Search found 22 matches
- Mon Mar 13, 2017 6:53 pm
- Forum: General Rate Laws
- Topic: Difference between equilibrium constant and rate constant
- Replies: 1
- Views: 5137
Difference between equilibrium constant and rate constant
What is the difference between these two constants and what are they each describing in a reaction?
- Sat Mar 04, 2017 4:26 pm
- Forum: *Alkanes
- Topic: Question 4.30 in the organic text book [ENDORSED]
- Replies: 2
- Views: 661
Question 4.30 in the organic text book [ENDORSED]
This question reads: the activation energy, in organic reaction is known to be 125 kJ•mol-1. Will this reaction occur at room temperature. Could someone help with this thanks!
- Sat Mar 04, 2017 3:39 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2761441
Re: Post All Chemistry Jokes Here
Did you hear about the man who got cooled to absolute zero? He's 0K now.
- Tue Feb 21, 2017 10:34 am
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Quiz 2 Practice Question 11
- Replies: 2
- Views: 543
Quiz 2 Practice Question 11
This question says: The rate constant for the reaction A --> B is 25 min-1 at 298 K and 35 min-1 and 350 K. Calculate the value of the rate constant at 770 K, give your answer in min-1. I am having trouble figuring out how to set up this problem could someone help thanks!
- Tue Feb 14, 2017 4:26 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Winter 2013 Midterm Q2A
- Replies: 10
- Views: 1488
Re: Winter 2013 Midterm Q2A
On part A, how would we determine that the q of the water is the one that is negative in the equation qice=-qwater?
- Mon Feb 06, 2017 10:53 am
- Forum: Balancing Redox Reactions
- Topic: Chapter 14 Question 3
- Replies: 7
- Views: 1683
Chapter 14 Question 3
This problem states, balance the following skeletal equations by using oxidation and reduction half reactions. All the reactions take place in acidic solution. The reaction is Cl2(g) + S2O3 2-(aq) --> Cl- (aq)+ SO4 2- (aq). I understand how to get which agent is oxidizing and which one is reducing b...
- Tue Jan 31, 2017 10:07 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Chapter 9 Question 43
- Replies: 1
- Views: 3208
Chapter 9 Question 43
This question states: Suppose that 50.0 g of H2O(l) at 20.0° C is mixed with 65.0g of H2O(l) at 50.0°C at constant atmospheric pressure in a thermally insulated vessel. Calculate ∆S and ∆Stot for the process. Could someone help me with this?
- Tue Jan 31, 2017 10:01 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Resources
- Replies: 3
- Views: 646
Re: Resources
I find that UA session and TA office hours are extremely helpful!
- Tue Jan 24, 2017 3:29 pm
- Forum: Phase Changes & Related Calculations
- Topic: Quiz prep 1 question 6
- Replies: 1
- Views: 473
Quiz prep 1 question 6
This question asks what mass of propane C3H8(g) must be burned to supply 2580 kJ of heat? The standard enthalpy of combustion of propane at 298 K is -2220 kJ/mol. Since there is no change in temperature how would I go about solving this problem?
- Thu Jan 19, 2017 12:42 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Chapter 8 problem 21 [ENDORSED]
- Replies: 3
- Views: 911
Chapter 8 problem 21 [ENDORSED]
Problem 21 states: A piece of copper of mass 20.0 g at 100.0°C is placed in a vessel of negligible heat capacity but containing 50.7 g of water at 22.0°C. Calculate the final temperature of the water. Assume that no energy is lost to the surroundings. Could someone help me out with this problem in s...
- Fri Jan 13, 2017 4:17 pm
- Forum: Phase Changes & Related Calculations
- Topic: Enthalpy vs Energy
- Replies: 2
- Views: 670
Re: Enthalpy vs Energy
Enthalpy is the heat flowing in or out of a system at a constant pressure that depends on the amount of substance present. Enthalpy will equal energy unless the reaction is performed at a very high pressure or there is a significant change in volume, which can be seen because the formula for enthalp...
- Thu Dec 01, 2016 6:36 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Final 2012: Q4
- Replies: 1
- Views: 605
Re: Final 2012: Q4
A radical occurs when there are an odd number of valence electrons, so instead of a lone pair, there is just a single electron. For instance, in the hydroxide radical, there is a single atom where a lone pair would normally be.
- Tue Nov 29, 2016 12:32 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Both Roots are positive
- Replies: 2
- Views: 529
Re: Both Roots are positive
There will be one root that is too big to subtract from the original concentration or partial pressure, so you would use the smaller one of the two.
- Mon Nov 21, 2016 12:56 pm
- Forum: Conjugate Acids & Bases
- Topic: pH and pOH
- Replies: 4
- Views: 1288
Re: pH and pOH
p is a shorthand notation for -log that is written to simplify the equations
- Tue Nov 15, 2016 4:15 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Quiz 3 Prep Fall 2014 [ENDORSED]
- Replies: 1
- Views: 473
Quiz 3 Prep Fall 2014 [ENDORSED]
On question number 6, it asks what conditions favor SO2(g) production in the equation 2SO3(g) <-> 2SO2(g) + O2(g). I understand how increasing the temperature would favor the products but the other condition is low pressure. Wouldn't lowering the pressure cause the molecule to shift towards the reac...
- Thu Nov 10, 2016 9:33 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2761441
Re: Post All Chemistry Jokes Here
I blew up my chemistry experiment... oxidants happen
- Tue Nov 01, 2016 10:38 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: 2012 Midterm Q3c
- Replies: 2
- Views: 718
Re: 2012 Midterm Q3c
In addition to the wavelengths of visie light I think we also should know the wavelengths of infrared and ultraviolet light and where they come in the spectra either before or after visible light.
- Mon Oct 24, 2016 3:56 pm
- Forum: Lewis Structures
- Topic: Expanded Octets
- Replies: 1
- Views: 464
Expanded Octets
I am wondering why Xe can have an expanded octet even though it is a noble gas with all its orbitals filled?
- Tue Oct 18, 2016 3:27 pm
- Forum: Ionic & Covalent Bonds
- Topic: Difference between Ionic bonds and Molecules Lewis Strructure [ENDORSED]
- Replies: 1
- Views: 582
Re: Difference between Ionic bonds and Molecules Lewis Strructure [ENDORSED]
The brackets around a ionic lewis structure are meant to show that their is an overall charge on the entire molecule, not just certain elements within the molecule.
- Tue Oct 11, 2016 3:46 pm
- Forum: DeBroglie Equation
- Topic: Workbook Prep Quiz Answers
- Replies: 3
- Views: 918
Re: Workbook Prep Quiz Answers
Yes, the answers in the workbook have the correct amount of significant figures!
- Wed Oct 05, 2016 10:39 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Heisenberg Post Module #5
- Replies: 1
- Views: 423
Re: Heisenberg Post Module #5
You would be correct, this is due to the fact that the position and momentum of a particle are complementary properties, meaning if one property is known then the other cannot be known simultaneously. As your measurement for one property gets more accurate, the other measurement becomes less accurate.
- Tue Sep 27, 2016 1:56 pm
- Forum: Significant Figures
- Topic: Which number to use?
- Replies: 6
- Views: 1217
Re: Which number to use?
When doing calculations, use as many sig figs as possible up until you have calculated your final answer, which should include the same amount of sig figs as the smallest numerical data being used. For instance if the smallest number in the original data has only 3 sig figs, then in your final answe...