Search found 30 matches
- Sun Jun 10, 2018 11:24 pm
- Forum: SI Units, Unit Conversions
- Topic: Sig Figs for Final
- Replies: 8
- Views: 1218
Re: Sig Figs for Final
I think sig figs will be graded on the final like they were on the midterm.
- Sun Jun 10, 2018 11:22 pm
- Forum: General Science Questions
- Topic: Final [ENDORSED]
- Replies: 10
- Views: 1401
Re: Final [ENDORSED]
I think the final will cover material from all the outlines.
- Sun Jun 10, 2018 11:21 pm
- Forum: Significant Figures
- Topic: Calculations
- Replies: 3
- Views: 595
Re: Calculations
Sig figs usually align with the value in the problem with the least number of places.
- Sun Jun 03, 2018 8:58 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Naming Structures
- Replies: 8
- Views: 1048
Re: Naming Structures
probably just to familiarize yourself with the names and their corresponding shapes
- Sun Jun 03, 2018 8:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: cis and trans
- Replies: 7
- Views: 1024
Re: cis and trans
In a cis- molecule the dipoles will not cancel, while in a trans- molecule the dipoles will cancel.
- Sun Jun 03, 2018 8:47 pm
- Forum: Hybridization
- Topic: Sigma and Pi Bonds
- Replies: 5
- Views: 571
Re: Sigma and Pi Bonds
single bond= sigma bond
double bond= sigma bond + pie bond
triple bond= sigma bond + 2 pie bonds
double bond= sigma bond + pie bond
triple bond= sigma bond + 2 pie bonds
- Sat May 26, 2018 2:59 pm
- Forum: Lewis Structures
- Topic: Why Resonance for SO2?
- Replies: 3
- Views: 3498
Re: Why Resonance for SO2?
Resonance structures should have the same energy levels.
- Sat May 26, 2018 2:49 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Regions of electron density
- Replies: 7
- Views: 742
Re: Regions of electron density
With VSPEPR I think we only consider lone pairs on the central atom.
- Sat May 26, 2018 2:46 pm
- Forum: Electronegativity
- Topic: Electronegativity Caluclations
- Replies: 4
- Views: 621
Re: Electronegativity Caluclations
I think we will be expected to estimate the electronegativity of elements based on their location on the periodic table.
- Sun May 20, 2018 11:19 pm
- Forum: Lewis Structures
- Topic: Lone pair electrons
- Replies: 5
- Views: 804
Re: Lone pair electrons
Lines are typically used to represent bonds between atoms.
- Sat May 19, 2018 7:14 pm
- Forum: Resonance Structures
- Topic: How does a resonance structure work?
- Replies: 10
- Views: 1156
Re: How does a resonance structure work?
You are able to rearrange the bonds in different equivalent locations and still have the same formal charges. The real structure will be a resonance hybrid.
- Sat May 19, 2018 7:09 pm
- Forum: Ionic & Covalent Bonds
- Topic: Radicals [ENDORSED]
- Replies: 5
- Views: 760
Re: Radicals [ENDORSED]
A radical is an atom with an unpaired electron.
- Sun May 13, 2018 10:15 pm
- Forum: Ionic & Covalent Bonds
- Topic: VALENCE ELECTRONS [ENDORSED]
- Replies: 16
- Views: 2132
Re: VALENCE ELECTRONS [ENDORSED]
I count the columns of the s and p block. For example, in row 2 Li=1 valence electron, BE=2, B=3, C=4, N=5, O=6, F=7, Ne=8.
- Sun May 13, 2018 10:08 pm
- Forum: Resonance Structures
- Topic: resonance structures on exams
- Replies: 5
- Views: 691
Re: resonance structures on exams
I think the question should be clear about what it is expecting from us in the answer. Resonance structures are probably only required if asked for.
- Sun May 13, 2018 10:06 pm
- Forum: Ionic & Covalent Bonds
- Topic: Why can't hydrogen be a central atom? [ENDORSED]
- Replies: 6
- Views: 3809
Re: Why can't hydrogen be a central atom? [ENDORSED]
Hydrogen only has a 1s orbital, so once it forms a bond with another atom, its single orbital is full.
- Sun May 13, 2018 10:03 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: cations vs anions
- Replies: 4
- Views: 656
Re: cations vs anions
The way I think about it is when a cation forms, it loses a(n) electron(s). In this case Na becomes Na+, so loses 1 electron. Now the ratio of protons to electrons is higher (there are 11 protons and 10 electrons). The protons will have a stronger pull on the electrons (the electrons will become clo...
- Sat May 12, 2018 1:23 pm
- Forum: Resonance Structures
- Topic: Resonance structure of benzene
- Replies: 4
- Views: 662
- Sun May 06, 2018 9:39 pm
- Forum: SI Units, Unit Conversions
- Topic: formula units [ENDORSED]
- Replies: 69
- Views: 32788
Re: formula units [ENDORSED]
I had this question too, I don't think it will be unclear like this on the test.
- Sun May 06, 2018 9:33 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configurations and Unpaired e- [ENDORSED]
- Replies: 3
- Views: 504
Re: Electron Configurations and Unpaired e- [ENDORSED]
There are 3 orbitals total that each hold two electrons (so 6 total) for p. The first 3 electrons are evenly distributed in the 3 orbitals and then the fourth is paired in the first orbital. This leaves two orbitals with unpaired electrons.
- Sun May 06, 2018 9:29 pm
- Forum: Empirical & Molecular Formulas
- Topic: Test 1/ Question 8 [ENDORSED]
- Replies: 6
- Views: 1030
Re: Test 1/ Question 8 [ENDORSED]
You find the molecular formula by counting how many of each element there is and then simplify the molecular formula for the empirical formula. The mass is not needed.
- Thu May 03, 2018 10:34 am
- Forum: Trends in The Periodic Table
- Topic: Periodic Table Trends on the Midterm
- Replies: 4
- Views: 575
Re: Periodic Table Trends on the Midterm
I don't believe periodic trends will be required for the first test, but it will be important to understand them for future tests.
- Sun Apr 22, 2018 10:32 pm
- Forum: Photoelectric Effect
- Topic: nm vs m
- Replies: 3
- Views: 420
Re: nm vs m
I think the problem will be clear if it prefers a different unit over nm.
- Sun Apr 22, 2018 10:26 pm
- Forum: Properties of Light
- Topic: Memorizing formulas test 2
- Replies: 16
- Views: 1755
Re: Memorizing formulas test 2
A good way to learn them is to do lots of practice problems to familiarize yourself with the different formulas. Focus more on application and less on memorization since they're provided.
- Sun Apr 22, 2018 10:21 pm
- Forum: Properties of Light
- Topic: Wavelengths
- Replies: 8
- Views: 695
Re: Wavelengths
Probably need to understand their differences relative to each other.
- Sun Apr 15, 2018 9:41 pm
- Forum: Empirical & Molecular Formulas
- Topic: Molecular to Empirical
- Replies: 9
- Views: 1183
Molecular to Empirical
If we are given the molecular formula NH4OH, is it best to write the empirical formula as H5NO or would it remain the same?
- Sun Apr 15, 2018 9:21 pm
- Forum: Significant Figures
- Topic: Rounding: when and where?
- Replies: 10
- Views: 889
Re: Rounding: when and where?
I usually don't round until I get my final answer.
- Sun Apr 15, 2018 9:17 pm
- Forum: SI Units, Unit Conversions
- Topic: Units for Answer
- Replies: 10
- Views: 1194
Re: Units for Answer
I usually go by the units given in the original problem unless specified otherwise. This may require converting a couple of times.
- Sun Apr 15, 2018 9:11 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Which mass of oxygen should be used? [ENDORSED]
- Replies: 23
- Views: 3334
Re: Which mass of oxygen should be used? [ENDORSED]
The periodic table given to us on the test is 15.9994 g/mol. I don't usually round until I get the final answer.
- Sun Apr 15, 2018 9:02 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Memorizing equations [ENDORSED]
- Replies: 5
- Views: 900
Re: Memorizing equations [ENDORSED]
I believe the cover sheet that was on our first test will be the formulas provided to us.
- Sun Apr 15, 2018 8:59 pm
- Forum: Empirical & Molecular Formulas
- Topic: Similar Formulas [ENDORSED]
- Replies: 3
- Views: 564
Re: Similar Formulas [ENDORSED]
That's correct!