## 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: 1004

### Re: Photos Chem 14B Winter 2015

Excellence in Chemistry Education Video Awards - Lecture 3

Sun Jan 11, 2015 11:43 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacity of ideal gas
Replies: 4
Views: 676

### 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: 313

### 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: 309

### 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: 8242
Views: 1437605

### 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.
Tue Nov 25, 2014 11:04 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: How does an equation go to equilibrium?
Replies: 2
Views: 522

### 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
Replies: 2
Views: 463

### 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: 1888

### 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: 675

### 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: 368

### 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: 788

### 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: 990

### 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...

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