Search found 54 matches
- Sat Mar 16, 2024 9:16 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic Cell Diagram
- Replies: 2
- Views: 52
Re: Galvanic Cell Diagram
I do not think so I think just knowing the notation of the cell diagram should be sufficient since the textbook questions are generally representative and we were not asked to do that
- Sat Mar 16, 2024 9:13 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm 1 question
- Replies: 2
- Views: 101
Re: Midterm 1 question
so here we are essentially finding the equilibrium constant for the conjugate base of the acid in the equation provided. you can solve for Ka and then use the formula provided in the previous reply in order to solve for Kb since we know Kw and Ka.
- Sat Mar 16, 2024 9:12 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam Equations
- Replies: 1
- Views: 43
Re: Final Exam Equations
I think knowing how to manipulate the equations and apply them is what's important since the main equations are given.
- Sat Mar 16, 2024 9:11 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Derivations
- Replies: 3
- Views: 59
Re: Derivations
the derivative of this equation would look like this: -RTlnK = -H - Ts lnK= (H/-RT) - (Ts/-RT) lnK = (H/-RT) + (q/RT) lnK = (H/-RT) + (H/RT) lnK = -H/R (1/T - 1/T) lnK2 - lnK1 = -H/R (1/T2 - 1/T1) ln(K2/K1) = -H/R (1/T2 - 1/T1) Van't Hoff equation * H is the change in H and s is the change in s - I ...
- Sat Mar 16, 2024 6:27 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6L 7a
- Replies: 1
- Views: 31
6L 7a
Why is the cell diagram here have Ag(s) as both the anode and cathode. If the reaction is AgBr -> Ag+ + Br- and Ag is being reduced at the cathode and Br- is reduced at the anode- why is Ag(s) the electrode for both the anode and cathode. Why isn't Br(s) the anode? Also where would the entire solid ...
- Fri Mar 15, 2024 11:52 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: question 6D.7
- Replies: 1
- Views: 30
question 6D.7
how do we know here that we should be calculating work as well as the enthalpy? how do we infer work is being done from the information given?
- Fri Mar 15, 2024 9:28 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: exothermic reactions
- Replies: 5
- Views: 44
exothermic reactions
why aren't all exothermic reactions spontaneous if they do not require energy? is there a real life example of an exothermic reaction that is not spontaneous
- Fri Mar 15, 2024 6:47 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: free expansion
- Replies: 2
- Views: 53
free expansion
why is no work done under free expansion?
- Fri Mar 15, 2024 5:19 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: question 10 midterm 1
- Replies: 2
- Views: 44
question 10 midterm 1
I was wondering if the reasoning for question 10 was that because as the temperature increases the equilibrium constant increases showing that there is favoring of products as the temperature increases which would mean that heat is being used up to counter the increase in temperature and endothermic...
- Fri Mar 15, 2024 3:20 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: deciding what the anode or cathode are
- Replies: 2
- Views: 32
Re: deciding what the anode or cathode are
sorry I mean the anode since it has to be oxidized instead of reduced
- Fri Mar 15, 2024 3:19 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: deciding what the anode or cathode are
- Replies: 2
- Views: 32
deciding what the anode or cathode are
suppose you are given a question where hydrogen is one electrode and and other electrode is another solid metal with an aqueous solution surrounding it. How would you decipher which one is the cathode or anode? Would it be because we should know the reduction potential of H2 is 0 and therefore would...
- Fri Mar 15, 2024 2:55 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: peroxide
- Replies: 2
- Views: 38
peroxide
what would the oxidation numbers be for each in this equation:
H2O2 -> 2H2O + O2 ?
H2O2 -> 2H2O + O2 ?
- Fri Mar 15, 2024 1:39 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: chemical equation question
- Replies: 3
- Views: 74
chemical equation question
when sodium fluoride dissociates in water why do we get HF and OH- instead of NaOH?
- Thu Mar 14, 2024 7:01 pm
- Forum: Balancing Redox Reactions
- Topic: 6K5 (b)
- Replies: 1
- Views: 36
6K5 (b)
can someone explain how we are able to add H2O on both sides for this. I thought the rules were as follows for basic conditions for oxidation: identify species being oxidized write oxidation skeletal half reaction balance O by adding H2O on the left balance H+ by adding OH- on the same side of H2O c...
- Wed Mar 13, 2024 7:49 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: number 20 Achieve
- Replies: 1
- Views: 18
number 20 Achieve
is anyone able to pinpoint what I am doing wrong here...I keep getting the incorrect answer: this is my working out: kcat/kuncat = (e^(-Ea/RT))/(e^(-Ea/RT)) convert Ea to joules per mole = (e^(-70000/8.314*295))/(e^(-133000/8.314*295)) = (e^(-70000/2452.63))/(e^(-133000/2452.63)) = (e^(-28.54))/(e^(...
- Mon Mar 11, 2024 11:16 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: reaction quotient units
- Replies: 4
- Views: 60
Re: reaction quotient units
partial pressures are associated with gas and concentration with other phases meaning that they are essentially giving the same answer- do not worry about the units of Q
- Mon Mar 11, 2024 11:15 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Equilibrium in an Electrochemical cell
- Replies: 3
- Views: 117
Re: Equilibrium in an Electrochemical cell
when the standard potential is positive the reaction is spontaneous meaning that the products are favored. This means that the equilibrium constant is larger and often greater than 1 to show that a lot of the reactants are dissociating.
- Mon Mar 11, 2024 11:13 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: 6N #9
- Replies: 2
- Views: 35
6N #9
why is tin assumed to be the electrode of the anode? How is this inferred from the question? what happens to the NO3- in the half equation?
- Mon Mar 11, 2024 12:04 pm
- Forum: Balancing Redox Reactions
- Topic: 6K #1
- Replies: 3
- Views: 66
Re: 6K #1
not understanding how C2H5OH -> C2H4O + 2H+ + 2e-
Where is the water in the equation, why don't we include it and wouldn't the 2H+ and 2e- cancel each other out and the charges still would not be balanced?
Where is the water in the equation, why don't we include it and wouldn't the 2H+ and 2e- cancel each other out and the charges still would not be balanced?
- Mon Mar 11, 2024 10:55 am
- Forum: Balancing Redox Reactions
- Topic: 6K #1
- Replies: 3
- Views: 66
6K #1
can someone explain the steps to how we knew how to balance both the half equations for number 1.
- Mon Mar 11, 2024 10:35 am
- Forum: Balancing Redox Reactions
- Topic: how to know when there is acidic conditions?
- Replies: 2
- Views: 35
how to know when there is acidic conditions?
in the equation Zn + BrO3- -> Zn2+ + Br-1
the balanced eqn is 3Zn + BrO3- + 3H+ -> 3Zn2+ + Br-1 + 3H2O
how do we know to use hydrogen here and how do we know this is under acidic conditions
the balanced eqn is 3Zn + BrO3- + 3H+ -> 3Zn2+ + Br-1 + 3H2O
how do we know to use hydrogen here and how do we know this is under acidic conditions
- Sun Mar 03, 2024 9:16 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: lecture notes question
- Replies: 1
- Views: 24
lecture notes question
can someone explain how from lecture on Monday when describing the concentration the E was described as having typically low voltage...why is this important?
- Sun Mar 03, 2024 9:15 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nerst Equation
- Replies: 4
- Views: 74
Re: Nerst Equation
when the cell reaches equilibrium we know the change in G cell is 0 and Q=K. therefore E standard =( RT/nF) (lnK)
- Sun Mar 03, 2024 9:14 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: E cell vs Ecell (standard)
- Replies: 3
- Views: 34
Re: E cell vs Ecell (standard)
also to note for the standard E cell the equation will be E standard= (0.0592/n)logK
- Sun Mar 03, 2024 9:12 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Achieve Question 15
- Replies: 4
- Views: 66
Re: Achieve Question 15
thank you I figured it out
- Sun Mar 03, 2024 9:08 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Achieve Question 15
- Replies: 4
- Views: 66
Re: Achieve Question 15
still not seeing what I am doing wrong here?
- Sun Mar 03, 2024 3:26 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Achieve Question 15
- Replies: 4
- Views: 66
Achieve Question 15
I can't figure out what I am doing wrong here but I keep getting this wrong on achieve. This is my working out:
E= E - (RT/zF)lnQ
E= 1.94 - [(8.3145)(298.15)/(2)(96485)] ln(0.79/0.013)
E= 1.94- 0.12846(4.107)
E= 1.41
E= E - (RT/zF)lnQ
E= 1.94 - [(8.3145)(298.15)/(2)(96485)] ln(0.79/0.013)
E= 1.94- 0.12846(4.107)
E= 1.41
- Wed Feb 28, 2024 4:28 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: writing a cell notation
- Replies: 3
- Views: 43
Re: writing a cell notation
the anode is always negative charge and losing electrons which oxidizes while the cathode always positive and allows for gain of electrons /reduction - electrons flow from anode to cathode
- Wed Feb 28, 2024 4:27 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram
- Replies: 2
- Views: 38
Re: Cell Diagram
platinum is only separated by one line because electrons can flow through it
- Wed Feb 28, 2024 4:25 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: salt bridge
- Replies: 1
- Views: 26
salt bridge
can someone clarify the significance of the salt bridge?
- Wed Feb 28, 2024 4:22 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Electrochemistry
- Replies: 2
- Views: 77
Electrochemistry
Can someone clarify the use of the salt bridge?
- Wed Feb 28, 2024 4:21 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student [ENDORSED]
- Replies: 297
- Views: 604309
Re: Advice from a Medical Student [ENDORSED]
Thank you so much for this advice! It is really helpful to hear about other people's journeys.
- Wed Feb 28, 2024 4:18 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: OILRIG
- Replies: 1
- Views: 35
OILRIG
My acronym to remember oxidation and reduction is OILRIG
Oxidation
Is
Loss
Reduction
Is
Gain
Oxidation
Is
Loss
Reduction
Is
Gain
- Tue Feb 20, 2024 3:41 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 4.29 textbook
- Replies: 1
- Views: 38
4.29 textbook
Hi for question 4.9 part c why must the reaction be cooled to maintain a constant T? If the reaction is exothermic doesn't that mean the temperature of the surroundings is increasing and therefore the temperature of the reaction is decreasing since it is releasing heat. Wouldn't that suggest that yo...
- Tue Feb 20, 2024 1:47 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hmw: 7.53
- Replies: 6
- Views: 4233
Re: Hmw: 7.53
why does it matter which one the limiting reagent is
- Mon Feb 19, 2024 8:05 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 4J.13
- Replies: 1
- Views: 34
4J.13
determine which of the following. compounds are stable with respect to decomposition into their elements under standard conditions at 25C. PCl5 which has a free energy of formation of -305kJ/mol which because is less than 0 means the forward reaction is spontaneous and the products are more stable t...
- Mon Feb 19, 2024 4:00 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: confused on total entropy
- Replies: 1
- Views: 20
confused on total entropy
why is it that when a reversible process occurs the total entropy would be 0
- Mon Feb 19, 2024 12:53 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 4E.9
- Replies: 1
- Views: 27
4E.9
can someone explain the reasoning behind this question specifically the part about resonance and how it affects the body enthalpy benzene is more stable and less reactive than would be predicted from its Kekule structures. Use the data to calculate the lowering in molar energy when resonance is allo...
- Tue Feb 13, 2024 10:57 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: equation
- Replies: 2
- Views: 42
equation
in lecture there was an equation mentioned qp = gCsp(change in T)
I was wondering what the Csp stood for?
I was wondering what the Csp stood for?
- Tue Feb 13, 2024 10:55 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: enthalpy
- Replies: 2
- Views: 40
enthalpy
is the change in H the same thing as q?
- Tue Feb 13, 2024 10:55 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Reversible and Irreversible
- Replies: 3
- Views: 50
Re: Reversible and Irreversible
usually irreversible reactions are faster and are usually biological
- Tue Feb 13, 2024 10:54 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Isothermal Expansion
- Replies: 4
- Views: 64
Re: Isothermal Expansion
temperature always held constant but volume changing and pressure changing which is why the equation turns out to be what was said in previous response
- Mon Jan 29, 2024 10:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Outline 1 5I 13
- Replies: 1
- Views: 35
Re: Outline 1 5I 13
Cl2 is the most thermodynamically stable because it is in its lowest state of energy
- Mon Jan 29, 2024 10:30 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Achieve 1 Q4
- Replies: 1
- Views: 32
Re: Achieve 1 Q4
I believe its because the PCl5 is what is being initially placed for the reaction.
- Mon Jan 29, 2024 8:32 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: diprotic acids
- Replies: 1
- Views: 27
diprotic acids
under what conditions do we ignore the second deprotonation of the acid
- Mon Jan 29, 2024 8:28 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: number 7 HW2
- Replies: 1
- Views: 27
number 7 HW2
For number 7 I am using the equation:
H+ + ClO- + Na+ + ClO- + H2O -> HClO- + OH- + Na+
I am wondering what happened to the H+ and why my equation might be wrong
H+ + ClO- + Na+ + ClO- + H2O -> HClO- + OH- + Na+
I am wondering what happened to the H+ and why my equation might be wrong
- Mon Jan 22, 2024 11:20 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: The "Seesaw" concept
- Replies: 2
- Views: 57
Re: The "Seesaw" concept
the seasaw concept is just showing us that with a stronger acid there is a weaker conjugate base and with a stronger base there is a weaker conjugate acid
- Mon Jan 22, 2024 11:19 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: cubic equation
- Replies: 2
- Views: 49
cubic equation
can someone explain what was said about solving the cubic equation in the lecture, im not fully understanding. I know that I should not solve the entire thing via factorization and there is an approximation/trick I can use
- Mon Jan 22, 2024 11:17 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Autoprotolysis of Water
- Replies: 3
- Views: 42
Re: Autoprotolysis of Water
Yes this is still happening however since they only give a small amount to the solution they are neglected from the equation
- Mon Jan 22, 2024 11:14 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: weak acids and bases
- Replies: 1
- Views: 33
weak acids and bases
is the conjugate base or acid essentially the same as the salt being formed?
- Sun Jan 14, 2024 10:34 pm
- Forum: Ideal Gases
- Topic: Conversion between Kc and Kp
- Replies: 2
- Views: 126
Re: Conversion between Kc and Kp
partial pressure generally applies to gaseous state
- Sun Jan 14, 2024 10:33 pm
- Forum: Ideal Gases
- Topic: Pure substances
- Replies: 4
- Views: 137
Re: Pure substances
this is because they are present in excess and there change is insignificant
- Sun Jan 14, 2024 10:31 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: partial pressure
- Replies: 2
- Views: 53
partial pressure
how do we know when the partial pressure is 0
- Sat Jan 13, 2024 10:34 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Question 2 Achieve
- Replies: 2
- Views: 98
Question 2 Achieve
We are able to calculate the initial concentration of SO3 and then when calculating the equilibrium concentration...why is it that we must subtract the initial from the conc of the SO2? Why are subtracting from SO2 and why are we not also subtracting the O2?