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- Tue Mar 14, 2017 11:19 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3641790
- Tue Mar 14, 2017 11:11 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3641790
- Wed Feb 22, 2017 12:31 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3641790
- Sat Feb 11, 2017 1:42 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3641790
- Sun Feb 05, 2017 11:31 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3641790
Re: Post All Chemistry Jokes Here
(or sunday)
- Mon Jan 30, 2017 12:11 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3641790
- Tue Jan 24, 2017 1:35 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3641790
Re: Post All Chemistry Jokes Here
If there is H2O on the inside of a fire hydrant, what is on the outside?
K9P
K9P
- Mon Jan 16, 2017 12:11 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Examples of adiabatic systems
- Replies: 3
- Views: 844
Re: Examples of adiabatic systems
An adiabatic system, by definition, is a system where there is no transfer of heat, but work instead. The walls are insulated, not isolated because insulated just means it prevents the flow of heat. Isolated walls would mean that there would be absolutely no exchange between the system and its surro...
- Sat Dec 03, 2016 12:53 am
- Forum: *Titrations & Titration Calculations
- Topic: 2013 Final Q8B
- Replies: 1
- Views: 513
Re: 2013 Final Q8B
Since concentration is n(mols)/volume, you need to convert 0.20 M (molarity) to mols first.
In order to do that, you multiply 0.20 M with 10.0 mL to get 0.002 mols. Then you divide 0.002 mols by the total volume, 30.0 mL, to get the concentration 0.067 M.
In order to do that, you multiply 0.20 M with 10.0 mL to get 0.002 mols. Then you divide 0.002 mols by the total volume, 30.0 mL, to get the concentration 0.067 M.
- Sat Dec 03, 2016 12:23 am
- Forum: *Titrations & Titration Calculations
- Topic: 2012 Final Q #7A
- Replies: 1
- Views: 547
Re: 2012 Final Q #7A
For the two titrations, you could use the memory tool in the course reader to determine if the pH is equal to, below, or above 7. Even though this is not the correct logic, if a strong base is being added to a weak acid, it "dominates" the weak acid and pH will be greater than 7. Vice vers...
- Fri Dec 02, 2016 11:22 pm
- Forum: *Titrations & Titration Calculations
- Topic: weakbase-strong acid question
- Replies: 3
- Views: 778
Re: weakbase-strong acid question
It's because when the weak base's conjugate acid reacts with water, it creates an excess of H3O+ ions. For example, if HCl is used to titrate NH3, the chemical equation would look like this: HCl + NH3 + H2O--> NH4+ Cl- + H2O --> NH3 + H3O+ Cl- NH4+ gives a proton to H2O, making more H3O+ ions in the...
- Thu Dec 01, 2016 4:58 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Memorization of Acids and Bases
- Replies: 2
- Views: 742
Re: Memorization of Acids and Bases
Kim wrote:My TA suggested knowing all the strong acids and strong bases (I think theres 6 acids and 8 bases), so that you know every other one is weak
How about all the common monoprotic and polyprotic acids on p. 20? I know we don't have to memorize their Ka/Kb values, but how about all their formulas?
- Tue Nov 29, 2016 10:39 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Calculating pH of a weak acid and its salt
- Replies: 1
- Views: 584
Calculating pH of a weak acid and its salt
On pg. 162 of the course reader, there is an additional example that asks: what is the pH of a solution with 0.500 M Nitrous acid HNO2 (aq) and 0.100 M Potassium nitrite KNO2(aq)? HNO2(aq) + H2O(l) ---> H3O+(aq) + NO2-(aq) It then goes on to do ice box with the equation above and solve for pH, but I...
- Sun Nov 27, 2016 11:45 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Fall 2014 Final Exam Q3C
- Replies: 1
- Views: 571
Re: Fall 2014 Final Exam Q3C
Cl2+ is more stable than Cl2 because if you look at the p orbitals in Cl2, there are already two paired electrons and only one unpaired electron. It is extremely close to filling all of its p orbitals, making it more unstable. The p orbitals in Cl2+, on the other hand, have one unpaired electron in ...
- Sun Nov 27, 2016 12:35 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: Approximating X
- Replies: 1
- Views: 438
Approximating X
In the course reader when it gives an example of calculating pH (p. 156), it says, "if X is less than 5% of the initial then approximation is okay" and we can approximate since Ka is small (in this case, Ka = 1.8 x 10^-5). What is considered a "small" Ka value? And when do we cal...
- Sun Nov 20, 2016 4:12 pm
- Forum: Bronsted Acids & Bases
- Topic: question 12.43
- Replies: 1
- Views: 515
Re: question 12.43
It's a stronger acid because the 3 Cl- atoms (since yes, they are more electronegative) pull the electrons away from the rest of the phenol molecule, making it easier for the H+ ions to dissociate more easily. And since the strength of an acid is based on how much it dissociates, trichlorophenol is ...
- Sun Nov 20, 2016 3:36 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Why is water always a monodentate?
- Replies: 2
- Views: 898
Re: Why is water always a monodentate?
Even though oxygen has two lone pairs, there would only be one binding site between water and the central metal because its bent shape prevents it from binding both of its lone pairs. The lone pairs are both on the same atom (oxygen) and polydentate ligands form their bonds through lone pairs on dif...
- Wed Nov 16, 2016 1:12 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Naming Ligands
- Replies: 5
- Views: 1297
Naming Ligands
I looked up examples of naming ligands and one website named CN- as cyanido and F- as fluorido. What is the difference between cyano and cyanido or fluroro and fluorido? Where does the ending -ido come from?
- Tue Nov 01, 2016 9:56 pm
- Forum: Hybridization
- Topic: Unhybridized Orbitals
- Replies: 1
- Views: 702
Unhybridized Orbitals
How do you know when to use unhybridized orbitals vs. hybridized orbitals?