Search found 30 matches
- Wed Mar 08, 2017 12:03 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalyst vs. Intermediate Species
- Replies: 2
- Views: 1097
Catalyst vs. Intermediate Species
What is the difference between a catalyst and an intermediate species?
- Wed Mar 08, 2017 12:02 am
- Forum: Biological Examples
- Topic: Lecture Example: Homogeneous Catalyst
- Replies: 1
- Views: 1415
Lecture Example: Homogeneous Catalyst
In the example of the homogeneous catalyst (nitric oxide conversion), in the very last step, how was 3/2 O2(g) converted to O3(g)? Thank you!
- Tue Mar 07, 2017 11:56 pm
- Forum: *Electrophiles
- Topic: Question Regarding Alkenes
- Replies: 2
- Views: 1342
Question Regarding Alkenes
In regards to alkenes, it was said in lecture that in a chemical reaction the pi-bond would break rather than the sigma bond. Why is this?
- Mon Mar 06, 2017 12:37 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Pre-Equilibrium Approach
- Replies: 1
- Views: 428
Pre-Equilibrium Approach
In the Pre-Equilibrium approach is the 2nd step always the slow step?
- Sun Mar 05, 2017 10:57 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Ratio of Rate Constants (Energy Barriers)
- Replies: 2
- Views: 576
Ratio of Rate Constants (Energy Barriers)
When looking at the reverse rate (k') of a reaction, why is a lower rate constant required for a higher energy barrier? Visa versa for forward reaction (k), why is a higher rate constant required for a lower energy barrier?
- Thu Feb 23, 2017 1:41 am
- Forum: First Order Reactions
- Topic: Question About the 1st Order REaction Rate Law
- Replies: 2
- Views: 707
Question About the 1st Order REaction Rate Law
Will we ever have to use this rate law to calculate the product concentration or is it only used for reactant concentrations?
- Thu Feb 23, 2017 12:25 am
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Method of Initial Rates: Course Reader Question
- Replies: 1
- Views: 502
Method of Initial Rates: Course Reader Question
In the course under the section METHODS OF INITIAL RATES, the question was asked How does initial rate depend on the concentration of nitrogen dioxide [NO2 ? What was the answer to this question?
- Sun Jan 29, 2017 9:54 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3869135
Re: Post All Chemistry Jokes Here
"Don't trust atoms, they make up everything." ;)
- Sun Jan 29, 2017 9:52 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Question 8.65
- Replies: 2
- Views: 538
Re: Question 8.65
Yes, I had to balance it but forgot to type it in. Thank you for the clarification.
- Sun Jan 22, 2017 11:27 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Question 8.65
- Replies: 2
- Views: 538
Question 8.65
In question 8.65 the following equations:
1) 2NO +O2 --> 2NO2
2) 2NO2 + O2 --> N2O5
With the final equation reading:
2NO + 3/2 O2 --> N2O5
Following the process it appears that 2NO2 was cancelled out of the first and second, but why is that?
Thank you for your help!
1) 2NO +O2 --> 2NO2
2) 2NO2 + O2 --> N2O5
With the final equation reading:
2NO + 3/2 O2 --> N2O5
Following the process it appears that 2NO2 was cancelled out of the first and second, but why is that?
Thank you for your help!
- Sun Jan 22, 2017 11:14 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: State Property Difference
- Replies: 2
- Views: 594
Re: State Property Difference
Thank you
- Fri Jan 13, 2017 7:45 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: State Property Difference
- Replies: 2
- Views: 594
State Property Difference
Hi,
Can someone clarify the reason why temperature and pressure are state functions but work is not? Thank you.
Can someone clarify the reason why temperature and pressure are state functions but work is not? Thank you.
- Wed Jul 27, 2016 6:42 am
- Forum: Naming
- Topic: Naming with Ammines [ENDORSED]
- Replies: 1
- Views: 472
Naming with Ammines [ENDORSED]
Just a quick technical question. For example, if you had a compound with six ammines it would be hexa and ammine. Would you write the name as hexaamine or hexammine?
Thank you!
Thank you!
- Tue Jul 26, 2016 11:46 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: Spectator Ions?
- Replies: 5
- Views: 1413
Re: Spectator Ions?
Thank you!
- Tue Jul 26, 2016 11:35 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: Spectator Ions?
- Replies: 5
- Views: 1413
Re: Spectator Ions?
Oh ok. Would this also include the cations that are from groups 1 and 2 on the periodic table?
- Tue Jul 26, 2016 11:16 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: Spectator Ions?
- Replies: 5
- Views: 1413
Spectator Ions?
In a section on salts as acids and bases, the elements Na and Cl were referred to as spectator ions? Is there a specific definition for spectator ions or is this simply a colloquial term?
Thank you.
Thank you.
- Tue Jul 26, 2016 11:09 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: Finding Ka from Kw/Kb [ENDORSED]
- Replies: 2
- Views: 1373
Re: Finding Ka from Kw/Kb [ENDORSED]
Oh yes! Thank you very much
- Tue Jul 26, 2016 10:24 pm
- Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
- Topic: Weak Acids and Bases as Buffers [ENDORSED]
- Replies: 1
- Views: 554
Weak Acids and Bases as Buffers [ENDORSED]
Hello,
Just a question about the concept of weak acids and bases. How can a weak acid or base act as a buffer if the do not fully dissociate? Wouldn't it suffice to use a strong acid or base?
Thank you
Just a question about the concept of weak acids and bases. How can a weak acid or base act as a buffer if the do not fully dissociate? Wouldn't it suffice to use a strong acid or base?
Thank you
- Tue Jul 26, 2016 7:52 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: Finding Ka from Kw/Kb [ENDORSED]
- Replies: 2
- Views: 1373
Finding Ka from Kw/Kb [ENDORSED]
In an example in the course reader for calculating the pH of the 0.15M NH4Cl, the given Kb for NH3 = 1.8x10^-5. There is a step that calculated an amount for Ka by dividing Kw by Kb:
Ka Kb=Kw=10^-14
Ka =Kw/Kb= 5.6x 10^-10.
I am not sure how this answer for Ka was calculated.
Ka Kb=Kw=10^-14
Ka =Kw/Kb= 5.6x 10^-10.
I am not sure how this answer for Ka was calculated.
- Tue Jul 26, 2016 4:44 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Aqueous Solutions in Equilibrium Constant
- Replies: 2
- Views: 1555
Aqueous Solutions in Equilibrium Constant
For the following equations: NH4+ (aq) + H2O (l) ⇌ NH3 (aq) + H3O+ (aq), would only the concentration of H2O be removed or are aqueous solutions also not counted in the equilibrium constant?
The answer could either be:
K=[NH3][H3O]/[NH4]
or
K= 0
Thank you:)
The answer could either be:
K=[NH3][H3O]/[NH4]
or
K= 0
Thank you:)
- Sun Jul 24, 2016 11:58 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Increasing yield without adding reactants
- Replies: 3
- Views: 589
Re: Increasing yield without adding reactants
Yes, I understand now. Thank you!
- Sun Jul 24, 2016 8:46 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Increasing yield without adding reactants
- Replies: 3
- Views: 589
Increasing yield without adding reactants
This was a question in the course and I'm not sure if we went over it in lecture:
For the reaction N2(g)+3H2(g) (--->)(<----) 2NH3(g)
How would you increase increase the yield of ammonia without adding more reactants?
Thank you.
For the reaction N2(g)+3H2(g) (--->)(<----) 2NH3(g)
How would you increase increase the yield of ammonia without adding more reactants?
Thank you.
- Mon Jul 18, 2016 8:54 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Question About #5 on Post Module
- Replies: 1
- Views: 442
Question About #5 on Post Module
Hello, I am revisiting the Molarity and Dilution module. Question 5 in the post-module section is asking for the final molarity. After I finished converting the volume in mL to L, I was moving on to the molar calculations and the measurement is given in grams. Is the next step to convert the grams i...
- Tue Jul 05, 2016 5:07 pm
- Forum: Balancing Chemical Reactions
- Topic: Calculating Net Moles
- Replies: 1
- Views: 570
Calculating Net Moles
In one of the post-assessment question regarding balancing chemical equation, we are asked to find the net number of moles produced. How would you go about finding the net number of moles produced in a chemical reaction? Thank you
- Tue Jul 05, 2016 5:07 pm
- Forum: Balancing Chemical Reactions
- Topic: Calculating Net Moles
- Replies: 3
- Views: 1663
Calculating Net Moles
In one of the post-assessment question regarding balancing chemical equation, we are asked to find the net number of moles produced. How would you go about finding the net number of moles produced in a chemical reaction? Thank you
- Sat Mar 12, 2016 6:20 pm
- Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
- Topic: Highest Priority Atom.
- Replies: 2
- Views: 574
Re: Highest Priority Atom.
Thank you!
- Sat Mar 12, 2016 6:12 pm
- Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
- Topic: Highest Priority Atom.
- Replies: 2
- Views: 574
Highest Priority Atom.
How do you determine which atom or atom group is the highest priority?
- Wed Feb 24, 2016 3:32 pm
- Forum: *Electrophiles
- Topic: Thermody. and Kineticsof Organic Rxns Textbook Review
- Replies: 1
- Views: 481
Thermody. and Kineticsof Organic Rxns Textbook Review
I have the 5th edition chem textbook. Which chapter(s) go over the section on Thermodynamics and Kinetics of Organic reactions?
- Thu Jan 28, 2016 1:43 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Useful Summary of Thermodynamic Definitions
- Replies: 55
- Views: 18709
Re: Useful Summary of Thermodynamic Definitions
Thank you for posting this!
- Sat Nov 07, 2015 11:43 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Homo/Heterogenous Equilibria
- Replies: 2
- Views: 968
Re: Homo/Heterogenous Equilibria
In an equilibrium constant, which substances are not considered?