Search found 20 matches

by Edgar Khachatryan 3G
Wed Nov 30, 2016 8:09 pm
Forum: *Titrations & Titration Calculations
Topic: Hwk 13.29
Replies: 5
Views: 794

Re: Hwk 13.29

Haha awesome, thank you!
by Edgar Khachatryan 3G
Tue Nov 29, 2016 3:30 pm
Forum: *Titrations & Titration Calculations
Topic: Hwk 13.29
Replies: 5
Views: 794

Hwk 13.29

1.436g of NaOH is dissolved in 300.mL solution, 25.00mL of this solution is titrated to the stoichiometric point with 34.20mL of 0.0695 M HCl. What is the percentage purity of the original sample? 1. I converted g of NaOH to moles of NaOH. 2. I then converted 0.0695M HCl to moles of HCl. 3. I then d...
by Edgar Khachatryan 3G
Mon Nov 28, 2016 8:09 pm
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: Henderson-Hasselbalch equation
Replies: 4
Views: 1162

Re: Henderson-Hasselbalch equation

The Henderson-Hasselbalch equation is used to calculate the pH of solution containing an acid and its conjugate base as a salt OR to calculate the pOH of a base and its conjugate acid as a salt.

pH= pKa + log(A-/HA)

pOH= pKb + log(BH+/BH)
by Edgar Khachatryan 3G
Wed Nov 16, 2016 4:58 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7609
Views: 1020219

Re: Post All Chemistry Jokes Here

If you’re not part of the solution your part of the precipitate.
by Edgar Khachatryan 3G
Wed Nov 16, 2016 4:58 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7609
Views: 1020219

Re: Post All Chemistry Jokes Here

What does a chemist bring as a dessert while camping? A ‘gram’ cracker.
by Edgar Khachatryan 3G
Wed Nov 09, 2016 9:49 pm
Forum: Ideal Gases
Topic: Quiz 3 [ENDORSED]
Replies: 2
Views: 432

Re: Quiz 3 [ENDORSED]

I think everything covered in the Course Reader would be fair game for the quiz.
by Edgar Khachatryan 3G
Mon Nov 07, 2016 11:58 pm
Forum: Ionic & Covalent Bonds
Topic: Cation vs Anion
Replies: 4
Views: 699

Re: Cation vs Anion

Also, just to add on, cations are smaller than anions and have a positive charges.
by Edgar Khachatryan 3G
Tue Nov 01, 2016 11:35 pm
Forum: Photoelectric Effect
Topic: 2015 Midterm Question #3
Replies: 2
Views: 567

Re: 2015 Midterm Question #3

In order to use the kinetic equation you would need 2 of the 3 things: the energy of the photons being emitted onto the metallic surface, the threshold energy of the metallic surface, or the kinetic energy of the photons emitted(1/2mv^2). According to the De Broglie equation, Wave Length= h/p and p=...
by Edgar Khachatryan 3G
Tue Nov 01, 2016 11:25 pm
Forum: Hybridization
Topic: hybridization
Replies: 2
Views: 312

Re: hybridization

Px and Py form pi bonds. Pz forms sigma bonds. Elaborate on the first part of your question.
Thanks.
by Edgar Khachatryan 3G
Tue Nov 01, 2016 11:21 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Fall 2015 Midterm Question 4
Replies: 1
Views: 354

Re: Fall 2015 Midterm Question 4

Hi Katelyn! The electron arrangement assumes the shape trigonal bipyramidal, however, when we take into account the 3 lone pairs, the molecular shape is in fact linear. To see this more clearly, imagine a linear molecule(2 atoms on each end) and arrange the 3 lone pairs around the central atom. I wi...
by Edgar Khachatryan 3G
Tue Nov 01, 2016 10:28 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone pairs in polarity
Replies: 1
Views: 264

Re: Lone pairs in polarity

Yes, lone pairs affect the polarity of a molecule. If there is an individual lone pair, there won't be another pair of electrons to cancel out the dipole moment, therefore the molecule will be polar. If there are two lone pairs, it is possible for it to not affect the polarity of the molecule if the...
by Edgar Khachatryan 3G
Mon Oct 31, 2016 10:41 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pairs on Linear Molecule
Replies: 3
Views: 627

Re: Lone Pairs on Linear Molecule

Actually, after researching it appears that a molecule with AX2E3 is a linear molecule. Take I3- for example.
by Edgar Khachatryan 3G
Mon Oct 31, 2016 10:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pairs on Linear Molecule
Replies: 3
Views: 627

Lone Pairs on Linear Molecule

Can a molecule have lone pairs and still be linear? Wouldn't AX2E1 or AX2E2 be Bent Shape? Thanks for the help.
by Edgar Khachatryan 3G
Sun Oct 30, 2016 11:10 pm
Forum: Lewis Structures
Topic: (SO3)2- Lewis Structure Formal Charge
Replies: 1
Views: 2685

(SO3)2- Lewis Structure Formal Charge

Hi. The Lewis Structure for sulfite has 3 resonance structures in which the Sulfur has a formal charge of 0 and two of the oxygens have a formal charge of -1. Why couldn't there be a 3 double bonds instead? Wouldn't this contribute to Sulfur having a formal charge of -2 and the oxygens having a form...
by Edgar Khachatryan 3G
Mon Oct 24, 2016 9:45 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: S, P, D, and F Orbitals [ENDORSED]
Replies: 4
Views: 591

Re: S, P, D, and F Orbitals [ENDORSED]

An orbital is a mathematical representation of where an electron is likely to be found. Each orbital can hold up to two electrons with opposite spins. These orbitals are found in subshells(s,p,d,f) and the subshells are found in different energy levels(n).
by Edgar Khachatryan 3G
Tue Oct 18, 2016 9:08 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Aufbau's Principle [ENDORSED]
Replies: 3
Views: 435

Re: Aufbau's Principle [ENDORSED]

This is true for nearly all atoms with two exceptions: chromium and copper. I'd urge you to refer to the final paragraph of page 46 in the textbook as it would give a fairly thorough response as to why the exceptions exist. Hope this helped!
by Edgar Khachatryan 3G
Mon Oct 17, 2016 4:30 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Aufbau's Principle [ENDORSED]
Replies: 3
Views: 435

Re: Aufbau's Principle [ENDORSED]

Once they contain electrons, the 3d orbitals have lower energy than the 4s orbitals. Therefore, the 3d orbital must come before the 4s orbital.
by Edgar Khachatryan 3G
Mon Oct 10, 2016 7:17 pm
Forum: Properties of Light
Topic: Rydberg Equation
Replies: 5
Views: 615

Re: Rydberg Equation

Both can be used: the latter is just a simplified version.
by Edgar Khachatryan 3G
Tue Oct 04, 2016 3:49 pm
Forum: Properties of Light
Topic: C=λV units question
Replies: 3
Views: 1114

Re: C=λV units question

Wavelength must always be calculated or used in a calculation in meters.
by Edgar Khachatryan 3G
Thu Sep 29, 2016 11:49 pm
Forum: Properties of Light
Topic: Frequency, wavelength, and Energy of light
Replies: 5
Views: 520

Re: Frequency, wavelength, and Energy of light

What is the difference between the "energy" and "intensity" of a wave? Or are they referring to the same point in mind?

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