Search found 120 matches
- Wed Mar 10, 2021 1:04 am
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: N,M,L
- Replies: 3
- Views: 186
Re: N,M,L
are you refering to reaction order?
- Wed Mar 10, 2021 1:04 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Omitting compounds from Cell Diagrams
- Replies: 3
- Views: 258
Re: Omitting compounds from Cell Diagrams
I've been doing the textbook problems that have you write the cell diagrams, and for some of them I'm not sure why they wrote it in that particular format. For example: 6L.5.c. The Equation was Cl2(g) + H2(g) --> HCl(aq) and the cell diagram was: Pt(s) | H2 (g) | H+ (aq) || Cl- (aq) | Cl2 (g) | Pt(...
- Wed Mar 10, 2021 1:02 am
- Forum: *Enzyme Kinetics
- Topic: catalyst vs intermediate
- Replies: 13
- Views: 898
Re: catalyst vs intermediate
intermediates appear in the equations, but are cancelled out in the final equation, catalysts dont
- Wed Mar 10, 2021 1:01 am
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Exergonic vs Exothermic [ENDORSED]
- Replies: 4
- Views: 382
Re: Exergonic vs Exothermic [ENDORSED]
yep! exergonic refers to the fact that the gibbs free energy is being released. We can't say that it is exothermic it relies only on enthaply while gibbs free energy relies on both enthalpy and entropy
- Wed Mar 10, 2021 12:59 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Sapling W9/W10 #16 [ENDORSED]
- Replies: 3
- Views: 298
Re: Sapling W9/W10 #16 [ENDORSED]
For the reversible, one‑step reaction: A+A⥫⥬ B+C the rate constant for the forward reaction, k1, is 285 L⋅mol−1⋅min−1 and the rate constant for the reverse reaction, k1', is 377 L⋅mol−1⋅min−1 at a given temperature. The activation energy for the forward reaction is 44.6 kJ⋅mol−1, whereas the activa...
- Wed Mar 10, 2021 12:56 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Riya's 9am UA Session Today
- Replies: 4
- Views: 276
Re: Riya's 9am UA Session Today
Hello, Riya here Sorry for the inconvenience and thank you so much for a great quarter! Here is the answer key for the Week 10 worksheet. Please let your peers know. for number 6b, why do we take the -log(Kb) instead of -log(OH-) to find pOH? it was in the work in the answer sheet. please quote me!...
- Sat Mar 06, 2021 3:22 am
- Forum: General Rate Laws
- Topic: 7.C.7
- Replies: 2
- Views: 201
7.C.7
for the question about reacting nitric oxide with bromine, it has 2 elementary reaction steps STEP 1: NO + Br2 --> NoBr2 (slow) STEP 2: NOBr2 + NO --> NOBr + NOBr (fast) it asks for the rate law of the overall reaction I understand that the reaction is determined by the slow step, therefore the fast...
- Sat Mar 06, 2021 2:34 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Electrochemistry outline (emf and maximum potential difference) [ENDORSED]
- Replies: 1
- Views: 224
Electrochemistry outline (emf and maximum potential difference) [ENDORSED]
for the outline question "Know the definition of the electromotive force (emf, ℰ) and why it represents the maximum potential difference" I thought that the electromotive force is different from potential difference and only when no energy is passing through is maximum potential difference...
- Tue Mar 02, 2021 7:11 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Brooke week 9 q 1c
- Replies: 1
- Views: 137
Brooke week 9 q 1c
for the question, Co²⁺ + 2e⁻ → CO Estandard = -.28V Au³⁺ + 3e⁻ → Au Estandard = 1.50V What is the equilibrium constant? I calculated Estandard = 1.78V, deltaGstandard = -1030.5 KJ For the equilibrium constant, E = Estandard - (0.0592/n)logK # since at equilibrium, E = 0, I set the equation to zero #...
- Tue Mar 02, 2021 6:52 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram Question
- Replies: 3
- Views: 240
Re: Cell Diagram Question
to add on, you also don't need to have the coefficients in the diagram
- Tue Mar 02, 2021 6:50 pm
- Forum: First Order Reactions
- Topic: order reactions steps
- Replies: 3
- Views: 249
order reactions steps
can someone list the steps to calculate the order of each reaction?
I understand how it works for first order, but how do we generalize?
I understand how it works for first order, but how do we generalize?
- Tue Mar 02, 2021 6:48 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Q Value in Nenrst Equation
- Replies: 2
- Views: 220
Re: Q Value in Nenrst Equation
given the fact that it is in standard conditions, we can assume that the pressure, temp are the same for both so they would cancel. R constant will cance N and v are left for both.
- Tue Mar 02, 2021 6:47 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: cell diagram order
- Replies: 3
- Views: 214
Re: cell diagram order
which question is that? I think it might be because we put anode on left side and cathode on right.
- Tue Mar 02, 2021 6:44 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Electron flow in concentration cell
- Replies: 1
- Views: 404
Electron flow in concentration cell
I know that electron flows from low concentration solution to higher concentration solution. Can someone explain why it does that?
- Tue Feb 23, 2021 8:24 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Sapling 13
- Replies: 2
- Views: 170
Re: Sapling 13
you would look for the element with the Ered that is higher than the one oxidized, but lower than the one that isn't
- Tue Feb 23, 2021 8:22 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Sapling Question about the Explanation
- Replies: 2
- Views: 188
Re: Sapling Question about the Explanation
I also had the same question because wouldn't the ratios be off?
- Tue Feb 23, 2021 8:21 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Sapling 13 week 7/8
- Replies: 2
- Views: 145
Re: Sapling 13 week 7/8
Hi!
you find the element that has a higher Estandard than the one that is oxidized, but lower than the one that isn't
for example, if Zn is oxidized but not Sn.
Zn E= -0.76, Sn E= -0.14
Co2+ E = -0.28
so Co2+ would be the reagent
you find the element that has a higher Estandard than the one that is oxidized, but lower than the one that isn't
for example, if Zn is oxidized but not Sn.
Zn E= -0.76, Sn E= -0.14
Co2+ E = -0.28
so Co2+ would be the reagent
- Tue Feb 23, 2021 8:17 pm
- Forum: Balancing Redox Reactions
- Topic: Sapling Week 7/8 #5 terms
- Replies: 4
- Views: 303
Re: Sapling Week 7/8 #5 terms
the oxidizing agent is the one that is reduced. Solve this by using half equations and see how electrons are transfered
- Tue Feb 23, 2021 5:28 am
- Forum: Balancing Redox Reactions
- Topic: Sapling #4 Week 7/8
- Replies: 3
- Views: 326
Re: Sapling #4 Week 7/8
you will need to mulptiply HNO3 reaction by three in order to cancel the 3H out in the Au reaction
- Tue Feb 23, 2021 3:26 am
- Forum: Balancing Redox Reactions
- Topic: Sapling week 7/8 number 13
- Replies: 2
- Views: 215
Sapling week 7/8 number 13
How do we go about solving this?
"Which of the reagents would oxidize Zn to Zn2+ , but not Sn to Sn2+?"
Is there a faster way than finding the potential for each and seeing if it makes it spontaneous?
"Which of the reagents would oxidize Zn to Zn2+ , but not Sn to Sn2+?"
Is there a faster way than finding the potential for each and seeing if it makes it spontaneous?
- Wed Feb 17, 2021 5:21 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Midterm Review #12b
- Replies: 4
- Views: 270
Re: Midterm Review #12b
How do we calculate for this? because doesn't q1 and q3 cancel each other out?
- Wed Feb 17, 2021 5:08 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Reaction of glucose in human body
- Replies: 1
- Views: 138
Reaction of glucose in human body
For the equation C6H12O6 (s) + 6O2 (g) → 6CO2 (g) + 6H2O (l), it asks for Suppose a researcher finds that ∆Hrxn = -2756 kJ for the reaction at 200. C. Assuming all heat capacities are constant, calculate ∆Hrxn at the temperature of the human body, 37 C. Hint: Since enthalpy is a state function, the ...
- Wed Feb 17, 2021 4:34 am
- Forum: Calculating Work of Expansion
- Topic: When to use each work equatin?
- Replies: 2
- Views: 155
When to use each work equatin?
when do we use w = -(Pex)(deltaV) and w = -nRTln(V2/V1) ?
I know in a practice problem from Michael's section, we used w = -(Pex)(deltaV) for isobaric compression and w = -nRTln(V2/V1) for isothermal reversible reactions. Is it always this way?
I know in a practice problem from Michael's section, we used w = -(Pex)(deltaV) for isobaric compression and w = -nRTln(V2/V1) for isothermal reversible reactions. Is it always this way?
- Wed Feb 17, 2021 4:05 am
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Practice Midterm W18 #3A
- Replies: 3
- Views: 545
Re: Practice Midterm W18 #3A
I think we would use the molar heat capacity under constant volume, but would it be diatomic or monotonic?
- Wed Feb 17, 2021 4:04 am
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Practice Midterm W18 #3A
- Replies: 3
- Views: 545
Re: Practice Midterm W18 #3A
How would we know that the C value is?
- Mon Feb 15, 2021 6:28 am
- Forum: Van't Hoff Equation
- Topic: 5J.15
- Replies: 2
- Views: 348
5J.15
Hi! Could anyone help me calculate K at 150 C? Calculate the equilibrium constant at 25 °C and at 150 °C for each of the following reactions, using data available in Appendix 2A: (a) NH 4 Cl (s ) ⇌ NH 3 (g ) + HCl (g ) (b) H 2 (g ) + D 2 O (l ) ⇌ D 2 (g ) + H 2 O (l ) I figured out how to calculate ...
- Sun Feb 14, 2021 12:25 am
- Forum: Calculating Work of Expansion
- Topic: 4B 13 part A [ENDORSED]
- Replies: 1
- Views: 89
4B 13 part A [ENDORSED]
Hi! I was able to calculate the reversible expansion. But for irreversible, I used w = -PexdeltaV and got -2.23 J instead of the answer 226 J Calculate the work for each of the following processes beginning with a gas sample in a piston assembly with T = 305 K , P = 1.79 atm , and V = 4.29 L : (a) i...
- Tue Feb 09, 2021 3:10 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Calculation not working
- Replies: 3
- Views: 203
Re: Calculation not working
probably the way your calculator does PEMDAS. use () to avoid confusion for the calculator. I also write out each step and calculate that so the end is just simple addition
- Tue Feb 09, 2021 3:09 pm
- Forum: Student Social/Study Group
- Topic: Preparing for Midterm 2
- Replies: 14
- Views: 653
Re: Preparing for Midterm 2
I drink the same tea while studying and taking the test. It helps calm me down and jog my memory. I also use the same pencil
- Tue Feb 09, 2021 3:08 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: lecture 14 question
- Replies: 6
- Views: 290
Re: lecture 14 question
basically showing change of one interms of another. The same equation is on our equation sheet but with delta instead of derivative d
- Tue Feb 09, 2021 3:07 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm 2
- Replies: 6
- Views: 358
Re: Midterm 2
I think all of termochem that we weren't tested on last time and all of thermo dynamics
- Tue Feb 09, 2021 3:06 pm
- Forum: Ideal Gases
- Topic: Chem BL
- Replies: 107
- Views: 7134
Re: Chem BL
I plan on taking it next quarter or else im never gonna be able to finish my req classes
- Mon Feb 08, 2021 10:48 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Sapling week 5&6 #18
- Replies: 1
- Views: 88
Sapling week 5&6 #18
For the question which asks us to calculate K, why is delta G needed? Calculate the equilibrium constant, K , at 25.0°C for each of the reactions. Use the thermodynamic information provided in the table. The first step in the synthesis of trichloromethane (chloroform) from natural gas (methane). CH4...
- Mon Feb 08, 2021 9:16 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Sapling week 5&6 #7
- Replies: 2
- Views: 220
Sapling week 5&6 #7
Hi! can anyone help me with the problem below? I converted the Wats to energy and got 136800 J. and also converted the initial and final masses to mols ''Three liquid samples of known masses are heated to their boiling points with the use of a heater rated at 475.0 W . Once the boiling points of eac...
- Sat Feb 06, 2021 1:42 am
- Forum: Calculating Work of Expansion
- Topic: Friday Feb 5 lecture [ENDORSED]
- Replies: 1
- Views: 117
Friday Feb 5 lecture [ENDORSED]
Hi! I watched the lecture twice but am still kind of confused in general about expansion. Could anyone summarize for me?
- Thu Feb 04, 2021 1:23 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Confused about equations
- Replies: 6
- Views: 333
Re: Confused about equations
I literally feel you. I think thermo is something people have to learn multiple times to completely get!
- Thu Feb 04, 2021 1:21 am
- Forum: Student Social/Study Group
- Topic: Students Who Have a Job
- Replies: 103
- Views: 8978
Re: Students Who Have a Job
Hi! I worked about 20 hrs a week throughout high school and honestly the biggest trick is to write everything down. I have a planner where I write down what I plan to do at each time. Or, when I spend a day spontaneously doing many different homework assignments or even take it easy and have fun, I ...
- Thu Feb 04, 2021 1:18 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed system
- Replies: 43
- Views: 1468
Re: closed system
imagine you have a water bottle that is sealed closed, you could put the water bottle in another tub of hot water to heat the water inside, but cannot change the volume of the water inside without taking off the lid
- Thu Feb 04, 2021 1:17 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: delta U conceptual question
- Replies: 7
- Views: 296
Re: delta U conceptual question
im pretty sure delta u = zero when it is an isolated system
- Thu Feb 04, 2021 1:16 am
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Do Resonance Structures have more Degeneracy
- Replies: 6
- Views: 307
Re: Do Resonance Structures have more Degeneracy
I think so? since in the lecture he used the example of BF3 then BF2Cl and said that BF2Cl could have 3 possible lewis structures
- Thu Feb 04, 2021 1:14 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Sapling Week 3 and 4 Question 18
- Replies: 5
- Views: 158
Re: Sapling Week 3 and 4 Question 18
Hi! I think sapling gives out different numbers in the questions, here is mine [A 0.721 mol sample of SO2(g), initially at 298 K and 1.00 atm, is held at constant pressure while enough heat is applied to raise the temperature of the gas by 15.5 K. Calculate the amount of heat required to bring about...
- Thu Feb 04, 2021 1:08 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Sapling Question Week 3/4
- Replies: 4
- Views: 149
Re: Sapling Question Week 3/4
I wonder if Sapling gives out slightly different questions for each student. The one I got that was similar was [ A 0.617 mol sample of N2(g) initially at 298 K and 1.00 atm is held at constant volume while enough heat is applied to raise the temperature of the gas by 10.5 K. Assuming ideal gas beha...
- Wed Jan 27, 2021 7:41 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Midterm 1 Objectives
- Replies: 1
- Views: 77
Re: Midterm 1 Objectives
for the first one, I just talked about how the equation of ADP and free energy is used to creat ATP which is used by the cells. And because of that, we need to eat to give ADP molecules energy to form ATP. Osmotic pressure basically means that solvent basses between membranes until equilibrium is re...
- Wed Jan 27, 2021 2:00 am
- Forum: Student Social/Study Group
- Topic: Midterm Practice
- Replies: 6
- Views: 347
Re: Midterm Practice
Yep the UA worksheets have been extremely helpful! They also go over questions really well.
- Mon Jan 25, 2021 8:13 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Thermochem outline MT1 Questions
- Replies: 3
- Views: 252
Thermochem outline MT1 Questions
Does anyone know which bullet points in the thermochem outline we should focus on?
- Mon Jan 25, 2021 7:49 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: percentage ionization
- Replies: 2
- Views: 61
percentage ionization
for percentage ionization I know that it is [H3O+]/[HAinitial] *100%. However, I've been using [A-] instead and getting the same answer. do they both work?
- Mon Jan 25, 2021 7:06 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: changes in volume
- Replies: 4
- Views: 240
changes in volume
can someone explain to me why an increase in volume means that Q>K and a decrease in volume means Q<K? I know that when volume is increased the reaction shifts to the side with more moles of gas and when volume is decreased reaction shifts to less moles of gas, but how does that affect the Q value?
- Fri Jan 22, 2021 3:56 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: endothermic/exothermic Q and K
- Replies: 16
- Views: 2003
Re: endothermic/exothermic Q and K
K<Q reaction goes to reactants (K <-- Q )
K>Q reaction goes to products (K --> Q)
K>Q reaction goes to products (K --> Q)
- Fri Jan 22, 2021 3:54 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Homework Problem 6D.9
- Replies: 2
- Views: 212
Re: Homework Problem 6D.9
Hi! Could someone please walk me through how they solved this problem? 6D.9 The percentage deprotonation of benzoic acid in a 0.110 m solution is 2.4%. What is the pH of the solution and the Ka of benzoic acid? deprotonation is [A-]/[initial HA] * 100% = % [x]/[0.110M] * 100% = 2.4% x = [A-] [H3O+]...
- Fri Jan 22, 2021 3:48 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: What is Qp?
- Replies: 5
- Views: 283
Re: What is Qp?
Qp is the ratio that is similar to Kp when you don't know if the reaction is at equilibrium yet
- Fri Jan 22, 2021 3:47 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ka1 vs Ka2
- Replies: 6
- Views: 1191
Re: Ka1 vs Ka2
Ka2 is the constant of the second chemical equation where another proton is donated.
- Fri Jan 22, 2021 3:46 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Homework Problem 6C.13
- Replies: 3
- Views: 207
Re: Homework Problem 6C.13
^^ its important to remember that p X and X have an inverse relationship so when one is higher, the other must be lower. This applies to pKa, pKb, pH, etc.
- Fri Jan 22, 2021 3:34 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Percent ionization
- Replies: 13
- Views: 482
Re: Percent ionization
is the [H3O+] always the same as the conjugate base?
- Fri Jan 22, 2021 3:33 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: pKa and Ka
- Replies: 27
- Views: 821
Re: pKa and Ka
also,
high Ka = increased acidity
high pka = decreased acidity
high Kb = increased basicity
high pkb = decreased basicity
high Ka = increased acidity
high pka = decreased acidity
high Kb = increased basicity
high pkb = decreased basicity
- Wed Jan 13, 2021 7:18 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Conjugate Seesaw
- Replies: 3
- Views: 146
Re: Conjugate Seesaw
Yep! inverse is true. if you remember 14A acids and bases, we used the weak acid/base to determine if the solution when added to water would be acidic or basic
- Tue Jan 12, 2021 4:23 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Kw chapter 6A question 21
- Replies: 2
- Views: 106
Kw chapter 6A question 21
Was there a typo in question 21 of chapter 6a?
it states that Kw =2.1*10^-14 at 37degrees C and asks for the H3O+ and OH- concentrations. I thought that each would be half the Kw value = 1.05*10^-7 however, the answer key says that it is 1.4*10^-7
it states that Kw =2.1*10^-14 at 37degrees C and asks for the H3O+ and OH- concentrations. I thought that each would be half the Kw value = 1.05*10^-7 however, the answer key says that it is 1.4*10^-7
- Mon Jan 11, 2021 8:28 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Getting two positive x values when using quadratic
- Replies: 43
- Views: 4592
Re: Getting two positive x values when using quadratic
Hi, so from lecture, Dr. Lavelle talks about how we use the quadratic formula to solve for the x change value in ICE tables, and then proceeds to show how we omit the negative x value and use the positive one. What happens when we get two positive x values? Would we test both x values into the ICE ...
- Mon Jan 11, 2021 8:26 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Chapter 5 question 61
- Replies: 4
- Views: 159
Chapter 5 question 61
for the reaction 6CO2(g) + 6H20(g) <=> C6H12O6(aq) + 6O2(g) why would there be little to no change if the system was compressed. I thought that when a system is compressed, it shifts in the direction with less moles of non solid or liquid compounds. Wouldn't it be 6:7? or does aqueous moles not count?
- Mon Jan 11, 2021 8:23 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Chapter 5 question 35
- Replies: 2
- Views: 99
Chapter 5 question 35
For the question, we are given a graph of A decomposing into B and C based on partial pressure and time It first asks for the chemical equation. How would we be able to figure it out with just the graph? After looking at the answer key, I used the balanced equation but got a very different value fro...
- Fri Jan 08, 2021 3:04 am
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: 9.83 Homework Problem: using volume to find concentration
- Replies: 3
- Views: 3471
Re: 983 Homework Problem: using volume to find concentration
This reaction is taking place presumably at standard temperature and pressure, so the pressure is 1 atm and the temperature is 0 degrees Celsius. Assuming the gas has ideal behavior, we can use PV= nRT to find the moles of gas. The pressure is at 1 atm, and the problem provides the volume, You can ...
- Thu Jan 07, 2021 2:35 pm
- Forum: Ideal Gases
- Topic: reversing reactions
- Replies: 83
- Views: 4844
Re: reversing reactions
reverse is 1/K and when multiplied by a constant(n), K^n
- Thu Jan 07, 2021 2:30 pm
- Forum: Student Social/Study Group
- Topic: Learning Sessions
- Replies: 24
- Views: 1055
Re: Learning Sessions
I didn't attend the UA sessions last quarter, but did pretty well on midterms. During finals week, I went to all of the afternoon workshops, and OMG it changed my life. Even if you know the material, the UAs are REALLY good at making sure u have a wide range of knowledge.
- Thu Jan 07, 2021 2:29 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Intermediate Values of K
- Replies: 6
- Views: 131
Re: Intermediate Values of K
I think that if it is not strongly associated with either, there may be other test methods we can use.
- Thu Jan 07, 2021 12:41 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Writing Equilibrium Constant expression for reaction
- Replies: 3
- Views: 147
Re: Writing Equilibrium Constant expression for reaction
You should use the net ionic equation if the reaction involves ionic compounds that fully dissociate. You can read more about this on page 401 in your textbook. I took notes on that, but how would you know that the ionic compounds fully dissasociate? Would the problem tell us or is there specific m...
- Tue Jan 05, 2021 7:29 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kc vs Kp
- Replies: 14
- Views: 474
Re: Kc vs Kp
The values are different because one is talking about the concentration (mol/L) of each component, while the other is talking about the pressure.
To convert use PV=nRT
P = (n/V)RT
n/V = concentration because it is amount over volume (ex: mols/liters)
To convert use PV=nRT
P = (n/V)RT
n/V = concentration because it is amount over volume (ex: mols/liters)
- Tue Jan 05, 2021 7:21 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Writing Equilibrium Constant expression for reaction
- Replies: 3
- Views: 147
Writing Equilibrium Constant expression for reaction
Hi! In one of the UA sessions, the UA told us that when calculating the equilibrium constant, we should use the NET IONIC equation, not the whole equation. However, in another UA session, they just used the original equation. Ex: Pb(NO3)2 (aq) + 2KCL (aq) <=> PbCl2 (s) + 2KNO3 (aq) UA1: Pb^2+ + 2NO3...
- Fri Dec 11, 2020 9:38 pm
- Forum: Hybridization
- Topic: Focus Question 2.45
- Replies: 3
- Views: 241
Re: Focus Question 2.45
Why does the pi bonds not use hybrids?
- Fri Dec 11, 2020 4:25 am
- Forum: Bond Lengths & Energies
- Topic: Difference between bond multiplicity and bond order
- Replies: 2
- Views: 286
Difference between bond multiplicity and bond order
Initially, I thought they were the same, but after looking on google, it turns out that multiplicity refers to possible orientations? Can someone explain?
- Thu Dec 10, 2020 12:10 am
- Forum: Identifying Acidic & Basic Salts
- Topic: Why Salts of weak bases produce acidic solutions and salts of weak acids produce basic solutions
- Replies: 1
- Views: 59
Why Salts of weak bases produce acidic solutions and salts of weak acids produce basic solutions
Hi!
I am kind of confused about the question in outline 6 that asks "explain why Salts of weak bases produce acidic solutions and salts of weak acids produce basic solutions"
it would be great if someone could explain it to me with examples!
I am kind of confused about the question in outline 6 that asks "explain why Salts of weak bases produce acidic solutions and salts of weak acids produce basic solutions"
it would be great if someone could explain it to me with examples!
- Wed Dec 09, 2020 2:56 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Naming on Final
- Replies: 9
- Views: 609
Naming on Final
I just saw in his lecture that we can only have a calculator, periodic table, and our formula sheet. Does that mean we have to memorize all the ligands on the Naming Coordination Compound sheet? if so, does anyone have any memorization tricks?
Thanks!
Thanks!
- Tue Dec 08, 2020 11:30 pm
- Forum: Hybridization
- Topic: textbook #2F15
- Replies: 4
- Views: 238
Re: textbook #2F15
The question was: "Noting that the bond angle of an sp^3 hybridized atom is 109.5 degrees and that of an sp^2 hybridized atom is 102 degrees, do you expect the bond angle between two hybrid orbitals to increase or decrease as the s-character of the hybrids is increased? How would you solve thi...
- Tue Dec 08, 2020 11:25 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Sapling week 10 #14
- Replies: 1
- Views: 74
Sapling week 10 #14
I am sort of confused about pH and pKa. I get that when pH>pKa, it means that the acid is charged, and will get deprotonated because it is more acidic than its environment. However in question 14, it shows a weak base ionizing to form conjugate acid (B+H20 <--> BH+ OH-) where pKa= 8.83 and pH = 6.92...
- Sat Dec 05, 2020 8:40 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: AX3E2 T shaped?
- Replies: 3
- Views: 255
Re: AX3E2 T shaped?
The lone pairs react with the bonding pairs at an angle of 90 degrees. In the T-shape, there will be 4 lp/bp interactions, but in the case of a trigonal planar shape, when the lone pairs are placed at the top and bottom, the lone pairs will result in 6 lp/bp interactions, which causes more repulsio...
- Sat Dec 05, 2020 8:31 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Which is a stronger acid/base
- Replies: 1
- Views: 184
Which is a stronger acid/base
In 6C #17 asks for the stronger base between BrO- and C17H19O3N. After solving, I got that BrO- is stronger. (through realizing that it is the conjugate base of a relatively weak acid). Because C17H19O3N is basic because of a lone pair on the N and doesn't have an OH, the type of molecule is automat...
- Thu Dec 03, 2020 4:48 am
- Forum: Naming
- Topic: what does (en) mean?
- Replies: 23
- Views: 10040
Re: what does (en) mean?
Stephen Min 2K wrote:I think we do need to memorize en since it is a common ligand that we will probably use going forward. Its also on the common ligand table.
Where can we find the common ligand table used for this class?
- Thu Dec 03, 2020 4:46 am
- Forum: Student Social/Study Group
- Topic: How are you?
- Replies: 154
- Views: 12367
Re: How are you?
Really excited to start new classes! Our first finals are kind of scaring me though.
- Thu Dec 03, 2020 4:40 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: AX3E2 T shaped?
- Replies: 3
- Views: 255
AX3E2 T shaped?
Why would AX3E2 be t shaped if lone pairs want to be as far away from each other as possible? Shouldn't the LP be axial and the shape be trigonal planar?
- Thu Dec 03, 2020 4:03 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Outline 4 Shape and polar and IM forces
- Replies: 1
- Views: 146
Outline 4 Shape and polar and IM forces
In outline 4 it asks us to "Use shape and polar or non-polar properties, identify different intermolecular interactions/forces" does this just mean that shape and polar forces makes some intermolecular interactions possible? For example, dipole-dipole would be difficult to occur if electro...
- Mon Nov 30, 2020 10:47 pm
- Forum: Hybridization
- Topic: Difference between hybrid orbitals and hybridization
- Replies: 5
- Views: 1170
Re: Difference between hybrid orbitals and hybridization
Just to clarify, This means that AsF3 would have a hybridization of sp3 and is in the hybrid orbital of 4sp3?
- Sat Nov 28, 2020 11:30 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E #13c
- Replies: 2
- Views: 169
2E #13c
The question asks for the Lewis Structure, VSEPR, shape, and bond angles of IO3-. I drew my structure with Iodine having one lone pair, connected to two double bonds to 2 Oxygens and a single bond to 1 Oxygen (a more stable structure). However, the back of the book shows all single bonds to oxygen (...
- Thu Nov 26, 2020 5:12 am
- Forum: Administrative Questions and Class Announcements
- Topic: Chem 14B
- Replies: 5
- Views: 210
Re: Chem 14B
do you think he'll be able to record zoom classes if he isn't able to prerecord the videos? There weren't any other chem spots that wouldn't create an overlap in my schedule.
- Thu Nov 26, 2020 5:10 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Sapling Q18
- Replies: 1
- Views: 96
Re: Sapling Q18
I think it probably has something to do with the types of bonds since pi bonds don't allow rotation, while sigmas do
- Mon Nov 23, 2020 7:21 pm
- Forum: Student Social/Study Group
- Topic: Exercising Our Minds and Bodies
- Replies: 120
- Views: 15210
Re: Exercising Our Minds and Bodies
Lavelle has mentioned the importance of exercising our mind and body so I was interested to see what types of exercises everyone was up to! I usually just go for walks/runs with my dog. There are some really good exercise videos on youtube too! I usually do a full body one from Madfit or Pamela Reif.
- Thu Nov 19, 2020 3:47 pm
- Forum: Student Social/Study Group
- Topic: Big Sad: Midterm 2
- Replies: 86
- Views: 5450
Re: Big Sad: Midterm 2
I swear I somehow did worse on this one since math is a little easier for me than conceptual. I guess we'll see :(
- Wed Nov 18, 2020 12:22 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability of Anions and Cations
- Replies: 6
- Views: 989
Re: Polarizability of Anions and Cations
The larger the anion is, the more easily it is polarized (polarizable). The smaller the cation is, the more polarizing power it has
- Wed Nov 18, 2020 12:22 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability of Anions and Cations
- Replies: 6
- Views: 989
Re: Polarizability of Anions and Cations
The larger the anion is, the more easily it is polarized (polarizable). The smaller the cation is, the more polarizing power it has
- Wed Nov 18, 2020 12:20 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: London Dipole
- Replies: 3
- Views: 220
Re: London Dipole
London Dipoles are found in all intermolecular bonds. It is the only IMF when the Electronegativity of the two atoms are similar (ex: ch4)
- Sat Nov 14, 2020 11:27 pm
- Forum: Trends in The Periodic Table
- Topic: UA Riya Week 5 Question 4B
- Replies: 2
- Views: 98
UA Riya Week 5 Question 4B
Q: The first ionization enthalpy values (in kJ/mol) of group 13 elements are - B (801), Al (577), Ga (579), In (558), Ti (589). Explain the deviation in the general trend. For B --> Al, I understand that ionization energy decreases going down a period due to an increase in electron shielding and rad...
- Fri Nov 13, 2020 9:32 pm
- Forum: Dipole Moments
- Topic: 3F.1c
- Replies: 2
- Views: 103
3F.1c
could someone explain to me why H2SeO4 has dipole dipole forces? What region is more negative if it is all balanced around the Se?
- Thu Nov 12, 2020 4:04 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 2A.9 Which M2+ are predicted to have following ground state e- configuration
- Replies: 1
- Views: 85
2A.9 Which M2+ are predicted to have following ground state e- configuration
For problem a) [Ar]3d7, I just looked at the table and saw that it is equivalent to Co, however I read somewhere else that we needed to add two electrons to it to see the true state. If I do that, it doesn't line up with the answer at the back of the book, can someone please tell me how to figure ou...
- Wed Nov 11, 2020 5:23 am
- Forum: Resonance Structures
- Topic: Hybrid structures
- Replies: 2
- Views: 104
Re: Hybrid structures
I think it is true in nature because aren't resonance structures more stable than having single and double bonds. Since things aren't constantly exploding or having dramatic chemical reactions, I would assume it is because of that.
- Wed Nov 11, 2020 5:21 am
- Forum: Dipole Moments
- Topic: Week 5/6 Sapling Question
- Replies: 4
- Views: 480
Re: Week 5/6 Sapling Question
Hydrogen bonds could form when the hydrogen in the compound is attached to N, O, or F. In the diagram, there are 2 Nitrogen atoms each with one lone pair, and 1 Oxygen atom with 2 pairs of lone electrons. Those four lone pairs can each form a hydrogen bond. In addition, for each of the Hydrogens tha...
- Wed Nov 11, 2020 5:16 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Sampling week 5/6 Q5
- Replies: 3
- Views: 183
Re: Sampling week 5/6 Q5
For each, I plugged it into the formal charge equation FC = valence electron - ( (shared electrons in bonds/2 electrons per bond) - number of unpaired electrons) For example for carbon, there are 4 valence electrons (according to the periodic table), 4 electrons that are shared in bonds (2 with H, 2...
- Wed Nov 11, 2020 4:49 am
- Forum: Quantum Numbers and The H-Atom
- Topic: HW question 2.17 [ENDORSED]
- Replies: 7
- Views: 1773
Re: HW question 2.17 [ENDORSED]
Does just remembering the number of orbitals for s,p,d, and f always work for the number of orbitals, or should we always double-check with the ml -1,0,1 etc?
- Thu Nov 05, 2020 12:37 am
- Forum: Lewis Structures
- Topic: Formal Charge and Lewis Strucutre
- Replies: 7
- Views: 353
Formal Charge and Lewis Strucutre
Hi! Is there a faster way to calculate the formal charge for our structures besides for what we did in class? I find myself taking a long time which is fine for now, but not sure how I'll be able to answer all the questions on the midterm.
- Thu Nov 05, 2020 12:37 am
- Forum: Lewis Structures
- Topic: Formal Charge and Lewis Strucutre
- Replies: 3
- Views: 133
Formal Charge and Lewis Strucutre
Hi! Is there a faster way to calculate the formal charge for our structures besides for what we did in class? I find myself taking a long time which is fine for now, but not sure how I'll be able to answer all the questions on the midterm.
- Thu Nov 05, 2020 12:35 am
- Forum: Lewis Structures
- Topic: Week5/6 Sapling Q4
- Replies: 2
- Views: 82
Re: Week5/6 Sapling Q4
I don't think you can switch the C and N easily because of electron affinity and ionization energy. However, if you are looking for another structure, take a look at the other oxygen. What I did was I made the double bond bond the C with the OTHER oxygen atom. Hope that helps!
- Thu Nov 05, 2020 12:33 am
- Forum: Lewis Structures
- Topic: Lewis structures and charges
- Replies: 3
- Views: 136
Re: Lewis structures and charges
We also add and and subtract so we know the total number of electrons to put in our Lewis Structures. Later, I think it also helps to see how reactive an element is.
- Thu Nov 05, 2020 12:32 am
- Forum: Lewis Structures
- Topic: double bonds in Lewis structures
- Replies: 2
- Views: 173
Re: double bonds in Lewis structures
I believe its because Cl only needs to share one electron to get a full octet since it already has 7 valence electrons. On the other hand, oxygen has 6 valence electrons, so it wants to share two electrons to gain a full octet, and to do so you would have to form a double bond with carbon. It makes...
- Thu Nov 05, 2020 12:30 am
- Forum: Lewis Structures
- Topic: Chemical Formulas
- Replies: 8
- Views: 298
Re: Chemical Formulas
Does anyone have any memorization tricks for them? I find myself memorizing them for the semester/year and then completely forgetting about it later.