Search found 34 matches
- Sun Mar 19, 2023 1:38 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: difference between E and Ecell naught
- Replies: 6
- Views: 1313
Re: difference between E and Ecell naught
E refers to the cell's potential when it is under non-standard conditions, whereas E* is when the potential of the cell is at its standard positions, and is also not proportional to the amount of the substance.
- Sun Mar 19, 2023 12:59 am
- Forum: General Rate Laws
- Topic: Achieve week 8-10 #7
- Replies: 5
- Views: 547
Re: Achieve week 8-10 #7
you first have to know that in order to find [C] you have to compare experiment 1 and experiment 4. this should show you that the order of [C] is 0 since the rates of 1 and 4 are both independent from the concentration of C. To find [A] you do the same thing with experiments 1 and 2, which should le...
- Sun Mar 19, 2023 12:56 am
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Forward v Reverse Catalyst
- Replies: 12
- Views: 1615
Re: Forward v Reverse Catalyst
the rate of both a forward and reverse reaction are increased with the presence of a catalyst, since the catalyst allows for another path to be made available to the reaction allowing it to progress, which in turn lowers the activation energy.
- Sun Mar 19, 2023 12:49 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: - n F E
- Replies: 6
- Views: 533
Re: - n F E
when you calculate the change in the gibbs free energy, you are calculating the amount of work that a system is able to do. the system is doing this work on its surroundings. if both the gibbs freww energy, and the delta G max of a system are equal, that is where we get -nFE
- Sun Mar 19, 2023 12:46 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: chelating ligands [ENDORSED]
- Replies: 51
- Views: 110160
Re: chelating ligands [ENDORSED]
Elizabeth Harty 1A wrote:How do you know if there are sigma bonds available for rotation?
pi bonds are the bonds that are not able to rotate, but sigma bonds do have that ability
- Sun Mar 19, 2023 12:40 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Short Notation
- Replies: 5
- Views: 539
Re: Short Notation
you use a comma instead of a line to separate Fe since it is in the same aqueous state and of the same species.
- Sun Mar 19, 2023 12:39 am
- Forum: General Rate Laws
- Topic: Unique Reaction Rates [ENDORSED]
- Replies: 45
- Views: 171138
Re: Unique Reaction Rates [ENDORSED]
a unique reaction rate entails the rat being the same for the concentrations of both the products and the reactants when that reaction rate is multiplied by the coefficient that goes with it. there is no need to specify a species when you are writing a reaction rate.
- Sun Mar 19, 2023 12:37 am
- Forum: Balancing Redox Reactions
- Topic: oxidation number
- Replies: 18
- Views: 1669
Re: oxidation number
since any free element's oxidation number is 0, the oxidation number of O3 would be 0
- Sun Mar 19, 2023 12:34 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: pre-equilibrium reaction mechanism
- Replies: 5
- Views: 545
Re: pre-equilibrium reaction mechanism
when you are solving it in terms of pre-equilibrium you really only have to make sure that the steps prior are the ones that are at equilibrium. you continue to do this until there are only reactant concentrations left in the rate equation.
- Sun Mar 19, 2023 12:31 am
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: WK 8-10 HW #18
- Replies: 6
- Views: 495
Re: WK 8-10 HW #18
the way that you can tell if a species is a catalyst is by recognizing that it is first consumed and then produced. this would entail a species being a rectant in the first step and a product in the second one.
- Sun Mar 19, 2023 12:23 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: homework question
- Replies: 2
- Views: 433
homework question
The mechanism proposed for the oxidation of iodide ion, I−, by the hypochlorite ion, ClO−, in aqueous solution is shown. ClO−(aq)+H2O(l)⇌HClO(aq)+OH−(aq)fast in both directions I−(aq)+HClO(aq)→HIO(aq)+Cl−(aq) slow HIO(aq)+OH−(aq)→IO−(aq)+H2O(l) fast Complete the rate law for the formation of IO− imp...
- Sun Mar 19, 2023 12:22 am
- Forum: Second Order Reactions
- Topic: question on homework
- Replies: 3
- Views: 634
question on homework
Calculate the activation energy, Ea, in kilojoules per mole for a reaction at 74.0 ∘C that has a rate constant of 0.290 s−1 and a frequency factor of 9.26×1011 s−1
this question got me stuck. can anyone explain it?
.
this question got me stuck. can anyone explain it?
.
- Sun Mar 19, 2023 12:20 am
- Forum: General Rate Laws
- Topic: review question
- Replies: 2
- Views: 490
review question
The rate of the given reaction is 0.180 M/s.
A+3B⟶2C
What is the relative rate of change of each species in the reaction?
i got this quesiton correct on the homework, but i am not entirely sure why. can anyone help to walk me through it?
A+3B⟶2C
What is the relative rate of change of each species in the reaction?
i got this quesiton correct on the homework, but i am not entirely sure why. can anyone help to walk me through it?
- Sun Mar 05, 2023 11:04 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: homework confustion
- Replies: 1
- Views: 577
homework confustion
could someone please explain how to do this. i really dont undersatand
What would the potential of a standard hydrogen electrode (S.H.E.) be under the following conditions?
[H+]=0.53 MPH2=5.0 atmT=298 K
What would the potential of a standard hydrogen electrode (S.H.E.) be under the following conditions?
[H+]=0.53 MPH2=5.0 atmT=298 K
- Sun Mar 05, 2023 11:03 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: homework question
- Replies: 3
- Views: 349
homework question
on number 14 on the homework (Complete this table relating the values of E∘cell and ΔG∘ to K.) i figured out the table but im not sure i completely understnd why. could someone explain it to me?
- Sun Mar 05, 2023 11:01 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: homework question
- Replies: 1
- Views: 319
homework question
Identify the oxidizing and reducing agents in the skeletal (unbalanced) reaction. Then, balance the reaction, including the phase (solid, liquid, etc.) of each species. The reaction takes place in basic aqueous solution. Pb(OH)2−4(aq)+ClO−(aq)⟶PbO2(s)+Cl−(aq) i am confused on how to do the balanced ...
- Wed Feb 15, 2023 6:39 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Achieve Question
- Replies: 4
- Views: 171
Achieve Question
I'm super lost on this question
The ΔHvap
of a certain compound is 48.75 kJ·mol−1
and its ΔSvap
is 73.70 J·mol−1·K−1.
What is the boiling point of this compound?
The ΔHvap
of a certain compound is 48.75 kJ·mol−1
and its ΔSvap
is 73.70 J·mol−1·K−1.
What is the boiling point of this compound?
- Wed Feb 15, 2023 6:38 pm
- Forum: Environment, Fossil Fuels, Alternative Fuels
- Topic: Week 6-7 Homework Question
- Replies: 2
- Views: 504
Week 6-7 Homework Question
Can someone kind of just sum up the steps on this one? I keep thinking I have it and then ending up with very different, incorrect answers. Calculate the standard enthalpy, entropy, and Gibbs free energy at 298 K for the given reaction, using the data in the table of thermodynamic properties. NH4Cl(...
- Wed Feb 15, 2023 6:36 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Week 6-7 Homework Question [ENDORSED]
- Replies: 2
- Views: 220
Week 6-7 Homework Question [ENDORSED]
Consider a process in which an ideal gas is compressed to one-fourth of its original volume at a constant temperature.
Calculate the entropy change per mole of gas.
I'm confused about this question. Can anyone explain it to me?
Calculate the entropy change per mole of gas.
I'm confused about this question. Can anyone explain it to me?
- Thu Feb 09, 2023 3:56 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Question 4D7
- Replies: 2
- Views: 104
Re: Question 4D7
Unless otherwise specified, assume that the temperature is 298K (25 C). This is what I do when it's not given and it always works.
- Thu Feb 09, 2023 3:54 pm
- Forum: General Science Questions
- Topic: Rusty on High School Chem [ENDORSED]
- Replies: 347
- Views: 579604
Re: Rusty on High School Chem [ENDORSED]
I would say that doing as many practice problems as you can is the most helpful. Professor Lavelle posts textbook ones each week, and I've found these to be super useful! I would also say to watch ANY optional video/explanation he posts, they are always helpful. And when in doubt, go to the step-up ...
- Thu Feb 09, 2023 3:51 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: chelating ligands [ENDORSED]
- Replies: 51
- Views: 110160
Re: chelating ligands [ENDORSED]
Elizabeth Harty 1A wrote:How do you know if there are sigma bonds available for rotation?
pi bonds don't/can't rotate, but sigma bonds can.
- Sun Feb 05, 2023 9:20 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: HW #18
- Replies: 2
- Views: 228
HW #18
Im confused on this question on the homework A constant‑volume calorimeter was calibrated by carrying out a reaction known to release 1.51 kJ of heat in 0.400 L of solution in the calorimeter (q=−1.51 kJ) , resulting in a temperature rise of 3.98 ∘C . In a subsequent experiment, 200.0 mL of 0.40 M H...
- Sun Feb 05, 2023 9:19 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: HW #12
- Replies: 1
- Views: 168
HW #12
Im confused about the second part of #12 on the homework
Suppose a 3.805 g
sample of a second compound, compound B, is combusted in the same calorimeter, and the temperature rises from 23.49 ∘C
to 26.82 ∘C.
What is the heat of combustion per gram of compound B?
Suppose a 3.805 g
sample of a second compound, compound B, is combusted in the same calorimeter, and the temperature rises from 23.49 ∘C
to 26.82 ∘C.
What is the heat of combustion per gram of compound B?
- Sun Feb 05, 2023 9:18 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: HW #14
- Replies: 1
- Views: 114
HW #14
I'm confused on this question
Automobile airbags contain solid sodium azide, NaN3,
that reacts to produce nitrogen gas when heated, thus inflating the bag.
2NaN3(s)⟶2Na(s)+3N2(g)
Calculate the value of work, w,
for the system if 10.5 g NaN3
reacts completely at 1.00 atm
and 22 ∘
C.
Automobile airbags contain solid sodium azide, NaN3,
that reacts to produce nitrogen gas when heated, thus inflating the bag.
2NaN3(s)⟶2Na(s)+3N2(g)
Calculate the value of work, w,
for the system if 10.5 g NaN3
reacts completely at 1.00 atm
and 22 ∘
C.
- Sun Jan 29, 2023 11:18 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Kw
- Replies: 5
- Views: 360
Re: Kw
Kw is only used for water. The subscripts are what I use to remember: w for water, c for concentrations, and p for pressure.
- Sun Jan 29, 2023 11:14 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ka and Kb
- Replies: 10
- Views: 337
Re: Ka and Kb
Ka is the dissociation constant for weak acids and Kb is the dissociation constant for weak bases. They are both calculated in the same way that you would calculate Kc.l
- Sun Jan 29, 2023 11:10 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: pH of weak acids vs strong acids
- Replies: 9
- Views: 2669
Re: pH of weak acids vs strong acids
since strong acids will fully dissociate, they release more ions of H+. when more H+ ions are released, this gives you a lower pH value.
- Sun Jan 22, 2023 9:11 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Acids and Bases
- Replies: 264
- Views: 224188
Re: Acids and Bases
505968894 wrote:Is a negative pH possible?
even though the scale is usually 0-14, it is possible for pH to be negative.
- Sun Jan 22, 2023 9:10 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Acids and Bases
- Replies: 264
- Views: 224188
Re: Acids and Bases
Phoebe 1H wrote:Also, what does amphiprotic mean?
it means that it is able to react as both an acid and a base since it can donate and accept a proton
- Sun Jan 22, 2023 9:07 pm
- Forum: General Rate Laws
- Topic: Unique Reaction Rates [ENDORSED]
- Replies: 45
- Views: 171138
Re: Unique Reaction Rates [ENDORSED]
its unique because the reaction rate is the same for each concentration of products and reactions when it gets multiplied by the stoich coefficient.
- Sun Jan 15, 2023 4:49 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE tables: solids
- Replies: 22
- Views: 653
Re: ICE tables: solids
No, ICE tables are just used for calculating the equilibrium for gases.
- Sun Jan 15, 2023 4:46 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Textbook Inquiry [ENDORSED]
- Replies: 29
- Views: 70841
Re: Textbook Inquiry [ENDORSED]
Yes! In class he said that he allows us to download the book on up to 3 different devices for 4 years of use, so you can download it multiple ways!
- Sun Jan 15, 2023 4:44 pm
- Forum: Ideal Gases
- Topic: Q and K
- Replies: 130
- Views: 52522
Re: Q and K
K is the reactants and products of the reaction when it is at equilibrium. Q is the proportion at any given time during the reaction, so it is not the value at equilibrium.