Search found 31 matches
- Sun Mar 19, 2017 1:48 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Rate limiting step
- Replies: 4
- Views: 945
Re: Rate limiting step
"The overall rate law is the rate law of the slowest step." So technically yes it is.
- Sun Mar 19, 2017 1:47 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Naming priority
- Replies: 3
- Views: 935
Re: Naming priority
Functional groups get higher priority than double/triple bonds, which in turn have higher priority that substituents.
Hope this helps!
Hope this helps!
- Sun Mar 19, 2017 1:45 pm
- Forum: General Science Questions
- Topic: Final
- Replies: 9
- Views: 2280
Re: Final
I remember him stating that there would be a problem (or part of a problem) from the homework, and a problem that is "popping up" on Chemistry Community (don't really know how to find that one TBH).
But yeah, there are six problems, for a total of 160 points.
Hope this helps!
But yeah, there are six problems, for a total of 160 points.
Hope this helps!
- Sun Mar 19, 2017 1:42 pm
- Forum: *Alkanes
- Topic: Naming [ENDORSED]
- Replies: 93
- Views: 16838
Re: Naming [ENDORSED]
When you name something with an ether substituent in it how do you name it? Because we know that ether is a substituent, you replace the -yl at the end of the subsituent with -oxy. For example, if we have an ethyl substituent with an Oxygen molecule (i.e. -OCH 2 CH 3 ) we name it ethoxy instead. Ho...
- Sun Mar 19, 2017 1:30 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Writing a Cell Diagram
- Replies: 3
- Views: 760
Re: Writing a Cell Diagram
If a solid (s) does not exist on one of the sides of the salt bridge (remember: anode || cathode), then yes, you can insert Pt(s).
Hope this helps!
Hope this helps!
- Sun Mar 19, 2017 1:25 pm
- Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
- Topic: Chair conformation drawing
- Replies: 2
- Views: 1703
Re: Chair conformation drawing
Whether the foot rest points left or right, the two conformations of the char cyclohexanes have equal energy. But to be sure, I would have the foot rest pointing to the left, as it shows in the course reader ;) Also, remember to have the most bulky substituents on an equatorial axis , as it is the m...
- Sun Mar 19, 2017 1:20 pm
- Forum: General Rate Laws
- Topic: Order of Steps
- Replies: 3
- Views: 771
Re: Order of Steps
The rate law does not affect whether the slow step or the fast step comes first, but remember the slow step is the rate determining step of the entire equation.
Hope this helps!
Hope this helps!
- Sun Mar 19, 2017 1:17 pm
- Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
- Topic: Gauche vs Anti
- Replies: 4
- Views: 10992
Re: Gauche vs Anti
Use Anti (180 degrees apart) for the most stable Newman projection, and use eclipsed for the least stable Newman projection.
Hope this helps!
Hope this helps!
- Sun Mar 12, 2017 12:46 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3705080
Re: Post All Chemistry Jokes Here
It's true. ¯\_(ツ)_/¯
- Sun Mar 12, 2017 12:38 am
- Forum: *Alkanes
- Topic: Naming [ENDORSED]
- Replies: 93
- Views: 16838
Re: Naming [ENDORSED]
Dashes are used to separate not only numbers of the location of the substituents, bonds, etc., but also substituents. For example, for 2-methyl-pentane, we know that on the second carbon of the carbon chain of pentane, there is a methyl substituent located.
Hope this helps!
Hope this helps!
Re: Quiz 3
Yes, Quiz 3 will cover the Arrehnius equation (and anything that wasn't on the last quiz from ch. 15), as well as what we're learning this week for organic chemistry, such as Sn2 mechanisms, energy profiles, etc.
Hope this helps!
Hope this helps!
- Tue Feb 21, 2017 10:25 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Difference between Delta H and q?
- Replies: 3
- Views: 69977
Re: Difference between Delta H and q?
Q is the energy transfer due to thermal reactions such as heating water, cooking, etc. anywhere where there is a heat transfer. You can say that Q (Heat) is energy in transit . Enthalpy (Delta H), on the other hand, is the state of the system , the total heat content. They both can deal with heat (q...
- Tue Feb 21, 2017 10:10 am
- Forum: Student Social/Study Group
- Topic: Quiz 2
- Replies: 4
- Views: 1066
Re: Quiz 2
Read the Course Reader and Textbook Problems (I guess)? In my experience that's helped the most.
Hope this helps!
Hope this helps!
- Fri Feb 17, 2017 4:42 pm
- Forum: Balancing Redox Reactions
- Topic: H+ and e-
- Replies: 4
- Views: 4661
Re: H+ and e-
H + is actually used to balance out the "H" molecules in the equation, but e - electrons are needed to balance the charge, especially after (H 2 0) aq (for aqueous) or (OH - ) aq (for basic) are used to balance the Oxygen molecules. The electrons you use are needed to balance out the charg...
- Sat Feb 11, 2017 10:24 pm
- Forum: Balancing Redox Reactions
- Topic: order of half-reaction
- Replies: 2
- Views: 639
Re: order of half-reaction
Two things to consider when writing the balanced equation for a cell reaction: - have the oxidation be in the left, and the reduction on the right. The trend is that the element being oxidized is the anode , and that the element that is being reduced is the cathode . - the elements that are aqueous ...
- Sat Feb 04, 2017 1:28 am
- Forum: Balancing Redox Reactions
- Topic: Standard reduction potential (E)
- Replies: 2
- Views: 727
Re: Standard reduction potential (E)
For half reactions, the "E" value is based upon which element is being reduced and which element is being oxidized. Although the general trend is that the cathode will be positive, while the anode will be negative, this is due to the elements in the reaction. So, you can really say that it...
- Sat Feb 04, 2017 1:23 am
- Forum: Ideal Gases
- Topic: Reading the textbook
- Replies: 262
- Views: 152573
Re: Reading the textbook
When reading the textbook I make sure that I not only read what is important, but also jot it down in a notebook, such as a definition (unless it is something that Dr. Lavelle does not mention) or a formula, even if it is a derived formula. I feel like reading the textbook is very helpful, if you kn...
- Sun Jan 29, 2017 5:04 pm
- Forum: Calculating Work of Expansion
- Topic: Entropy - Reversible vs Irreversible
- Replies: 3
- Views: 873
Re: Entropy - Reversible vs Irreversible
Entropy is produced in irreversible processes, and reversible processes do not produce any entropy at all. All real process, such as mixing two gases, spontaneous combustion, and the transfer of heat, are not reversible at all, but we can find a measure of entropy for each of these processes. Hope t...
- Fri Jan 20, 2017 10:58 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: U=q+w [ENDORSED]
- Replies: 1
- Views: 515
Re: U=q+w [ENDORSED]
For the equation deltaU = q + w, q does not always have* to be at constant pressure. As this is a representation for the first law of thermodynamics, which states that energy can be converted from one form to another with the interaction of heat, work and internal energy, but it cannot be created no...
- Sat Jan 14, 2017 11:37 pm
- Forum: Phase Changes & Related Calculations
- Topic: Phase change
- Replies: 3
- Views: 914
Re: Phase change
To obtain the enthalpy change for the reverse for any process: Δ H reverse process = - Δ H forward process The enthalpy change for a reverse reaction is the negative of the enthalpy change for the forward reaction. Since we're reversing the reaction (from H 2 O(g) to H 2 O(l) ) we can use this formu...
- Tue Jan 10, 2017 8:11 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: delta H and delta Q
- Replies: 2
- Views: 9562
Re: delta H and delta Q
Q is the amount of heat transfered to a system. It is one of two means of energy transfer during most processes studied in thermodynamics, the other being work. Since these are the only means by which we can transfer energy between the system and its surroundings, we write the change of internal ene...
- Mon Jan 09, 2017 9:21 pm
- Forum: Phase Changes & Related Calculations
- Topic: Understanding why enthalpy is a state function
- Replies: 4
- Views: 6470
Re: Understanding why enthalpy is a state function
Enthalpy depends only on two thermodynamic properties of the state the substance is at the moment, not on the path that it took to get there. When calculating enthalpy, we use only two values (the temperature at the beginning, and the temperature at the end) to calculate our value, unlike heat, whic...
- Mon Dec 05, 2016 12:25 am
- Forum: General Science Questions
- Topic: Chem 14A Final Results [ENDORSED]
- Replies: 1
- Views: 920
Chem 14A Final Results [ENDORSED]
Hello!
When will we hear back about the Chem 14A Final Results?
When will we hear back about the Chem 14A Final Results?
- Tue Nov 29, 2016 2:23 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kp and Kc Same?
- Replies: 4
- Views: 1174
Re: Kp and Kc Same?
The difference between the constants Kc and Kp is that Kc is calculated using the molar concentrations of each substance involved, whereas Kp is calculated by using the partial pressures of the gasses involved.
- Sat Nov 26, 2016 8:16 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Can you classify acids as strong or weak from their formulas alone? [ENDORSED]
- Replies: 7
- Views: 1746
Re: Can you classify acids as strong or weak from their formulas alone? [ENDORSED]
Better to memorize the list of all strong acids and bases. I would assume that if an acid or base is not strong, then it is weak.
- Sat Nov 26, 2016 8:13 pm
- Forum: Amphoteric Compounds
- Topic: Difference between Amphoteric and Amphiprotic
- Replies: 2
- Views: 3481
Re: Difference between Amphoteric and Amphiprotic
Amphiprotic means the substance can both donate and accept a proton (H+). Amphoteric refers generally to a substance that can act as an acid or as a base. An example of a substance that is amphoteric is ZnO. ZnO cannot be considered amphiprotic since it cannot donate Hydrogen. However, due to the Le...
- Sun Nov 13, 2016 8:51 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Do we include (aq) in equilibrium equation?
- Replies: 3
- Views: 870
Re: Do we include (aq) in equilibrium equation?
Unlike gases and substances in solution, liquids and solids essentially have a constant concentration. This is because liquids and solids are practically incompressible, as the molecules in liquids and solids are very close together, with very little room to squeeze any closers, taking an enormous a...
- Mon Oct 31, 2016 2:33 pm
- Forum: Empirical & Molecular Formulas
- Topic: Mistake in the 2009 Midterm Solutions?
- Replies: 2
- Views: 781
Mistake in the 2009 Midterm Solutions?
For the 2009 Midterm for the "yellow book", is there an error in how the solution is solved? For example, the solution states that to find the molar ratio of the C, H, and O atoms, the book says to "divide each amount of moles by 0.2939". However, when dividing the moles of H20 a...
- Wed Oct 26, 2016 11:01 pm
- Forum: Hybridization
- Topic: Sigma Bonds vs Pi Bonds
- Replies: 2
- Views: 2828
Sigma Bonds vs Pi Bonds
Which type of bond is stronger: Sigma Bonds or Pi Bonds? Also, how are triple bonds weaker than both double and single bonds?
- Mon Oct 17, 2016 2:09 pm
- Forum: Trends in The Periodic Table
- Topic: Electronegativity and Electron Affinity. [ENDORSED]
- Replies: 3
- Views: 1954
Electronegativity and Electron Affinity. [ENDORSED]
What is the difference between electronegativity and electron affinity? I know that they both relate to attracting electrons, but is there a clear-cut difference between the two?
- Mon Sep 26, 2016 10:41 pm
- Forum: Properties of Light
- Topic: Atomic Spectra - Rydberg Constant, Balmer Series, Lyman Series
- Replies: 1
- Views: 570
Atomic Spectra - Rydberg Constant, Balmer Series, Lyman Series
Hello! Is the original formula for the equation, which includes the Rydberg constant, to find v (frequency) something that will be tested, or be really taken note of? I did not hear about Rydberg's constant nor the Balmer and Lyman series during lecture today, but I want to make sure if I should rea...