the most common principal oxidation states. Then when looking at the oxidations states, start a trial and error given the information we have. The three most common oxidation states for P: -3, +3, +5, and the three most common oxid...
by amyjunus1A
Tue Jan 26, 2016 9:01 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Expansion work
Replies: 4
Views: 590

Re: Expansion work

To make it even easier to understand, keep in mind that work can be converted to heat, and (although not all may be transferred) thus heat can be converted to work! Thus no change in volume (even though its the most common way to make work) is necessary for work. Hopefully this helps a little.
by amyjunus1A
Mon Jan 18, 2016 1:21 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Clarification on First Law of Thermodynamics
Replies: 1
Views: 255

Re: Clarification on First Law of Thermodynamics

I hope that this is correct, but according to my understanding an isolated system does not allow for any matter change and energy change. So in this case, no work is done/done on it and no heat is transferred/absorbed. Therefore, the deltaU will = 0. Hope that helps!
by amyjunus1A
Mon Jan 11, 2016 8:18 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: System Vs. Surrounding
Replies: 2
Views: 811

Re: System Vs. Surrounding

It's also much easier to understand enthalpy (at least for me) when you consider it in terms of the system first before the surroundings. If the change is positive then consider the system and you will be able to understand that the positive means heat is absorbed or added to the system. Then you ca...
by amyjunus1A
Mon Jan 11, 2016 8:15 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Q. 8.49 Assuming standard reactions
Replies: 1
Views: 336

Re: Q. 8.49 Assuming standard reactions

I believe in this case there is the assumption of normal conditions. While sometimes there are indications that standard conditions are used or not used, assumedly most of these questions will occur under normal conditions unless specifically told otherwise.
by amyjunus1A
Fri Jan 08, 2016 11:15 am
Forum: Phase Changes & Related Calculations
Topic: Heat Capacity and Phase Change
Replies: 2
Views: 334

Re: Heat Capacity and Phase Change

According my understand about phase changes, it is based off of the specific substance and the phase that its changing from and to. It is true that heat capacity is also specific to substances, so they may be related in that way, but other than that I'm not entirely sure. Hopefully this helps a litt...
by amyjunus1A
Sun Nov 29, 2015 5:05 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: VIDEO: Doing ICE-Box Equilibrium Problems
Replies: 3
Views: 414

Re: VIDEO: Doing ICE-Box Equilibrium Problems

Here is an MP4 version. I'm not too sure if this was needed, but I hope this helps.

My Movie.mp4 [ 34.65 MiB | Viewed 359 times ]

by amyjunus1A
Sat Nov 21, 2015 6:35 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Endothermic vs Exothermic problem notation
Replies: 2
Views: 749

Re: Endothermic vs Exothermic problem notation

Please correct me if I am wrong, but I believe (to make it a little simpler), that if there is a "+" then that means energy is required to push the reaction to occur. If energy is required, which normally comes in the form of heat, then the reaction is endothermic. So a positive sign typic...
by amyjunus1A
Mon Nov 09, 2015 9:11 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: VIDEO: Doing ICE-Box Equilibrium Problems
Replies: 3
Views: 414

VIDEO: Doing ICE-Box Equilibrium Problems

trim.EDBC2AC2-B012-4968-A526-A1E6A76C14E2.MOV [ 113.66 MiB | Viewed 414 times ]

by amyjunus1A
Sun Nov 08, 2015 3:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Calculating Chemical Equilibrium
Replies: 2
Views: 471

Re: Calculating Chemical Equilibrium

I believe what Dr. Lavelle mentioned in his last lecture was how even if you were to add the Concentrations of Solids and Liquids, they would not change (from product to reactant and vice versa) because they are pure. Hence they would cancel each other out in the equation when calculating the Equili...
by amyjunus1A
Sun Nov 08, 2015 3:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids and Liquids Chemical Equilibrium
Replies: 1
Views: 261

Re: Solids and Liquids Chemical Equilibrium

Correct me if I am wrong (since I do have an older version of the course reader), but I cannot find a reaction with all solids or liquids where Dr. Lavelle is attempting to find the equiibirum constant. I can find a reaction with solid and aqueous, in which case you woud use the aqueous, and I can f...
by amyjunus1A
Sun Nov 08, 2015 3:18 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium constant
Replies: 2
Views: 311

Re: Equilibrium constant

I am not quite too sure about the definite reason behind the choice of (Product Concentration)/(Reactant Concentration), but the reasoning of Millie seems quite legitimate. However to answer the other part of your question, I would suggest not switching them, because in Equilibrium problems, there i...
by amyjunus1A
Sun Nov 08, 2015 3:10 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Calculating the equilibrium composition
Replies: 4
Views: 476

Re: Calculating the equilibrium composition

Can you further explain your question? Do you mean in terms of change in molar concentration for equilibrium or for change in molar concentration in one molecule in general?
by amyjunus1A
Sat Oct 31, 2015 12:09 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Order and # of Electrons for stability
Replies: 3
Views: 725

Re: Bond Order and # of Electrons for stability

It may help to post what question this is, because I am not too sure.
However, I can say that perhaps this question has to do with lone pairs on the molecule, which would lead to less stability.
by amyjunus1A
Sat Oct 31, 2015 12:05 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Quiz 2 Preparation Fall 2013 #6
Replies: 1
Views: 200

Re: Quiz 2 Preparation Fall 2013 #6

I thought that I answered this question previously, but I guess it never uploaded. I would suggest just writing out the electron configuration in replacement of drawing out the entire MO Energy Diagram, which admittedly takes quite a while. I do believe that this is possible as long as we are aware ...
by amyjunus1A
Sat Oct 31, 2015 11:53 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: MO? Bond Order?
Replies: 2
Views: 574

Re: MO? Bond Order?

Just how we use atomic orbitals to gain a general sense of where the electron may be located, we would also want to gain a general sense of where an electron may be located in a molecule. However, since a molecule contains more bonding, we cannot just use the "simple" s, p, d, f, etc. orbi...
by amyjunus1A
Sat Oct 31, 2015 11:47 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: What order do you fill bonds?
Replies: 3
Views: 525

Re: What order do you fill bonds?

For this particular question, you fill up the specific energy levels before continuing on. Since pi and sigma bonds have different energy levels, you would fill up the (sigma pz) before the (pi px) and (pi py). However, remember that there can be Z<8 or Z>/= 8, each which fills up the MO in slightly...
by amyjunus1A
Fri Oct 23, 2015 2:24 pm
Forum: Hybridization
Topic: Energy Levels and Orbitals
Replies: 2
Views: 439

Re: Energy Levels and Orbitals

What really helps me understand this concept is going back to the idea of Quantum Numbers (n, l, m(l), m(s)). In this case, n is the principal quantum number or the shell (n=1,2,3,...). The next number, l, is the sub-shell or groups of orbitals (l=0(s), (1)p, (2)d, (3)f). Within these sub-shells are...
by amyjunus1A
Sat Oct 17, 2015 11:35 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape of Water
Replies: 2
Views: 429

Re: Molecular Shape of Water

I think it is also important to note that because of electron affinity/electronegativity, the water molecule has a dipole moment (has polarity). Since Oxygen has a greater electronegativity, it will attract the electrons and pull them closer thus creating a slight positive charge around its own atom...
by amyjunus1A
Fri Oct 09, 2015 1:52 pm
Forum: Significant Figures
Topic: Periodic Table Molar Masses
Replies: 1
Views: 478

Re: Periodic Table Molar Masses

Hello, I believe that on the quiz and exams, we will be given the information (molar masses), and we should use what information we are given. If there is a need to use less or more significant figures it should either be indicated with a new rounded or extended molar mass, or the significant figure...
by amyjunus1A
Fri Oct 02, 2015 3:52 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg Equation Purpose
Replies: 2
Views: 508

Re: Heisenberg Equation Purpose

At a basic level, the Heisenburg Indetermincy Equation is a simple, mathematical model for the Heisenburg Uncertainty Principle. It allows us to be able to quantitatively measure the uncertainty in a particle's (typically an electron's) velocity or position (according to my knowledge). In looking at...

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