Search found 51 matches

by smurphy1D
Tue Mar 17, 2020 3:22 pm
Forum: Student Social/Study Group
Topic: Coronavirus Joke
Replies: 14
Views: 813

Re: Coronavirus Joke

Lol just as everyone else should be!
by smurphy1D
Sat Mar 14, 2020 5:22 pm
Forum: Biological Examples
Topic: Nitric Oxide Catalyses
Replies: 7
Views: 768

Re: Nitric Oxide Catalyses

If NO is the catalyst then what one is the intermediate?
by smurphy1D
Sat Mar 14, 2020 5:19 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Adding water [ENDORSED]
Replies: 4
Views: 101

Adding water [ENDORSED]

If pure water is added to either a cathode or anode, would it change the E at all?
by smurphy1D
Sat Mar 14, 2020 5:17 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: What was your favorite chem topic?
Replies: 24
Views: 502

Re: What was your favorite chem topic?

Electrochemistry was my favorite, seemed to be the easiest as well.
by smurphy1D
Sat Mar 14, 2020 7:05 am
Forum: *Enzyme Kinetics
Topic: Bottleneck
Replies: 2
Views: 92

Bottleneck

Does the bottleneck effect cause a change in K overall?
by smurphy1D
Sat Mar 14, 2020 7:02 am
Forum: *Enzyme Kinetics
Topic: Heterogeneous catalyst
Replies: 3
Views: 82

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?
by smurphy1D
Sat Mar 14, 2020 6:57 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Slow step
Replies: 3
Views: 68

Slow step

How can you recognize what step is slow in the reaction?
by smurphy1D
Sat Mar 14, 2020 6:56 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Activation Energy vs Free Energy of Activation
Replies: 6
Views: 118

Re: Activation Energy vs Free Energy of Activation

The activation energy is the amount of energy needed for the reaction to occur
by smurphy1D
Sat Mar 14, 2020 6:52 am
Forum: *Enzyme Kinetics
Topic: 7.17
Replies: 3
Views: 88

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?
by smurphy1D
Sat Mar 14, 2020 6:50 am
Forum: Second Order Reactions
Topic: Finding out order
Replies: 12
Views: 185

Re: Finding out order

Units are useful because each order reaction has different units
by smurphy1D
Sat Mar 14, 2020 6:49 am
Forum: *Enzyme Kinetics
Topic: How to distinguish the intermediates and catalysts?
Replies: 8
Views: 134

Re: How to distinguish the intermediates and catalysts?

A catalyst in consumed first, whereas an intermediate is produced fist.
by smurphy1D
Thu Mar 12, 2020 10:08 am
Forum: *Enzyme Kinetics
Topic: 7.17
Replies: 3
Views: 88

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?
by smurphy1D
Thu Mar 12, 2020 9:24 am
Forum: First Order Reactions
Topic: 7A7
Replies: 3
Views: 52

7A7

Why are all of the units different for each order of reaction?
by smurphy1D
Thu Mar 12, 2020 9:21 am
Forum: General Rate Laws
Topic: Units
Replies: 4
Views: 83

Units

Are units for all rate constants M/s? And what does it mean if the s has a -1 attached in the denominator?
by smurphy1D
Tue Mar 10, 2020 9:25 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Activation Energy
Replies: 3
Views: 57

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?
by smurphy1D
Tue Mar 10, 2020 9:24 am
Forum: Biological Examples
Topic: adsorbtion
Replies: 4
Views: 77

adsorbtion

Does adsorbtion only occur for heterogeneous catalysts?
by smurphy1D
Mon Mar 09, 2020 10:41 am
Forum: Zero Order Reactions
Topic: Zero Order reaction rate constant
Replies: 8
Views: 91

Re: Zero Order reaction rate constant

if it is zero order then it is constant because anything to the 0 power is just 1
by smurphy1D
Mon Mar 09, 2020 10:39 am
Forum: Zero Order Reactions
Topic: Order of Reaction
Replies: 3
Views: 71

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].
by smurphy1D
Mon Mar 09, 2020 10:34 am
Forum: Zero Order Reactions
Topic: half life calculations
Replies: 3
Views: 127

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
by smurphy1D
Mon Mar 09, 2020 10:33 am
Forum: Zero Order Reactions
Topic: Graphs
Replies: 13
Views: 588

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.
by smurphy1D
Mon Mar 09, 2020 10:31 am
Forum: General Rate Laws
Topic: Definition
Replies: 4
Views: 112

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.
by smurphy1D
Mon Mar 09, 2020 10:29 am
Forum: General Rate Laws
Topic: Elementary reactions
Replies: 5
Views: 52

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.
by smurphy1D
Mon Mar 09, 2020 10:26 am
Forum: General Rate Laws
Topic: Enzyme saturation
Replies: 6
Views: 82

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.
by smurphy1D
Sun Mar 08, 2020 7:53 pm
Forum: Balancing Redox Reactions
Topic: Redox Table
Replies: 6
Views: 77

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?
by smurphy1D
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: 22

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?
by smurphy1D
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: 61

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?
by smurphy1D
Fri Feb 07, 2020 3:02 pm
Forum: Phase Changes & Related Calculations
Topic: Friday Thermochem/dynamics Lecture
Replies: 2
Views: 64

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
by smurphy1D
Tue Feb 04, 2020 11:32 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: 4F7
Replies: 1
Views: 51

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.
by smurphy1D
Mon Feb 03, 2020 10:26 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Phase change
Replies: 20
Views: 176

Re: Phase change

Delta H is positive because heat is being added in order to melt the ice
by smurphy1D
Mon Feb 03, 2020 10:24 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: First Law
Replies: 5
Views: 76

Re: First Law

U is the measurement of the random movement of molecules inside of a system
by smurphy1D
Mon Feb 03, 2020 10:21 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: delta V
Replies: 4
Views: 47

Re: delta V

Delta V equals 0 in closed or isolated systems
by smurphy1D
Mon Feb 03, 2020 10:19 am
Forum: Calculating Work of Expansion
Topic: Derivative
Replies: 3
Views: 73

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?
by smurphy1D
Mon Feb 03, 2020 10:17 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Types of Systems
Replies: 7
Views: 162

Re: Types of Systems

Is pressure always Constant in a closed system? Is pressure constant in an open system too?
by smurphy1D
Sat Feb 01, 2020 9:31 am
Forum: Phase Changes & Related Calculations
Topic: Reversible and Irreversible
Replies: 5
Views: 82

Re: Reversible and Irreversible

Would irreversible reactions occur in open containers then? If the pressure is constant is it always a irreversible reaction?
by smurphy1D
Sat Feb 01, 2020 9:29 am
Forum: Phase Changes & Related Calculations
Topic: Internal Energy, U
Replies: 6
Views: 80

Internal Energy, U

Is Delta U always equal to Delta H?
by smurphy1D
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: 59

Lewis Structures Method 2

In order to use the bond enthalpies method, is it necessary to write out the lewis structures of each compound?
by smurphy1D
Sun Jan 26, 2020 2:22 pm
Forum: Phase Changes & Related Calculations
Topic: Phase Changes endo/exo
Replies: 3
Views: 26

Re: Phase Changes endo/exo

Yes some phase changes are exothermic, as long as it is releasing heat.
by smurphy1D
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: 55

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?
by smurphy1D
Fri Jan 24, 2020 10:08 am
Forum: Phase Changes & Related Calculations
Topic: Phase Changes
Replies: 3
Views: 47

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?
by smurphy1D
Sun Jan 19, 2020 12:32 pm
Forum: Ideal Gases
Topic: ICE Table
Replies: 11
Views: 223

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?
by smurphy1D
Fri Jan 17, 2020 1:01 pm
Forum: Ideal Gases
Topic: PV=nRT equation manipulation
Replies: 13
Views: 254

Re: PV=nRT equation manipulation

Is R a constant in every equation? Or does it differ depending on the chemical equation ?
by smurphy1D
Fri Jan 17, 2020 12:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Acids and Bases
Replies: 6
Views: 80

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?
by smurphy1D
Fri Jan 17, 2020 12:56 pm
Forum: Ideal Gases
Topic: ph
Replies: 10
Views: 168

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?
by smurphy1D
Tue Jan 14, 2020 9:31 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.5
Replies: 4
Views: 68

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!
by smurphy1D
Tue Jan 14, 2020 9:28 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE Table
Replies: 8
Views: 98

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?
by smurphy1D
Tue Jan 14, 2020 9:25 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Acids and Bases
Replies: 6
Views: 80

Re: Acids and Bases

How do you incorporate the temperature into a Kw=[H3O+][OH-] equation?
by smurphy1D
Fri Jan 10, 2020 9:21 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.5
Replies: 4
Views: 68

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...
by smurphy1D
Thu Jan 09, 2020 10:10 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Meaning of equilibrium constant
Replies: 5
Views: 65

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.
by smurphy1D
Thu Jan 09, 2020 9:58 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: liquids and aqueous solutions
Replies: 4
Views: 39

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?
by smurphy1D
Wed Jan 08, 2020 9:35 am
Forum: Ideal Gases
Topic: Dynamic Equilibrium
Replies: 10
Views: 123

Re: Dynamic Equilibrium

It is at dynamic equilibrium when the rate of the forward reaction is equal to the rate of the reverse reaction
by smurphy1D
Wed Jan 08, 2020 9:31 am
Forum: Ideal Gases
Topic: Equilibrium
Replies: 7
Views: 87

Equilibrium

What is the difference between Q and K?

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