Search found 21 matches

by joannali1027
Thu Mar 10, 2016 10:47 pm
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: flagpole interaction
Replies: 1
Views: 3297

Re: flagpole interaction

The flagpole interactions are specifically for the hydrogens or substituents that take up the two axial up positions, thus why they are flagpoles. Due to the boat conformation being this shape, it produces two axial up positions that look like flagpoles and result in steric strain.
by joannali1027
Sun Mar 06, 2016 1:35 am
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Eclipsed Conformation and Torsional Strain
Replies: 1
Views: 262

Re: Eclipsed Conformation and Torsional Strain

Torsional strain is defined as strain caused as the force applied in the gauche conformation rotates the atom or atom group towards another group. Torsional strain is something that occurs during the eclipsed conformation. Torsional strain is an explanation as to why the eclipsed conformation has a ...
by joannali1027
Mon Feb 29, 2016 4:54 pm
Forum: *Electrophilic Addition
Topic: Transition and Intermediate states
Replies: 1
Views: 293

Re: Transition and Intermediate states

This is because energy is needed for the bonds in the first TS to form and thus more energy is required. In the second TS, there are still bonds formed. Because energy is needed to reach each transition state and intermediate, they will be higher in energy.
by joannali1027
Sun Feb 21, 2016 11:52 pm
Forum: *Nucleophiles
Topic: Ambident Nucleophile
Replies: 2
Views: 445

Re: Ambident Nucleophile

SCN is the only option where there are lone pairs on different atoms, Sulfur and Nitrogen. In the other examples, the lone pair is only on one of the atoms.
by joannali1027
Mon Feb 15, 2016 12:49 am
Forum: First Order Reactions
Topic: Homework Question 23: Finding [A]
Replies: 2
Views: 432

Re: Homework Question 23: Finding [A]

In part C, you are given the initial value of [A] as well as the change in concentration of product B. Based on the equation, you know that for 2 moles of A, you produce one mole of B. Knowing this, and knowing the concentration of B, you can find how many moles of A were used up. And since the equa...
by joannali1027
Sat Feb 06, 2016 11:39 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Standard Cell Potential Pattern
Replies: 1
Views: 338

Standard Cell Potential Pattern

Hi, I was wondering if there were any patterns to the standard cell potentials. Can you predict based on where the element is located if it has a larger or smaller value than another element? Thank you!
by joannali1027
Sat Jan 30, 2016 9:20 pm
Forum: Balancing Redox Reactions
Topic: oxidation and reduction
Replies: 2
Views: 321

Re: oxidation and reduction

The thing being oxidized is the has its electron(s) removed. The oxidizing agent is the species that removes the electron, and is itself reduced. The reducing agent is the one that supplies the electron and thus gets oxidized. So as long as you know what is being oxidized and what's being reduced, t...
by joannali1027
Sun Jan 24, 2016 10:57 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free energy and spontaneity
Replies: 1
Views: 347

Re: Gibbs Free energy and spontaneity

The relationship between Gibbs Free Energy and Entropy is mostly found in the equation \Delta G= \Delta H-T\Delta S On Friday's lecture, Lavelle showed that when you divide that equation by -T, you get \frac{\Delta G}{-T}=\frac{-\Delta H}{T}+\Delta S Since we know that \frac{-\Delta H}{T} is equival...
by joannali1027
Tue Jan 19, 2016 1:31 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Reversible vs Irreversible
Replies: 1
Views: 204

Reversible vs Irreversible

In the book, it says that for the equation Change in Entropy= q/T, they say that heat must be able to be transferred reversibly. It then goes on to say that you can assume that something that is irreversible can be viewed as reversible due to the fact that entropy is a state function. Can someone pl...
by joannali1027
Mon Jan 11, 2016 1:31 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Molar heat capacity
Replies: 3
Views: 559

Re: Molar heat capacity

How did the values 5/2R and 3/2R come about? I'm not too clear on how they were derived and when we're supposed to use them.
by joannali1027
Sat Dec 05, 2015 3:04 am
Forum: *Titrations & Titration Calculations
Topic: Titration of a weak base with a strong acid
Replies: 1
Views: 398

Re: Titration of a weak base with a strong acid

Once you've reached the stoichiometric point, the reaction becomes that the strong acid is protonating the water since the weak base has been all changed to acid. This is because at the stoichiometric point, the concentrations of the weak base and the strong acid are equal, and thus you can think of...
by joannali1027
Sun Nov 29, 2015 6:34 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Second Deprotonations of Diprotic Acids
Replies: 4
Views: 3478

Re: Second Deprotonations of Diprotic Acids

To add on, it's because once you lose one proton, it gets much harder for another Hydrogen atom to leave when the molecule is now negatively charged. Because of this, the Ka will be smaller as it favors the reactants. However, H2SO4 is an exception where the first is fully deprotonized and is a stro...
by joannali1027
Sun Nov 29, 2015 6:30 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Basic and Acidic Oxides
Replies: 1
Views: 488

Basic and Acidic Oxides

How do you tell when an oxide is acidic or basic? What are we supposed to look at? For instance, in number 17, it gives you BaO and SO3. How can you tell if one is acidic and the other is basic? What would the acidic oxide be donating? Or is it asking for Lewis acids?
by joannali1027
Mon Nov 23, 2015 1:22 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Ignoring the change in equilibrium
Replies: 3
Views: 525

Re: Ignoring the change in equilibrium

Yes because at 1*10^-4, that is when it is appropriate to approximate since the value is very small. I think in terms of regular K values, it is that anything smaller than 10^-3 is considered small enough.
by joannali1027
Sat Nov 14, 2015 5:30 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Calculating K and Multiplying vs Adding
Replies: 1
Views: 268

Re: Calculating K and Multiplying vs Adding

If you look on pages 439 and 440 in the textbook you will see an example of it there.
by joannali1027
Sun Nov 08, 2015 3:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Activity
Replies: 1
Views: 249

Re: Activity

Activity is just the numerical value of the pressure or molarity. So if you're looking at gasses, the activity is just the pressure of the gas molecule. If you're looking at the concentrations of the reactants and products in a reaction, then the activity is simply the value of the concentrations. I...
by joannali1027
Sat Oct 31, 2015 9:32 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Carbon Monoxide (CO)
Replies: 1
Views: 290

Re: Carbon Monoxide (CO)

Oxygen is much more electronegative. This means that the orbitals are lower because they have a greater pull on the electrons (think polarity) and also that oxygen will make the larger contribution to the lowest-energy MO. By drawing the orbitals lower, it also helps one to visualize the fact that t...
by joannali1027
Sun Oct 25, 2015 11:26 am
Forum: Octet Exceptions
Topic: Expanded Octet
Replies: 9
Views: 1740

Re: Expanded Octet

Is there a limit to how many electrons an atom can accommodate? Say, the sulfur atom has an electron configuration of and 2 empty spaces in its d-orbital. Does this mean sulfur can thus accommodate 2 more electrons/one extra loan pair? Can it accommodate more? If so, why is that?
by joannali1027
Sat Oct 17, 2015 6:30 pm
Forum: Octet Exceptions
Topic: Expanded Octet
Replies: 9
Views: 1740

Re: Expanded Octet

So by third shell should we just assume that they all can have an expanded octet? Also, can there be expanded octets before n=3?
by joannali1027
Sat Oct 17, 2015 6:27 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Quiz 1 Preparation #3
Replies: 3
Views: 810

Re: Quiz 1 Preparation #3

During lecture, Professor Lavelle used the equation Δp x Δv > h/4pi. Does this work too? I thought the equation was ΔpXΔx but he did examples using the first equation. Is there a way to get one equation from the other? Or did I just write down the wrong information?
by joannali1027
Wed Oct 07, 2015 2:07 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Difference between Wave Functions and Orbitals
Replies: 2
Views: 1373

Re: Difference between Wave Functions and Orbitals

The wavefunction is a mathematical way of expressing the x,y,z or really, r, theta, and phi of the electron. The wavefunction gives the probability of the electron being in that area. The three coordinates create a point in 3-dimensional space which are also represented by orbitals. Since we don't n...

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