Search found 57 matches
- Sun Mar 17, 2019 7:16 pm
- Forum: Student Social/Study Group
- Topic: Chemistry Community
- Replies: 8
- Views: 1357
Re: Chemistry Community
I heard it was 3 times a week last quarter , but i think it might depend on how your TA grades
- Sun Mar 17, 2019 7:14 pm
- Forum: General Science Questions
- Topic: sig figs
- Replies: 4
- Views: 815
Re: sig figs
sig figs are usually 2 digits rounded
- Sun Mar 17, 2019 7:14 pm
- Forum: General Science Questions
- Topic: SIG FIGS
- Replies: 5
- Views: 933
Re: SIG FIGS
it is usually two digits rounded
- Sun Mar 17, 2019 7:13 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chemistry community posts
- Replies: 5
- Views: 1018
Re: Chemistry community posts
I think you have to post 3 times a week , thats what he said last quarter but im not sure about this one
- Sun Mar 17, 2019 7:11 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Grade Release Date?
- Replies: 7
- Views: 999
Re: Final Grade Release Date?
I think we can pick it up after spring break starting week 3.
- Sun Mar 17, 2019 7:10 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student [ENDORSED]
- Replies: 297
- Views: 408820
Re: Advice from a Medical Student [ENDORSED]
Thank you for the advice ! I'll be sure to save my notes for later
- Sun Mar 03, 2019 6:51 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: delta G = 0 ??
- Replies: 5
- Views: 2874
Re: delta G = 0 ??
delta G= 0: rxn is at equilibrium
- Sun Mar 03, 2019 6:46 pm
- Forum: Balancing Redox Reactions
- Topic: Adding H+ and H2O
- Replies: 13
- Views: 2893
Re: Adding H+ and H2O
you add both in order to balance the Hs and Os on each side of the reaction
- Sun Mar 03, 2019 6:45 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2 Scores
- Replies: 6
- Views: 605
Re: Test 2 Scores
probably during our next discussion
- Sun Feb 24, 2019 9:08 pm
- Forum: Balancing Redox Reactions
- Topic: Which Equation to Flip?
- Replies: 9
- Views: 4811
Re: Which Equation to Flip?
i flip the anode equation
- Sun Feb 24, 2019 9:07 pm
- Forum: Student Social/Study Group
- Topic: Test #2
- Replies: 7
- Views: 700
Re: Test #2
gibbs free energy, electrochemistry
- Sun Feb 24, 2019 9:05 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Spontaneous?
- Replies: 13
- Views: 1586
Re: Spontaneous?
they are usually spontaneous if they're values are negative, meaning they are releasing energy
- Sun Feb 17, 2019 9:55 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Midterm Grades
- Replies: 35
- Views: 2773
Re: Midterm Grades
next week during discussion
- Sun Feb 17, 2019 9:53 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: delta G
- Replies: 3
- Views: 430
Re: delta G
delta G tells us if a reaction releases( if delta G is negative) or absorbs ( if delta G is positive) energy
- Sun Feb 17, 2019 9:52 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy
- Replies: 3
- Views: 398
Re: Gibbs Free Energy
higher negative gibbs free energy doesnt affect the rate of reaction, it just mean that the reaction will release more energy
- Sun Feb 10, 2019 7:38 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Units for enthalpy
- Replies: 6
- Views: 752
Re: Units for enthalpy
you can use either one
- Sun Feb 10, 2019 7:30 pm
- Forum: Phase Changes & Related Calculations
- Topic: heat units
- Replies: 3
- Views: 419
Re: heat units
i think it would be best to convert to J in case
- Sun Feb 10, 2019 7:29 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: calculation of change in entropy
- Replies: 3
- Views: 413
Re: calculation of change in entropy
you do both the method for calculating change in volume: deltaS= nR ln(V2/V1) and for change in temperature: change in delta S= C ln(T2/T1) , and then add the two entropies
- Sun Feb 03, 2019 6:26 pm
- Forum: Phase Changes & Related Calculations
- Topic: Type of systems
- Replies: 12
- Views: 1339
Re: Type of systems
they are different systems- and closed system can exchange energy but not matter with its surroundings while an isolated system cant exchange either one
- Sun Feb 03, 2019 6:15 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: 2nd law of thermodynamics
- Replies: 5
- Views: 571
Re: 2nd law of thermodynamics
the second law says that energy transformation is not 100% efficient, the degree of disorder of the universe increases with every transformation
- Sun Feb 03, 2019 6:13 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: isolated vs closed system
- Replies: 7
- Views: 898
Re: isolated vs closed system
Isolated system: cannot exchange energy or matter with surroundings
Closed system: can exchange energy, nut not matter with surroundings
Closed system: can exchange energy, nut not matter with surroundings
- Sun Jan 27, 2019 9:04 pm
- Forum: Phase Changes & Related Calculations
- Topic: Memorizing unit conversions?
- Replies: 3
- Views: 372
Re: Memorizing unit conversions?
i dont think its necessary to memorize any units , it may be helpful but i think the conversions will be provided when needed
- Sun Jan 27, 2019 9:03 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Catalysts in Kc
- Replies: 6
- Views: 720
Re: Catalysts in Kc
catalysts only change how fast a reaction is performed but doesnt change any of the concentrations
- Sun Jan 27, 2019 9:01 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: ICE
- Replies: 19
- Views: 1498
Re: ICE
concentration at equilibrium
- Sun Jan 20, 2019 7:38 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Is it an acid or a base?
- Replies: 8
- Views: 714
Re: Is it an acid or a base?
an acids donates a proton H+ and a base accepts the proton
- Sun Jan 20, 2019 7:37 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Changes in Temperature
- Replies: 8
- Views: 1139
Re: Changes in Temperature
endothermic- formation of products is favored by a increase in temperature
raising the temperature of a reaction mixture at equilibrium will shift the reaction in the endothermic direction
exothermic- formation of products is favored by a decrease in temperature
raising the temperature of a reaction mixture at equilibrium will shift the reaction in the endothermic direction
exothermic- formation of products is favored by a decrease in temperature
- Sun Jan 20, 2019 7:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ka and Kb as Inverses?
- Replies: 7
- Views: 1873
Re: Ka and Kb as Inverses?
the safest thing to do is use the acid base formula to make sure
- Sun Jan 13, 2019 8:36 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: equations
- Replies: 10
- Views: 742
Re: equations
Usually the reactant are on the right and the products on the left seen using the basic model equation Aa+Bb<->Cc+Dd
- Sun Jan 13, 2019 8:26 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q and K
- Replies: 8
- Views: 630
Re: Q and K
Q: gives the reaction quotient at any moment
K: gives the reaction quotient at equilibrium
Q<K : forward reaction favored
Q>K : reverse reaction favored
K: gives the reaction quotient at equilibrium
Q<K : forward reaction favored
Q>K : reverse reaction favored
- Sun Jan 13, 2019 8:20 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Example in Class
- Replies: 7
- Views: 444
Re: Example in Class
The yield of NH3 Increases when the amount of NH3 decreases because if the yield didn't increase then system wouldn't be in chemical equilibrium, decreasing product leads to more reactions on the reactant side which lead to an increase in product.
- Sun Dec 09, 2018 6:45 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Seesaw
- Replies: 13
- Views: 2090
Re: Seesaw
the angles for seesaw are <90 and <120
- Sun Dec 09, 2018 6:41 pm
- Forum: Naming
- Topic: Chloro vs Chlorito
- Replies: 10
- Views: 1240
Re: Chloro vs Chlorito
they accept both chloro is the traditional way of calling it and chlorito is the new way
- Sun Dec 09, 2018 6:40 pm
- Forum: Bronsted Acids & Bases
- Topic: Lewis vs Bronsted
- Replies: 10
- Views: 1580
Re: Lewis vs Bronsted
for bronsted : acids donate protons and bases accepts protons
for lewis: acids accept electrons and bases donate electron
for lewis: acids accept electrons and bases donate electron
- Sun Dec 02, 2018 11:20 pm
- Forum: Coordinate Covalent Bonds
- Topic: Oxidation states "()" in naming coord compounds
- Replies: 4
- Views: 680
Re: Oxidation states "()" in naming coord compounds
Yes the Roman numerals will always be positive
- Sun Dec 02, 2018 11:18 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Water
- Replies: 4
- Views: 538
Re: Water
Water is neutral because it can both receive an proton (act as base) and give a proton (act as acid )
- Sun Dec 02, 2018 11:17 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Seesaw
- Replies: 13
- Views: 2090
Re: Seesaw
Since there is an electron pair , instead of having a 90 and 120 bond angle twist have a <120 and <90 bond angle
- Sat Nov 24, 2018 3:09 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Slightly less than bond angles
- Replies: 4
- Views: 452
Re: Slightly less than bond angles
lavelle said in lecture that you don't need to know the exact bond angle of the angles that are slightly less than the regular angle , you just have to show that you know it is slightly less than the regular angle
- Sat Nov 24, 2018 3:05 pm
- Forum: Hybridization
- Topic: double bonds
- Replies: 14
- Views: 1242
Re: double bonds
single bond consists of a sigma bond
double bond consists of a sigma bond and pi bond
triple bond consists of a sigma bond and a pi bond
double bond consists of a sigma bond and pi bond
triple bond consists of a sigma bond and a pi bond
- Sat Nov 24, 2018 3:03 pm
- Forum: Hybridization
- Topic: Test 3
- Replies: 13
- Views: 1181
Re: Test 3
the outline is posted online if you wanna know more into detail on what we're gonna be tested on but you should study the lectures from after the midterm up to last monday's lecture before break
- Sun Nov 18, 2018 3:02 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Drawing Molecules
- Replies: 5
- Views: 437
Re: Drawing Molecules
in lecture i think he said he would make sure that we wouldn't have to worry about drawing the 3d versions of the shapes since they can be difficult to draw , im not sure how we would show the shapes though, maybe just the 2d version
- Sun Nov 18, 2018 3:00 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Square Planar vs Tetrahedral
- Replies: 8
- Views: 2434
Re: Square Planar vs Tetrahedral
although they both have four bonds the square planar has 2 more areas of electron density because of the extra 2 lone pairs, therefore they have to be different shapes
- Sun Nov 18, 2018 2:57 pm
- Forum: Hybridization
- Topic: Bond Angles
- Replies: 12
- Views: 1151
Re: Bond Angles
im not sure but i think its the most effective and reliable way to figure it out, maybe you can use the VSEPR formula to figure it out
- Sun Nov 11, 2018 4:32 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability Trend
- Replies: 6
- Views: 6483
Re: Polarizability Trend
polarizability increases right to left and up to down , which is the same as atomic radius and opposite of electronegativity
- Sun Nov 11, 2018 4:29 pm
- Forum: Properties of Electrons
- Topic: Polar vs Non polar
- Replies: 15
- Views: 4764
Re: Polar vs Non polar
polar molecules result from polar bonding between atoms where electrons are not shared equally atoms from the same element do not form polar bonds because they share electrons equally the greater the difference in electronegativity then the more ionic the bond is and bonds that have ionic bonds nonp...
- Sun Nov 11, 2018 4:22 pm
- Forum: Lewis Structures
- Topic: Formal charges
- Replies: 15
- Views: 1301
Re: Formal charges
i dont think you have to write it but it should be used to create your structure and make sure you did it correctly and have no extra overall charges (whether positive or negative) in your structure
- Sun Nov 04, 2018 12:06 pm
- Forum: Administrative Questions and Class Announcements
- Topic: What the Midterm Will Cover
- Replies: 5
- Views: 484
Re: What the Midterm Will Cover
i would look over the outlines he provided up to lewis acids and bases which is where he ended the lecture that he said the midterm was up to
- Sun Nov 04, 2018 12:01 pm
- Forum: Electronegativity
- Topic: What are the trends useful for?
- Replies: 12
- Views: 1010
Re: What are the trends useful for?
the trends are useful for figuring out which element does in the center when drawing a lewis structure
- Sun Nov 04, 2018 11:57 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: s-block, p-block, d-block
- Replies: 3
- Views: 272
Re: s-block, p-block, d-block
yeah we should know the first three rows of the s p and d block and also know the exceptions like Cu and Cr
- Tue Oct 23, 2018 8:24 pm
- Forum: Properties of Light
- Topic: EM Energy Spectrum
- Replies: 4
- Views: 432
Re: EM Energy Spectrum
I'm pretty sure that the quantities of wavelengths for the light category that we need to use will be given to us, the outline doesn't say that we need to memorize them
- Tue Oct 23, 2018 8:19 pm
- Forum: Properties of Light
- Topic: Test 2 Equations
- Replies: 14
- Views: 1084
Re: Test 2 Equations
i think the most important thing to know is what each equations is associated with and the keywords problems have that let you know what formula to use, and the units that go with each part of the equations so your answer has the correct units at the end
- Tue Oct 23, 2018 8:15 pm
- Forum: *Particle in a Box
- Topic: Test 2
- Replies: 9
- Views: 1373
Re: Test 2
I think test 2 test up the multi electron atoms which is where we left off on in last Friday's lecture
- Thu Oct 18, 2018 7:33 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Equation
- Replies: 3
- Views: 338
Re: Rydberg Equation
i would ask to your TA if you can show work using the Rydberg equation
- Thu Oct 18, 2018 7:31 pm
- Forum: Photoelectric Effect
- Topic: units
- Replies: 12
- Views: 1133
Re: units
yes to calculate wavelength you should always convert to meters to make sure youre converting correctly, and im pretty sure that most problems use joules as the unit for energy
- Thu Oct 18, 2018 7:25 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Bohr Formula
- Replies: 4
- Views: 455
Re: Bohr Formula
theres a negative number to show that when the energy levels decrease, energy is lost , so the calculated energy using this formula will be negative
- Sun Oct 07, 2018 12:12 pm
- Forum: Empirical & Molecular Formulas
- Topic: Molecular Formula
- Replies: 12
- Views: 599
Re: Molecular Formula
Because the molecular formula basically tells exactly the amount of atoms that are in each element and not the ratio, then all you have to do is count how many atoms are of each element type and make them your subscript for that element in the molecular formula
- Sun Oct 07, 2018 12:07 pm
- Forum: Administrative Questions and Class Announcements
- Topic: WHAT TYPE OF CALCULATOR IS ALLOWED ON EXAMS??
- Replies: 5
- Views: 1178
Re: WHAT TYPE OF CALCULATOR IS ALLOWED ON EXAMS??
Scientific calculator is the best option , in lecture he said non-graphic calculators or calculators where you could store information or equations
- Wed Oct 03, 2018 12:19 am
- Forum: SI Units, Unit Conversions
- Topic: Week 1 Homework Assignment [ENDORSED]
- Replies: 16
- Views: 1294
Re: Week 1 Homework Assignment [ENDORSED]
Yeah I think doing the modules will be really helpful even because they show what topics to focus on and what we might get tested on later