Search found 63 matches

by Tony Ong 3K
Sat Mar 16, 2019 1:47 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Week 10 Discussion Notes (2E,2I,2K)
Replies: 6
Views: 225

Re: Week 10 Discussion Notes (2E,2I,2K)

Thank you so much this quarter Joyce!!!
Definitely the greatest TA to have walked this Earth.
by Tony Ong 3K
Sat Mar 16, 2019 1:36 pm
Forum: Administrative Questions and Class Announcements
Topic: LYNDON'S PORK RAMEN REVIEW
Replies: 37
Views: 1693

Re: LYNDON'S PORK RAMEN REVIEW

thank you sensei, you are much appreciated
by Tony Ong 3K
Thu Mar 14, 2019 6:56 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Pseudo Equlibrium
Replies: 2
Views: 18

Pseudo Equlibrium

Will the final have pseudo equilibrium constants on it where we have to calculate it?
by Tony Ong 3K
Tue Mar 12, 2019 8:51 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Entropy and Heat
Replies: 1
Views: 18

Entropy and Heat

9.101 A heat pump heats a house in winter by extracting heat from the cold outdoors and releasing it into the warm interior. For the transfer of a given amount of heat, (a) how do the entropies of the interior and exterior of the house change (increase or decrease)? (b) Which change is greater? Assu...
by Tony Ong 3K
Sun Mar 10, 2019 11:56 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Calculating heat
Replies: 1
Views: 21

Calculating heat

What would be the process to solve this question: Suppose 2 mole ice cube at -10 C is placed in 20.0mole of water at 20 C. Enthalpy of fusion of ice is 6.01kj/mol and molar heat capacities of ice and water at constant pressure are 37.7 J/K/mol and 75.3 J/K/mol. Calculate temperature after thermal eq...
by Tony Ong 3K
Sun Mar 10, 2019 11:50 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Final Exam
Replies: 23
Views: 155

Re: Final Exam

of course it is...it's part of the outlines...
by Tony Ong 3K
Sun Mar 10, 2019 11:49 pm
Forum: General Rate Laws
Topic: Slow step of reactions
Replies: 3
Views: 23

Re: Slow step of reactions

Yes, always take into account the slowest step. The rate law would be the rate constant times the reactants of that step.
by Tony Ong 3K
Sun Mar 10, 2019 11:47 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Residual Entropy
Replies: 2
Views: 22

Residual Entropy

Why does NO have greater residual entropy than BF3 at 0K???
by Tony Ong 3K
Sun Mar 03, 2019 10:01 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Electrochemistry
Replies: 3
Views: 67

Electrochemistry

a) The standard Gibbs free energy of formation of Ti3+(aq) is 215 kJ/mol at 25 degrees C. Calculate the standard
potential of the Ti3+/Ti couple.
b) Will Ti+ disproportionate in aqueous solution?

Why is the 215kj/mol switched to -215jk/mol in part a of this problem's solution?
by Tony Ong 3K
Wed Feb 27, 2019 6:02 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Neutralization
Replies: 1
Views: 17

Neutralization

Write the half-reactions and the balanced equation for the cell reaction for each of the following galvanic cells:
(d) Pt(s) |O2(g)| H+(aq) || OH-(aq)| O2(g) | Pt(s)

How do I find the half reactions and balanced ???
by Tony Ong 3K
Tue Feb 26, 2019 10:39 pm
Forum: Balancing Redox Reactions
Topic: Gibbs Free Energy
Replies: 2
Views: 38

Gibbs Free Energy

The reaction taking place in a nicad (nickel–cadmium) cell is Cd(s) +
2 Ni(OH)3(s) S Cd(OH)2(s) + 2 Ni(OH)2(s), and the cell potential when fully
charged is +1.25 V. What is the reaction Gibbs free energy?
by Tony Ong 3K
Fri Feb 22, 2019 12:05 am
Forum: Calculating Work of Expansion
Topic: Nonexpansion work vs expansion work
Replies: 3
Views: 43

Re: Nonexpansion work vs expansion work

you can also think of it as expansion work is done by the system to the environment therefore the value for work is negative.
by Tony Ong 3K
Fri Feb 22, 2019 12:04 am
Forum: Balancing Redox Reactions
Topic: redox reactions
Replies: 3
Views: 33

Re: redox reactions

an agent which is becoming oxidized essentially loses its electrons and becomes a more positive charge whereas ones that become reduced gain electrons and become more negatively charged
by Tony Ong 3K
Fri Feb 22, 2019 12:03 am
Forum: Student Social/Study Group
Topic: Midterm Results
Replies: 4
Views: 70

Re: Midterm Results

does anyone know if we can argue our midterm scores?
by Tony Ong 3K
Mon Feb 18, 2019 12:16 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 802176

Re: Post All Chemistry Jokes Here

Q: What do you do with a sick chemist?
A. First you try to helium, then you try to curium, but if this fails then you have to barium.
by Tony Ong 3K
Mon Feb 18, 2019 12:16 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 802176

Re: Post All Chemistry Jokes Here

Q: What do chemists call a benzene ring with iron atoms replacing the carbon atoms?
A: A ferrous wheel:
Fe - Fe
/ \
Fe Fe
\ /
Fe - Fe
by Tony Ong 3K
Mon Feb 18, 2019 12:15 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 802176

Re: Post All Chemistry Jokes Here

Outside his buckyball home, one molecule overheard another molecule saying, "I'm positive that a free electron once stripped me of an electron after he lepton me. You gotta keep your ION them."

hahahhahahhaa
by Tony Ong 3K
Mon Feb 11, 2019 11:01 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 802176

Re: Post All Chemistry Jokes Here

hehe this ones a goood one

Q: What did the scientist say when he found 2 isotopes of helium?
A: HeHe

hehe get it?
by Tony Ong 3K
Mon Feb 11, 2019 11:01 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 802176

Re: Post All Chemistry Jokes Here

Q: Did you hear oxygen went on a date with potassium?
A: It went OK.
by Tony Ong 3K
Mon Feb 11, 2019 11:00 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 802176

Re: Post All Chemistry Jokes Here

Q: What is the chemical formula for "coffee"?
A: CoFe2

hehehehehe
by Tony Ong 3K
Sun Feb 03, 2019 10:38 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 802176

Re: Post All Chemistry Jokes Here

Did you hear the joke about the chemist?
Me neither.
by Tony Ong 3K
Sun Feb 03, 2019 10:35 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 802176

Re: Post All Chemistry Jokes Here

What should you do if no one laughs at your chemistry jokes?
Keep telling them until you get a reaction.
by Tony Ong 3K
Sun Feb 03, 2019 10:34 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 802176

Re: Post All Chemistry Jokes Here

Two chemists walk into a bar.
One says, “I’ll have an ‎H2O.” The other says, “I’ll have an ‎H2O, too.” The second chemist dies.

*H202 is hydrogen peroxide
by Tony Ong 3K
Sun Jan 27, 2019 11:20 pm
Forum: Ideal Gases
Topic: Approximations for ICE
Replies: 20
Views: 160

Re: Approximations for ICE

as a means to check if your approximations are correct,
remember the 5% rule at the end!
by Tony Ong 3K
Sun Jan 27, 2019 11:19 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Ph and Pka
Replies: 5
Views: 51

Re: Ph and Pka

pKA usually deals more with weak acids which cannot dissociate fully as opposed to strong acids where we can automatically calculate the pH because we know it dissociates completely.
by Tony Ong 3K
Sun Jan 27, 2019 11:18 pm
Forum: Phase Changes & Related Calculations
Topic: Phase changes
Replies: 14
Views: 115

Re: Phase changes

I believe that negative delta H is exothermic so it gives off heat and positive delta H is endothermic, so it requires heat. But would that be the same for negative delta G and positive?
by Tony Ong 3K
Sun Jan 20, 2019 10:36 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Water in ICE tables
Replies: 10
Views: 87

Re: Water in ICE tables

Moreso on that, think of water, or any other forms of pure liquids, as solvents. Usually, solvents are larger in concentration than its solute constituents. Therefore, even during equilibrium the relative concentration of solvents remain the same.
by Tony Ong 3K
Sun Jan 20, 2019 10:34 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5% rule
Replies: 11
Views: 106

Re: 5% rule

Keep in mind that when approximating, Professor Lavelle said that it should be less than 10^-3 values. The 5% rule is simply a mechanism to check whether or not your approximations are valid.
by Tony Ong 3K
Sun Jan 20, 2019 10:33 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Pressure Notation
Replies: 5
Views: 60

Re: Pressure Notation

Kc is regarding molar concentrations whereas Kp is for homogeneous gas equilibria.

If in any case you're required to convert from Kp to Kc or vice versa, you can use the formula:
Kp=Kc(RT)^deltaN
by Tony Ong 3K
Sat Jan 12, 2019 1:50 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Adding a liquid
Replies: 7
Views: 68

Re: Adding a liquid

during lecture, Professor Lavelle pointed out that changing pressure does not change the Kc value, but changing the temperature is what changes the Kc value.
by Tony Ong 3K
Sat Jan 12, 2019 1:14 am
Forum: Ideal Gases
Topic: Q and K [ENDORSED]
Replies: 35
Views: 923

Re: Q and K [ENDORSED]

nope no difference! Hope that helped because I have to sleep now!
by Tony Ong 3K
Sat Jan 12, 2019 1:11 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Endothermic
Replies: 6
Views: 88

Re: Endothermic

you can also think of it in the sense that endothermic reactions REQUIRE energy and thus can be in the form of heat where exothermic reaction RELEASES energy, which can be in the form of heat as well.
by Tony Ong 3K
Sun Dec 09, 2018 6:46 pm
Forum: Administrative Questions and Class Announcements
Topic: Saying Thank You to Dr. Lavelle
Replies: 200
Views: 44159

Re: Saying Thank You to Dr. Lavelle

Hello Professor Lavelle!
I appreciate your dad hat and your quirky humor. You bring light upon the clouded world of chemistry. I cannot wait to take 14B with you.
But for now, I must depart and I hope your winter break is brimming with chemistry among your family members and friends.
by Tony Ong 3K
Sun Dec 09, 2018 6:44 pm
Forum: Naming
Topic: Order of ligands
Replies: 6
Views: 88

Re: Order of ligands

does not matter but I would say just to be safe follow the order given in the name
by Tony Ong 3K
Sun Dec 09, 2018 6:43 pm
Forum: Naming
Topic: Chloro vs Chlorito
Replies: 8
Views: 99

Re: Chloro vs Chlorito

either is fine... -o or -ido are both acceptable suffixes.
by Tony Ong 3K
Sun Dec 02, 2018 12:56 am
Forum: Hybridization
Topic: lone pairs
Replies: 20
Views: 167

Re: lone pairs

yes lone pairs dictates the molecular shape.
For instance, let us assume that a central atom has a steric number of 4. This means that its electron arrangement is tetrahedral, however say it has 2 lone pairs. This means that the molecular shape is angular.

Anyhow, Have a nice night!!!
by Tony Ong 3K
Sun Dec 02, 2018 12:53 am
Forum: Lewis Acids & Bases
Topic: bronsted acid vs. lewis acid
Replies: 4
Views: 56

Re: bronsted acid vs. lewis acid

they're both the same thing, just defined differently
bronsted acid is proton donor while lewis definition of acid is electron acceptor
by Tony Ong 3K
Sun Dec 02, 2018 12:51 am
Forum: Lewis Acids & Bases
Topic: Strong acids and strong bases
Replies: 5
Views: 47

Re: Strong acids and strong bases

yes, they always completely dissociate
by Tony Ong 3K
Mon Nov 26, 2018 12:26 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar vs. Non-polar
Replies: 3
Views: 57

Re: Polar vs. Non-polar

Polar bonds have partial charges due to the unequal distribution of charges/electrons whereas nonpolar bonds have an equal distribution. Usually symmetrical molecules are nonpolar because the charges are evenly distributed. All Carbon-Hydrogen bonds are nonpolar.
by Tony Ong 3K
Mon Nov 26, 2018 12:25 am
Forum: Resonance Structures
Topic: Resonance Structures Higher Energy?
Replies: 1
Views: 39

Re: Resonance Structures Higher Energy?

i believe neither; it is just more spread out, and thus entropically favored.
by Tony Ong 3K
Mon Nov 26, 2018 12:24 am
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Like dissolves like
Replies: 3
Views: 64

Re: Like dissolves like

nonpolar compounds have a tendency to aggregate together...such is the case in a cell's lipid bilayer, where the nonpolar, hydrophobic tails face inwards towards another while the hydrophilic, polar heads face outwards. This is key towards regulating a cell's metabolism.
by Tony Ong 3K
Sat Nov 17, 2018 11:25 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Determining Shape
Replies: 10
Views: 144

Re: Determining Shape

you want to draw out the lewis structure always to determine what the Steric Number is for the central atom...then you can determine shape from there. Don't cheat your way with shortcuts!!!! It'll be your ultimate downfall! oh and steric number means bonded pairs of electrons (double bond counts as ...
by Tony Ong 3K
Sat Nov 17, 2018 11:22 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Determining Shape
Replies: 10
Views: 144

Re: Determining Shape

you want to draw out the lewis structure always to determine what the Steric Number is for the central atom...then you can determine shape from there. Don't cheat your way with shortcuts!!!! It'll be your ultimate downfall! oh and steric number means bonded pairs of electrons (double bond counts as ...
by Tony Ong 3K
Sat Nov 17, 2018 11:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 3
Replies: 19
Views: 244

Re: Test 3

My TA Joyce emailed out her notes and it's incredibly useful for the VSPER Model chart, detailing lone pairs, electron density, and molecular shape that you should memorize!
by Tony Ong 3K
Sat Nov 17, 2018 11:18 pm
Forum: Administrative Questions and Class Announcements
Topic: Thanksgiving Wednesday Class
Replies: 19
Views: 308

Re: Thanksgiving Wednesday Class

NO CLASS WOOOO ENJOY YOUR THANKSGIVING!!!
by Tony Ong 3K
Sat Nov 10, 2018 12:17 am
Forum: Dipole Moments
Topic: Dipole
Replies: 8
Views: 126

Re: Dipole

I thought dipole moments would only be taken into consideration when drawing VSPER models?? Isn't lewis structures mainly just the elements present in a molecule and its lone pairs of electrons?
by Tony Ong 3K
Sat Nov 10, 2018 12:15 am
Forum: *Shrodinger Equation
Topic: Shrodinger Equation
Replies: 2
Views: 84

Re: Shrodinger Equation

don't worry about deriving the Schrodinger's equation because that requires 2nd level derivatives but for now, the quantum numbers that we use
(n, l, ml, ms) are derived from the Schrodinger's equation.
by Tony Ong 3K
Sat Nov 10, 2018 12:13 am
Forum: Lewis Structures
Topic: Molecular shape and structure
Replies: 5
Views: 101

Re: Molecular shape and structure

no those are for VSPER models.
Lewis structures is a 2D structure that depicts the lone pair electrons that may exist in a molecule
by Tony Ong 3K
Sat Nov 03, 2018 10:47 pm
Forum: Balancing Chemical Reactions
Topic: Combustion Chemical Reactions
Replies: 2
Views: 82

Re: Combustion Chemical Reactions

In combustion, the reactants is always whatever they give you with Oxygen (O2) and the products is H20 and CO2...however, make sure to balance the equation my friend!

Hope this helps ?? Lemme know if it doesn't I will respond with more explanations :)
Goodnight
by Tony Ong 3K
Sat Nov 03, 2018 10:45 pm
Forum: Ionic & Covalent Bonds
Topic: Uncertainty Principles
Replies: 2
Views: 31

Uncertainty Principles

For uncertainty of velocity, if they give you that the speed is 373.23 plus or minus .34 m/s, is the uncertainty in velocity 373.23 or .34 or how do you calculate it??
by Tony Ong 3K
Sat Nov 03, 2018 10:40 pm
Forum: Ionic & Covalent Bonds
Topic: Chem Midterm
Replies: 13
Views: 127

Chem Midterm

How many questions are on the midterm?
by Tony Ong 3K
Sat Oct 27, 2018 10:43 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Degeneracy
Replies: 6
Views: 114

Re: Degeneracy

You can also think of degeneracy as when we learned the quantum numbers. The values of Ml represent the number of degeneracy. In a 2s orbital, n=2 and l=0, therefore the only value for Ml is 0. Therefore there is 1 degeneracy. In a 3p orbital, n=3 and l=1, therefore the values for Ml is -1, 0, 1. Th...
by Tony Ong 3K
Sat Oct 27, 2018 10:40 pm
Forum: Trends in The Periodic Table
Topic: P-block elements
Replies: 3
Views: 57

Re: P-block elements

Normally, the ones with less than 4 valence electrons loses its electrons while the ones over 4 valence electrons want to gain electrons. Both want to fulfill the octet rule in the least possible manner of gaining or losing electrons possible if that makes sense.
by Tony Ong 3K
Sat Oct 27, 2018 10:38 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity Trend
Replies: 9
Views: 141

Re: Electron Affinity Trend

Something that is also interesting is that Chlorine actually has a higher electron affinity than Fluorine. Fluorine is smaller than Chlorine, therefore there is less space availalbe in its 2p orbital. Chlorine's outer orbital is a 3p, so therefore there's more space for electrons to be shared in thi...
by Tony Ong 3K
Thu Oct 18, 2018 11:55 pm
Forum: *Black Body Radiation
Topic: Black Body
Replies: 9
Views: 239

Re: Black Body

Do we have to understand the concepts of black body for the midterms? I don't remember Professor Lavelle going over this thoroughly or at all during class?
by Tony Ong 3K
Thu Oct 18, 2018 11:46 pm
Forum: Einstein Equation
Topic: Values of Each Symbol
Replies: 3
Views: 77

Re: Values of Each Symbol

All values and equations are given to you! But I suggest for the sake of time on your tests to memorize the more commonly used values such as Planck's constant (h) or the speed of light (c) or even the mass of an electron 9.109*10^-31 kg.
by Tony Ong 3K
Thu Oct 11, 2018 1:21 am
Forum: Einstein Equation
Topic: 7th 1B.15 When do you use E = hv or Ek = 1/2m v^2?
Replies: 4
Views: 81

Re: 7th 1B.15 When do you use E = hv or Ek = 1/2m v^2?

You can think of the Kinetic Energy as the "excess" energy emitted if that helps. Professor Lavelle mentioned that there can only be Kinetic energy released if the E (photon) > Work function. So knowing this, if E(photon) equals threshold/work function, then kinetic energy is 0. So wheneve...
by Tony Ong 3K
Thu Oct 11, 2018 1:15 am
Forum: Molarity, Solutions, Dilutions
Topic: Post Module Assessment
Replies: 2
Views: 137

Re: Post Module Assessment

First you use molar mass of KMnO4 to find its moles. Convert 5.00 g KMnO4 into moles by dividing by the molar mass, (5.00 g KMnO4)/(158.04 g/mol KMnO4)= 0.0316 mol KMnO4. Then divide by the volume of the solution made to find the concentration, (0.0316 mol KMnO4)/(.15000 L)= 0.211 mol/L KMnO4 soluti...
by Tony Ong 3K
Thu Oct 11, 2018 1:07 am
Forum: Significant Figures
Topic: Module: Molarity #15
Replies: 6
Views: 193

Re: Module: Molarity #15

That is strange! I would say to always keep the habit of putting the correct sig figs regardless because it's 1 point off per question on the midterms and finals!
by Tony Ong 3K
Thu Oct 11, 2018 1:03 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Finding Energy Level for H-Atom
Replies: 2
Views: 35

Re: Finding Energy Level for H-Atom

For a line at 102.6nm, you convert into meters and then do following: V=c/λ =(3.00*10^8ms^-1)/102.6*10^9m= 2.922 * 10^15 s^-1 Then use Rydberg to find values for N : V=R[(1/n1^2)-(1/n2^2)]. We know that hydrogen has n1= 1, so 1/n2^2= 1/1^2 - V/R 1/n2^2= 1 - ( 2.922 * 10^15 s^-1)/(3.29 * 10^15 s ^-1)...
by Tony Ong 3K
Wed Oct 03, 2018 3:14 pm
Forum: Balancing Chemical Reactions
Topic: Example H1, seventh edition.
Replies: 2
Views: 57

Re: Example H1, seventh edition.

If you look in Dr. Lavelle's Outline 1: Review of Chemical and Physical Principles objectives that we should know by the end of the section, it just states that we should be able to "write symbols for elements given their names." So I'm sure at this point in time, we do not need to memoriz...
by Tony Ong 3K
Wed Oct 03, 2018 3:04 pm
Forum: Molarity, Solutions, Dilutions
Topic: Coefficients and Subscripts
Replies: 4
Views: 67

Re: Coefficients and Subscripts

Multiplying by the subscripts would change the chemical structure of the molecule and make an entirely different molecule. However when you multiply by the stoichiometric coefficients, you're essentially multiplying the subscripts as well because the stoichiometric coefficients apply to the entire m...
by Tony Ong 3K
Wed Oct 03, 2018 3:01 pm
Forum: Limiting Reactant Calculations
Topic: Finding theoretical yield
Replies: 6
Views: 90

Re: Finding theoretical yield

If I understood your question correctly, then in order to figure out the theoretical yield of a specific product, you would have to use the moles of the limiting reagent and multiply by the molar ratio of the product to the limiting reagent given in the chemical equation to find the maximum moles of...

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