Search found 26 matches
- Fri Mar 17, 2017 11:14 pm
- Forum: *Cycloalkanes
- Topic: 1.16 in ochem book
- Replies: 1
- Views: 1292
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?
- Fri Mar 17, 2017 8:28 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: q=mCT vs q=cT
- Replies: 1
- Views: 18397
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
- Sat Mar 11, 2017 3:27 pm
- Forum: *Haloalkenes
- Topic: 2.16 Intro to Ochem chapter 2
- Replies: 3
- Views: 1420
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.
- Mon Mar 06, 2017 12:34 am
- Forum: *Alkanes
- Topic: Quiz prep 3 question 1 [ENDORSED]
- Replies: 3
- Views: 935
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...
- Sun Feb 26, 2017 2:15 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalysts in rate law
- Replies: 1
- Views: 443
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.
- Wed Feb 15, 2017 2:59 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: 14.85
- Replies: 2
- Views: 650
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 ...
- 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: 999
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.
- Wed Feb 15, 2017 8:19 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Winter 2013 Midterm: Question #4
- Replies: 3
- Views: 795
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.
- Fri Feb 10, 2017 11:09 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Inert Electrodes
- Replies: 2
- Views: 1150
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...
- Sun Feb 05, 2017 4:17 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing reactions
- Replies: 4
- Views: 816
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.
- Tue Jan 24, 2017 5:30 pm
- Forum: Calculating Work of Expansion
- Topic: Quiz 1 || Question 3 || Which R?
- Replies: 1
- Views: 504
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.
- Thu Jan 19, 2017 9:11 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Example p. 20 of Course Reader
- Replies: 2
- Views: 570
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.
- Fri Jan 13, 2017 11:13 am
- Forum: Phase Changes & Related Calculations
- Topic: Phase change
- Replies: 3
- Views: 685
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.
- Sat Dec 03, 2016 12:34 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Question 12.27
- Replies: 1
- Views: 543
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.
- Sat Dec 03, 2016 12:31 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Kw and temperature
- Replies: 1
- Views: 481
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.
- Sat Dec 03, 2016 12:29 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Bar [ENDORSED]
- Replies: 1
- Views: 444
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.
- Fri Dec 02, 2016 10:45 am
- Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
- Topic: 5 Percent Rule
- Replies: 4
- Views: 1234
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 ...
- Sat Nov 26, 2016 5:22 pm
- Forum: Amphoteric Compounds
- Topic: Difference between Amphoteric and Amphiprotic
- Replies: 2
- Views: 3478
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...
- Fri Nov 18, 2016 4:12 pm
- Forum: Properties & Structures of Inorganic & Organic Bases
- Topic: Acidity constants [ENDORSED]
- Replies: 2
- Views: 934
Re: Acidity constants [ENDORSED]
They can be used interchangeably since they are both describing the equilibrium constant of acid dissociation.
- Fri Nov 11, 2016 1:38 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Molecular Orbitals of Different Metals
- Replies: 1
- Views: 428
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.
- Fri Nov 04, 2016 9:18 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Bond Order?
- Replies: 5
- Views: 1091
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.
- Mon Oct 31, 2016 3:59 pm
- Forum: Lewis Structures
- Topic: Oxidation Number of Thallium in Tl2O3
- Replies: 3
- Views: 1636
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.
- Mon Oct 31, 2016 3:55 pm
- Forum: Empirical & Molecular Formulas
- Topic: Mistake in the 2009 Midterm Solutions?
- Replies: 2
- Views: 781
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...
- Fri Oct 21, 2016 12:33 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Relation between Formal Charge and Oxidation Number
- Replies: 2
- Views: 819
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 ...
- Fri Oct 07, 2016 3:31 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbital Question [ENDORSED]
- Replies: 3
- Views: 848
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.
- Fri Sep 30, 2016 11:26 am
- Forum: Photoelectric Effect
- Topic: Finding the kinetic energy of ejected electrons?
- Replies: 1
- Views: 1034
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.