Search found 40 matches
- Mon Dec 02, 2019 8:36 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pH calcuations
- Replies: 8
- Views: 478
Re: pH calcuations
It may also be helpful to remember that pH + pOH = 14.
- Mon Dec 02, 2019 8:35 am
- Forum: Calculating the pH of Salt Solutions
- Topic: pH formula?
- Replies: 69
- Views: 4396
Re: pH formula?
The formula for pH is -log[H+] and pOH is -log[OH-]. I don't think we need to know the derivation, but it is helpful to know that pH + pOH = 14
- Mon Dec 02, 2019 8:31 am
- Forum: Calculating the pH of Salt Solutions
- Topic: pH of acids
- Replies: 13
- Views: 3606
Re: pH of acids
The lower the pH is, the more H+ ions it has, making it more acidic. Higher pHs have a lower H+ concentration and are weaker acids.
- Mon Dec 02, 2019 8:29 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pH scale
- Replies: 12
- Views: 677
Re: pH scale
Most solutions fall between 0 and 14, there are very few acids that would be negative and very few bases that would fall above 14.
- Mon Dec 02, 2019 8:28 am
- Forum: Identifying Acidic & Basic Salts
- Topic: Final: Strong/ Weak Acids/Bases
- Replies: 11
- Views: 1549
Re: Final: Strong/ Weak Acids/Bases
I believe it would be best to memorize the strong acids and strong bases for the final.
- Sat Nov 23, 2019 6:10 pm
- Forum: Naming
- Topic: Naming Order
- Replies: 6
- Views: 370
Re: Naming Order
I believe you would list the ligands in alphabetical order.
- Sat Nov 23, 2019 6:09 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: [Fe(CN)6]4-
- Replies: 5
- Views: 495
Re: [Fe(CN)6]4-
Since CN has a -1 charge, the -4 overall charge is given to calculate the charge of iron (Fe), which is +2.
- Sat Nov 23, 2019 6:07 pm
- Forum: Naming
- Topic: Cation/Anion
- Replies: 7
- Views: 874
Re: Cation/Anion
In the chemical formula, the cation will be listed first followed by the anion.
- Sat Nov 23, 2019 6:06 pm
- Forum: Naming
- Topic: Chloro vs Chlorito
- Replies: 10
- Views: 1262
Re: Chloro vs Chlorito
I think that both suffixes are acceptable, but the -o form would probably be best to use since that is what we are taught in lectures.
- Sat Nov 23, 2019 6:03 pm
- Forum: Naming
- Topic: Naming Compounds (general question)
- Replies: 5
- Views: 485
Re: Naming Compounds (general question)
I think we would only have to know the general rules for naming coordination complexes.
- Sun Nov 17, 2019 12:39 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: axial vs equitorial
- Replies: 3
- Views: 302
Re: axial vs equitorial
Axial bonds are parallel to the axis of the ring while equatorial bonds are perpendicular to the axis (at the equator).
- Sun Nov 17, 2019 12:38 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 4
- Views: 332
Re: Bond Angles
I believe you only need to be able to state that the bond angle is less than the expected angle. I don't think you need to give a more exact approximation.
- Sun Nov 17, 2019 12:36 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 4
- Views: 281
Re: Bond Angles
The electronegativity of the atoms can slightly change the bond angles even if two molecules have the same shape.
- Sun Nov 17, 2019 12:32 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: What is VSPER
- Replies: 14
- Views: 1029
Re: What is VSPER
The VSEPR model stands for the Valence-Shell Electron-Pair Repulsion model. You do not need to have the acronym memorized. However, it may help with your understanding of the concepts of the model.
- Sun Nov 17, 2019 12:31 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: polar or non polar?
- Replies: 7
- Views: 553
Re: polar or non polar?
In order to determine if the molecule is polar or non-polar, you would use the electronegativity of the atoms as well as the Lewis structure. The electronegativity would show you the charges of the bonds and the Lewis structure would show you if the dipoles cancel.
- Sat Nov 09, 2019 5:29 pm
- Forum: Lewis Structures
- Topic: Drawing Lewis Structures
- Replies: 18
- Views: 713
Re: Drawing Lewis Structures
You should draw the Lewis structure so that the sum of the formal charges is the charge of the overall molecule, which may not necessarily be zero.
- Sat Nov 09, 2019 5:28 pm
- Forum: Lewis Structures
- Topic: When to draw Resonance Structures
- Replies: 14
- Views: 1032
Re: When to draw Resonance Structures
If the question specifically says to asks to draw resonance structures than you should do so. Otherwise, just draw the most stable Lewis Structure.
- Sat Nov 09, 2019 5:25 pm
- Forum: Lewis Structures
- Topic: Formal Charges
- Replies: 15
- Views: 1012
Re: Formal Charges
Since the central atom is usually the least electronegative, the surrounding atoms would have the charge.
- Sat Nov 09, 2019 5:23 pm
- Forum: Lewis Structures
- Topic: Lewis Structures
- Replies: 4
- Views: 374
Re: Lewis Structures
Electrons are shifted toward the more electronegative atom, so the more electronegative atom is the one with the negative charge.
- Sat Nov 09, 2019 5:21 pm
- Forum: Lewis Structures
- Topic: Midterm grades
- Replies: 26
- Views: 1487
Re: Midterm grades
Dr. Lavelle announced that the midterms would be handed back during lecture on Wednesday (11/13).
- Sun Oct 27, 2019 10:12 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent Bonds
- Replies: 11
- Views: 577
Re: Covalent Bonds
Correct, covalent bonds occur between two non-metals. This differs from the metal-nonmetal ionic bonds.
- Sun Oct 27, 2019 10:10 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic VS. Covalent Bond
- Replies: 8
- Views: 476
Re: Ionic VS. Covalent Bond
Ionic bonds occur between a metal and a non-metal. Covalent bonds result from the bonding of two non-metals.
- Sun Oct 27, 2019 10:09 pm
- Forum: Ionic & Covalent Bonds
- Topic: Homework
- Replies: 13
- Views: 684
Re: Homework
I believe you can do problems from either section. However, it might be beneficial to focus this week's homework on chemical bonds since it is a new topic.
- Sun Oct 27, 2019 10:06 pm
- Forum: DeBroglie Equation
- Topic: Protons and Electrons
- Replies: 4
- Views: 296
Re: Protons and Electrons
Since protons and neutrons have the same mass, if they had the same velocity they would also have the same wavelength.
- Sun Oct 27, 2019 10:04 pm
- Forum: Ionic & Covalent Bonds
- Topic: periodic table
- Replies: 10
- Views: 425
Re: periodic table
Electronegativity increases from left to right of the periodic table and decreases as you move down a group.
- Sat Oct 19, 2019 9:00 pm
- Forum: Properties of Light
- Topic: Midterm Exam
- Replies: 21
- Views: 734
Re: Midterm Exam
The midterm should cover weeks 1-5, so fundamentals, quantum world, and chemical bonding.
- Sat Oct 19, 2019 8:59 pm
- Forum: Properties of Light
- Topic: Equations and Constants
- Replies: 6
- Views: 279
Re: Equations and Constants
My TA said all of the equations and constants will be provided on exams (same formula sheet as Test 1).
- Sat Oct 19, 2019 8:58 pm
- Forum: Properties of Light
- Topic: What are the units of hertz
- Replies: 41
- Views: 2227
Re: What are the units of hertz
Hertz is a unit of frequency measured as cycles per second.
- Sat Oct 19, 2019 8:56 pm
- Forum: Properties of Light
- Topic: Next test
- Replies: 23
- Views: 1117
Re: Next test
Since the equation sheet given to us on the first test had many formulas and constants that we didn't need for Test 1, I'm assuming the same sheet will be used for the entire quarter for every exam.
- Sat Oct 19, 2019 8:54 pm
- Forum: Properties of Light
- Topic: Unit for Wavelength
- Replies: 34
- Views: 2555
Re: Unit for Wavelength
The standard unit for wavelength is meters (m). However it is often shown in problems as picometers (pm), nanometers (nm), or even Angstroms (A).
- Sun Oct 13, 2019 4:25 pm
- Forum: General Science Questions
- Topic: Rusty on High School Chem [ENDORSED]
- Replies: 347
- Views: 463544
Re: Rusty on High School Chem [ENDORSED]
There are so many resources provided on the class website to help brush up on high school chemistry. Especially the video modules and lectures. Reviewing topics from the textbook will also help knock the rust off.
- Sun Oct 13, 2019 4:22 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student - Part II [ENDORSED]
- Replies: 298
- Views: 304818
Re: Advice from a Medical Student - Part II [ENDORSED]
Thank you for sharing your story! It was so helpful and provided wonderful insight. Your feedback and advice is appreciated!
- Sun Oct 13, 2019 4:20 pm
- Forum: Limiting Reactant Calculations
- Topic: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
- Replies: 68
- Views: 7372
Re: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
You don’t have to show as much work. However, it may help so if you make a calculating mistake, graders can see each step and you can get partial credit for completing the steps correctly even with a calculating error.
- Sun Oct 13, 2019 4:17 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 2 Homework Problems [ENDORSED]
- Replies: 67
- Views: 8378
Re: Week 2 Homework Problems [ENDORSED]
Week 2 homework can be on the fundamentals or quantum world since lectures are on QW but the test during W2 is on the fundamentals. The Week 3 homework must be on the QW though.
- Sun Oct 13, 2019 4:15 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Test 1 [ENDORSED]
- Replies: 107
- Views: 27685
Re: Test 1 [ENDORSED]
All of the materials for the Tests (1 & 2) and Exams (Midterm & Final) are provided. There is also a conversions/formula sheet on the first page. Also remember to have a scientific calculator instead of a graphing since graphing calculators are not allowed.
- Fri Oct 04, 2019 5:14 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Theoretical vs. Actual Yield
- Replies: 38
- Views: 14167
Re: Theoretical vs. Actual Yield
Theoretical yield will never be higher than actual yield. Theoretical yield is the result if the reaction is 100% efficient and there are no impurities or errors during the experiment. Theoretical yield represents the maximum yield.
- Fri Oct 04, 2019 5:12 pm
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 418213
Re: Final Jitters
I recommend not studying right before the test starts because it will make you more nervous and also psych you out on the material. I always tell myself that I’ve studied the material well and it helps me feel prepared.
- Fri Oct 04, 2019 5:04 pm
- Forum: Empirical & Molecular Formulas
- Topic: When should one start rounding in a problem?
- Replies: 11
- Views: 608
Re: When should one start rounding in a problem?
It’s best to round at the very end of the problem once you have an answer so that you are more precise. Rounding during steps in the problem can result in errors.
- Fri Oct 04, 2019 4:59 pm
- Forum: SI Units, Unit Conversions
- Topic: Question about Showing Work
- Replies: 22
- Views: 1093
Re: Question about Showing Work
I think it’s best to show each step since graders can follow along with your work and see if you made a simple calculation error or if you didn’t apply the correct concept/formula for the problem.
- Fri Oct 04, 2019 12:19 pm
- Forum: Ideal Gases
- Topic: Reading the textbook
- Replies: 262
- Views: 155978
Re: Reading the textbook
Does anyone know of some good video websites or Youtube channels that could help with explaining the introductory material? I feel like I'm more receptive to listening and visual presentations than reading lines from the textbook.