Search found 26 matches

by Emily Wang 1H
Fri Mar 17, 2017 11:14 pm
Forum: *Cycloalkanes
Topic: 1.16 in ochem book
Replies: 1
Views: 441

1.16 in ochem book

The answer says 2-isopropyl-1,1-dimethylcyclopentane. How do we know to use IUPAC or common naming? If we were to do IUPAC, would it be 1-methyl-2-ethyl-1,1-dimethyl-cyclopentane?
by Emily Wang 1H
Fri Mar 17, 2017 8:28 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: q=mCT vs q=cT
Replies: 1
Views: 5847

Re: q=mCT vs q=cT

You use q=mCT when finding the heat of a particular substance with a mass, change in temp, and specific heat capacity. However when solving a problem with a bomb calorimeter, the mass is not necessary to solve for a value. A more specific notation would be q(calorimeter) = C(calorimeter)T
by Emily Wang 1H
Sat Mar 11, 2017 3:27 pm
Forum: *Haloalkenes
Topic: 2.16 Intro to Ochem chapter 2
Replies: 3
Views: 453

Re: 2.16 Intro to Ochem chapter 2

When naming substituents (whether they are alkyl groups or halogens), I think we are supposed to follow the alphabetical rule. The last two pages of this link explain it: https://www.utdallas.edu/~scortes/ochem/OChem1_Lecture/Class_Materials/07_org_nomenclature1.pdf.
by Emily Wang 1H
Mon Mar 06, 2017 12:34 am
Forum: *Alkanes
Topic: Quiz prep 3 question 1 [ENDORSED]
Replies: 3
Views: 464

Re: Quiz prep 3 question 1 [ENDORSED]

For the IUPAC name, you get decane from the chain with 10 carbons. The 4 comes from the isopropyl group being attached to the 4th carbon from the left. You wouldn't start from the right because then it would be 6, and you always want the lowest number for IUPAC naming. Then, the 1 comes from the iso...
by Emily Wang 1H
Sun Feb 26, 2017 2:15 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts in rate law
Replies: 1
Views: 194

Re: Catalysts in rate law

Catalysts aren't used up on the reaction, but they do show up in the overall rate law because the rate depends on their concentration.
by Emily Wang 1H
Wed Feb 15, 2017 2:59 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: 14.85
Replies: 2
Views: 299

Re: 14.85

It depends on the electrochemical series, which would probably be given. The higher up the element on the table, the more likely the element is able to be an oxidizing agent, or in other words, be reduced. To order the elements from most reducing to least reducing, you would list them in order from ...
by Emily Wang 1H
Wed Feb 15, 2017 8:22 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 2013 Midterm 8B
Replies: 4
Views: 476

Re: 2013 Midterm 8B

You can use either log or ln and the answers will turn out to be the same. Just remember that ln is log base e. If you want to convert between the two, lnx = 2.303logx.
by Emily Wang 1H
Wed Feb 15, 2017 8:19 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Winter 2013 Midterm: Question #4
Replies: 3
Views: 420

Re: Winter 2013 Midterm: Question #4

Yes, if there is no change in volume, then there is no work done by expansion because delta V will be 0.
by Emily Wang 1H
Fri Feb 10, 2017 11:09 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Inert Electrodes
Replies: 2
Views: 334

Re: Inert Electrodes

An inert electrode basically acts as a sink for electrons while not actually taking part in the electrode reaction. In other words, inert means the electrode is not reactive. You would use an inert electrode if the reactant can't function as an electrode, but if you have a metal involved, it won't n...
by Emily Wang 1H
Sun Feb 05, 2017 4:17 pm
Forum: Balancing Redox Reactions
Topic: Balancing reactions
Replies: 4
Views: 392

Re: Balancing reactions

E(nought) of the entire cell is the standard reduction potential, which is the difference between the two E values of each half reaction, so if you're multiplying by a number when the moles increase, the difference is still the same.
by Emily Wang 1H
Tue Jan 24, 2017 5:30 pm
Forum: Calculating Work of Expansion
Topic: Quiz 1 || Question 3 || Which R?
Replies: 1
Views: 246

Re: Quiz 1 || Question 3 || Which R?

Both are the R constant and they are equal. The R value of 8.314 J/ K*mol value just converts L*atm into joules, by using the conversion factor of 1 L*atm = 101.32500 joules.
by Emily Wang 1H
Thu Jan 19, 2017 9:11 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Example p. 20 of Course Reader
Replies: 2
Views: 270

Re: Example p. 20 of Course Reader

The reaction is exothermic because the temperature went up from 25C to 31.9C. This means the reaction released heat into the surrounding water in the calorimeter to heat it up, making it exothermic.
by Emily Wang 1H
Fri Jan 13, 2017 11:13 am
Forum: Phase Changes & Related Calculations
Topic: Phase change
Replies: 3
Views: 352

Re: Phase change

A problem involving a phase change will probably state it in the problem specifically, such as asking the energy needed to change solid water at a certain temp to gaseous steam at a certain temp.
by Emily Wang 1H
Sat Dec 03, 2016 12:34 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Question 12.27
Replies: 1
Views: 277

Re: Question 12.27

We can find the number of moles of HCl given what the concentration and volume should have been. However the technician put it in a different volume, which would change the molarity. Now, we can find the pH of both since we can find out the concentration of both.
by Emily Wang 1H
Sat Dec 03, 2016 12:31 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Kw and temperature
Replies: 1
Views: 229

Re: Kw and temperature

I don't think we need to know how to calculate changes in K based on changes in temperature for what we've learned so far. They just give us the temperature at that point for the K value.
by Emily Wang 1H
Sat Dec 03, 2016 12:29 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Bar [ENDORSED]
Replies: 1
Views: 244

Re: Bar [ENDORSED]

Bar is a unit of pressure. It can be converted between atm, mmHg, Torr, and pascals to fit whatever the question is asking for.
by Emily Wang 1H
Fri Dec 02, 2016 10:45 am
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: 5 Percent Rule
Replies: 4
Views: 596

Re: 5 Percent Rule

Generally you would find the solution first assuming that x is negligible (less than 5% of your initial concentration), then see if the answer is actually less than 5% of whatever concentration you started out with. If it is, then your solution is viable; if not, you would have to redo the question ...
by Emily Wang 1H
Sat Nov 26, 2016 5:22 pm
Forum: Amphoteric Compounds
Topic: Difference between Amphoteric and Amphiprotic
Replies: 2
Views: 987

Re: Difference between Amphoteric and Amphiprotic

Both terms are describing properties of acids and bases, but amphiprotic is a bit more specific. Amphiprotic refers to a substance that can either gain or lose a proton, while amphoteric refers to a substance that can either be an acid or a base. However, there are multiple definitions for acids and...
by Emily Wang 1H
Fri Nov 18, 2016 4:12 pm
Forum: Properties & Structures of Inorganic & Organic Bases
Topic: Acidity constants [ENDORSED]
Replies: 2
Views: 493

Re: Acidity constants [ENDORSED]

They can be used interchangeably since they are both describing the equilibrium constant of acid dissociation.
by Emily Wang 1H
Fri Nov 11, 2016 1:38 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Molecular Orbitals of Different Metals
Replies: 1
Views: 217

Re: Molecular Orbitals of Different Metals

The probability of an electron being at N or O depends on the polarity of the element. The more polar, the stronger the pull of the element on the shared electrons, so the higher the probability of an electron being there.
by Emily Wang 1H
Fri Nov 04, 2016 9:18 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Order?
Replies: 5
Views: 537

Re: Bond Order?

One example of a non-integer bond could be a molecule with two bonds, one of which is a double bond and the other a single. Then it'd be 3 divided by 2 and result in a bond order of 1.5.
by Emily Wang 1H
Mon Oct 31, 2016 3:59 pm
Forum: Lewis Structures
Topic: Oxidation Number of Thallium in Tl2O3
Replies: 3
Views: 607

Re: Oxidation Number of Thallium in Tl2O3

When solving for oxidation numbers, there's a set of rules to follow first, which states that oxygen in a molecule will usually have an oxidation number of -2. So for Tl2O3 to be neutral overall, Tl will need to have an oxidation number of +3.
by Emily Wang 1H
Mon Oct 31, 2016 3:55 pm
Forum: Empirical & Molecular Formulas
Topic: Mistake in the 2009 Midterm Solutions?
Replies: 2
Views: 425

Re: Mistake in the 2009 Midterm Solutions?

I think what you might've done is divide the grams of C, H, and O by 0.02939 moles. For example, if you convert 0.4942 g Carbon to moles, you get 0.04114904 moles C, and if you then divide that by 0.02939, you do get 1.4. The ratio comes out to be 1.4:1.2:1 once you convert grams to moles first befo...
by Emily Wang 1H
Fri Oct 21, 2016 12:33 am
Forum: Formal Charge and Oxidation Numbers
Topic: Relation between Formal Charge and Oxidation Number
Replies: 2
Views: 483

Re: Relation between Formal Charge and Oxidation Number

The formal charge and oxidation number are two separate concepts. Formal charges are mainly calculated for structural purposes, such as drawing the most accurate Lewis structures, and do not actually denote charges on atoms in a molecule. On the other hand, the oxidation number of atoms tell us how ...
by Emily Wang 1H
Fri Oct 07, 2016 3:31 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbital Question [ENDORSED]
Replies: 3
Views: 442

Re: Orbital Question [ENDORSED]

Yes, both notations are correct, it's just that the second one is more specific in that it specifies the orientation of the electrons of the p-orbital.
by Emily Wang 1H
Fri Sep 30, 2016 11:26 am
Forum: Photoelectric Effect
Topic: Finding the kinetic energy of ejected electrons?
Replies: 1
Views: 380

Re: Finding the kinetic energy of ejected electrons?

Since we're trying to find the energy of the electron, the mass used in the formula should be of an electron. 9.109 x 10^-31 kg is the mass of a single electron, and that number is just given to us since it is a constant.

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