Search found 51 matches
- Fri Dec 06, 2019 11:08 am
- Forum: Bronsted Acids & Bases
- Topic: Lewis vs Bronsted
- Replies: 3
- Views: 319
Lewis vs Bronsted
How can you tell the difference between Lewis acids/bases and Bronsted acids/bases?
- Fri Dec 06, 2019 11:07 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligand Definition
- Replies: 4
- Views: 370
Ligand Definition
What exactly is a ligand? I still don't completely understand what it is and how much of ligands we need to know for the final?
- Fri Dec 06, 2019 11:04 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Determining polarity from VSPER
- Replies: 4
- Views: 481
Re: Determining polarity from VSPER
VSEPR is used to determine the shape and once you have the shape, you can determine the polarity from there!
- Fri Dec 06, 2019 10:54 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: HW 6D.11.
- Replies: 1
- Views: 204
HW 6D.11.
6D.11. Decide whether an aqueous solution of each of the following salts has a pH equal to, greater than, or less than 7. If pH > 7 or pH < 7, write a chemical equation to justify your answer. a) NH4Br b) Na2CO3 c) KF d) KBr e) AlCl3 f) Cu(NO3)2 I need help understanding how to determine if the pH i...
- Fri Dec 06, 2019 2:20 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: HW 6C.17.
- Replies: 1
- Views: 189
HW 6C.17.
6C.17. Which is the stronger base, the hypobromite ion (BrO-), or morphine (C17H19O3N)? Justify your answer.
Please help, and thank you!!
Please help, and thank you!!
- Sun Dec 01, 2019 10:38 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Studying for final exam
- Replies: 8
- Views: 659
Re: Studying for final exam
I think going over the learning outcomes/outlines on the class website, and checking off all of the bullet points on those sheets once you understand them will also be helpful since those are the main points for each topic we learned this quarter. Good luck and hope this helps!!
- Sun Dec 01, 2019 10:34 pm
- Forum: Hybridization
- Topic: Hybridization Order
- Replies: 2
- Views: 232
Hybridization Order
Does the "s" always come before the "p" when writing the hybridization? Does it matter? Thank you!
- Sun Dec 01, 2019 10:33 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar vs Non-polar
- Replies: 4
- Views: 300
Polar vs Non-polar
Do non-polar molecules have to be symmetrical? Or can molecules be non-polar as long as the forces all around cancel out?
- Sun Dec 01, 2019 10:31 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Hydrogen Bond Sites
- Replies: 5
- Views: 395
Hydrogen Bond Sites
Are hydrogen bond sites defined by how many hydrogen atoms there are branched off of the molecule? Or are there specific properties/conditions that a branched off hydrogen atom must follow to be considered a hydrogen bonding site?
- Tue Nov 26, 2019 9:24 am
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam Content
- Replies: 14
- Views: 819
Final Exam Content
Is the final exam going to be everything from throughout the quarter, or is it going to be everything from the midterm and beyond?
- Fri Nov 22, 2019 12:00 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: AXE Format
- Replies: 34
- Views: 1297
AXE Format
Whenever there's only one X or one E, do we have to write a subscript of "1," or do we just write "X" and "E?" I have both in my notes and want to make sure I do whatever is preferred. Thank you!
- Thu Nov 21, 2019 11:57 pm
- Forum: Sigma & Pi Bonds
- Topic: How to Find Sigma Bonds and Pi Bonds
- Replies: 15
- Views: 1239
Re: How to Find Sigma Bonds and Pi Bonds
Baoying Li 4H wrote:First, draw the Lewis structure. Observe the bond between atoms.
Use these rules can help you find Sigma bonds and Pi bonds:
Single bond-one sigma bond
Double bond-one sigma bond and one pi bond
Triple bond-one sigma bond and two pi bonds
Thank you so much! Super helpful!
- Thu Nov 21, 2019 8:59 pm
- Forum: Sigma & Pi Bonds
- Topic: HW 2F.3.
- Replies: 5
- Views: 975
HW 2F.3.
2F.3. How many sigma-bonds and how many pi-bonds are there in
a) H2S ?
b) SO2 ?
How do you find how many sigma and pi bonds there are in a molecule?
Please help and thank you!
a) H2S ?
b) SO2 ?
How do you find how many sigma and pi bonds there are in a molecule?
Please help and thank you!
- Thu Nov 21, 2019 8:40 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: When to Use Formal Charge
- Replies: 4
- Views: 456
When to Use Formal Charge
How do you determine when to use the formal charge formula to draw your structures? And does the one with the most negative formal charge go on the left or right?
- Thu Nov 21, 2019 8:35 pm
- Forum: Sigma & Pi Bonds
- Topic: How to Find Sigma Bonds and Pi Bonds
- Replies: 15
- Views: 1239
How to Find Sigma Bonds and Pi Bonds
How do you find sigma and pi bonds?
- Thu Nov 21, 2019 8:17 pm
- Forum: Hybridization
- Topic: HW 2F.5.
- Replies: 3
- Views: 313
HW 2F.5.
2F.5. State the hybridization of the atom in boldface red type in each of the following molecules and ions:
a) BeCl2
b) BH3
c) BH4-
d) SiF4
How do you find the hybridization? Thank you!
a) BeCl2
b) BH3
c) BH4-
d) SiF4
How do you find the hybridization? Thank you!
- Thu Nov 14, 2019 6:29 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Drawing Molecular Structures
- Replies: 8
- Views: 555
Drawing Molecular Structures
When drawing molecular structures, how can you tell when to draw a line (covalent bond), a shaded triangle, and dashes?
- Thu Nov 14, 2019 6:14 pm
- Forum: Electronegativity
- Topic: Increasing/Decreasing Electronegativity
- Replies: 14
- Views: 2878
Increasing/Decreasing Electronegativity
Does the electronegativity increase/decrease across a group or period? And why?
- Thu Nov 14, 2019 6:02 pm
- Forum: Lewis Structures
- Topic: Balanced Lewis Structures
- Replies: 6
- Views: 457
Balanced Lewis Structures
How can you tell which way to write a Lewis structure is the most balanced? For example, some are written with the atoms bonded vertically to the central atom, while others are written with the atoms bonded horizontally to the central atom.
- Thu Nov 14, 2019 5:21 pm
- Forum: Lewis Structures
- Topic: Homework Problem 2A.3 (omit C)
- Replies: 2
- Views: 216
Homework Problem 2A.3 (omit C)
2A.3. Give the ground-state electron configuration expected fo reach of the following ions:
a) S^2-
b) As^3+
d) Ge^2+
Why is the answer for a) listed as just [Ar]?
Please help! Thank you!
a) S^2-
b) As^3+
d) Ge^2+
Why is the answer for a) listed as just [Ar]?
Please help! Thank you!
- Thu Nov 14, 2019 5:15 pm
- Forum: Lewis Structures
- Topic: Ground-State Electron Configuration
- Replies: 5
- Views: 366
Ground-State Electron Configuration
Some sections of my notes say "ground-state" electron configurations while other sections of my notes just say "electron configurations." Is there a difference between the two?
- Fri Nov 08, 2019 11:19 am
- Forum: DeBroglie Equation
- Topic: De Broglie Equation Derivation and Use
- Replies: 7
- Views: 1195
De Broglie Equation Derivation and Use
How do you derive the De Broglie equation and when do you use it?
- Wed Nov 06, 2019 1:21 pm
- Forum: Properties of Light
- Topic: Frequency vs. Velocity
- Replies: 8
- Views: 878
Frequency vs. Velocity
When talking about light, are velocity and frequency the same thing?
- Wed Nov 06, 2019 1:12 pm
- Forum: Properties of Light
- Topic: Speed of Light
- Replies: 7
- Views: 644
Speed of Light
When using the equation, c = lambda x v, c equals the speed of light. Is the standard unit for "c" nanometers or meters?
- Wed Nov 06, 2019 1:09 pm
- Forum: Einstein Equation
- Topic: Einstein Equation
- Replies: 10
- Views: 1891
Einstein Equation
What do the "h" and "v" stand for in Einstein's equation, E=hv?
- Wed Nov 06, 2019 1:03 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Molarity Formula / Calculation
- Replies: 5
- Views: 2980
Molarity Formula / Calculation
How do you find molarity? Trying to review for the midterm and I can't seem to grasp it. Thank you for any help you can give me!
- Thu Oct 31, 2019 8:08 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Hw problem 2A.13
- Replies: 4
- Views: 189
Re: Hw problem 2A.13
First, you will have to write out the electron configurations for each of the elements in the question, then remove electrons from the highest energy orbital/outermost layer. For example, you will see that Zn has the highest energy orbital 4s^2, which is the outermost layer. You would remove electro...
- Thu Oct 31, 2019 8:01 pm
- Forum: Lewis Structures
- Topic: Angstrom Measurements on Lewis Structures
- Replies: 3
- Views: 256
Angstrom Measurements on Lewis Structures
My notes have Angstrom measurements on them where I drew Lewis structures/covalent bonds. How do you calculate these, and are they important to know for this class?
- Thu Oct 31, 2019 7:59 pm
- Forum: Photoelectric Effect
- Topic: Ionization Energy vs Threshold Energy
- Replies: 4
- Views: 325
Ionization Energy vs Threshold Energy
Are ionization energy and threshold energy the same thing?
- Thu Oct 31, 2019 7:58 pm
- Forum: Photoelectric Effect
- Topic: Threshold Energy
- Replies: 2
- Views: 117
Threshold Energy
What is the definition of threshold energy and how do we find it?
- Thu Oct 31, 2019 7:58 pm
- Forum: Trends in The Periodic Table
- Topic: Electronegativity Trend
- Replies: 2
- Views: 130
Electronegativity Trend
Does electronegativity increase or decrease as you move down on the periodic table? How about move across from left to right?
- Fri Oct 25, 2019 9:13 pm
- Forum: Resonance Structures
- Topic: Lewis Structure vs. Resonance Structure
- Replies: 4
- Views: 681
Lewis Structure vs. Resonance Structure
What is the difference between a Lewis structure and a resonance structure? And how can you identify them?
- Fri Oct 25, 2019 9:10 pm
- Forum: Ionic & Covalent Bonds
- Topic: Expanded Valence Shells
- Replies: 4
- Views: 170
Expanded Valence Shells
What is an expanded valence shell, and how do you identify one?
- Fri Oct 25, 2019 8:56 pm
- Forum: Lewis Structures
- Topic: Drawing Lewis Structures
- Replies: 2
- Views: 109
Drawing Lewis Structures
If the problem does not state a positively or negatively charged element/ion, there is no need to subtract or add electrons (due to the -1/ +1 rule for cations and anions) when drawing the Lewis structure, right?
- Fri Oct 25, 2019 8:50 pm
- Forum: Ionic & Covalent Bonds
- Topic: Meaning of Brackets
- Replies: 7
- Views: 383
Meaning of Brackets
What do the brackets mean in chemistry?
For example, [Ar], [Ne], [He], etc.
For example, [Ar], [Ne], [He], etc.
- Fri Oct 25, 2019 10:07 am
- Forum: Ionic & Covalent Bonds
- Topic: Calculating Number of Valence Electrons
- Replies: 7
- Views: 598
Calculating Number of Valence Electrons
How do you calculate the number of valence electrons just from the problem giving you the name of the element?
- Fri Oct 18, 2019 1:49 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Problem 1E.7
- Replies: 2
- Views: 190
Problem 1E.7
1E.7. Determine whether each of the following electron configurations represents the ground state or an excited state of the atom given.
The correct answer is D. but I don't understand why. Can someone please help? Thank you!
The correct answer is D. but I don't understand why. Can someone please help? Thank you!
- Fri Oct 18, 2019 1:17 am
- Forum: Photoelectric Effect
- Topic: Problem 1B.3
- Replies: 4
- Views: 167
Problem 1B.3
1B.3. From the following list of observations, select the one that best supports the idea that electromagnetic radiation has the properties of particles. Explain your reasoning. a) black-body radiation b) electron diffraction c) atomic spectra d) the photoelectric effect The photoelectric effect is ...
- Fri Oct 18, 2019 1:01 am
- Forum: Properties of Light
- Topic: Unit Conversions
- Replies: 6
- Views: 331
Unit Conversions
What's the easiest way to convert from nanometers to picometers, etc? My skills are a little rusty.
- Fri Oct 18, 2019 12:56 am
- Forum: Properties of Light
- Topic: Unit for Wavelength
- Replies: 34
- Views: 2549
Unit for Wavelength
Since "Hz" is for frequency and "m/s" is for speed, is there a label/unit for wavelength?
- Thu Oct 17, 2019 9:14 pm
- Forum: Properties of Light
- Topic: Problem 1A.7
- Replies: 5
- Views: 263
Problem 1A.7
1A.7. a) The frequency of violet light is 7.1 x 10^14 Hz. What is the wavelength (in nanometers) of violet light? b) When an electron beam strikes a block of copper, x-rays with a frequency of 2.0 x 10^18 Hz are emitted. What is the wavelength (in picometers) of these x-rays? I need help with this p...
- Thu Oct 10, 2019 8:56 pm
- Forum: SI Units, Unit Conversions
- Topic: Accuracy vs Precision
- Replies: 11
- Views: 801
Re: Accuracy vs Precision
Accuracy is how close you are to the true value, while precision is how consistent your results are in relation to each other. For example, you can keep getting similar results that are all far off from the true value (this is good precision with poor accuracy). Hope this helps!
- Thu Oct 10, 2019 8:44 pm
- Forum: Limiting Reactant Calculations
- Topic: Finding Limiting Reactant
- Replies: 3
- Views: 359
Finding Limiting Reactant
What is a limiting reactant and how do you find/calculate it?
- Thu Oct 10, 2019 7:19 pm
- Forum: Significant Figures
- Topic: Sig Figs on Tests
- Replies: 24
- Views: 2285
Sig Figs on Tests
How many significant figures should we calculate with / round to on tests?
- Thu Oct 10, 2019 7:02 pm
- Forum: SI Units, Unit Conversions
- Topic: Problem E27
- Replies: 1
- Views: 258
Problem E27
E27.
a) Calculate the mass, in grams, of one water molecule.
b) Determine the number of H2O molecules in 1.00 kg of water.
I need help with this problem. Please and thank you!!
a) Calculate the mass, in grams, of one water molecule.
b) Determine the number of H2O molecules in 1.00 kg of water.
I need help with this problem. Please and thank you!!
- Thu Oct 10, 2019 6:29 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Avogadro's Constant
- Replies: 3
- Views: 284
Avogadro's Constant
What does Avogadro's constant mean/measure? When do we need to use it?
- Sun Oct 06, 2019 2:26 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Molar Mass
- Replies: 4
- Views: 187
Molar Mass
Will we need to have the molar masses of different elements memorized for the tests? If so, how many significant figures should we have down? If not, how do you calculate the molar masses?
- Sun Oct 06, 2019 2:05 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Test Equation Sheet
- Replies: 8
- Views: 460
Re: Test Equation Sheet
My understanding is that we will be provided formulas and maybe info/tips on what units the answers need to be written with and what format the answer needs to be in. Hope this helps!
- Sun Oct 06, 2019 1:41 pm
- Forum: Significant Figures
- Topic: Sig Figs
- Replies: 3
- Views: 184
Re: Sig Figs
In this number, there is a trailing zero. Trailing zeros are only significant if they are part of the measurement. In scientific notation, this number would be written as 8.34 x 10^3 so the trailing zero is not significant since it is not part of the measurement. Therefore, there are only 3 signific...
- Sun Oct 06, 2019 1:25 pm
- Forum: Balancing Chemical Reactions
- Topic: Advice for Test 1
- Replies: 7
- Views: 439
Re: Advice for Test 1
The best advice I can give is to take the topics that will be covered on the test, go to the syllabus and find the topics, and go through the homework problems listed on there for each topic. I also suggest going through the outlines of the learning outcomes (scroll down on the class website) for th...
- Sun Oct 06, 2019 1:15 pm
- Forum: Limiting Reactant Calculations
- Topic: Reactant vs. Reagent
- Replies: 4
- Views: 302
Reactant vs. Reagent
Why do my notes have "reactant" and "reagent?" Is there a difference between the two?