Search found 46 matches

by Aleck Sun 1J
Sun Mar 13, 2016 10:10 am
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Stable conformation for 1-chloro-3methylcyclohexane
Replies: 1
Views: 398

Re: Stable conformation for 1-chloro-3methylcyclohexane

For cis/trans, you don't look at whether or not the substituents are equitorial vs. axial. This is because all substituents on different carbons will always be on the equitorial position to be the most stable. Instead, for cis/trans, you look at whether the substituent is pointing up or pointing dow...
by Aleck Sun 1J
Sat Mar 12, 2016 10:22 pm
Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
Topic: Cis and Trans for 3 substuents
Replies: 3
Views: 418

Re: Cis and Trans for 3 substuents

My question was actually how do we assign cis and trans for 3 substituents in an alkane not alkene, since I was told that cis/trans also applies to cyclic rings.
by Aleck Sun 1J
Sat Mar 12, 2016 8:26 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Internal Energy for a Reversible Adiabatic
Replies: 1
Views: 393

Internal Energy for a Reversible Adiabatic

In a reversible adiabatic system, q=0. That means that internal energy is equal to work. Why is internal energy equal to nCvdeltaT? Can delta U also be -nRTln(V2/V1) since it's reversible?
by Aleck Sun 1J
Sat Mar 12, 2016 7:49 pm
Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
Topic: Cis and Trans for 3 substuents
Replies: 3
Views: 418

Cis and Trans for 3 substuents

How would you designate cis and trans for 3 substituents (if you can) in a cycloalkane? Would you only look at the two highest priority subsituents when determining cis vs. trans?
by Aleck Sun 1J
Sat Mar 12, 2016 7:44 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Determining Oxidation and Reduction in a Concentration Cell
Replies: 1
Views: 286

Determining Oxidation and Reduction in a Concentration Cell

In a concentration cell, both sides of the battery consists of the same ions, but at different concentrations. For example if one side of the cell is 10 M and the other side is 1 M, how do you determine which side is oxidation and which side is reduction?
by Aleck Sun 1J
Sat Mar 12, 2016 11:08 am
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Torsional vs. Steric Strain Identification.
Replies: 1
Views: 406

Torsional vs. Steric Strain Identification.

I understand that torsional strain is a force that opposes rotation due to electrons causing it to repel. I also understand that steric strain results in two large molecules that want to occupy thr same space. I was wondering if a molecule has steric strain, would it be assumed that it also has tors...
by Aleck Sun 1J
Wed Mar 09, 2016 6:52 pm
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Question 7C from Final 2011
Replies: 1
Views: 334

Re: Question 7C from Final 2011

Yes, the oxygen does come from the heptanone. The suffix -one, means that there is a functional group, ketone. The ketone functional group has three carbons single bonded to each other and an oxygen double bonded to the middle carbon.
by Aleck Sun 1J
Tue Mar 08, 2016 4:48 pm
Forum: *Ketones
Topic: 2, 2-Dimethyl-3-Pentanone
Replies: 1
Views: 704

2, 2-Dimethyl-3-Pentanone

In the organic textbook, question 2.27 asks to draw the structure for 2, 2-Dimethyl-3-Pentanone. I was wondering why the ketone doesn't get the lowest number when naming. When naming a parent chain, aren't we supposed to ensure that the lowest number goes to the functional groups before moving on to...
by Aleck Sun 1J
Tue Mar 08, 2016 12:09 am
Forum: *Alcohols
Topic: Alcohol Types
Replies: 1
Views: 365

Re: Alcohol Types

Types of alcohols are divided based on which carbon the -OH group is attached to. For example, the secondary alcohol has the -OH group attached to a secondary carbon (a carbon attached to two other carbons, hence the name secondary). Likewise, a tertiary alcohol is an alcohol attached to a tertiary ...
by Aleck Sun 1J
Wed Mar 02, 2016 10:49 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Nucleophilic and Electrophilic Interaction
Replies: 1
Views: 409

Nucleophilic and Electrophilic Interaction

In the molecule CH2O, I understand that when a nucleophile interacts with it, the electrons from the double bond would move towards the O leaving it slightly negative. The carbon would be slightly positive so the nucleophile would attach to the carbon. I don't understand whether the electrons from t...
by Aleck Sun 1J
Mon Feb 29, 2016 8:56 pm
Forum: *Cycloalkanes
Topic: Bicycloalkanes
Replies: 1
Views: 465

Bicycloalkanes

How would you interpret the longest chains and substituents in a bicycloalkane in order to name it based on its line structure? For example, in problem 1.18, they give us the line structure for the alkane which is nonlinear and asks us to name it? Is there any difference in naming cycloalkanes and b...
by Aleck Sun 1J
Sat Feb 27, 2016 1:34 am
Forum: *Cycloalkanes
Topic: C8H16 Line Structure
Replies: 1
Views: 610

C8H16 Line Structure

In Wednesday's lecture, Dr. Casey did an example of drawing the line structure of C8H16. She drew it as a cyclopentane with an isopropyl substituent with it. How did she know that it was a cyclopropane with substituents instead of a cyclooctane ring with no substituents? If the reason is because cyc...
by Aleck Sun 1J
Fri Feb 26, 2016 11:32 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Intermediates/Activation Energies 15.95d
Replies: 1
Views: 326

Re: Intermediates/Activation Energies 15.95d

In an energy profile, the intermediates are represented by the "valley" in between the peaks of the graph. If you were looking at the peaks of the graph, those represent the transition states that the reaction undergoes. Because the transition states are unstable, they will quickly form th...
by Aleck Sun 1J
Tue Feb 23, 2016 10:37 pm
Forum: *Free Energy of Activation vs Activation Energy
Topic: Reaction Profiles TS 1 vs. TS 2
Replies: 1
Views: 298

Reaction Profiles TS 1 vs. TS 2

Based on most if not all reaction profiles in the "Introduction to Organic Chemistry", the gibbs free energy for TS 1 is always greater than TS 2. Will this be true in all reactions? What do those peaks tell us about the reaction?
by Aleck Sun 1J
Sat Feb 20, 2016 11:34 pm
Forum: *Free Energy of Activation vs Activation Energy
Topic: Activation Energy
Replies: 7
Views: 414

Re: Activation Energy

Based on the graph, I think it means that you need a lot of free energy added to the reactants to get the reaction started, but once it reaches the peak of the graph (achieves activation energy), it releases a lot of energy, more than what it started out with in the first place (to get the products'...
by Aleck Sun 1J
Tue Feb 09, 2016 3:16 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Winter 2014 Midterm Q3C Pokemon Battle
Replies: 1
Views: 381

Winter 2014 Midterm Q3C Pokemon Battle

For part C of the question, it asks to find the volume of water that would create a steam at 100°C. In the solutions, it used the equation q(fire) =q(water) = mCdeltaT + ndeltaH. I was wondering why there isn't a negative sign in front of the q(water) like in q(sys) = -q(surr). Is it because there r...
by Aleck Sun 1J
Sat Feb 06, 2016 1:54 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Which Equation to Use to Find K
Replies: 1
Views: 320

Which Equation to Use to Find K

Given the delta G for a reaction, how would you find K? Should we use the log K = nE/0.0592V or the G=-RTlnK formula. If I'm not mistaken, one formula is derived from the other, but both dont produce the same answer. So which one is the right one to use?
by Aleck Sun 1J
Sat Feb 06, 2016 12:15 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Winter Midterm 2011 Q4
Replies: 1
Views: 222

Winter Midterm 2011 Q4

For this question, the equation PCl3(g) + Cl2(g) -> PCl5(g) is given as well as the Gibbs free energy of PCl5 and PCl3. In the solutions, when they calculated the delta G, they only used those two values using the G(products)-G(reactants) formula for the overall reaction. I was wondering why they ne...
by Aleck Sun 1J
Tue Feb 02, 2016 8:59 pm
Forum: Phase Changes & Related Calculations
Topic: Quick significant figures question
Replies: 4
Views: 655

Re: Quick significant figures question

When you use the gas constant R in your calculations, you are most likely using other values with lesser significant figures than R to multiply it with. Because the rule of significant figures and multiplication is to use the smallest number of significant figures in the factors, you would most like...
by Aleck Sun 1J
Mon Feb 01, 2016 11:12 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Self Test 14.4 Finding n of e-
Replies: 1
Views: 368

Self Test 14.4 Finding n of e-

The self test 14.3A asks to find the reaction Gibbs Free Energy of the reaction Cd(s) + 2Ni(OH)3(s) -> Cd(OH)2(s) + 2Ni(OH)2 (s) with a cell potential of +1.25 V. I am fully aware that we need to use the equation delta G = -nFE and that n is the moles of electrons. However, I'm confused about determ...
by Aleck Sun 1J
Thu Jan 28, 2016 7:38 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Entropy of Aqueous Solutions/Ions/Compounds
Replies: 1
Views: 2805

Entropy of Aqueous Solutions/Ions/Compounds

Does an aqueous ion/compound have a higher entropy than a solid? How would its entropy compare with solids, liquids, and gases?
by Aleck Sun 1J
Tue Jan 19, 2016 4:07 pm
Forum: Phase Changes & Related Calculations
Topic: Heat of Fusion Title
Replies: 2
Views: 488

Heat of Fusion Title

I don't quite understand why the term "heat of fusion" is used to describe the heat required to undergo a phase change from solid to liquid. I'm fairly sure that fusion means to combine different substances to form one. However, the heat of fusion is like the amount of heat required to sep...
by Aleck Sun 1J
Mon Jan 18, 2016 11:06 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: HW Question 8.67 (b)
Replies: 1
Views: 308

Re: HW Question 8.67 (b)

For enthalpies of formation, we use carbon (graphite) because it is the most stable form of carbon. I'm not completely sure, but I don't think that diatomic carbon gas exists. The diatomic gases that exist are Hydrogen, Oxygen, Fluorine, Bromine, Iodine, Nitrogen, and Chlorine.
by Aleck Sun 1J
Sat Jan 16, 2016 10:46 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law vs. Bond Enthalpy vs. Std. Enthalpy Formation
Replies: 1
Views: 330

Hess's Law vs. Bond Enthalpy vs. Std. Enthalpy Formation

How do you specifically know which method of reaction enthalpy to use when performing calculations? Well in the book problems, there were clear headings of each section to help us understand, but that will obviously not be there on quizzes/exams. For example, on 8.57, they didn't necessarily give us...
by Aleck Sun 1J
Sun Jan 10, 2016 9:19 pm
Forum: Phase Changes & Related Calculations
Topic: Bond Enthalpy
Replies: 1
Views: 293

Re: Bond Enthalpy

Yes, pi bonds and sigma bonds require different energies. I believe that we will be given the energy required to break both of the bonds, and if needed we would be given the energy of the sigma bond to reform that single bond.
by Aleck Sun 1J
Fri Jan 08, 2016 2:39 pm
Forum: Phase Changes & Related Calculations
Topic: Definition of a State Function
Replies: 2
Views: 341

Re: Definition of a State Function

Work is also not a state function because it depends on the method used to reach the same location/point. A non chemistry example that Dr. Lavelle used in his lecture is walking to Ackerman after lecture. People may take different paths to get to Ackerman. Some people may go directly to Ackerman, wh...
by Aleck Sun 1J
Fri Jan 08, 2016 1:59 pm
Forum: Phase Changes & Related Calculations
Topic: Temperature vs. heat (heat content) vs. energy
Replies: 1
Views: 252

Re: Temperature vs. heat (heat content) vs. energy

Heat is the energy transferred as a result of a temperature difference. Temperature is the specific measurement of heat. It is easier to determine the amount of heat supplied by using temperature instead of heat because heat is the direct amount of energy used. An increase of heat will always increa...
by Aleck Sun 1J
Tue Dec 01, 2015 9:17 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pH of Pure Water with Increased Temperature
Replies: 1
Views: 427

pH of Pure Water with Increased Temperature

As I was reading the textbook, I came across a thinking point question that asked the following: "Do you expect the pH of pure water to increase or decrease with increasing temperature?" I'm not sure how temperature is related the pH of a solution. Could someone please explain this to me?
by Aleck Sun 1J
Fri Nov 27, 2015 10:22 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Homework Question 12.65
Replies: 1
Views: 385

Homework Question 12.65

The question asks to determine whether an aqueous solution has a pH<7, pH>7, or pH=7, while listing salts. I was wondering how to determine whether the pH of a salt aqueous solution is basic, acidic, or neutral without performing any calculations. As an example, these were some of the salts given: N...
by Aleck Sun 1J
Thu Nov 26, 2015 11:21 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: conjugate acids and bases
Replies: 2
Views: 390

Re: conjugate acids and bases

Yes, I agree with Christine. You can use that formula to explain why if one acid is strong, it's conjugate base must be weak. To explain it conceptually, a strong acid is completely dissociated and gives up it's H+. Since a strong acid is able to readily deprotonate, that means that its conjugate ba...
by Aleck Sun 1J
Sun Nov 22, 2015 10:01 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pH below or above 7 or neutral
Replies: 4
Views: 1283

Re: pH below or above 7 or neutral

In the course reader, it mentions that small highly charged metal cations act as lewis acids to increase [H3O+]. This would include Fe3+, Cr3+, Al3+, Fe2+, Cu2+, Ni2+ (all aq). So, I believe that means that any salt with these metals will be acidic. On the contrary, salts that contain the conjugate ...
by Aleck Sun 1J
Sun Nov 22, 2015 9:47 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.30 b) pH and pOH
Replies: 1
Views: 343

Re: 12.30 b) pH and pOH

Since HCl is a strong acid, you can use the formula pH=-log[H3O+] to find the pH of the HCl. Since the concentration of the HCl solution represents the amount of [H3O+], you can substitute that value for [H3O+]. After you find the pH, you can subtract that value from 14 to obtain the pOH since pH+pO...
by Aleck Sun 1J
Tue Nov 17, 2015 9:03 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Le Chatelier's Principle Conditions
Replies: 3
Views: 755

Re: Le Chatelier's Principle Conditions

So when a balanced chemical equation involves both solids and gases, and pressure is changed (volume is changed), do we just use the quick method in the course reader? (V decreases and more moles of gas on left, then reaction shifts to the right. And vice versa) We would then just count the moles of...
by Aleck Sun 1J
Sun Nov 15, 2015 3:50 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Le Chatelier's Principle Conditions
Replies: 3
Views: 755

Le Chatelier's Principle Conditions

Does increasing the amount of reactants always result in the equation shifting to the right like what Le Chatelier's Principle states? Or are there certain circumstances where Le Chatelier's Principle doesn't apply? Would Le Chatelier's Principle apply to a reaction with both gases and a solid (whil...
by Aleck Sun 1J
Sun Nov 15, 2015 10:25 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homework Question 11.1 (d)
Replies: 2
Views: 404

Homework Question 11.1 (d)

In this question, the problem states to determine if the following statement is true or false. "If one starts with higher concentrations of reactants, the equilibrium concentrations of the products will be larger." I know that the solutions manual says that this statement is true. I was th...
by Aleck Sun 1J
Sat Nov 07, 2015 6:03 pm
Forum: Naming
Topic: Naming
Replies: 1
Views: 323

Re: Naming

The H2O outside of the brackets indicates that the H2O is not attached directly to the transition metal within the brackets. In other words, it is not bounded to the coordination sphere of the coordination compound. However, it is still a part of the compound.
by Aleck Sun 1J
Sat Nov 07, 2015 5:45 pm
Forum: Naming
Topic: Bis v Di
Replies: 2
Views: 562

Re: Bis v Di

According to the course reader on page 104, you use di- to indicate the number of ligands attached to the transition metal. For the anion, if you already used the di- prefix for the ligand, then you use bis- to name the anions. So, basically stick with di- as a priority, but if you already used it o...
by Aleck Sun 1J
Sat Oct 31, 2015 8:09 pm
Forum: Bond Lengths & Energies
Topic: Bond lengths and molecular orbital theory
Replies: 4
Views: 1919

Re: Bond lengths and molecular orbital theory

If each bond order number represents what type of bond it is (BO 1=single, BO 2=double, and BO 3=triple), what does it mean when the bond order is 1/2 or a non whole number?
by Aleck Sun 1J
Sat Oct 31, 2015 5:16 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Order and # of Electrons for stability
Replies: 3
Views: 665

Re: Bond Order and # of Electrons for stability

If you are referring to the workbook Quiz #2 preparation Fall 2013 question 5, then the answer of increasing stability is valid. The higher the bond order, the more stable it is. In question 5, it gives both the electrons and the bond order, but I only looked at the bond order to determine the stabi...
by Aleck Sun 1J
Sat Oct 31, 2015 9:26 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Quiz 2 Preparation Fall 2013 #6
Replies: 1
Views: 181

Quiz 2 Preparation Fall 2013 #6

The question gives a list of diatomic molecules and it asks to determine which of molecules is diamagnetic. I was wondering if there is a way to determine which molecule is diamagnetic without drawing the MO Energy diagram for each one because there are five to select from in this problem. Also a si...
by Aleck Sun 1J
Fri Oct 30, 2015 6:40 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: HW 4.77 Drawing Bonding Orbitals
Replies: 3
Views: 342

Re: HW 4.77 Drawing Bonding Orbitals

Yes, we went over the molecular orbital energy level diagram in class. For H2, since it only has one orbital in its first shell, then there would be one orbital for each hydrogen atom. Each hydrogen atom would have one electron, but when they are bonded together, they will fill up the bonding molecu...
by Aleck Sun 1J
Sun Oct 25, 2015 7:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar/Nonpolar structures
Replies: 3
Views: 363

Re: Polar/Nonpolar structures

If a structure is polar, that means that the dipoles do not cancel. The dipoles indicate the force at which the molecule is pulling. The force at which the molecule is pulling tends to be stronger towards the larger (or the higher atomic mass) atom. For example, if you look at HF, the molecule is po...
by Aleck Sun 1J
Mon Oct 19, 2015 12:28 am
Forum: Coordinate Covalent Bonds
Topic: How to Know When Compounds Have a Coordinate Covalent Bonds
Replies: 1
Views: 2018

How to Know When Compounds Have a Coordinate Covalent Bonds

I know in the textbook, it defines a coordinate covalent bond as "a bond in which both electrons come from one of the atoms". Besides BF3, what are some other compounds that have coordinate covalent bonds? How can you tell? Do you need to draw its Lewis structures to figure it out?
by Aleck Sun 1J
Sun Oct 11, 2015 10:55 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Quiz 1 Preparation #3
Replies: 3
Views: 830

Quiz 1 Preparation #3

"Find the uncertainty in the position of a marble of mass 1.5 g given that its speed is known to within ±0.55 m.s^-1." Would we need to use the Δp=m x Δv formula to solve for Δp? Then use the Δp that we received and plug it into the Heisenberg Uncertainty Equation to obtain Δx, which is th...
by Aleck Sun 1J
Fri Oct 09, 2015 11:13 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Quiz 1 Question 10
Replies: 2
Views: 412

Re: Quiz 1 Question 10

Since frequency is given in the first place, I don't think you need to use the equation E=hv to get the energy. The Rydberg equation is v(frequency)=R(1/n^2 -1/n^2). So all you need to do is substitute the frequency given for v and n=4 for (n sub 2) and you should be able to get the principle quantu...
by Aleck Sun 1J
Sat Oct 03, 2015 12:02 pm
Forum: *Shrodinger Equation
Topic: Schrodinger Equation
Replies: 2
Views: 497

Re: Schrodinger Equation

The Schrodinger Equation tells us that the electron has wave like properties and an uncertain momentum and position. The purpose of this equation is to be able to calculate the change in wave function and energy. The left hand side or the “Hamiltonian” tells us the concavity or the curve of the wave...

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