Excellence in Chemistry Education Video Awards - Lecture 3
Search found 12 matches
- Fri Mar 13, 2015 2:56 am
- Forum: Administrative Questions and Class Announcements
- Topic: Photos Chem 14B Winter 2015
- Replies: 2
- Views: 1165
- Sun Jan 11, 2015 11:43 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Capacity of ideal gas
- Replies: 4
- Views: 979
Re: Heat Capacity of ideal gas
I believe Yifan is referring to section 7.10 of the book about heat capacity of ideal gases, not the question.
- Tue Dec 09, 2014 4:45 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Electron in the Nucleus
- Replies: 2
- Views: 453
Re: Electron in the Nucleus
An electron cannot be located inside the nucleus because if you plugged the diameter of the nucleus into Heisenberg's Uncertainty Principle you would find that the uncertainty in velocity (delta V) would be greater than the speed of light (2.9972 x 10 8 m/s), which is impossible since nothing can ex...
- Tue Dec 09, 2014 2:02 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pH of H2O when temperature changes
- Replies: 1
- Views: 495
Re: pH of H2O when temperature changes
The question gives the Kw for water as 2.1 x 10 -14 at 37 degrees Celsius so you have to use that and set up an ICE table to calculate the new values of [H 3 O + ] and [OH - ]. Temperature does affect the pH because it changes the K value. This is a result of the shifting of the chemical equilibrium...
- Thu Nov 27, 2014 8:20 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3650625
Re: Chemistry Jokes
Two friends walk into a bar. The first says, "I'll have some H2O." The second says, "I'll have some H2O too." Then he dies.
Why did the white bear dissolve in water? Because it was polar.
Why did the white bear dissolve in water? Because it was polar.
- Tue Nov 25, 2014 11:04 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: How does an equation go to equilibrium?
- Replies: 2
- Views: 693
Re: How does an equation go to equilibrium?
A reaction moves to equilibrium either by having the reactants react to form more product if Q < K or if the products react to form more reactants if Q > K. If Q < K, then [R] > [P] and the forward reaction is favored meaning products are formed. K is given in the textbook and may or may not be supp...
- Wed Nov 12, 2014 11:59 pm
- Forum: Trends in The Periodic Table
- Topic: Ionic radius
- Replies: 2
- Views: 697
Re: Ionic radius
All three ions are isoelectronic i.e. with the same number of electrons, 18. However, their atomic numbers differ so Phosphorous, which has 15 protons, will not be able to hold its electrons as closely together as Sulfur, which has 16 protons, or Chlorine, which has 17 protons because it has a lower...
- Thu Oct 30, 2014 6:09 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: 2.81 Polarizability
- Replies: 2
- Views: 2357
Re: 2.81 Polarizability
Hi Shannon, Anions that are large are said to be highly polarizable because their outer electrons are held more loosely so the electron cloud of a large anion like I- is easily distorted. Br- is the largest anion in the question so it has the highest polarizing power while Cl- is the second biggest ...
- Wed Oct 29, 2014 7:10 pm
- Forum: Lewis Structures
- Topic: Expanded Octets
- Replies: 3
- Views: 1058
Re: Expanded Octets
Yes, elements in the 3rd period use their 3d orbital to expand their octets. The 3d orbital is in the same energy level as the 3p and 3s orbitals (they are all on energy level n=3) so it is not in a higher shell.
- Fri Oct 17, 2014 2:31 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: What do shapes of orbitals reprensent?
- Replies: 1
- Views: 554
Re: What do shapes of orbitals reprensent?
The shapes of atomic orbitals are the solutions to the Schrodinger Wave Function Equation, Ψ. They are the three-dimensional regions where an electron may be found. Ψ describes the position of the electron in three-dimensional space while Ψ^2 is the probability of finding an electron at a particular...
- Thu Oct 16, 2014 10:28 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Energy Levels
- Replies: 4
- Views: 1054
Re: Energy Levels
L is the angular momentum quantum number and can have values from 0 to n-1 so if the principle quantum number, n=3, L can have the values of 0, 1, and 2. ml is the magnetic quantum number and its values are from L to -L so if n=2 then the values of ml are -2, -1, 0, 1, and 2. Hope this helped!
- Thu Oct 16, 2014 10:10 pm
- Forum: SI Units, Unit Conversions
- Topic: Avogradros constant and Formula Units
- Replies: 3
- Views: 1303
Re: Avogradros constant and Formula Units
I think the formula sheet Lavelle will give us should be similar if not the same as one on the back of the laminated periodic table we got when we purchased his course reader. Here's a link to his periodic table /formula sheet that you can buy on amazon: http://www.amazon.com/Laminated-Periodic-Form...