Search found 40 matches
- Wed Jun 13, 2018 10:34 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Oxidation Number
- Replies: 5
- Views: 872
Re: Oxidation Number
How do you find the oxidation number of a metal?
- Sun May 27, 2018 9:14 pm
- Forum: Lewis Structures
- Topic: Central atom and octet rule?
- Replies: 12
- Views: 2977
Re: Central atom and octet rule?
it depends on the element usually
- Sun May 27, 2018 9:11 pm
- Forum: Octet Exceptions
- Topic: expanded octets
- Replies: 5
- Views: 709
Re: expanded octets
usually i add bonds from each element to the central element and try and give them each an octet with what remaining electrons i have
- Sun May 27, 2018 9:08 pm
- Forum: Bond Lengths & Energies
- Topic: Test 3 bond length question
- Replies: 8
- Views: 977
Re: Test 3 bond length question
the bond that is shortest is stronger and the bonds that are longer are weakest. It goes, in order of increasing bond strength and in order of decreasing bond length: single bond<double bond<triple bond
- Sun May 20, 2018 4:01 pm
- Forum: Lewis Structures
- Topic: Different ways to write the lewis structure?
- Replies: 6
- Views: 803
Different ways to write the lewis structure?
I was wondering if it was okay if the way we draw our Lewis structure was different from the solutions manual, in that it has the same number of valence electrons and each element is correctly bonded, but the structuring and order is different? This example is CH3OH.
- Sun May 20, 2018 2:46 pm
- Forum: Lewis Structures
- Topic: Chemical Formula Name
- Replies: 3
- Views: 494
Re: Chemical Formula Name
I think for the test he would give us the chemical formula since we have not gone over how to write the chemical formula from just the name.
- Sun May 20, 2018 2:44 pm
- Forum: Lewis Structures
- Topic: 3.39
- Replies: 5
- Views: 689
Re: 3.39
I was also wondering if we needed to know how to convert the wording of chemical formulas into the actual chemical formula, especially for the upcoming test, but we haven't learned about it yet. My TA gave the names for us, however, if this is helpful to you: a) ammonium chloride, NH4Cl^+ b) potassi...
- Sun May 13, 2018 8:48 pm
- Forum: Resonance Structures
- Topic: Bonds or Lone Pairs more important?
- Replies: 7
- Views: 1063
Re: Bonds or Lone Pairs more important?
This really depends on the molecule and you'd have to access where a single or double bond should be fit
- Sun May 13, 2018 8:47 pm
- Forum: Lewis Structures
- Topic: Valence shell on Noble gases
- Replies: 4
- Views: 583
Re: Valence shell on Noble gases
They are at their fullest and are content that way so no
- Sun May 13, 2018 8:45 pm
- Forum: Lewis Structures
- Topic: Cations and Anions
- Replies: 3
- Views: 656
Re: Cations and Anions
yes usually lewis structures will have a charge outside of the brackets
- Sun May 06, 2018 8:21 pm
- Forum: Ionic & Covalent Bonds
- Topic: Atomic and Ionic Radius
- Replies: 2
- Views: 456
Re: Atomic and Ionic Radius
The ionic radius is the the distance from the nucleus to the outermost electrons in a ion, while the atomic radius is the distance from the nucleus to the normal valence electrons. The ionic radius in a positive ion is less than the distance from the nucleus to the valence electrons and the ionic ra...
- Sun May 06, 2018 8:13 pm
- Forum: Empirical & Molecular Formulas
- Topic: Order of Elements [ENDORSED]
- Replies: 3
- Views: 559
Re: Order of Elements [ENDORSED]
Generally, in the order their given I would put them in that order, for example if given the percentage of C,H, then O, I would write it as CHO. It probably doesn't matter but to be safe I would keep them in order :-)
- Sun May 06, 2018 8:11 pm
- Forum: Ionic & Covalent Bonds
- Topic: Midterm Topics [ENDORSED]
- Replies: 33
- Views: 4571
Re: Midterm Topics [ENDORSED]
Megan Potter 1G wrote:How far in the periodic table do we need to know for electron configuration stuff? To krypton (so 3d, 4s, 4p)?
Im assuming its only up to the d orbital, not the f orbital.
- Sun May 06, 2018 8:09 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: midterm practice q.8
- Replies: 1
- Views: 321
midterm practice q.8
A bullet of mass 2.8 g travels at 373.23 ± .34 m/s. What is the indeterminacy of position?
could someone explain this question and how to do it? thanks!
could someone explain this question and how to do it? thanks!
- Sun May 06, 2018 7:20 pm
- Forum: Ionic & Covalent Bonds
- Topic: Midterm Topics [ENDORSED]
- Replies: 33
- Views: 4571
Re: Midterm Topics [ENDORSED]
Nienjou Claire 1E wrote:Also, does anyone know where we can get practice midterms? Does the test bank have any?
These arent lavelles exams but it is good practice from Scerri! http://www.bruintestbank.com/chemistry/
- Sun May 06, 2018 6:04 pm
- Forum: Ionic & Covalent Bonds
- Topic: Midterm Topics [ENDORSED]
- Replies: 33
- Views: 4571
Re: Midterm Topics [ENDORSED]
DomMaiorca_1I wrote:Will we need to be able to draw electron configurations for the midterm?
Yes I believe we should know how to draw them or at least write them seeing as we've done so in class
- Sun May 06, 2018 5:54 pm
- Forum: Properties of Light
- Topic: 4b practice midterm
- Replies: 11
- Views: 1527
4b practice midterm
" A newly designed laser pointer with a certain frequency is pointed at a sodium metal surface. An electron is ejected from the metal surface with wavelength 1.10 nm. What is the frequency of the light from the laser pointer? The work function of sodium is 150.6 kJ∙mol-1" So sometimes to f...
- Sun Apr 29, 2018 4:46 pm
- Forum: DeBroglie Equation
- Topic: Test #2: Q5 [ENDORSED]
- Replies: 9
- Views: 1251
Re: Test #2: Q5 [ENDORSED]
How were you able to see the quiz earlier than discussion?
- Sun Apr 29, 2018 4:45 pm
- Forum: Properties of Electrons
- Topic: electron mass
- Replies: 15
- Views: 1544
Re: electron mass
the test should definitely give you the mass of an electron, proton, and photon i believe
- Sun Apr 29, 2018 4:40 pm
- Forum: Properties of Electrons
- Topic: Information Provided on Exam
- Replies: 6
- Views: 709
Re: Information Provided on Exam
its usually not provided, you should probably just know a ballpark around what each wavelength represents
- Sun Apr 29, 2018 4:36 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: What do l and m represent? [ENDORSED]
- Replies: 6
- Views: 1021
Re: What do l and m represent? [ENDORSED]
l represents the type of orbital and m represents which of the l orbitals you're in
- Sun Apr 29, 2018 4:33 pm
- Forum: Properties of Electrons
- Topic: Mass of an Electron [ENDORSED]
- Replies: 4
- Views: 608
Re: Mass of an Electron [ENDORSED]
on the equations sheet we see that the mass of an electron is 9.1095 x 10^-31 kg
- Sun Apr 29, 2018 4:28 pm
- Forum: Ideal Gases
- Topic: Reading the textbook
- Replies: 262
- Views: 144092
Re: Reading the textbook
Jocelyn1B wrote:How do you balance your other classes while still studying for chemistry?
typically I set a certain amount of time each week just for chemistry, at least three times a week while also studying for a test the week before so I don't get overwhelmed
- Sat Apr 28, 2018 4:26 pm
- Forum: Photoelectric Effect
- Topic: What is work function? [ENDORSED]
- Replies: 15
- Views: 5572
Re: What is work function? [ENDORSED]
Its just the energy required to remove an electron
- Tue Apr 24, 2018 10:59 am
- Forum: Properties of Light
- Topic: Test 2 Material
- Replies: 12
- Views: 1110
Re: Test 2 Material
Should we understand the ranges of wavelengths of light? like the specific ranges of wavelength (visible light, UV,etc...) because I know some module questions asked that and I don't know the range off the top of my head. thanks!
- Sun Apr 22, 2018 5:50 pm
- Forum: Empirical & Molecular Formulas
- Topic: Rounding atomic weight (general question) [ENDORSED]
- Replies: 8
- Views: 997
Re: Rounding atomic weight (general question) [ENDORSED]
I would just use the periodic table atomic masses. I usually round when finding amount in moles to have a whole number
- Sun Apr 22, 2018 5:49 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Units - L or mL? [ENDORSED]
- Replies: 15
- Views: 4489
Re: Units - L or mL? [ENDORSED]
I would change it to liters to keep it all consistent
- Sun Apr 22, 2018 5:48 pm
- Forum: Significant Figures
- Topic: Use of sigfigs
- Replies: 8
- Views: 887
Re: Use of sigfigs
I would just in case it states otherwise
- Sun Apr 22, 2018 5:38 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg [ENDORSED]
- Replies: 5
- Views: 722
Re: Rydberg [ENDORSED]
would use for wavelength but can also be manipulated for other uses
- Sun Apr 22, 2018 5:35 pm
- Forum: Einstein Equation
- Topic: Planck's Constant Value [ENDORSED]
- Replies: 7
- Views: 3318
Re: Planck's Constant Value [ENDORSED]
I would use whats given or whatever has more decimals just to be more accurate
- Sun Apr 22, 2018 5:32 pm
- Forum: Properties of Electrons
- Topic: electron mass
- Replies: 15
- Views: 1544
Re: electron mass
yes it's important to consider it
- Sun Apr 22, 2018 5:29 pm
- Forum: Ideal Gases
- Topic: Reading the textbook
- Replies: 262
- Views: 144092
Re: Reading the textbook
what's the best way to learn the material for someone who's not so familiar with chemistry concepts?
- Sun Apr 22, 2018 5:27 pm
- Forum: Properties of Light
- Topic: still don't uderrsatnd what a photon is [ENDORSED]
- Replies: 20
- Views: 1273
Re: still don't uderrsatnd what a photon is [ENDORSED]
its basically a particle representing a quantum of light or other electromagnetic radiation. It carries energy proportional to the radiation frequency but with zero mass
- Sun Apr 15, 2018 8:05 pm
- Forum: Significant Figures
- Topic: Rounding: when and where?
- Replies: 10
- Views: 818
Re: Rounding: when and where?
usually I round to however many numbers are in the question.
- Sun Apr 15, 2018 8:02 pm
- Forum: SI Units, Unit Conversions
- Topic: Length Units
- Replies: 15
- Views: 1392
Re: Length Units
typically yes you should use SI units
- Sun Apr 15, 2018 8:01 pm
- Forum: SI Units, Unit Conversions
- Topic: writing out conversions in one long line vs. steps
- Replies: 16
- Views: 1362
Re: writing out conversions in one long line vs. steps
If you do it the longer way, you're able to see the units and therefore can easily figure out what units you'll want in the end.
- Sun Apr 15, 2018 8:00 pm
- Forum: Limiting Reactant Calculations
- Topic: Reagent vs. Reactant [ENDORSED]
- Replies: 6
- Views: 1333
Re: Reagent vs. Reactant [ENDORSED]
a reactant is the starting material that will eventually undergo changes in a chemical rxtn while a reagent is the compound added to a system in order to cause a chemical rxtn. sometimes you can use them interchangeably.
- Sun Apr 15, 2018 7:51 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Which mass of oxygen should be used? [ENDORSED]
- Replies: 23
- Views: 3115
Re: Which mass of oxygen should be used? [ENDORSED]
I typically use 16 just to get an even number of moles if thats what im trying to find
- Mon Apr 09, 2018 9:00 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Homework Question E9a
- Replies: 2
- Views: 369
Re: Homework Question E9a
Mg: 24.305 (atomic mass) x 1(amount of element) S: 32.06 x 1 = 32.06 O: 16 x 4 = 64 for the 7H20 you bring 7 and multiply it by 2 for hydrogen to get 14 hydrogen and 7 multiplied by one oxygen is 7 oxygen H: 1.008 x 14 = 14.112 O: 16 x 7=112 add all of these and you should get 246.477 which, because...
- Mon Apr 09, 2018 8:39 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: question on fundamentals G
- Replies: 5
- Views: 829
question on fundamentals G
Hey! I'm not very sure how to go about this question G.5: A student prepared a solution of sodium carbonate by adding 2.111 g of the solid to a 250.0-mL volumetric flask and adding water to the mark. Some of this solution was transferred to a buret. What volume of solution should the student transfe...