CHEMISTRY COMMUNITY

Celine_Ngo_3L

: 96089c71dae843c6a84ed0faa2157f37.jpg (15.08 KiB) Viewed 17357 times

Celine_Ngo_3L

: c22269901ae37af0fddc331ac6e0f661.jpg (10.38 KiB) Viewed 17357 times

Celine_Ngo_3L

Celine_Ngo_3L

Celine_Ngo_3L

(or sunday)

Celine_Ngo_3L

: 954cb361299dbf962caaba2829ce6bd1.jpg (10.42 KiB) Viewed 22151 times

Celine_Ngo_3L

If there is H₂O on the inside of a fire hydrant, what is on the outside?

K₉P

Celine_Ngo_3L

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...

Celine_Ngo_3L

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.

Celine_Ngo_3L

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...

Celine_Ngo_3L

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...

Celine_Ngo_3L

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?

Celine_Ngo_3L

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...

Celine_Ngo_3L

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 ...

Celine_Ngo_3L

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...

Celine_Ngo_3L

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 ...

Celine_Ngo_3L

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...

Celine_Ngo_3L

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?

Celine_Ngo_3L

How do you know when to use unhybridized orbitals vs. hybridized orbitals?

CHEMISTRY COMMUNITY

Search found 19 matches

Re: Post All Chemistry Jokes Here

Re: Post All Chemistry Jokes Here

Re: Post All Chemistry Jokes Here

Re: Post All Chemistry Jokes Here

Re: Post All Chemistry Jokes Here

Re: Post All Chemistry Jokes Here

Re: Post All Chemistry Jokes Here

Re: Examples of adiabatic systems

Re: 2013 Final Q8B

Re: 2012 Final Q #7A

Re: weakbase-strong acid question

Re: Memorization of Acids and Bases

Calculating pH of a weak acid and its salt

Re: Fall 2014 Final Exam Q3C

Approximating X

Re: question 12.43

Re: Why is water always a monodentate?

Naming Ligands

Unhybridized Orbitals