Search found 31 matches
- Tue Mar 12, 2019 11:08 pm
- Forum: Ideal Gases
- Topic: How do I know what is an Ideal Gas
- Replies: 11
- Views: 993
Re: How do I know what is an Ideal Gas
Note ideal gases are usually exemplified by noble gases ie helium argon etc. This is because the molecules are singular
- Tue Mar 12, 2019 11:06 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Spontaneous Reaction
- Replies: 5
- Views: 787
Re: Spontaneous Reaction
I don't think this is the way to answer the question but something that helps me conceptualize it is that heat diffuses out. If a sample of water is in a 10 degree Celsius space, heat leaves the sample and the bonds form spontaneously because of the conditions it is in.
- Tue Mar 12, 2019 11:04 pm
- Forum: General Science Questions
- Topic: Organic Molec Naming?
- Replies: 2
- Views: 561
Re: Organic Molec Naming?
I don't think it is on the course outline either so I think we're in the clear
- Tue Mar 12, 2019 10:54 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: catalyst and equilibrium constant
- Replies: 2
- Views: 274
Re: catalyst and equilibrium constant
Don't we also have to keep the catalysts saturated with reactants? Or am I misrembering it.
- Tue Mar 12, 2019 10:53 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Sig Figs
- Replies: 9
- Views: 1176
Re: Sig Figs
They definitely did check sig figs on the midterm
- Tue Mar 12, 2019 10:52 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Intermediates
- Replies: 2
- Views: 330
Re: Intermediates
You have the general idea down. Note that reactions with intermediates are elementary steps and when added up completely it should produce the final reaction
- Tue Mar 12, 2019 10:49 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: fast equilibrium approach v steady state equilibrium
- Replies: 1
- Views: 224
Re: fast equilibrium approach v steady state equilibrium
Honestly, steady-state is so math intensive and so time consuming that it is most likely best to avoid it at all circumstances.
- Tue Mar 12, 2019 10:47 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: organic chem stuff
- Replies: 1
- Views: 283
Re: organic chem stuff
I would think if it isn't included in the outline that it wouldn't be included in the test
- Tue Mar 12, 2019 10:46 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst
- Replies: 14
- Views: 1235
Re: Nernst
Yes, it is the amount of electrons released in a balanced galvanic reaction
- Tue Mar 12, 2019 10:44 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Ice melting
- Replies: 4
- Views: 755
Re: Ice melting
The melting of ice is spontaneous because its something that occurs naturally (in the right temperature). The way I like to think about it is that in an area with high heat the ice cube (devoid of heat) will naturally see energy diffuse into the ice breaking the bonds at the same time. The combustio...
- Tue Mar 12, 2019 10:41 pm
- Forum: Balancing Redox Reactions
- Topic: Coefficients
- Replies: 3
- Views: 1108
Re: Coefficients
So that means oxidation number is extensive or intensive? Or would it be neither
- Tue Mar 12, 2019 10:39 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Pre-equilibrium vs. steady-state
- Replies: 4
- Views: 515
Re: Pre-equilibrium vs. steady-state
I would avoid steady-state even as a sanity check primarily because it's long math intensive and time consuming.
- Tue Mar 12, 2019 10:38 pm
- Forum: Zero Order Reactions
- Topic: Reaction Rate
- Replies: 10
- Views: 1241
Re: Reaction Rate
Wait, I thought initial concentration would be included especially for second order reactions
- Tue Mar 12, 2019 10:35 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Reaction mechanisms- elementary steps
- Replies: 1
- Views: 236
Re: Reaction mechanisms- elementary steps
I think so, because the slow reaction is rate defining. Much in the same way if the second elementary step is slow here is a bottle neck in the first elementary step which has to be fast and the fast step has a reversible reaction
- Tue Mar 12, 2019 10:33 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Sig Figs
- Replies: 9
- Views: 1176
Re: Sig Figs
I would assume so, but I can't confirm. I also have concerns about how sig figs are graded. They seem to mark you down on sig figs if you so much as have another decimal place beyond the sigfigs in the work.
- Tue Mar 12, 2019 10:27 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: Boltzmann Equation
- Replies: 3
- Views: 771
Re: Boltzmann Equation
A usual tip off to use the boltzman's equation is that they talk about micro states or state spaces. The midterm problem described the state spaces of nanoparticles.
- Wed Feb 06, 2019 11:05 am
- Forum: Calculating Work of Expansion
- Topic: Isothermal Expansions
- Replies: 3
- Views: 381
Re: Isothermal Expansions
isothermal refers to the fact that the system will have the same amount of heat no matter what process occurs. This may mean work takes the form of heat. reversible and irreversible are terms relating to the way pressure is exerted on a system
- Wed Feb 06, 2019 11:03 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Midterm [ENDORSED]
- Replies: 49
- Views: 5043
Re: Midterm [ENDORSED]
Some UA's and LA's provide worksheets for more practice problems. These sometimes come with walkthroughs. Linden's reviews are usually pretty good.
- Wed Feb 06, 2019 11:02 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Irreversible/Reversible Processes
- Replies: 3
- Views: 414
Re: Irreversible/Reversible Processes
Isothermal reversible reactions produce more work because it is done slowly and done with tiny steps and allows the system to come back to equilibrium. Irreversible processes in comparison is one massive push that doesn't achieve the same amount of work because it is less efficient.
- Mon Jan 28, 2019 2:07 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Extensive vs intensive
- Replies: 2
- Views: 266
Re: Extensive vs intensive
Extensive properties are things that are not universal properties and are sample dependent. This can include weight and temperature, where as intensive properties are properties that pertain to all samples of an object such as the number of protons in an element.
- Mon Jan 28, 2019 2:05 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Q and H
- Replies: 2
- Views: 320
Re: Q and H
H is a state function which means that whichever way it goes there is always a net change and takes into account the whole reaction, where as q is the change of heat and may be dependent on the reaction itself as well as the possibility of incomplete reactions (I think)
- Sun Jan 27, 2019 10:28 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: energy production
- Replies: 4
- Views: 534
Re: energy production
The breaking of bonds between glucose creates an exothermic reaction which subsequently powers the process of cellular respiration an endothermic process. Cellular respiration produces ATP which dissociates into ADP and P(inorganic) and produces a muscle contraction within the heart.
- Sat Jan 26, 2019 3:15 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: H and Q
- Replies: 4
- Views: 506
Re: H and Q
In Enthalpy delta H is a state function of the holistic change in energy configuration, where as q is the heat flow either into or out of the reaction as a result of the change in delta H Sources: https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_M...
- Sat Jan 26, 2019 3:12 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Standard enthalpy of formation
- Replies: 2
- Views: 241
Re: Standard enthalpy of formation
Standard enthalpy of formation is the change of enthalpy when only one mole of that molecule is formed by its constituent elements ie elements found in their natural forms such as H2 and N2. Standard reaction enthalpy is the change in enthalpy that occurs in a system when matter is transformed by a ...
- Sat Jan 26, 2019 3:06 pm
- Forum: Phase Changes & Related Calculations
- Topic: Sublimation
- Replies: 6
- Views: 572
Re: Sublimation
I suppose it would be able to bypass the step of turning into a liquid because of incredibly strong intermolecular forces, however I do not know if this would create solid materials or incredibly viscous non-newtonian-like fluids
- Mon Jan 14, 2019 10:22 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Concentration Affecting K
- Replies: 7
- Views: 1075
Re: Concentration Affecting K
Adding more concentration of reactants or products will not change Kc. This is because Kc focuses on the rates of the reaction rather than the equality of the concentrates. The reaction will naturally begin to move back to its state of equilibrium but with increased values on both sides.
- Mon Jan 14, 2019 10:19 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Exothermic Reaction
- Replies: 3
- Views: 256
Re: Exothermic Reaction
An exothermic reaction shifts toward the formation of products because the products are at a lower energy level than the reactants. The universe naturally wants to gravitate to the lowest energy level and the most chaos through entropy. Because of this the decomposition of a complex (high energy) mo...
- Mon Jan 14, 2019 10:15 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Example from lecture on Wednesday
- Replies: 2
- Views: 204
Re: Example from lecture on Wednesday
In the problem he gave us the given reaction of ATP hydrolysis of ATP + H2O --> ADP + P(inorganic) The initial concentrations were based on real numbers from both healthy and dead tissues. The equilibrium point isn't necesarilly an equilibrium point more as the end point of the reaction as the last ...
- Thu Jan 10, 2019 3:41 pm
- Forum: Ideal Gases
- Topic: Equilibrium Constant and Reaction Quotient
- Replies: 3
- Views: 550
Re: Equilibrium Constant and Reaction Quotient
The reaction quotient is the ratio of products and reactants with their stoichiometric counterparts of an equilibrium reaction at ANY point. Equilibrium constants however is this ratio at equilibrium. Q and K are both calculated the same exact way but at (possibly) different points of the equilibriu...
- Thu Jan 10, 2019 3:38 pm
- Forum: Ideal Gases
- Topic: Reaction Quotient
- Replies: 6
- Views: 433
Re: Reaction Quotient
Because they do not affect the concentrations of reactants and products, liquids are not taken into account for equilibrium reactions. That being said H2O undergoes a acid base reaction with itself when it produces hydrogen ions and hydroxide ions spontaneously, but it goes disregarded because water...
- Thu Jan 10, 2019 3:35 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Solid and Liquids in reaction equilibrium situations
- Replies: 1
- Views: 216
Solid and Liquids in reaction equilibrium situations
Water has a dynamic of producing hydroxide and hydronium ions forming H3O+ and OH-, which then can react to form H2O. Are there any examples of solids doing anything akin to this?