## Search found 95 matches

Sun Mar 15, 2020 7:37 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Solving for rates
Replies: 3
Views: 63

### Re: Solving for rates

what section of chapter 7 is this from, so i can reference my work
Sun Mar 15, 2020 7:33 am
Forum: General Rate Laws
Topic: Hw 7A.13
Replies: 8
Views: 129

### Re: Hw 7A.13

in the homework there were some reactions (7A and 7B) that were larger than second order. We don't need to know much about these (like how to graph them), right?
Sun Mar 15, 2020 7:32 am
Forum: General Rate Laws
Topic: Hw 7A.13
Replies: 8
Views: 129

### Re: Hw 7A.13

in the homework there were some reactions (7A and 7B) that were larger than second order. We don't need to know much about these (like how to graph them), right?
Sun Mar 15, 2020 7:29 am
Forum: First Order Reactions
Topic: Pseudo first order rxn
Replies: 5
Views: 95

### Re: Pseudo first order rxn

Hi, I attached some helpful information that I wrote regarding pseudo ordered reactions. Essentially, pseudo ordered reactions are used when you have more than one reactant and one (or two) of the reactants is in excess. Because they are in excess, we can assume their rates are essentially constant...
Sun Mar 15, 2020 7:24 am
Forum: First Order Reactions
Topic: How to solve
Replies: 3
Views: 60

### Re: How to solve

I would say so for the most part. The hardest part is discerning whether it is a first, second, or zeroth order reaction. Don't count on just knowing the basic equations for the final though, I would make sure you are well versed in the reaction graphs (section 7B) and how to analyze them.
Sun Mar 15, 2020 7:06 am
Forum: First Order Reactions
Topic: First order vs zero-order
Replies: 4
Views: 85

### Re: First order vs zero-order

to ease some stress before the final, know that we will most likely not be asked to graph these ourselves by hand, but maybe only asked to interpret graphs. KEY IS TO REMEMBER:
zeroth: [A]t vs t (-k)
first order: ln[A]t vs t (-k)
second order: 1/[A]t vs t (k)
Sun Mar 15, 2020 7:01 am
Forum: First Order Reactions
Topic: Pseudo first order rxn
Replies: 5
Views: 95

### Re: Pseudo first order rxn

Basically, if there is a reaction that appears to be 2nd order, we can assume that there is excess reactant in a pseudo first order. The concentration of excess reactant is treated as constant since the change in the amount of excess reactant is negligible as the reaction proceeds. So now we treat t...
Sun Mar 15, 2020 6:59 am
Forum: First Order Reactions
Topic: Pseudo first order rxn
Replies: 5
Views: 95

### Re: Pseudo first order rxn

i found this video really helpful since the textbook barely explained this concept.
https://youtu.be/0BTyxuVRLf8
Sun Mar 15, 2020 6:54 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: What was your favorite chem topic?
Replies: 24
Views: 451

### Re: What was your favorite chem topic?

Definitely Enjoyed Kinetics from 14B the most, and I especially loves molecular shape and structure from 14A. I am a visual learner
Sun Mar 15, 2020 5:00 am
Forum: General Rate Laws
Topic: Hw 7A.13
Replies: 8
Views: 129

### Re: Hw 7A.13

so if both are first order independently, does this make the reaction an overall 2nd order reaction?
Sun Mar 15, 2020 4:57 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: relationship of K and time
Replies: 3
Views: 74

### relationship of K and time

Will the instantaneous rate always decrease as the reaction proceeds? is there ever a chance we will see a reaction where the rate of reaction increases as time increases?
Sun Mar 15, 2020 4:55 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: order of reaction
Replies: 6
Views: 109

### Re: order of reaction

You can also think of this graphically. I doubt we will ever be asked to do this by hand on a test, but if you graph the concentration [A]t vs time and you get a straight line, it is zeroth order. If you graph the natural log of the [A]t vs time and get a linear graph, it is first order. if you grap...
Sun Mar 15, 2020 4:37 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: 7B 3(c)
Replies: 2
Views: 68

### Re: 7B 3(c)

Since .034M of product B was created, than (according to the stoichiometric coefficients) we can assume that 2(.034M) of reactant A was consumed.
We then subtract .153(initial concentration of A) - 2(.034M) = .085M
.085M = [A]t
Mon Mar 09, 2020 4:51 pm
Forum: Zero Order Reactions
Topic: Graphs
Replies: 13
Views: 526

### Re: Graphs

Melissa Villanueva1K wrote:Is there a possibility that there will be graphs given or we will have to draw graphs in accordance to the order of the reaction? Thanks!

since none of the assigned homework problems had us drawing graphs ourselves and finding slopes, I doubt we will be expected to on a test.
Mon Mar 09, 2020 4:47 pm
Forum: First Order Reactions
Topic: Half Life
Replies: 8
Views: 60

### Re: Half Life

If you look at how half life is derived from the original 1st order reaction equation the initial concentration is canceled out when deriving the half life, which is why it doesn't matter. let's work this out: we know ln([A]t/[A]0) = -kt if we divide both sides by (-k), we get: t = (1/k)*ln([A]0/[A...
Mon Mar 09, 2020 4:42 pm
Forum: First Order Reactions
Topic: Textbook question 7B.15
Replies: 2
Views: 38

### Re: Textbook question 7B.15

Now that we have [A]0, we can plug it into out first order reaction equaition

[A]t = [A]0*e^-kt
[A]t = [.00004148]e^-(2.8E-3min-)(90min)

[A]t = .0000322M

now you convert this back to grams...
.000032mol/L * 2500L * (135g/mol) = 10.8grams
Mon Mar 09, 2020 4:38 pm
Forum: First Order Reactions
Topic: Textbook question 7B.15
Replies: 2
Views: 38

### Re: Textbook question 7B.15

so we know k=2.8E-3 min-1 1.5 hours=90 minutes let's convert 14.0 grams to moles 14.0 g / (135g/mol) = .1037 mol, then divide by total liters to get an initial molarity of .000041481.... seeing that your final molarity is so high, I would go back and check this first step with your work too see wher...
Mon Mar 09, 2020 4:35 pm
Forum: First Order Reactions
Topic: Textbook question 7B.3
Replies: 5
Views: 100

### Re: Textbook question 7B.3

after you get the new concentration [A]t = 0.085, you can set up the equation to solve for the rate constant:

ln[0.085] = -k*(115 seconds) + ln[.153]

so I got k=5.1E-3, but what would the units be and how do I differentiate the units on k for first and second order reactions?
Mon Mar 09, 2020 4:29 pm
Forum: General Rate Laws
Topic: integrated rate law vs general
Replies: 8
Views: 121

### Re: integrated rate law vs general

what’s the difference between the integrated rate laws vs the general rate law? think of driving in a car (this is example used in textbook). general rate law is like saying you took an hour trip, and ended up driving 30 miles. your average (general) speed for the entire hour time period is 30 mph....
Mon Mar 09, 2020 4:25 pm
Forum: General Rate Laws
Topic: 7A.15
Replies: 3
Views: 77

### Re: 7A.15

How are you supposed to know something is Zeroth order? is there a specific rule to know that it is zeroth order?
Mon Mar 09, 2020 4:23 pm
Forum: General Rate Laws
Topic: 7B9 part a
Replies: 2
Views: 89

### Re: 7B9 part a

think of this being like an ICE chart (except we aren't really talking about equilibrium, just a helpful model to figure out proportions): A B C I: .015M 0M ... C: -.006M +.018M .... E: .009M Since we are only considering the rate in terms of the consumption of A, then we only need the final concent...
Mon Mar 09, 2020 4:17 pm
Forum: General Rate Laws
Topic: 7A3
Replies: 2
Views: 53

### Re: 7A3

we know from the unique rate equations for a reaction:
aA + bB --> cC + dD

the rate = -(1/a)d[A]/dt, -(1/b)d[B]/dt, (1/c)d[C]/dt, (1/d)d[D]/dt.
The stoichiometric coeff goes on denominator of the rate of production or consumption. I think this should help you.
Mon Mar 09, 2020 4:14 pm
Forum: General Rate Laws
Topic: stopped flow experiment
Replies: 1
Views: 52

### stopped flow experiment

can someone help explain the stopped flow technique to measuring the rate of a really quick reaction? After reading about it in the textbook and looking at the diagram I still don't understand.
Sat Feb 22, 2020 2:41 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L. 9
Replies: 2
Views: 56

### 6L. 9

WRITE balanced half reactions for the redox reaction of an acidified solution of potassium permanganate and iron(II) chloride.

Step by step help on this one please. How do I express an acidified half reaction?
Sat Feb 22, 2020 2:32 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.7 C
Replies: 2
Views: 46

### 6L.7 C

Write half reactions and devise a galvanic cell to study each of the following reactions: (C) Cd + Ni(OH)3 —> Cd(OH)2 + 2Ni(OH)2 I don’t understand how in the answers for the homework, the half reaction for cathode looks like : Ni(OH)3 + e- —> Ni(OH)2 + OH- and then the cell diagram for the right si...
Sat Feb 22, 2020 2:09 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.7
Replies: 2
Views: 26

### Re: 6L.7

I’m also very confused because in the textbook answers, it says the anode reaction would be Ag + Br- —> AgBr + e- and the cathode rxn would be Ag+ + e- —> Ag. How are we supposed to infer this from just being given the reaction
AgBr <—> Ag+ + Br-
Sat Feb 22, 2020 2:08 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.7
Replies: 2
Views: 26

### Re: 6L.7

I’m also very confused because in the textbook answers, it says the anode reaction would be Ag + Br- —> AgBr + e- and the cathode rxn would be Ag+ + e- —> Ag. How are we supposed to infer this from just being given the reaction
AgBr <—> Ag+ + Br-
Sat Feb 22, 2020 1:58 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.5
Replies: 4
Views: 72

### Re: 6L.5

Oxidation occurs in the anode and Reduction occurs in the cathode. In this problem, Au is both the oxidizing and reducing agent. Au+ is being oxidized when it goes to Au3+ since it goes from having an oxidation state of +1 to +3. It is being reduced when Au+ goes to Au(s) since it goes from having ...
Sat Feb 22, 2020 1:54 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.5 D.
Replies: 7
Views: 92

### 6L.5 D.

“Write the half rxns, the balanced rxn, and the cell diagram for each of the following skeletal equations...
...(d) Au+ —> Au + Au3+

Can someone explain to me how to write the haLf reactions for this ?
Wed Feb 19, 2020 10:40 am
Forum: Balancing Redox Reactions
Topic: 6K. D
Replies: 3
Views: 102

### 6K. D

d) P4 (s) ---> H2PO2(^-1) (aq) + PH3 (aq)

I know how to balance the reduction reaction, but can someone explain how to balance the oxidation reaction ?
Tue Feb 18, 2020 1:25 pm
Forum: Balancing Redox Reactions
Topic: 6k3 part d
Replies: 4
Views: 44

### Re: 6k3 part d

I had the same question. but I guess if it's a typo then it makes sense. If there were to be Cl2 on both sides of the equation would it be solvable? if it had Cl2 on both sides, they would cancel i believe and it wouldn't be solvable. You have to take into account the typo as mentioned above: "...
Tue Feb 18, 2020 12:21 pm
Forum: Balancing Redox Reactions
Topic: 6K.1 Homework
Replies: 1
Views: 25

### 6K.1 Homework

I am confused on 6K.1 part a. I thought from previous high school chemistry that the species being reduced or oxidized had to be metal (like Fe or Cu) and that is what is typically seen in all the examples from class. I can easily see that Cr is being reduced, but what is being oxidized because I do...
Tue Feb 18, 2020 12:06 pm
Forum: Balancing Redox Reactions
Topic: Why do we split equations?
Replies: 12
Views: 116

### Re: Why do we split equations?

It is mostly used to balance redox reactions that happen in aqueous solutions of H2O. This is because in these aqueous solutions, water can dissociate into H+(meaning there will be acidic conditions) or water can dissociate into OH- ions (meaning there will be basic conditions). With this added fact...
Tue Feb 18, 2020 11:51 am
Forum: Balancing Redox Reactions
Topic: Balancing and Adding together Half-Rxns
Replies: 6
Views: 75

### Balancing and Adding together Half-Rxns

Why do electrons have to cancel when you balance the half reactions ? (why would the electrons released by oxidation have to be the same as the number used in reduction??)

All i know is that it has to happen, but i don't quite understand why.
Tue Feb 18, 2020 11:38 am
Forum: Balancing Redox Reactions
Topic: Reduction vs. oxidation
Replies: 29
Views: 276

### Re: Reduction vs. oxidation

it is actually not only dependent on proton transfer! i believe you are thinking of bronsted-lowry acid and base reaction from 14A. ReDox rxns depend on the transferring of charges based on electron gains and losses. LEO says GER! Lose Electrons: Oxidation Gain Electrons: Reduction (fun acronym to r...
Tue Feb 18, 2020 11:34 am
Forum: Balancing Redox Reactions
Topic: Free Electrons?
Replies: 3
Views: 46

### Free Electrons?

When writing the half-reactions for redox equations, we get something along the lines of ...
AG+ + e- ---> AG(s) (reduction, gaining electron).
Can the single electron actually exist as an electron in space?
I didn't think it could, so if not, why do we write it this way?
Tue Jan 28, 2020 11:19 pm
Forum: Calculating Work of Expansion
Topic: 4A.3
Replies: 9
Views: 203

### Re: 4A.3

On part C of this problem, why would the change in internal energy of the system be different then how much work is done in the compression? w= -Pex(deltaV) where Pex= constant external pressure delta V= Vfinal-Vinitial ( the expansion/compressiom of the system) when deltaV is positive , the intern...
Tue Jan 28, 2020 4:50 pm
Forum: Calculating Work of Expansion
Topic: 4A.3
Replies: 9
Views: 203

### 4A.3

On part C of this problem, why would the change in internal energy of the system be different then how much work is done in the compression?
Tue Jan 28, 2020 4:45 pm
Forum: Calculating Work of Expansion
Topic: 4A 3
Replies: 5
Views: 92

### Re: 4A 3

After you calculate the dimension change of the pump, you multiply by the external pressure, which is given as 2 atm. Remember to convert this to pascals, whether that is before or after the calculation. This should give you an answer of 28.
Tue Jan 21, 2020 12:08 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 5.35
Replies: 2
Views: 65

### Re: 5.35

If you look at the graph provided in the question, you will be able to determine the amount of A consumed and the amount of B and C formed in reaction in establishing equilibrium. If you set up an ICE table and plug in the initial and equilibrium partial pressure values, you can determine the chang...
Tue Jan 21, 2020 12:07 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5.33
Replies: 6
Views: 43

### Re: 5.33

Shannon Asay 1C wrote:It would increase the formation of X because the reaction is endothermic and an increase in the temperature would increase the k value. This means an increase in the number of products.
How would you know it’s endothermic? Is it because breaking a halogen apart requires heat?
Tue Jan 21, 2020 12:03 pm
Forum: Ideal Gases
Topic: Topics for Test 1
Replies: 17
Views: 207

### Re: Topics for Test 1

has anyone done the peer learning worksheets? are the problems beginner level to provide guidance or a great tool to use when studying for the tests? I just took the test today and I think the peer learning worksheets are really great for nailing the fundamentals metals and if you have the time you...
Tue Jan 21, 2020 12:02 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5j #11
Replies: 4
Views: 46

### Re: 5j #11

So In 5J.11 b, the equation is X2->2X, where x is a halogen. In this equation, it is essentially breaking a bond, which means it requires energy and is endothermic. In an endothermic reaction, when you raise the temperature, the value of k increases. If k increases, that means the equilibria is fav...
Tue Jan 21, 2020 12:00 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5j #11
Replies: 4
Views: 46

### Re: 5j #11

Amanda Lin 2I wrote:Endothermic reactions favor the formation of products.

I think this is too general of a statement. Endothermic reactions favor the products when the reaction is heated.
Tue Jan 21, 2020 11:59 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: HW 5j #5
Replies: 4
Views: 49

### Re: HW 5j #5

I see now that there are two moles on the right side of the equation and 2 moles (one mole of H2 and one mole of D2), which means there is no overall change with volume change
Tue Jan 14, 2020 5:32 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 5.35
Replies: 2
Views: 65

### 5.35

For problem 35 at the end of chapter 5, how do you know the balance to Quetion between the reactant A and the two products B and C?
Tue Jan 14, 2020 5:28 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5.33
Replies: 6
Views: 43

### 5.33

On problem number 33 at the end of chapter 5, why would increasing the temperature increase the formation of X? I thought there would be no change.
Tue Jan 14, 2020 5:24 pm
Forum: Ideal Gases
Topic: Topics for Test 1
Replies: 17
Views: 207

### Re: Topics for Test 1

Definitely DEFINITELY master the ice tables. I think it’s a good idea to go back over homework problems with either a really small K or a really large K when you can use the method of estimating.
Tue Jan 14, 2020 5:21 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5j #11
Replies: 4
Views: 46

### 5j #11

Why would 5J.11 part b favor the products? I thought there would be no change when heating.
Tue Jan 14, 2020 5:18 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: HW 5j #5
Replies: 4
Views: 49

### HW 5j #5

Can someone explain to me why the answer to 5J#5 part D is No Change? I thought it would be the reactant favored.
Wed Nov 27, 2019 7:19 pm
Forum: Bronsted Acids & Bases
Topic: Naming Acids and Bases
Replies: 3
Views: 51

### Re: Naming Acids and Bases

What i remember from high school chemistry is a rule about "-ate" and "-ite" if the anion in the acid ends in "-ate," the new name of the acid is now "-ic" if the anion in the acid ends in "-ite," the new name of the acid is now "-ous" for ...
Wed Nov 27, 2019 7:13 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Carboxyl Acidic Hydrogens?
Replies: 2
Views: 40

### Carboxyl Acidic Hydrogens?

I understand the rule that any acid with a carboxyl group is considered a weak acid. Why?

For example:
CH3COOH is a weak acid.
Wed Nov 27, 2019 7:01 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: How to take the log to get the pH?
Replies: 8
Views: 81

### Re: How to take the log to get the pH?

would a really weak base be close to 7? or as far away from 7 as possible?

for example:
would a pH of 8 be more or less basic than a pH of 12?
Wed Nov 27, 2019 6:51 pm
Forum: Air Pollution & Acid Rain
Topic: other biological examples
Replies: 4
Views: 383

### Re: other biological examples

Might also be important to know that carbonic acid is formed by the reaction of water and CO 2 , which happen to be the products of cellular respiration. this refers to acid rain. also remember that CO2 is a product of A LOT of other biological and inorganic processes, like decomposition and pollut...
Wed Nov 27, 2019 6:48 pm
Forum: Conjugate Acids & Bases
Topic: strength of an acid and its conjugate base
Replies: 3
Views: 41

### Re: strength of an acid and its conjugate base

Yes! this is very true and can be seen through hydrochloric acid (HCl).
HCl(aq) is a very strong acid. The conjugate base of HCl is Cl-(aq), which is also a very weak base.
Mon Nov 25, 2019 3:30 pm
Forum: Naming
Topic: Roman numerals
Replies: 4
Views: 59

### Re: Roman numerals

The roman numeral indicates the positive charge of the transition metal cation. This notation is often used since transition metals can take on multiple oxidation states. For example, to distinguish Fe 2+ and Fe 3+ you would write Iron (II) or Iron (III). If we have the coordination compound [Co (N...
Mon Nov 25, 2019 3:20 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: How do you know is an acid is strong or weak?
Replies: 6
Views: 81

### How do you know is an acid is strong or weak?

If i were given a random acidic compound, how would i go about determining if it is strong or weak?
Mon Nov 25, 2019 3:15 pm
Forum: Air Pollution & Acid Rain
Topic: Clean Coal vs Dirty Coal?
Replies: 16
Views: 202

### Clean Coal vs Dirty Coal?

can someone explain the difference between clean coal and dirty coal? I remember it being explained in the lecture in terms of Carbon of Sulfur dominant, but I don't remember which was clean and which was dirty.
Mon Nov 25, 2019 3:13 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Homework 9C.5
Replies: 1
Views: 44

### Homework 9C.5

can someone help me with finding the oxidation numbers it is asking for in homework question 9C.5?
Mon Nov 25, 2019 3:10 pm
Forum: Amphoteric Compounds
Topic: Bi2O3
Replies: 2
Views: 21

### Re: Bi2O3

I'm not sure why Bi would be since it is not in the band of the Amphoteric elements discussed in lecture...
...Be, Al, Ga, Sn, Sb, Pb are the elements that i was able to record in lecture, and i have the same question about Bi.
Wed Nov 20, 2019 4:13 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: T-Shaped ??
Replies: 9
Views: 151

### T-Shaped ??

What are the VSEPR formulas (e.g. AX2E) for the two different types of molecules that are T-Shaped?
Wed Nov 20, 2019 4:07 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.25
Replies: 3
Views: 58

### Re: 2E.25

The question is: Draw the Lewis structure and predict whether each of the following molecules is polar or nonpolar. The molecule I am confused about is CH2Cl2 because I put the two hydrogens on opposite sides of the carbon atom and the two chlorines on the other two sides on the carbon, which cance...
Wed Nov 20, 2019 3:36 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: electron cloud distortion
Replies: 3
Views: 145

### Re: electron cloud distortion

to add to the person above, the highly polarizable atom is typically a very large anion. when polarizability is high, typically it means the anion is extremely large, with electrons distant to the nucleus. When you mix a very large anion with a very small highly charged cation, you get strong forces...
Wed Nov 20, 2019 3:33 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: polarizability
Replies: 9
Views: 216

### Re: polarizability

to add on, typically, the larger the molecule, the larger the polarizability. this is because the electrons are farther away from the nucleus and the valence electrons are more shielded from the pulling power of the nucleus.
Wed Nov 20, 2019 3:30 pm
Forum: Sigma & Pi Bonds
Topic: Resonance and Sigma/Pi Bonds
Replies: 3
Views: 204

### Re: Resonance and Sigma/Pi Bonds

Typically, you look at the molecule as a whole when describing pi and sigma bonds. So every resonance structure would have the same number of sigma and pi bonds. But as the response above has stated, I would just draw in the specific pi and sigma bonds for each resonance structure if a test or homew...
Wed Nov 20, 2019 3:23 pm
Forum: Octet Exceptions
Topic: Antioxidants
Replies: 9
Views: 268

### Re: Antioxidants

Rita Chen 1C wrote:What happens to the antioxidants afterward?

Afterwards, the antioxidants are simply excreted from the body! typically in the form of urination
Wed Nov 20, 2019 3:20 pm
Forum: Resonance Structures
Topic: Bond length
Replies: 5
Views: 174

### Re: Bond length

Also keep in mind that bond length has an inversely proportional relationship with bond strength.

As bond length increases, bond strength decreases. (vice versa)
Fri Nov 01, 2019 3:18 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizing Power: Size vs. Charge
Replies: 4
Views: 420

### Re: Polarizing Power: Size vs. Charge

So revisiting the original question, does one play a more significant role than the other (size or charge?). If so, why?
Fri Nov 01, 2019 3:17 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability
Replies: 3
Views: 48

### Re: Polarizability

can someone explain why the size of the cation plays a role in how polarizing it can be?
Fri Nov 01, 2019 3:13 pm
Forum: Octet Exceptions
Topic: 2C.5
Replies: 4
Views: 75

### Re: 2C.5

First, I just set up the molecule as described in the problem. From there, I added all of the 22 other electrons onto the atoms to give them octets. At first I gave Cl 6 free electrons, Oxygen 4, Nitrogen 0 and each of the oxygens 6. However, with this setup, nitrogen didn't have an octet. So, I mo...
Fri Nov 01, 2019 3:11 pm
Forum: Octet Exceptions
Topic: 2C.9
Replies: 4
Views: 63

### Re: 2C.9

If your lewis structure is correct, there will be a double bond between Xe and O, single bonds between each F and the Xe, and a lone pair on the central atom, Xe. Now you take the equation for formal charge = V - (L + 1/2*B) Since Xe is in the very last group it has a value of V = 8. There are 2 lon...
Fri Nov 01, 2019 3:03 pm
Forum: Dipole Moments
Topic: van der waal
Replies: 4
Views: 87

### Re: van der waal

are we supposed to know this already??? This type of bonding was just touched on in lecture recently, so its ok if youre not extremely familiar with it. These four types of interactions are all pretty much the same if I am not mistaken: 1. dispersion = 2. induced dipole - induced dipole = 3. London...
Fri Nov 01, 2019 3:00 pm
Forum: Ionic & Covalent Bonds
Topic: Distorted e- with Ionic Bonds
Replies: 5
Views: 109

### Distorted e- with Ionic Bonds

Can someone explain how the anions distortion somehow makes the ionic bond now have covalent characteristics?
Mon Oct 21, 2019 4:27 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 4
Views: 51

### Electron Affinity

Can someone describe the trends in the periodic table referring to Electron Affinity? I understand that it is the energy released when an electron is added, but i do not quite understand how i would be able to qualitatively decide which elements have a higher E(ea) value.
Mon Oct 21, 2019 4:24 pm
Forum: Trends in The Periodic Table
Topic: 1st and 2nd Ionization
Replies: 5
Views: 61

### Re: 1st and 2nd Ionization

What is the difference between 1st ionization energy and second ionization energy? As discussed in a previous lecture, removing a second electron always requires more energy than removing the first electron. looking at this example of Copper: Cu(g) --> Cu+(g) and e-(g) with a first ionization energ...
Mon Oct 21, 2019 4:19 pm
Forum: Quantum Numbers and The H-Atom
Topic: Electron spin
Replies: 5
Views: 75

### Re: Electron spin

What is the significance of the direction in which an electron spins? the directions an electron spins is merely for the purpose of qualitatively analyzing. the "spin up" and "spin down" don't literally mean the electrons are spinning in a clockwise or counterclockwise direction...
Mon Oct 21, 2019 4:12 pm
Forum: Quantum Numbers and The H-Atom
Topic: f- orbitals?
Replies: 4
Views: 67

### f- orbitals?

in lecture, lavelle really only said we needed to be familiar with s, p, and d blocks when writing electron configurations . but in homework problem 1D.21 part C, the answer was in terms of the f orbital. do we still only need to know the s, p, and d blocks, or should i familiarize myself with "...
Mon Oct 21, 2019 4:12 pm
Forum: Quantum Numbers and The H-Atom
Topic: f- orbitals?
Replies: 7
Views: 74

### f- orbitals?

in lecture, lavelle really only said we needed to be familiar with s, p, and d blocks when writing electron configurations . but in homework problem 1D.21 part C, the answer was in terms of the f orbital. do we still only need to know the s, p, and d blocks, or should i familiarize myself with "...
Mon Oct 21, 2019 4:05 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Homework Question 1E.9
Replies: 3
Views: 53

### Homework Question 1E.9

Can someone explain to me why the quantum numbers for 1E.9 part B are not possible? I understand part A and C, but something about B is really throwing me off.
Thanks so much!
Fri Oct 18, 2019 3:32 pm
Topic: Will this concept be tested
Replies: 8
Views: 737

### Re: Will this concept be tested

nicknavejas1B wrote:I heard Professor Lavelle mention that we wont need to prepared to be tested on this concept, can anyone confirm?

it will not be tested, but i read over it in the textbook because i feel the information provided was interesting, yet very confusing.
Fri Oct 18, 2019 3:29 pm
Forum: Trends in The Periodic Table
Topic: Bond Lenghts
Replies: 7
Views: 524

### Re: Bond Lenghts

Rithana Srikanth 3L wrote:I think you would have to draw the Lewis structure to figure it out.

do we need to know how to draw lewis structures for our test over the quantum world?
I would need to brush up on that (even though it is literally so simple haha)
Fri Oct 18, 2019 3:24 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: removing electrons
Replies: 5
Views: 356

### Re: removing electrons

You always remove electrons from the highest energy orbital As an example, you would remove electrons from 4p before you would pull from 4s.
Fri Oct 18, 2019 3:21 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: how to prepare
Replies: 22
Views: 238

### Re: how to prepare

I'm really stressed out right now. The textbook is a lot of information with lots of formulas to know. Any advice for understanding the material better & to help me feel more prepared & confident? if you are referring to the section in the textbook 1D that has the chart of all the formulas,...
Mon Oct 14, 2019 6:00 pm
Forum: *Shrodinger Equation
Topic: More Modules coming?...
Replies: 3
Views: 65

### More Modules coming?...

Does anyone know if Dr. Lavelle will be uploading any further modules on the rest of the Quantum Unit? I find them extremely helpful and would love to have more.
Wed Oct 09, 2019 3:25 pm
Forum: Properties of Light
Topic: Light intensity
Replies: 6
Views: 96

### Re: Light intensity

McKenna_4A wrote:When Dr. Lavelle states that light can be at "higher intensity," what does this mean with respect to wave properties?

Intensity can be found mathematically too! Intensity = (Amplitude)^2 if i am not mistaken.
Wed Oct 09, 2019 3:23 pm
Forum: Einstein Equation
Topic: Numbers to memorize [ENDORSED]
Replies: 37
Views: 1749

### Re: Numbers to memorize[ENDORSED]

On tests (for Dr.Lavelle and I am sure all other professors) you are given both a formula chart AND periodic table to assist you.
Wed Oct 09, 2019 3:21 pm
Forum: DeBroglie Equation
Topic: Units for DeBroglie
Replies: 4
Views: 95

### Re: Units for DeBroglie

Yes! definitely would need to change from km*g to m*kg!! thanks to metric conversions the dimensional analysis is quite straightforward.
Wed Oct 09, 2019 3:20 pm
Forum: DeBroglie Equation
Topic: How to know which equation to use
Replies: 9
Views: 195

### Re: How to know which equation to use

When trying to find the velocity of an object, how do you know whether to use the equation v=c/(wavelength) or v=h/(mass x wavelength)? the "v" is not in reference to velocity as it would be in Physics. the "v" is the frequency of the light!! definitely a distinction that needs ...
Wed Oct 09, 2019 3:15 pm
Topic: Black Bodies and Temperature
Replies: 2
Views: 359

### Re: Black Bodies and Temperature

i think WHAT happens was explained, but i am still not understanding exactly WHY the temperature is seen to increase. Can anyone explain to me in a different light what is going on here?
Wed Oct 09, 2019 3:12 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg equation [ENDORSED]
Replies: 73
Views: 3726

### Re: Rydberg equation[ENDORSED]

The rydberg equation, if i am correct, is derived from Bohr's equation. Dr. Lavelle prefers to use Bohr's over the Rydberg equation though.
Wed Oct 02, 2019 3:21 pm
Forum: Properties of Light
Topic: Amplitude? [ENDORSED]
Replies: 8
Views: 190

### Amplitude?[ENDORSED]

Can someone explain to me in more detail what amplitude is? I was not quite sure when it was explained in class.
Wed Oct 02, 2019 3:20 pm
Forum: Empirical & Molecular Formulas
Topic: Mass Percent Composition
Replies: 5
Views: 102

### Re: Mass Percent Composition

You only have to imagine there is 100 grams when %composistion is given but not the mass. (the number of grams you used is not fixed, you can use whatever you want as long as you keep the calculation simple and clear, but usually, 100 grams is the most straightforward and simple) I definitely agree...
Wed Oct 02, 2019 3:18 pm
Forum: Properties of Light
Topic: Colors and Frequency
Replies: 14
Views: 790

### Re: Colors and Frequency

I believe that is would be helpful to know the two opposing ends of the spectrum, with red and blue light, and where they fall into the entire Electromagnetic spectrum.
Wed Oct 02, 2019 3:16 pm
Forum: Properties of Light
Topic: electromagnetic field and magnetic field
Replies: 3
Views: 65

### Re: electromagnetic field and magnetic field

If i am not mistaken, the electric field no and magnetic field are perpendicular in a 3 dimensional space.
Wed Oct 02, 2019 3:13 pm
Forum: Significant Figures
Topic: Sig Fig Decimal
Replies: 10
Views: 135

### Re: Sig Fig Decimal

Does that mean 114.0 would be 4 sig figs?