Search found 32 matches
- Thu Jun 14, 2018 1:59 am
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam [ENDORSED]
- Replies: 5
- Views: 704
Re: Final Exam [ENDORSED]
Everything is fair game! Good luck everybody!
- Mon Jun 11, 2018 11:06 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3007660
Re: Post All Chemistry Jokes Here
"The name's bond. Sigma bond."
-007
-007
- Mon Jun 11, 2018 11:02 pm
- Forum: Conjugate Acids & Bases
- Topic: Conjugate Acids/Bases
- Replies: 8
- Views: 1181
Re: Conjugate Acids/Bases
Did we cover this in class?
- Sun Jun 03, 2018 11:55 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR shape and bond angles
- Replies: 5
- Views: 688
Re: VSEPR shape and bond angles
Do we have to know the specific bond angles for certain molecular shapes. For example, would it be acceptable to say (on a test) that sulfite ion, SO3 2-, have bond angles less than 109.5? Are approximations ok to state?
- Sun Jun 03, 2018 11:51 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: 4 ligands shape?
- Replies: 6
- Views: 732
Re: 4 ligands shape?
Square planar has four ligands and two lone pairs. A difference between the two is that the bond angles of the square planar shape are smaller than 109.5 because the atoms are pulled closer together by the repulsion of the lone pairs.
- Sun Jun 03, 2018 11:46 pm
- Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
- Topic: When to use the Henderson-Hasselbalch Equation
- Replies: 4
- Views: 2933
Re: When to use the Henderson-Hasselbalch Equation
Will we have to know this equation for the final? We haven't learned about it in lecture yet, right?
- Thu May 24, 2018 8:38 pm
- Forum: Ionic & Covalent Bonds
- Topic: ionic and covalent character
- Replies: 7
- Views: 3070
Re: ionic and covalent character
So when determining if a molecule is ionic or covalent, it is not always/only dependent on the electronegativity difference? For example, MgI2 has a electronegativity difference of 1.3 (which is smaller than 1.67, the rule to be a covalent bond). However, MgI2 is an ionic bond right?
- Thu May 24, 2018 8:29 pm
- Forum: Electronegativity
- Topic: Question for Exams [ENDORSED]
- Replies: 5
- Views: 885
Re: Question for Exams [ENDORSED]
So for electronegativity, we should be able to recall that it increases as you go across the periodic table and decreases as you go down the periodic table. The greater the difference in electronegativity, then greater ionic character the bond has.
- Mon May 21, 2018 8:02 pm
- Forum: Electronegativity
- Topic: Trends? [ENDORSED]
- Replies: 10
- Views: 1600
Re: Trends? [ENDORSED]
Is there a trend involved in the second ionization energy?
- Thu May 17, 2018 9:48 pm
- Forum: Lewis Structures
- Topic: Finding a Lewis Structure with the Lowest Energy
- Replies: 5
- Views: 613
Re: Finding a Lewis Structure with the Lowest Energy
Just to clarify, lowest energy means that the molecule has a formal charge of 0 (or close to 0), right?
- Thu May 17, 2018 9:46 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge
- Replies: 3
- Views: 588
Re: Formal Charge
Yes! A - means that the molecule is an anion, meaning you ADD an electron. A + means the molecule is a cation, meaning you REMOVE an electron.
- Thu May 17, 2018 9:40 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formula Provided
- Replies: 6
- Views: 971
Re: Formula Provided
Formal charge can be used to determine if a structure is stable. In drawing lewis structures for tests, the correct answer would be a lewis structure of a molecule with the formal charge of 0 (or close to zero).
- Thu May 17, 2018 9:28 pm
- Forum: Student Social/Study Group
- Topic: Final Study Group
- Replies: 1
- Views: 404
Re: Final Study Group
I would like to be part of the study group if one is organized!
My email is mariah.guerrero99@gmail.com
My email is mariah.guerrero99@gmail.com
- Mon May 14, 2018 12:32 am
- Forum: Photoelectric Effect
- Topic: Incoming Light [ENDORSED]
- Replies: 4
- Views: 2081
Re: Incoming Light [ENDORSED]
I refreshed the page and the answer UV rays is still marked as incorrect.
- Mon May 14, 2018 12:30 am
- Forum: Lewis Structures
- Topic: Formal Energy / Formal Charge [ENDORSED]
- Replies: 2
- Views: 561
Re: Formal Energy / Formal Charge [ENDORSED]
From my understanding, yes these terms are interchangeable. A charge determines the energy of an atom. Formal charge indicates a gain or loss of electrons while forming covalent bonds; thus, the charge determines energy gain or loss.
- Sun May 13, 2018 5:07 pm
- Forum: Resonance Structures
- Topic: Resonance Structures and Formal charges
- Replies: 7
- Views: 944
Re: Resonance Structures and Formal charges
So for our upcoming tests, the only acceptable lewis structures are those with a formal charge of 0?
- Sun May 13, 2018 4:31 pm
- Forum: Trends in The Periodic Table
- Topic: electron affinity [ENDORSED]
- Replies: 15
- Views: 1930
Re: electron affinity [ENDORSED]
Can someone explain the difference between electron affinity and electron negativity again? I understand that both properties have the same periodic trend. Is there an easier way that I can remember the difference?
- Sun May 13, 2018 4:28 pm
- Forum: Ionic & Covalent Bonds
- Topic: cation vs anion
- Replies: 14
- Views: 3608
Re: cation vs anion
Are there any trends that occur on the periodic table with cations and anions?
- Mon May 07, 2018 12:14 am
- Forum: Trends in The Periodic Table
- Topic: Ground state and excited electrons [ENDORSED]
- Replies: 1
- Views: 357
Re: Ground state and excited electrons [ENDORSED]
In the simplest terms, ground state refers to an electron in its lowest energy and excited electrons refers to an electron that absorbs energy.
Here's a great video that goes into more detail of the difference! https://www.youtube.com/watch?v=62ll5Tt_3zY
Hope this helps!
Here's a great video that goes into more detail of the difference! https://www.youtube.com/watch?v=62ll5Tt_3zY
Hope this helps!
- Mon May 07, 2018 12:09 am
- Forum: Photoelectric Effect
- Topic: Incoming Light [ENDORSED]
- Replies: 4
- Views: 2081
Incoming Light [ENDORSED]
Hello! I am working on n the post-module for the audio-visual focus topics and this question came up: In photoelectric experiments, typically what part of the electromagnetic spectrum is the incoming light? A. Ultraviolet B. Infrared C. Visible light D. Gamma rays E. None of the above I assumed the ...
- Mon Apr 30, 2018 12:21 am
- Forum: DeBroglie Equation
- Topic: Diffraction patterns
- Replies: 1
- Views: 327
Diffraction patterns
Electrons have diffraction patterns that result from constructive or destructive interference. How does this relate to De Broglie's equation?
- Mon Apr 30, 2018 12:11 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: test
- Replies: 3
- Views: 426
Re: test
You can use Rydberg's Equation to solve for the energy levels (n). E= -hR/n^2
If the energy is given in the problem, you would simply have to rearrange the equation in terms of n as it is the only unknown in this case.
If the energy is given in the problem, you would simply have to rearrange the equation in terms of n as it is the only unknown in this case.
- Mon Apr 30, 2018 12:07 am
- Forum: *Shrodinger Equation
- Topic: Energy equation
- Replies: 1
- Views: 374
Re: Energy equation
If energies (E photon and work function) are given in the problem or you can solve for them, then you do not need to use the KE equation. Subtract the work function (also called the threshold energy or ionization energy) from E photon to find the KE. However, if only KE is asked with no other inform...
- Mon Apr 23, 2018 1:35 pm
- Forum: General Science Questions
- Topic: Test #2 [ENDORSED]
- Replies: 6
- Views: 882
Re: Test #2 [ENDORSED]
I think the problems listed from chapter one will not all be on the test; some of these problems are similar to one another. The most important thing for us to do with these problems is to understand the concepts and be able to apply those concepts any which way that is asked.
- Fri Apr 20, 2018 12:21 am
- Forum: General Science Questions
- Topic: Test #2 [ENDORSED]
- Replies: 6
- Views: 882
Test #2 [ENDORSED]
Hello all!
I cannot seem to find the post Dr. Lavelle created that states the specific chapter problems we should focus on for test 2. (He showed us the post at the beginning of class on Wednesday.) Can someone help me locate the info?
I cannot seem to find the post Dr. Lavelle created that states the specific chapter problems we should focus on for test 2. (He showed us the post at the beginning of class on Wednesday.) Can someone help me locate the info?
- Fri Apr 20, 2018 12:13 am
- Forum: Student Social/Study Group
- Topic: Study Group
- Replies: 8
- Views: 992
Re: Study Group
I would be interested in joining a study group as well! Let me know if one is created please! My email is mariah.guerrero99@gmail.com!
- Sun Apr 15, 2018 8:03 pm
- Forum: Properties of Light
- Topic: HW 1.5 [ENDORSED]
- Replies: 2
- Views: 242
HW 1.5 [ENDORSED]
Question 1.5 states to arrange the following types of photons of electromagnetic radiation in order of increasing energy y rays, visible light, ultraviolet radiation, microwaves, x rays. I understand the order of increasing energy is y ray, x ray, ultraviolet, visible, infrared, microwave and radio....
- Sun Apr 15, 2018 7:16 pm
- Forum: Balancing Chemical Reactions
- Topic: Writing Products
- Replies: 2
- Views: 341
Re: Writing Products
Combustion refers to the burning of air, with a reaction with molecular oxygen. Therefore, to start off by writing the correct chemical equation you would write KCl + O2= . Writing the reactants as one (letter B) creates a new, separate molecule that will produce a different outcome. KCl reacts with...
- Sun Apr 15, 2018 7:09 pm
- Forum: SI Units, Unit Conversions
- Topic: Extensive vs. Intensive Properties?
- Replies: 3
- Views: 1906
Re: Extensive vs. Intensive Properties?
An extensive property is a property that does depend on the size or the "extent" of the sample. In this case, mass and density are an extensive properties. An intensive property is independent of the size of the sample. Volume and temperature are examples of extensive properties.
- Sun Apr 15, 2018 7:02 pm
- Forum: Limiting Reactant Calculations
- Topic: Reagent vs. Reactant [ENDORSED]
- Replies: 6
- Views: 1357
Reagent vs. Reactant [ENDORSED]
What is the difference between reagent and reactant? Or are these terms interchangeable?
- Thu Apr 12, 2018 11:46 pm
- Forum: Limiting Reactant Calculations
- Topic: Two limiting reactants?
- Replies: 10
- Views: 2419
Two limiting reactants?
Can a reaction have two limiting reactants?
- Thu Apr 12, 2018 10:58 pm
- Forum: Limiting Reactant Calculations
- Topic: Q.22 on Audio-Visual Focus-Topic [ENDORSED]
- Replies: 2
- Views: 287
Q.22 on Audio-Visual Focus-Topic [ENDORSED]
I am reviewing the post-assessment for the audio-visual focus-topic for limiting reactants, and I am stuck on this problem. According to the following equation, 0.750 g of C6H9Cl3 is mixed with 1.000 kg of AgNO3 in a flask of water. A white solid, AgCl, completely precipitates out. What is the mass ...