Search found 59 matches
- Mon Mar 12, 2018 2:53 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: 15.61
- Replies: 4
- Views: 516
Re: 15.61
k would be the rate constant of the forward reaction. k' would be the rate constant of the reverse reaction.
- Mon Mar 12, 2018 2:51 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
No, a catalyst isn't a record of the cows you own
- Mon Mar 12, 2018 2:48 pm
- Forum: *Enzyme Kinetics
- Topic: Adsorption
- Replies: 13
- Views: 3103
Re: Adsorption
At least from what I understand about it, I think one would just act as a cover whereas the other one would become part of the catalyst?? I'm not sure about this though.
- Thu Mar 08, 2018 7:17 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Intermediate [ENDORSED]
- Replies: 7
- Views: 890
Re: Intermediate [ENDORSED]
Right so when you compare them in separate reactions, we essentially cancel them out which is why they are not shown in the final reaction equation.
- Thu Mar 08, 2018 7:12 pm
- Forum: General Rate Laws
- Topic: Integrated Rate Laws
- Replies: 6
- Views: 802
Re: Integrated Rate Laws
I thought that derivations were fair game.
- Thu Mar 08, 2018 7:11 pm
- Forum: General Rate Laws
- Topic: 15.19
- Replies: 2
- Views: 426
Re: 15.19
I thought that we keep it to whatever units they give us. Unless they give us another piece of information that deals with another unit then we would convert it.
- Fri Mar 02, 2018 2:53 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
Why did the liquid smell good?
Because it didn't past gas.
Because it didn't past gas.
- Fri Mar 02, 2018 2:52 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
Chemistry doesn't just matter, it is matter.
- Tue Feb 27, 2018 11:19 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
The atom asks the electron, "why are you small?" The electron replies, "because I have a low charge!
- Tue Feb 27, 2018 11:19 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
504754253 wrote:what kind of car do chemist drive? mercedes benzene
That was sodium funny...i slapped my neon that one
- Tue Feb 27, 2018 11:16 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
The noble gases walk into a bar. No one reacts.
- Tue Feb 27, 2018 11:16 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
504754253 wrote:how come every time i tell a joke there is no reaction?!
good one
- Mon Feb 19, 2018 8:52 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram Order (14.11) [ENDORSED]
- Replies: 4
- Views: 646
Re: Cell Diagram Order (14.11) [ENDORSED]
I have a similar question and also on part c why is it written as ||Ce4+,Ce3+| because I thought it was supposed to be written as ||Ce4+|Ce3+
- Mon Feb 19, 2018 8:49 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Test Equations Sheet
- Replies: 2
- Views: 294
Test Equations Sheet
For Test 2 will we be provided a similar page to that of Appendix 2b to help us determine what half-reactions and standard cell potential values we will have to use?
- Mon Feb 19, 2018 8:47 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 14.15A
- Replies: 4
- Views: 503
Re: 14.15A
For this question, I was confused in how oxidation numbers were distributed in the original question because I thought Ag was +1 and Br was -1 and they stayed the same throughout because the ions split but this does not make sense in regards to reduction/oxidation half-reactions.
- Wed Feb 14, 2018 1:38 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Effect of solids and liquids on K
- Replies: 3
- Views: 431
Re: Effect of solids and liquids on K
yes thats correct
- Wed Feb 14, 2018 1:36 pm
- Forum: Calculating Work of Expansion
- Topic: Calculating work for winter 2013 midterm 4.B.
- Replies: 4
- Views: 610
Re: Calculating work for winter 2013 midterm 4.B.
we can't use the regular w=-p*deltaV is the irreversible equation, also the pressure isn't constant from point b to c
- Wed Feb 14, 2018 1:35 pm
- Forum: Calculating Work of Expansion
- Topic: Calculating work for winter 2013 midterm 4.B.
- Replies: 4
- Views: 610
Re: Calculating work for winter 2013 midterm 4.B.
Going from point B to point C, we are told that it is a reversible reaction so we use the equation that is w--nRTln(V2/V1)
- Fri Feb 09, 2018 1:31 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
I try to tell chemistry jokes, but sometimes there's just no reaction.
- Fri Feb 09, 2018 1:29 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
What did the Fe2+ say to the H+ that turned into H2?
"I'm sorry I reduced you! I swear it was an oxidant!"
"I'm sorry I reduced you! I swear it was an oxidant!"
- Fri Feb 09, 2018 1:25 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Which molecule has higher Standard Molar Entropy
- Replies: 1
- Views: 5572
Re: Which molecule has higher Standard Molar Entropy
Both benzene and 1-propanol both have 12 atoms compared to the 6 atoms for methanol. And benzene has a more rigid planar ring structure so 1-propanol has the highest standard molar entropy of all three.
- Wed Jan 31, 2018 6:13 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: 9.13
- Replies: 5
- Views: 662
Re: 9.13
Correct me if I'm wrong, but 3/2R represents a monatomic gas, 5/2R represents a diatomic gas, and 7/2R represents a polyatomic gas?
- Wed Jan 31, 2018 6:11 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
Have you heard that entropy isn't what it used to be?
- Wed Jan 31, 2018 6:09 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Homework 9.5 [ENDORSED]
- Replies: 11
- Views: 1203
Re: Homework 9.5 [ENDORSED]
I'm pretty sure Sfinal -Sinitial works to solve most problems.
- Thu Jan 25, 2018 2:08 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: Molar Entropy vs Residual molar entropy
- Replies: 2
- Views: 418
Re: Molar Entropy vs Residual molar entropy
Molar entropy would be entropy content of one mole of substance under a standard state. Residual molar entropy is more specific in that it is the entropy at zero Kelvin.
- Thu Jan 25, 2018 2:05 pm
- Forum: Calculating Work of Expansion
- Topic: Integrals [ENDORSED]
- Replies: 3
- Views: 464
Re: Integrals [ENDORSED]
As Vincent said above, I would agree in saying that integrals are used because they represent the value of the sum between two values.
- Thu Jan 25, 2018 2:02 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: constant volume vs constant pressure
- Replies: 3
- Views: 438
Re: constant volume vs constant pressure
Yes I agree with Sammy. Also note that when they say mention constant pressure in the problem. The Specific Heat Capacity can be found by 5/2 multipled by R. And for constant volume the specific heat capacity can be found by 3/2 multiplied by R.
- Tue Jan 16, 2018 11:08 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Delta H and q Interchangeability
- Replies: 5
- Views: 597
Re: Delta H and q Interchangeability
I think Delta H is only equal to q with a subscript "p" because the pressure has to remain constant for the equation to hold
- Tue Jan 16, 2018 11:03 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: question 8.55
- Replies: 1
- Views: 134
Re: question 8.55
I think that it does count, but I would do one of the assigned problems just in case. If anything, it's extra practice :)
- Tue Jan 16, 2018 11:02 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: homework question 8.57
- Replies: 1
- Views: 139
Re: homework question 8.57
The subscript c on the delta H represents that it's the standard enthalpy value for a combustion reaction.
- Fri Jan 12, 2018 5:57 pm
- Forum: Phase Changes & Related Calculations
- Topic: Methods of Enthalpy
- Replies: 8
- Views: 816
Re: Methods of Enthalpy
I think we have to use different methods depending on what we're given in the problem.
- Fri Jan 12, 2018 5:51 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
Watch out for the enthalpy pirate.....he'll steal your joules.
- Fri Jan 12, 2018 5:46 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Question 8.41
- Replies: 2
- Views: 148
Re: Question 8.41
The enthalpy change for the water in the ice cube will be composed of two terms: the heat to melt the ice at 0 degrees Celsius and the heat required to raise the ice form 0 degrees Celsius to the final temperature.
- Thu Dec 07, 2017 9:37 am
- Forum: Administrative Questions and Class Announcements
- Topic: Thursday discussion canceled? and other questions
- Replies: 3
- Views: 632
Re: Thursday discussion canceled? and other questions
Even though class is cancelled today, it says that campus is still open so will the review sessions held in CS 24 and 50 still be taking place?
- Tue Dec 05, 2017 2:07 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Determinig Strength of Acids
- Replies: 1
- Views: 236
Re: Determinig Strength of Acids
From what I understand, I believe it depends on the type of molecule. For instance, if you're comparing HCl vs. HF, you can determine that HCl is a stronger acid by looking at the bong length (HCl has a long, weak bond). However, if you're comparing HClO2 vs. HClO, you can determine that HClO2 is a ...
- Tue Dec 05, 2017 2:03 pm
- Forum: Lewis Acids & Bases
- Topic: 12.15
- Replies: 3
- Views: 563
Re: 12.15
Well PF5 has a neutral charge and by adding the F- ion, it results in the overall compound having a negative charge.
- Tue Nov 28, 2017 6:19 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 4.9 Problem
- Replies: 4
- Views: 679
Re: 4.9 Problem
Well if the lone pairs weren't taken into account then it could just be trigonal planar but I think those two extra lone pairs on the iodine cause the chloride ions to have a bond angle of 90 degrees rather than 120 degrees.
- Mon Nov 27, 2017 8:52 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Bond Order
- Replies: 5
- Views: 651
Re: Bond Order
For the Chapter 4 test, do we have to know what type of molecular orbital an unpaired electron would occupy? Or anything about bond order in general?
- Wed Nov 22, 2017 2:23 pm
- Forum: Naming
- Topic: Question 17.29a
- Replies: 3
- Views: 413
Re: Question 17.29a
The name of the transition metal never really changes, it's just that when naming the molecules you use their latin names rather than the ones that appear on the periodic table.
- Wed Nov 22, 2017 2:13 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 4.9 Problem
- Replies: 4
- Views: 679
4.9 Problem
For the molecule ICl3 can someone please explain to me why its molecular shape is T-shaped and not trigonal planar?
- Thu Nov 16, 2017 10:10 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 4.1 Lone pairs
- Replies: 6
- Views: 835
Re: 4.1 Lone pairs
But in part b, there are two areas of electron density and it's linear so I thought that there wouldn't be any lone pairs. But the answer says that there may be lone pairs.
- Thu Nov 16, 2017 9:58 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
What do chemists call a benzene ring with iron atoms replacing the carbon atoms?
A ferrous wheel.
A ferrous wheel.
- Thu Nov 16, 2017 9:52 am
- Forum: Lewis Structures
- Topic: Midterm
- Replies: 4
- Views: 288
Re: Midterm
Okay cool, thanks guys!
- Sun Nov 12, 2017 8:46 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
I am a [censored], a planet, and I can measure heat? What am I?
Mercury
Mercury
- Sun Nov 12, 2017 8:45 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
What can eat a lot of iron without getting sick?
Rust
Rust
- Wed Nov 08, 2017 9:50 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3000982
Re: Post All Chemistry Jokes Here
What did the scientist say when he found 2 atoms of helium?
HeHe
HeHe
- Sat Nov 04, 2017 3:18 pm
- Forum: Ionic & Covalent Bonds
- Topic: covalent and ionic bonds
- Replies: 3
- Views: 463
Re: covalent and ionic bonds
An element can have either ionic or covalent bonds, but an ionic bond can have covalent character and vice versa.
- Sat Nov 04, 2017 3:15 pm
- Forum: Resonance Structures
- Topic: Bonds
- Replies: 4
- Views: 567
Re: Bonds
Some atoms are stronger and essentially more stable if you can make it a double or triple bond.
- Fri Nov 03, 2017 5:16 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 3D shape Lewis Diagrams
- Replies: 4
- Views: 841
Re: 3D shape Lewis Diagrams
So we don't need to determine which bonds will be shaded or be represented by spaced lines?
- Fri Nov 03, 2017 11:48 am
- Forum: Lewis Structures
- Topic: Midterm
- Replies: 4
- Views: 288
Midterm
Lewis structures and the rest of chapter 3 is going to be on the midterm right?
- Fri Oct 27, 2017 8:56 am
- Forum: *Shrodinger Equation
- Topic: Upcoming Test
- Replies: 4
- Views: 616
Re: Upcoming Test
For the Week 3 test, we just need to know the end of Chapter 1 and Chapter 2, not Chapter 3 right?
- Fri Oct 27, 2017 8:52 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: s- electrons vs p- electrons [ENDORSED]
- Replies: 7
- Views: 1597
Re: s- electrons vs p- electrons [ENDORSED]
From what I understand the further the atoms the electrons are from the nucleus, the more energy they have.
- Thu Oct 19, 2017 1:50 pm
- Forum: Photoelectric Effect
- Topic: Post- Module Assessment #24
- Replies: 3
- Views: 496
Re: Post- Module Assessment #24
I think gamma rays would work, but UV light is just easier to use. I'm not completely sure though
- Thu Oct 19, 2017 1:47 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Upcoming Test
- Replies: 5
- Views: 536
Re: Upcoming Test
I think our Week 3 HW can be either chapter 1 or 2, and then next week (week 4) will be chapter 2 for sure since he just started teaching us about it.
- Tue Oct 17, 2017 6:32 am
- Forum: Properties of Light
- Topic: Module for Atomic Spectra Question 26
- Replies: 2
- Views: 281
Re: Module for Atomic Spectra Question 26
So each element and molecule have their own unique spectral pattern or fingerprint.
- Thu Oct 12, 2017 10:44 am
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect
- Replies: 8
- Views: 773
Re: Photoelectric Effect
The photoelectric experiment has to be done under a vacuum because otherwise the ejected electrons interact with molecules in the air.
- Thu Oct 12, 2017 10:41 am
- Forum: Photoelectric Effect
- Topic: Q29 from PhotoElectric Effect Post-Module Assessment
- Replies: 1
- Views: 299
Q29 from PhotoElectric Effect Post-Module Assessment
Hi! This may seem like a silly question, but I wasn't too sure about how to go about solving this problem. The question is: Light hits a sodium metal surface and the velocity of the ejected electron is 6.61 x 105 m.s-1. The work function for sodium is 150.6 kJ.mol-1. How much energy is required to r...
- Thu Oct 05, 2017 8:03 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: G. 21
- Replies: 3
- Views: 556
Re: G. 21
For this problem, in part a) I first converted KCl, K2S, and K3PO4 from grams to moles and then I added each of the moles together which was 2.29 x 10^-2 mole and then I divided that by 0.5 L because Molarity multipled by Volume = moles and got 4.58 x 10^-2M. In part b) I used the grams of K2S to fi...
- Thu Oct 05, 2017 7:43 pm
- Forum: Empirical & Molecular Formulas
- Topic: Problem L.35
- Replies: 2
- Views: 451
Problem L.35
Hey! Can anybody help me set up problem L.35 because I know I first have to balance the three reactions and then convert the tons into grams, but then afterwards do I basically work backwards from 8 mol NaBr to the mol of Fe using stoichiometry?