Search found 51 matches
- Tue Mar 17, 2020 3:22 pm
- Forum: Student Social/Study Group
- Topic: Coronavirus Joke
- Replies: 14
- Views: 1761
Re: Coronavirus Joke
Lol just as everyone else should be!
- Sat Mar 14, 2020 5:22 pm
- Forum: Biological Examples
- Topic: Nitric Oxide Catalyses
- Replies: 7
- Views: 1621
Re: Nitric Oxide Catalyses
If NO is the catalyst then what one is the intermediate?
- Sat Mar 14, 2020 5:19 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Adding water [ENDORSED]
- Replies: 4
- Views: 341
Adding water [ENDORSED]
If pure water is added to either a cathode or anode, would it change the E at all?
- Sat Mar 14, 2020 5:17 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: What was your favorite chem topic?
- Replies: 137
- Views: 8634
Re: What was your favorite chem topic?
Electrochemistry was my favorite, seemed to be the easiest as well.
- Sat Mar 14, 2020 7:05 am
- Forum: *Enzyme Kinetics
- Topic: Bottleneck
- Replies: 2
- Views: 361
Bottleneck
Does the bottleneck effect cause a change in K overall?
- Sat Mar 14, 2020 7:02 am
- Forum: *Enzyme Kinetics
- Topic: Heterogeneous catalyst
- Replies: 3
- Views: 396
Heterogeneous catalyst
If the catalyst is a solid, in lecture it was said that the reactants sit on top and are adsorbed, does this mean the solution is literally a liquid on top of the solid or are they just in a container with each other?
- Sat Mar 14, 2020 6:57 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Slow step
- Replies: 3
- Views: 261
Slow step
How can you recognize what step is slow in the reaction?
- Sat Mar 14, 2020 6:56 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Activation Energy vs Free Energy of Activation
- Replies: 6
- Views: 538
Re: Activation Energy vs Free Energy of Activation
The activation energy is the amount of energy needed for the reaction to occur
- Sat Mar 14, 2020 6:52 am
- Forum: *Enzyme Kinetics
- Topic: 7.17
- Replies: 3
- Views: 422
Re: 7.17
Thanks! So would I then be able to tell if a catalyst is involved if i am able to spot an intermediate just from the graph?
- Sat Mar 14, 2020 6:50 am
- Forum: Second Order Reactions
- Topic: Finding out order
- Replies: 22
- Views: 965
Re: Finding out order
Units are useful because each order reaction has different units
- Sat Mar 14, 2020 6:49 am
- Forum: *Enzyme Kinetics
- Topic: How to distinguish the intermediates and catalysts?
- Replies: 9
- Views: 819
Re: How to distinguish the intermediates and catalysts?
A catalyst in consumed first, whereas an intermediate is produced fist.
- Thu Mar 12, 2020 10:08 am
- Forum: *Enzyme Kinetics
- Topic: 7.17
- Replies: 3
- Views: 422
7.17
What is an intermediate in a reaction and how can you tell when they occur? For example this problem shows a graph and states there are 2, but how can I tell?
- Thu Mar 12, 2020 9:24 am
- Forum: First Order Reactions
- Topic: 7A7
- Replies: 3
- Views: 279
7A7
Why are all of the units different for each order of reaction?
- Thu Mar 12, 2020 9:21 am
- Forum: General Rate Laws
- Topic: Units
- Replies: 4
- Views: 366
Units
Are units for all rate constants M/s? And what does it mean if the s has a -1 attached in the denominator?
- Tue Mar 10, 2020 9:25 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Activation Energy
- Replies: 3
- Views: 232
Activation Energy
In the Arrhenious Equation, the Ea being on the top, if it is larger or in absence of a catalyst, would A be larger or smaller than one with a catalyst?
- Tue Mar 10, 2020 9:24 am
- Forum: Biological Examples
- Topic: adsorbtion
- Replies: 6
- Views: 798
adsorbtion
Does adsorbtion only occur for heterogeneous catalysts?
- Mon Mar 09, 2020 10:41 am
- Forum: Zero Order Reactions
- Topic: Zero Order reaction rate constant
- Replies: 8
- Views: 455
Re: Zero Order reaction rate constant
if it is zero order then it is constant because anything to the 0 power is just 1
- Mon Mar 09, 2020 10:39 am
- Forum: Zero Order Reactions
- Topic: Order of Reaction
- Replies: 3
- Views: 319
Re: Order of Reaction
By looking at the rate law, a 0 order equation with be the simplest looking [A]= -kt + [A]. The first order equation always has ln before [A] so , ln[A]= -kt + ln[A]. Finally 2nd order has [A] in a fraction over 1, so 1/[A]= kt + 1/[A].
- Mon Mar 09, 2020 10:34 am
- Forum: Zero Order Reactions
- Topic: half life calculations
- Replies: 3
- Views: 386
Re: half life calculations
Quarter life of a reaction would be essentially the same as a half life, but anywhere you would put 1/2 in the equation would be replaced with 1/4
- Mon Mar 09, 2020 10:33 am
- Forum: Zero Order Reactions
- Topic: Graphs
- Replies: 13
- Views: 1312
Re: Graphs
For graphs, we should just know the relationship between what order the reaction is with what goes on the x axis, as well as the direction of the slope on the graph and whether k is positive or negative.
- Mon Mar 09, 2020 10:31 am
- Forum: General Rate Laws
- Topic: Definition
- Replies: 4
- Views: 374
Re: Definition
We should know the 0, 1st, and 2nd rate laws, their rates in relation to k, what the graph and slope looks like, and most likely the half life equations.
- Mon Mar 09, 2020 10:29 am
- Forum: General Rate Laws
- Topic: Elementary reactions
- Replies: 5
- Views: 295
Re: Elementary reactions
i think an elementary reaction would be something such as 2A + B yeilds 4C, and given a simple rate for one of the products such as .5 M/s of A, knowing that for every 2 A being consumed, there is a x amount of C being produced, and using the rate given to find the rate of product.
- Mon Mar 09, 2020 10:26 am
- Forum: General Rate Laws
- Topic: Enzyme saturation
- Replies: 6
- Views: 376
Re: Enzyme saturation
Saturation of an enzyme meas that all of the active sites of the enzymes have been occupied, so once this limit is reached, there can be further increase of reaction rate, it has reached its peak.
- Sun Mar 08, 2020 7:53 pm
- Forum: Balancing Redox Reactions
- Topic: Redox Table
- Replies: 6
- Views: 396
Redox Table
If all of the reactions in the table represent reductions, for the oxidizing half reaction, it would be made negative, then would the sign in the Ecat-Eanode change to addition or would we subtract it?
- Sun Feb 09, 2020 8:47 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: 4G1
- Replies: 1
- Views: 88
4G1
If it says the nanostructure is made up of 64 molecules all aligned in the same direction, would W just be 64?
For part b it says they can be in any one of four orientations would n be 4 and W would be 2^4?
For part b it says they can be in any one of four orientations would n be 4 and W would be 2^4?
- Sun Feb 09, 2020 8:26 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: Degrees of Change in Entropy
- Replies: 5
- Views: 181
Degrees of Change in Entropy
What is the difference between delta S and delta S with the dregrees symbol? Is it degrees celsius or kelvin?
- Fri Feb 07, 2020 3:02 pm
- Forum: Phase Changes & Related Calculations
- Topic: Friday Thermochem/dynamics Lecture
- Replies: 2
- Views: 182
Friday Thermochem/dynamics Lecture
Hi to whoever sees this, I was unable to attend lecture today due to a family situation and I wanted to see if anyone is willing to share their notes with me via email. It would be greatly appreciated! My email is smurphy2021@g.ucla.edu
- Tue Feb 04, 2020 11:32 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: 4F7
- Replies: 1
- Views: 134
4F7
How would I solve for entropy change when i am only given the moles and two temperature calculations? Pressure and volume are assumed to be constant. I have converted them to K and found the delta T, but I am not sure what to do next.
- Mon Feb 03, 2020 10:26 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Phase change
- Replies: 20
- Views: 788
Re: Phase change
Delta H is positive because heat is being added in order to melt the ice
- Mon Feb 03, 2020 10:24 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: First Law
- Replies: 5
- Views: 323
Re: First Law
U is the measurement of the random movement of molecules inside of a system
- Mon Feb 03, 2020 10:21 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: delta V
- Replies: 4
- Views: 146
Re: delta V
Delta V equals 0 in closed or isolated systems
- Mon Feb 03, 2020 10:19 am
- Forum: Calculating Work of Expansion
- Topic: Derivative
- Replies: 3
- Views: 216
Derivative
Since the equation involving the derivative can be worked out to a much easier equation, under what instance is it necessary that we actually have to use it?
- Mon Feb 03, 2020 10:17 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Types of Systems
- Replies: 7
- Views: 420
Re: Types of Systems
Is pressure always Constant in a closed system? Is pressure constant in an open system too?
- Sat Feb 01, 2020 9:31 am
- Forum: Phase Changes & Related Calculations
- Topic: Reversible and Irreversible
- Replies: 5
- Views: 235
Re: Reversible and Irreversible
Would irreversible reactions occur in open containers then? If the pressure is constant is it always a irreversible reaction?
- Sat Feb 01, 2020 9:29 am
- Forum: Phase Changes & Related Calculations
- Topic: Internal Energy, U
- Replies: 6
- Views: 276
Internal Energy, U
Is Delta U always equal to Delta H?
- Sun Jan 26, 2020 2:26 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Lewis Structures Method 2
- Replies: 6
- Views: 147
Lewis Structures Method 2
In order to use the bond enthalpies method, is it necessary to write out the lewis structures of each compound?
- Sun Jan 26, 2020 2:22 pm
- Forum: Phase Changes & Related Calculations
- Topic: Phase Changes endo/exo
- Replies: 3
- Views: 121
Re: Phase Changes endo/exo
Yes some phase changes are exothermic, as long as it is releasing heat.
- Sun Jan 26, 2020 2:19 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Method One (Hess’s Law)
- Replies: 4
- Views: 153
Re: Method One (Hess’s Law)
Are the equations we add together ones we have to put together ourselves or will they usually be given?
- Fri Jan 24, 2020 10:08 am
- Forum: Phase Changes & Related Calculations
- Topic: Phase Changes
- Replies: 3
- Views: 162
Re: Phase Changes
For all phase change equations, do we always subtract the end phase by the beginning phase stat, just like we would do in equilibrium equations?
- Sun Jan 19, 2020 12:32 pm
- Forum: Ideal Gases
- Topic: ICE Table
- Replies: 11
- Views: 786
Re: ICE Table
If the reaction is favoring a forward reaction, in the ice box, would the reactant side of the reaction that gives a negative 'x' and the products would be gaining a 'x' value?
- Fri Jan 17, 2020 1:01 pm
- Forum: Ideal Gases
- Topic: PV=nRT equation manipulation
- Replies: 13
- Views: 683
Re: PV=nRT equation manipulation
Is R a constant in every equation? Or does it differ depending on the chemical equation ?
- Fri Jan 17, 2020 12:59 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Acids and Bases
- Replies: 6
- Views: 221
Re: Acids and Bases
If we want to use approximation do we have to find the percentage of certainty every time or only it it asks for it?
- Fri Jan 17, 2020 12:56 pm
- Forum: Ideal Gases
- Topic: ph
- Replies: 10
- Views: 479
Re: ph
when trying to find the pH or poH of something, do We take the - log of the opposite concentration of the one we are trying to find?
- Tue Jan 14, 2020 9:31 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5I.5
- Replies: 4
- Views: 143
Re: 5I.5
Renee Grange 1I wrote:I think the reason you are getting the wrong answer is because you are using 1.8 bar instead of 1.18 bar, but your steps are correct.
Yes, got it thank you!
- Tue Jan 14, 2020 9:28 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE Table
- Replies: 8
- Views: 271
Re: ICE Table 5J19
For the ICE tables , if the product side has 2 moles that are both the reactants combined, would the x value be 2x because its doubling in moles?
- Tue Jan 14, 2020 9:25 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Acids and Bases
- Replies: 6
- Views: 221
Re: Acids and Bases
How do you incorporate the temperature into a Kw=[H3O+][OH-] equation?
- Fri Jan 10, 2020 9:21 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5I.5
- Replies: 4
- Views: 143
5I.5
In this equation I am given the value of K and 2 partial pressure values. I need to solve to find the P for the last one. I am dividing and multiplying the other values around to solve for x but I keep getting the wrong answer. Am I forgetting a step? Ppcl5= Ppcl3 + Pcl2 1.8 bar =(x) + 5.43 bar K=25...
- Thu Jan 09, 2020 10:10 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Meaning of equilibrium constant
- Replies: 5
- Views: 217
Re: Meaning of equilibrium constant
when the valve is an intermediate valve, neither product or reactant is strongly favored. You can refer to them as slightly favoring one of the other.
- Thu Jan 09, 2020 9:58 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: liquids and aqueous solutions
- Replies: 4
- Views: 110
liquids and aqueous solutions
If liquids and solids cant be used to determine k then why can aqueous solutions be used? If aqueous solutions are liquid as well?
- Wed Jan 08, 2020 9:35 am
- Forum: Ideal Gases
- Topic: Dynamic Equilibrium
- Replies: 10
- Views: 358
Re: Dynamic Equilibrium
It is at dynamic equilibrium when the rate of the forward reaction is equal to the rate of the reverse reaction
- Wed Jan 08, 2020 9:31 am
- Forum: Ideal Gases
- Topic: Equilibrium
- Replies: 7
- Views: 207
Equilibrium
What is the difference between Q and K?