Search found 130 matches

by Diana_Diep2I
Sat Mar 14, 2020 9:46 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: k
Replies: 7
Views: 130

k

Does the value of k affect the rate of a reaction? Like if k is large, does it mean that the rate of reaction is faster?
by Diana_Diep2I
Sat Mar 14, 2020 9:36 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Slow step
Replies: 2
Views: 31

Re: Slow step

Are you talking about the pre-equilibrium approach? But yes you can ignore the reverse reaction. If you're talking about the pre-equilibrium approach, then for the fast step before the slow one, the reverse must be taken into account.
by Diana_Diep2I
Sat Mar 14, 2020 9:31 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: comparison
Replies: 3
Views: 114

Re: comparison

It is easier to use only the concentrations of the reactants rather than both reactants and products. The reaction may go to equilibrium and it is harder to measure the rates of both R and P.
by Diana_Diep2I
Fri Mar 13, 2020 2:17 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 14F
Replies: 1
Views: 37

14F

On Lyndon's review worksheet, how would we use the preequilibrium approach to figure out k[A][E]?
by Diana_Diep2I
Thu Mar 12, 2020 10:25 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Homework 7E1
Replies: 4
Views: 33

Re: Homework 7E1

It also speeds up the rate of the reverse reaction and because a catalyst only affects speed, it does not affect enthalpy.
by Diana_Diep2I
Thu Mar 12, 2020 10:23 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: K
Replies: 3
Views: 44

K

Why does k have to be in [M]/s?
by Diana_Diep2I
Tue Mar 10, 2020 4:05 pm
Forum: Administrative Questions and Class Announcements
Topic: Chemistry 14B Final
Replies: 9
Views: 246

Chemistry 14B Final

Does anyone know how the Chemistry 14B Final will be given now that classes have gone online? Are all the review sessions cancelled/online now? Will the grading scheme for the course remain the same?
by Diana_Diep2I
Sat Mar 07, 2020 9:02 pm
Forum: General Rate Laws
Topic: Elementary and overall
Replies: 2
Views: 44

Elementary and overall

The exponent in an overall rate is not the same as the exponent in the elementary step right? What is the difference?
by Diana_Diep2I
Sat Mar 07, 2020 12:53 am
Forum: General Rate Laws
Topic: 7A.15
Replies: 3
Views: 77

Re: 7A.15

When you find the ratio between Rate 1 and Rate 4, you will see that [C] will be in zeroth order. That means that now the differential rate law is k[A][B]. Now, when finding the orders of A and B, you don't need to take into account [C] because the reaction does not depend on the concentration of [C].
by Diana_Diep2I
Tue Mar 03, 2020 2:35 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6O1
Replies: 1
Views: 60

6O1

How come the answer key says to choose the reduction reaction with the highest standard reduction potential and to choose the oxidation reaction with the lowest reduction potential and then proceeds to do the opposite?
by Diana_Diep2I
Tue Mar 03, 2020 10:21 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Ions
Replies: 2
Views: 16

Ions

When do we add things like NO3 in the half-reaction and when do we not add it? How do we know to add OH- in the reaction?
by Diana_Diep2I
Tue Mar 03, 2020 10:15 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L 3 part b)
Replies: 1
Views: 25

Re: 6L 3 part b)

These inert electrodes are there because there are no conducting solids for the H2 reaction and the Cl2 reaction. Add them when you don't have a conducting solid. For example, when Fe3+ gets reduced to Fe2+, both still are in aqueous solution. However, you need a conducting solid like Pt(s) that all...
by Diana_Diep2I
Tue Mar 03, 2020 10:12 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L7c
Replies: 2
Views: 57

6L7c

Why is there a KOH in the answer?
by Diana_Diep2I
Tue Mar 03, 2020 10:10 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.5 (d)
Replies: 1
Views: 30

Re: 6L.5 (d)

Yeah unfortunately there is no given reaction for Au3+(aq) + 2e-, but there is a reaction for Au3+ +3e- --> Au. So you work with what you have. You still want to end up with some form of the given reaction in the problem. How do you combine the appendix reactions to give you the same Au+(aq) --> Au(...
by Diana_Diep2I
Sun Mar 01, 2020 2:06 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Standard Cell Potential
Replies: 3
Views: 31

Re: Standard Cell Potential

The objective is to make the cell potential positive so that the cell can do work. If it is negative, the cell is unable to do work and the reaction is unfavorable. Hence, try to combine your values in a way so that you get a positive value. This is for galvanic cells. Electrolytic cells have negati...
by Diana_Diep2I
Thu Feb 27, 2020 5:54 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6O1
Replies: 1
Views: 61

6O1

Why is water used in this problem? They said that SO4- doesn't oxidize and I am wondering why?
by Diana_Diep2I
Thu Feb 27, 2020 10:23 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Hg and Hg2
Replies: 1
Views: 27

Hg and Hg2

Can I assume that 2Hg has no charge while Hg2 has a 2+ charge?
by Diana_Diep2I
Tue Feb 25, 2020 11:13 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Cell Diagram to Redox Reactions
Replies: 2
Views: 34

Re: Cell Diagram to Redox Reactions

How do we know that 2Cl- is being oxidized to Cl2 rather than Cl2 being reduced to 2Cl-?
by Diana_Diep2I
Tue Feb 25, 2020 10:38 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Cell Diagram to Redox Reactions
Replies: 2
Views: 34

Cell Diagram to Redox Reactions

Is there a guideline for translating cell diagrams to redox reactions? For example, in 6N3c, the book switches the anode and the cathode so that the anode reaction is on the right and the cathode reaction is on the left.
by Diana_Diep2I
Tue Feb 25, 2020 10:27 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6N3c
Replies: 2
Views: 55

6N3c

In the 6N3 c) problem, the book combines pressure and concentration in the Q expression. I know that they cancel out the units of pressure, but I still don't understand?
by Diana_Diep2I
Tue Feb 25, 2020 6:12 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6N.1
Replies: 2
Views: 51

Re: 6N.1

I think you're looking at the wrong problem for the answer.
by Diana_Diep2I
Tue Feb 25, 2020 6:10 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: log and ln in Nernst
Replies: 8
Views: 77

log and ln in Nernst

When do we use log and when do we use ln when using the Nernst equation? Or does it not matter?
by Diana_Diep2I
Sat Feb 22, 2020 10:22 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Hg
Replies: 2
Views: 27

Hg

What is the difference between 2Hg^2+ and Hg2^2+? Does one reduce to the other?
by Diana_Diep2I
Fri Feb 21, 2020 8:59 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: H2O, O2 in 6L7b
Replies: 1
Views: 40

H2O, O2 in 6L7b

There are two reactions involving oxygen in basic and acidic solution. How do I determine which one is the anode and which one is the cathode?
by Diana_Diep2I
Fri Feb 21, 2020 4:47 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: galvanic cell
Replies: 2
Views: 31

Re: galvanic cell

I think a nonspontaneous reaction requires an external input of energy, like charging a battery. And if it's dead then yes I don't think any reaction happens unless you add that external energy.
by Diana_Diep2I
Fri Feb 21, 2020 4:36 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge
Replies: 3
Views: 41

Re: Salt Bridge

Sorry, I forgot the positive ion. If it's a salt bridge, something like NaCl will be inside. So if Cl- moves to the side that is being oxidized, Na+ would move to the side that is being reduced.
by Diana_Diep2I
Fri Feb 21, 2020 4:30 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge
Replies: 3
Views: 41

Re: Salt Bridge

It allows ions to flow between the solutions so as to keep both of the solutions in the cells neutral. For example, if Zn is being oxidized to Zn2+, ions like Cl- will flow through the salt bridge to keep the Zn side from becoming too positive.
by Diana_Diep2I
Fri Feb 21, 2020 4:27 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Writing half reactions given cell diagram
Replies: 1
Views: 19

Writing half reactions given cell diagram

If Hg is being oxidized in Hg2Cl2, do we write Hg --> 1/2Hg2 or 2Hg -- Hg2? Do I include the Cl2?
by Diana_Diep2I
Fri Feb 21, 2020 4:21 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram
Replies: 2
Views: 13

Cell Diagram

If the cell diagram has all single lines, how can we determine where the porous disk so as to determine reductions and oxidations?
by Diana_Diep2I
Fri Feb 14, 2020 9:51 pm
Forum: Calculating Work of Expansion
Topic: work = 0
Replies: 14
Views: 239

Re: work = 0

I think it is because the system isn't pushing/expanding any pressure from the outside
by Diana_Diep2I
Fri Feb 14, 2020 9:46 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Delta S
Replies: 2
Views: 49

Re: Delta S

To add to the previous post, in an irreversible reaction, delta S is 0 because the surroundings is basically a vacuum. So yes, there is no opposing force
by Diana_Diep2I
Fri Feb 14, 2020 9:45 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: 4F.1
Replies: 2
Views: 49

Re: 4F.1

Yes, because the temperature is larger in the denominator, the fraction would be smaller compared to if the temperature was smaller. This is also why a certain amount of heat has more effect on the entropy when the temperature is lower.
by Diana_Diep2I
Fri Feb 14, 2020 9:42 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Residual Entropy
Replies: 6
Views: 154

Re: Residual Entropy

It is the only entropy that is left after you take out all types of entropy like thermal entropy. When you reduce the temperature and try to get to 0 Kelvin, the molecules would not be in motion. The only entropy that would be left is the positional entropy. One molecule could be in multiple orienta...
by Diana_Diep2I
Fri Feb 14, 2020 9:17 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Entropy in reversible and irreversible
Replies: 3
Views: 52

Entropy in reversible and irreversible

What is the difference in entropy when it comes to a reversible reaction? Irreversible? Do we calculate it the same way using the deltaS=nRln(V2/V1)?
by Diana_Diep2I
Wed Feb 12, 2020 12:20 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Why is delta U a state function?
Replies: 4
Views: 67

Re: Why is delta U a state function?

Two systems can transfer different amounts of heat and do different amounts of work and still arrive at the same deltaU.
by Diana_Diep2I
Sun Feb 09, 2020 6:53 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 4F11
Replies: 1
Views: 31

4F11

This problem requires the two S equations. The answer key uses R for change in volume AND change in temperature. When do we use C and when do we use R?
by Diana_Diep2I
Sat Feb 08, 2020 10:32 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 4J.5
Replies: 2
Views: 53

Re: 4J.5

The Δ G value in the table will be a bit off compared to if you were to actually calculate it using the values of ΔH and ΔS in Δ G = Δ H − T Δ S
by Diana_Diep2I
Thu Feb 06, 2020 9:03 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: chen discussion [ENDORSED]
Replies: 5
Views: 91

Re: chen discussion [ENDORSED]

When do we use C and when do we use R?
by Diana_Diep2I
Thu Feb 06, 2020 9:02 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Homework Problem 4F.9
Replies: 3
Views: 41

Re: Homework Problem 4F.9

You use the same format as volume, but this time you put P1 above P2 because of Boyle's Law. P1V1=P2V2, so P1/P2=V2/V1. This makes sense because pressure decreases when volume increases. You could expect the entropy to increase.
by Diana_Diep2I
Wed Feb 05, 2020 10:16 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 4F12
Replies: 3
Views: 22

Re: 4F12

Wait, sorry the book uses R in 4F11, but 4F12 tests the same concept
by Diana_Diep2I
Wed Feb 05, 2020 10:15 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 4F12
Replies: 3
Views: 22

4F12

When do we use nCvln(T2/T1) and when do we use nRln(T2/T1)? In this problem the book uses R instead of C and I was wondering when we should use either of them?
by Diana_Diep2I
Mon Feb 03, 2020 10:39 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 4D15
Replies: 1
Views: 34

4D15

How come the answer for this problem is -312 kJ/mol instead of 312 kJ/mol? I used the third method to find the answer, and I got 312. How did the book get a negative answer?
by Diana_Diep2I
Mon Feb 03, 2020 12:58 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: States of a system
Replies: 3
Views: 33

Re: States of a system

It is the number of states to the power of the number of particles.
by Diana_Diep2I
Fri Jan 31, 2020 9:32 pm
Forum: Phase Changes & Related Calculations
Topic: 4A5
Replies: 2
Views: 25

4A5

The answer key uses the reversible isothermic equation to answer part b, but we didn't learn that in lecture? Are we supposed to know it for the midterm?
by Diana_Diep2I
Thu Jan 30, 2020 9:48 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: qp and qv
Replies: 8
Views: 73

qp and qv

Why is qp=∆H and not qv?
by Diana_Diep2I
Thu Jan 30, 2020 9:40 am
Forum: Calculating Work of Expansion
Topic: Integral
Replies: 4
Views: 43

Integral

Will we be using the integral equation? When will we use w=-P∆V and when will we use the integral? What is the difference between them? Is it because in the integral, external pressure may not be constant?
by Diana_Diep2I
Thu Jan 30, 2020 9:33 am
Forum: Calculating Work of Expansion
Topic: reversible and irreversible
Replies: 2
Views: 17

reversible and irreversible

What is the clear difference between reversible and irreversible expansion? I am confused about the role external pressure plays on both of these.
by Diana_Diep2I
Mon Jan 27, 2020 8:04 pm
Forum: Phase Changes & Related Calculations
Topic: #4C11
Replies: 2
Views: 36

#4C11

The answer key gives 6.01 kJ/mol as one of the values. Where did they get it?
by Diana_Diep2I
Mon Jan 27, 2020 7:43 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: q and deltaH
Replies: 3
Views: 25

q and deltaH

What is the difference between q and delta H?
by Diana_Diep2I
Wed Jan 22, 2020 8:24 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Acids and Bases
Replies: 6
Views: 65

Re: Acids and Bases

No we don't. Dr. Lavelle said that polyprotic acids required multiple steps for each time the acid donates a proton.
by Diana_Diep2I
Wed Jan 22, 2020 8:23 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 6D 15b
Replies: 2
Views: 18

Re: 6D 15b

Ka should be in a table in the book. This problem tests 14A material. You're supposed to know that Al3+ can serve as a metal cation that can have multiple bonds (coordination compounds)
by Diana_Diep2I
Wed Jan 22, 2020 8:20 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Approximation
Replies: 2
Views: 14

Re: Approximation

You can check the percent protonation to see if it's less than 5%. You can also check the Ka/Kb value. if the value is less than 10^-3, you can almost safely approximate.
by Diana_Diep2I
Wed Jan 22, 2020 8:19 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE Box vs just solving
Replies: 2
Views: 20

Re: ICE Box vs just solving

Use the ICE box for when the problem asks for something like the pH or pOH of a weak acid/base and you have to find the concentration of the H3O+/OH-. Or, when the problem asks for the equilibrium compositions of the reaction. Then you'd have to find the concentrations for the reactants using the IC...
by Diana_Diep2I
Wed Jan 22, 2020 8:17 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5G5
Replies: 1
Views: 22

5G5

Can someone explain the difference between the third and fourth flask in this problem?
by Diana_Diep2I
Tue Jan 21, 2020 9:58 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Autoprotolysis
Replies: 1
Views: 26

Re: Autoprotolysis

If [H3O+] < 10^-7, then the solution is considered neutral because we know that autoprotolysis generates 10^-7 M H3O+
by Diana_Diep2I
Thu Jan 16, 2020 5:53 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Negative pH
Replies: 6
Views: 45

Re: Negative pH

You get a negative pH when the concentration provided is greater than 1
by Diana_Diep2I
Thu Jan 16, 2020 5:43 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: weak acids and weak bases
Replies: 3
Views: 27

Re: weak acids and weak bases

I'm not exactly sure what kind of calculations you are talking about You would have to use an ICE chart, with Ka and Kb. The problem would most likely ask for the pH/pOH and the concentrations of H3O+/OH-.
by Diana_Diep2I
Tue Jan 14, 2020 6:01 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Endothermic and exothermic reactions
Replies: 11
Views: 633

Endothermic and exothermic reactions

Can someone explain why endothermic reactions favor product formation while exothermic reactions favor reactant formation? I don't understand how the graphs and delta H relate to the concept when explaining product/reactant formation.
by Diana_Diep2I
Tue Jan 14, 2020 4:45 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.16
Replies: 2
Views: 31

Re: 5I.16

Yeah, I was wondering if K would just equal to the total pressure (7.68) bar? Since solids and liquids are not included in the constant expression?
by Diana_Diep2I
Tue Jan 14, 2020 4:42 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5l.13
Replies: 2
Views: 53

Re: 5l.13

Create an ICE chart for the reaction Cl2-->2Cl (it's in the table 5G2). You will find the equilibrium compositions of Cl2 and Cl using the given Kc at 1000 K. Do the same thing for F2. Compare the concentrations you find between Cl2 and Cl/F2 and F. If the concentration of the reactant is greater th...
by Diana_Diep2I
Tue Jan 14, 2020 4:36 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6B.9 Hw problem
Replies: 3
Views: 72

Re: 6B.9 Hw problem

I think we get that when the pH scale exceeds 14. This usually occurs when the molarity or concentration of H3O+ or OH- is greater than 1.
by Diana_Diep2I
Fri Jan 10, 2020 10:07 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Today's Lecture
Replies: 3
Views: 44

Re: Today's Lecture

The proper explanation was the comparison of Q to K, where the concentration doubled due to the volume being halved. When the concentration doubled and we found Q(this is before we wait for the system to return to equilibrium), we found that Q<K. And when Q<K, the reaction shifts to the right.
by Diana_Diep2I
Fri Jan 10, 2020 9:50 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: predicting effects
Replies: 9
Views: 149

Re: predicting effects

I think because it's on the products side, removing one of the products would increase the production of both compounds (NO and SO3)?
by Diana_Diep2I
Thu Jan 09, 2020 12:57 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q vs K
Replies: 8
Views: 76

Re: Q vs K

Q is for when the reaction isn't at equilibrium. K is for when the reaction is at equilibrium.
by Diana_Diep2I
Thu Jan 09, 2020 12:55 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K expression
Replies: 6
Views: 63

Re: K expression

There technically isn't a concentration for a solid b/c it doesn't make sense. We're measuring the change in concentration of compounds in K. As for pure liquids, the concentration isn't changed much. The change is negligible it's practically 0. So if we put something like the concentration of water...
by Diana_Diep2I
Thu Jan 09, 2020 12:51 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5G3
Replies: 8
Views: 63

5G3

Do we include H2O in the gas phase? I know we don't include it in the liquid phase but I am unsure about gas.
by Diana_Diep2I
Thu Jan 09, 2020 12:50 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K being small or large
Replies: 4
Views: 33

Re: K being small or large

Like the post above me said, the reaction favors the reactants if K is small. The reactants are more stable. If K is big, the reaction favors the products and the products are more stable.
by Diana_Diep2I
Sat Dec 07, 2019 2:09 pm
Forum: Dipole Moments
Topic: Dipole Moments Cancel in Tetrahedral?
Replies: 5
Views: 155

Re: Dipole Moments Cancel in Tetrahedral?

If you draw the tetrahedral lewis structure in its actual shape, you would see that they would not cancel due to the vectors pointing upwards or downwards. The structure does not have bond angles of 90º. There would be a net dipole going up or down. For example, CH2Cl2 would still be polar and like ...
by Diana_Diep2I
Tue Dec 03, 2019 8:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond angles of compounds with different atoms
Replies: 2
Views: 75

Re: Bond angles of compounds with different atoms

I'm not sure if it has what I'm asking. I'm asking if having different atoms surrounding the central atom affects the bond angles?
by Diana_Diep2I
Tue Dec 03, 2019 12:15 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond angles of compounds with different atoms
Replies: 2
Views: 75

Bond angles of compounds with different atoms

What would the bond angle of COH3 be? I know that it is a tetrahedral structure, but would the bond angle be any different due to the oxygen atom?
by Diana_Diep2I
Mon Dec 02, 2019 10:56 pm
Forum: Properties & Structures of Inorganic & Organic Bases
Topic: Oxides of main group elements
Replies: 2
Views: 99

Oxides of main group elements

Are oxides of main group elements considered bases? Or do they have to react with water to form bases/acids? For example, Na2O has to react with H2O to form NaOH. Is Na2O considered a base? Or is it the NaOH?
by Diana_Diep2I
Mon Dec 02, 2019 10:11 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: HW 6D11
Replies: 2
Views: 109

Re: HW 6D11

Sorry I forgot to mention that you should look for the strong conjugate acids/bases that come from weak acids/bases. Like for example in a) NH4Br, Br- is a weak conjugate base of the strong acid HBr so it doesn't affect the pH and you shouldn't pay attention to that. NH4+ on the other hand, is a str...
by Diana_Diep2I
Mon Dec 02, 2019 10:05 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: HW 6D11
Replies: 2
Views: 109

Re: HW 6D11

In c), F- is the anion of a weak acid (HF). In lecture today we learned that the conjugate base of a weak acid will raise the pH of the solution by removing protons from water to generate OH-. As a result, the pH will be >7. e) Al3+ is the transition metal that is hydrated and has strong e- withdraw...
by Diana_Diep2I
Fri Nov 29, 2019 2:34 pm
Forum: Hybridization
Topic: #2F16
Replies: 1
Views: 35

#2F16

In problem 2F16, it asks if the N2px orbital participates in hybridization for NH2+ and NH2- if the 2px orbital is lying perpendicular to the plane of the molecule. I am not quite sure as to how to answer this question. How do I know if a particular orbital participates in a hybridization?
by Diana_Diep2I
Wed Nov 27, 2019 4:08 pm
Forum: Biological Examples
Topic: EDTA
Replies: 8
Views: 106

Re: EDTA

It is ethylene-diamine-tetra-acetate and it removes metals from the blood by chelating or binding to cations, aka metals. It has six binding sites(2 amino-nitrogen atoms and 4 carboxylic groups)
by Diana_Diep2I
Wed Nov 27, 2019 4:04 pm
Forum: Naming
Topic: OH2 vs H2O Coordination Complex Chemical Formula
Replies: 3
Views: 33

Re: OH2 vs H2O Coordination Complex Chemical Formula

There really is no difference between the two as both are water, but it is most likely to show that it is oxygen that binds to the complex and not the hydrogen. The formula OH2 gives a more accurate depiction of the structure just like how Dr. Lavelle reversed NH3 and H3N during lecture.
by Diana_Diep2I
Wed Nov 27, 2019 3:51 pm
Forum: Naming
Topic: 9C.3
Replies: 6
Views: 68

Re: 9C.3

The order in which you put your ligands does not matter, but the naming process matters because then you have to take into account alphabetical order.
by Diana_Diep2I
Wed Nov 27, 2019 3:46 pm
Forum: Naming
Topic: HW 9c.9
Replies: 4
Views: 56

Re: HW 9c.9

6 because en has two binding sites. Because it is a bidentate and there are two of them, it binds at four sites. Add the four to the two Cl sites and you get 6.
by Diana_Diep2I
Wed Nov 27, 2019 3:16 pm
Forum: Lewis Acids & Bases
Topic: Bronsted and Lewis Acids
Replies: 4
Views: 61

Bronsted and Lewis Acids

What is the difference between Bronsted and Lewis acids and bases?
by Diana_Diep2I
Sat Nov 23, 2019 2:59 pm
Forum: Naming
Topic: #9C3 d
Replies: 2
Views: 69

#9C3 d

How come bisoxalato comes before diaqua in the name? For reference, the name of the complex is sodium bisoxalato(diaqua)ferrate(III). I thought we were supposed to ignore the greek prefixes and only pay attention to the ligand itself?
by Diana_Diep2I
Wed Nov 20, 2019 6:56 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: 3F.19
Replies: 5
Views: 105

Re: 3F.19

doesn't the strength of london disperson forces take priority over dipole-dipole forces when determining which compound has a higher boiling point? Not really. You have to first compare IMF strength before comparing different London dispersion force factors like size or number of electrons. In this...
by Diana_Diep2I
Tue Nov 19, 2019 12:05 am
Forum: Dipole Moments
Topic: 2E30
Replies: 1
Views: 68

2E30

Question 2E30b asks which molecule has the largest dipole moment and I am conflicted between 1 and 3. Can someone help? Thanks!
by Diana_Diep2I
Mon Nov 18, 2019 10:34 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: ion dipole interactions
Replies: 3
Views: 39

Re: ion dipole interactions

Yes. The phrase "like dissolves like" basically means that polar molecules dissolve in polar molecules, or anything with a charge basically. Because Cl- ion has a negative charge, it will be hydrated. But something like C6H6 cannot dissolve in water or polar substances because it is a nonp...
by Diana_Diep2I
Mon Nov 18, 2019 10:32 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: hydrogen bonds
Replies: 4
Views: 31

Re: hydrogen bonds

Yes they are considered a special dipole-dipole interaction. For example, (HF interacting with NH). However, it is considered stronger than other dipole-dipole interactions.
by Diana_Diep2I
Sat Nov 16, 2019 8:17 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Size and Electronegativity difference
Replies: 3
Views: 68

Size and Electronegativity difference

When do we look at size and when do we look at electronegativity difference when it comes to checking to see which molecule has the higher boiling point? For example, H2S vs H2Se or SiH4 vs SiF4. Do I look at the electronegativity or the size/polarizability of the molecule?
by Diana_Diep2I
Sat Nov 16, 2019 7:56 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Potential energy
Replies: 1
Views: 34

Potential energy

Can someone explain to me what exactly potential energy is between interacting molecules?
by Diana_Diep2I
Thu Nov 14, 2019 11:53 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Polar Vs Nonpolar
Replies: 7
Views: 85

Polar Vs Nonpolar

How can we tell if a molecule is polar or nonpolar? For example: CH2Cl2. How would I be able to find the forces that occur between that molecule besides London forces?
by Diana_Diep2I
Thu Nov 14, 2019 11:43 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Ion-Dipole
Replies: 2
Views: 55

Re: Ion-Dipole

I get what the post above is saying, but what does "extent of hydration" mean? Is it like how many H2O molecules the ion attracts?
by Diana_Diep2I
Thu Nov 14, 2019 11:40 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: question concerning london dispersion forces and molecular formula
Replies: 2
Views: 28

Re: question concerning london dispersion forces and molecular formula

The "increase in mass" actually refers to the increase in C and H atoms because an increase in mass means an increase in the number of electrons. So actually it does not have much to do with the actual mass but rather the increase in the number of electrons when you add C and H. This cause...
by Diana_Diep2I
Thu Nov 14, 2019 11:01 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Electronegativity and Diplole Moments
Replies: 2
Views: 30

Re: Electronegativity and Diplole Moments

In addition to the post above me, this gives rise to intermolecular interactions. The partial charges on the molecules can induce dipoles on other molecules.
by Diana_Diep2I
Thu Nov 14, 2019 10:59 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: London vs Dipole induced dipole
Replies: 2
Views: 24

London vs Dipole induced dipole

I know in lecture that Dr. Lavelle said that London interactions and dipole-induced dipoles were similar and interchanged, but the book says that London forces are between nonpolar molecules while dipole-induced dipoles were between a polar molecule and a nonpolar molecule. Which is it?
by Diana_Diep2I
Fri Nov 08, 2019 9:55 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Water molecules
Replies: 9
Views: 447

Re: Water molecules

It uses both of its hydrogens to form hydrogen bonds with other water molecules but keep in mind that these are not actual bonds. They are interactions between the oxygen atom and the hydrogen atom.
by Diana_Diep2I
Fri Nov 08, 2019 9:51 am
Forum: Photoelectric Effect
Topic: Midterm 1
Replies: 9
Views: 307

Re: Midterm 1

Emily_4B wrote:Do you guys know if we’ll get the midterm back or be able to look at it in office hours to review this question?

I was told that we would get our midterm back next Wednesday during lecture.
by Diana_Diep2I
Fri Nov 08, 2019 9:46 am
Forum: Hybridization
Topic: Pi bonds
Replies: 8
Views: 486

Re: Pi bonds

605110118 wrote:What is the difference between pi and sigma?

sigma is all single bonds and pi is the second bond in a double bond
by Diana_Diep2I
Fri Nov 08, 2019 9:44 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Formal Charge
Replies: 9
Views: 739

Re: Formal Charge

VioletKo3F wrote:What's the equation for the formal charge?

V-(L+S/2) where V is for valence electrons, L is for number of lone electrons, and S is for number of shared electrons.
by Diana_Diep2I
Fri Nov 08, 2019 9:41 am
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarisability vs Polarizing Power
Replies: 15
Views: 289

Re: Polarisability vs Polarizing Power

To add to the replies above, a large anion is usually polarizable because the outer electrons are further from the nucleus and are more likely to feel less of an effective nuclear charge. Meanwhile, a small cation has more polarizing power because of its stronger nuclear charge.
by Diana_Diep2I
Fri Nov 08, 2019 9:36 am
Forum: Sigma & Pi Bonds
Topic: Double bond
Replies: 15
Views: 202

Re: Double bond

How would a double bond help stabilize a structure? In most cases, it would help reduce the formal charge of the atom to 0. For example, oxygen with a single bond and 3 lone pairs has a formal charge of -1. But if you change its bond to a double bond with two lone pairs, it will have a formal charg...

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