Search found 57 matches

by Grace Ramey 2K
Tue Mar 13, 2018 5:39 pm
Forum: *Enzyme Kinetics
Topic: HW 15.101b
Replies: 1
Views: 157

HW 15.101b

The question asks for the rate law for the following mechanism: ClO- + H2O ----> HClO + OH- (fast equilibrium) HClO + I- ----> HIO + Cl- (very slow) HIO + OH- -----> IO- + H2O (fast equilibrium) However, the rate in the solutions manual is rate = (k2k1/k1') [OCl-][I-]/[OH-] Isn't OH- an intermediate...
by Grace Ramey 2K
Mon Mar 12, 2018 8:12 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.79
Replies: 2
Views: 121

Re: 15.79

Here is the question (15.79): In some reactions, two or more different products can be formed by different pathways. If the product formed by the faster reaction predominates, the reaction is considered to be under kinetic control. If the predominant product is the more thermodynamically stable, the...
by Grace Ramey 2K
Mon Mar 12, 2018 2:14 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 15.65 b [ENDORSED]
Replies: 1
Views: 81

15.65 b [ENDORSED]

15.65 For the reversible, one-step reaction 2A---><--- B + C, the forward rate constant for the formation of B is 265 L/mol x min and the rate constant for the reverse reaction is 392 L/mol x min. The activation energy for the forward reaction is 39.7 kJ/mol and that of the reverse reaction is 25.4 ...
by Grace Ramey 2K
Mon Mar 12, 2018 2:07 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: Greater Residual Entropy: NO or BF3
Replies: 2
Views: 138

Greater Residual Entropy: NO or BF3

Which has greater residual entropy at 0 K, NO or BF3?

The correct answer is NO, but doesn't BF3 have more bonds and more atoms in it? Why is the answer NO?

Thanks for your help!
by Grace Ramey 2K
Mon Mar 12, 2018 2:05 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Identigying Anode/Cathode when just given species names and concentrations
Replies: 4
Views: 139

Identigying Anode/Cathode when just given species names and concentrations

The following items are obtained from the stockroom for the construction of a galvanic cell: two 250-mL beakers and a salt bridge, a voltmeter with attached wires and clips, 200 mL of 0.0080 M CrCl3 (aq), 200 mL of 0.12 M CuSO4 (aq), a piece of copper wire, and a chrome-plated piece of metal. The qu...
by Grace Ramey 2K
Tue Mar 06, 2018 2:25 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 15.51
Replies: 6
Views: 151

Re: 15.51

Yes, the fast step doesn't factor into the overall reaction rate, only the slow step does. So, since the rate for the slow step is k[NO][Br2], that should be the overall reaction rate.
by Grace Ramey 2K
Tue Mar 06, 2018 2:21 pm
Forum: First Order Reactions
Topic: 15.37
Replies: 3
Views: 99

Re: 15.37

In this case, the mass can be used in place of the concentration because the conversion to concentration will cancel out in the first order integrated rate law: ln[A] = -kt + ln[A]o rewritten as ([A]/[A]o) = e^(-kt) On the left-hand side, in [A]/[A]o, any conversion factors to mol/L will cancel out,...
by Grace Ramey 2K
Tue Mar 06, 2018 11:48 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 15.55c
Replies: 1
Views: 59

15.55c

The answer to 15.55c is false, and I understand the reasoning behind the answer that the solutions manual gives (increasing the concentration of a reactant increases the rate of a reaction, but not be increasing the rate constant itself). However, I thought that increasing the concentration of a rea...
by Grace Ramey 2K
Sun Mar 04, 2018 5:44 pm
Forum: Second Order Reactions
Topic: 15.39a
Replies: 2
Views: 81

15.39a

For 15.39a, can someone explain why we do not have to take the "2" into account in the equation 2A ---> B + C when solving the problem?

Thank you for your help!
by Grace Ramey 2K
Mon Feb 26, 2018 5:22 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Units for Concentration
Replies: 4
Views: 121

Units for Concentration

Is it necessary, when using "Method 1" (using initial concentrations to find rates and constants), to convert all of the concentrations to mol/L instead of mmol/L? Will the final answer be different?

Thanks!
by Grace Ramey 2K
Mon Feb 26, 2018 5:13 pm
Forum: Second Order Reactions
Topic: 15.19
Replies: 2
Views: 90

15.19

In 15.19, for the part where we determine the order of the the concentration of substance B ([B]), the answer is that it is second order because increasing the concentration of B by 3.02 to 1.25 increases the reaction rate to (3.02/1.25)^2. Were we supposed to be able to recognize the ratio of the r...
by Grace Ramey 2K
Tue Feb 20, 2018 5:53 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.13d
Replies: 1
Views: 91

14.13d

For this question, the balanced reaction is 3 Au+ (aq) ---> 2 Au (s) + Au3+ (aq) The cell diagram, though, is not written with Au+ as the reactant on both the anode and cathode side of the diagram. Can someone explain why this is? I thought the cell diagram is written based off of the balanced equat...
by Grace Ramey 2K
Tue Feb 20, 2018 5:16 pm
Forum: Balancing Redox Reactions
Topic: 14.11d [ENDORSED]
Replies: 2
Views: 137

14.11d [ENDORSED]

For this question, on the right side of the salt bridge in the cell diagram (the cathode), the order of compounds is II OH- (aq) I O2 (g) I was under the impression that the compounds are listed "reactant I product" in cell diagrams. Yet, in the solutions manual, the balanced equation for ...
by Grace Ramey 2K
Mon Feb 19, 2018 10:27 pm
Forum: Balancing Redox Reactions
Topic: 14.5 d steps
Replies: 2
Views: 88

14.5 d steps

Would someone mind maybe writing out the steps of how to balance the reduction half reaction of 14.5d (P4 ---> PH3)? The solutions manual doesn't give a very detailed description of how it got the balanced half reaction, and I am not exactly sure how to go about balancing the hydrogens properly. Tha...
by Grace Ramey 2K
Mon Feb 12, 2018 3:57 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 9.63
Replies: 2
Views: 109

9.63

9.63 Determine which of the following compounds are stable with respect to decomposition into their elements under standard conditions at 25 degrees C (see Appendix 2A): (a) PCl5(g); (b) HCN(g); (c) NO(g); (d) SO2(g). Can someone explain in more detail what the phrase "stable with respect to de...
by Grace Ramey 2K
Mon Feb 12, 2018 11:52 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 9.35 number of moles question [ENDORSED]
Replies: 1
Views: 111

9.35 number of moles question [ENDORSED]

9.35 Container A is fi lled with 1.0 mol of the atoms of an ideal monatomic gas. Container B has 1.0 mol of atoms bound together as diatomic molecules that are not vibrationally active. Container C has 1.0 mol of atoms bound together as diatomic molecules that are vibrationally active. The container...
by Grace Ramey 2K
Mon Feb 12, 2018 10:33 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 8.117
Replies: 1
Views: 90

8.117

8.117 One step in the production of hydrogen as a fuel is the reaction of methane with water vapor: CH4 (g) + H2O (g) -------> CO2 (g) + 3 H2 (g) delta H = -318 kJ What is the change in internal energy for the production of 1.00 mol H2? How did the solutions manual get a delta n (change in moles) of...
by Grace Ramey 2K
Tue Feb 06, 2018 10:57 am
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: 9.75
Replies: 2
Views: 100

9.75

9.75 Considering positional disorder, would you expect a crystal of octahedral cis-MX2Y4 to have the same, higher, or lower residual entropy than the corresponding trans isomer? Explain your conclusion. In the solutions manual, it says that the cis molecule has 12 orientations while the trans isomer...
by Grace Ramey 2K
Mon Feb 05, 2018 10:16 am
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: 9.37d
Replies: 1
Views: 84

9.37d

The question asks for the standard reaction entropy (and the interpretation of its sign and magnitude) for the decomposition of potassium chlorate: 4 KClO3 (s) --------> 3 KClO4 (s) + KCl (s) The solutions manual states that there is a decrease in entropy because 4 moles of solid products are more o...
by Grace Ramey 2K
Mon Feb 05, 2018 10:11 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 9.31d
Replies: 1
Views: 46

9.31d

The correct answer for this question is that 1-pentene (C5H10) has a higher entropy than cyclopentane (C5H10), because 1-pentene has a linear structure and is more "flexible". Is it always the case that linear molecules have more entropy?
by Grace Ramey 2K
Tue Jan 30, 2018 9:49 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Question from 1/24/18 Lecture
Replies: 2
Views: 74

Question from 1/24/18 Lecture

It was mentioned that in the equation (delta S) = (kB)ln(V2/V1), kB (Boltzmann's constant) can be made equal to nR (moles times gas constant). This gives the equation (delta S) = nR(ln(V2/V1)).
Can someone tell me why we can equate kB and nR?

Thank you for your help!
by Grace Ramey 2K
Mon Jan 29, 2018 10:04 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: 9.15a [ENDORSED]
Replies: 2
Views: 69

9.15a [ENDORSED]

9.15 Use data in Table 8.3 or appendix 2A to calculate the entropy change for a) the freezing of 1.00 mol H20 (l) at 0 degrees C. I know in class we talked about delta S = (q(rev))/T) which in this case would equal ((delta H fus)/ T(melting)). So I understand where the solutions manual got (6.01 kJ/...
by Grace Ramey 2K
Mon Jan 29, 2018 9:56 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 9.13 [ENDORSED]
Replies: 6
Views: 349

Re: 9.13 [ENDORSED]

I had another question about 9.13. The question states "assume ideal behavior" for the nitrogen gas described in the problem. Can someone remind me specifically what "ideal behavior" of a gas implies? Thank you for your help!
by Grace Ramey 2K
Thu Jan 25, 2018 5:38 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: 9.1 Entropy Higher or Lower at Higher Temperatures
Replies: 2
Views: 71

9.1 Entropy Higher or Lower at Higher Temperatures

9.1 A human body generates heat at the rate of about 100. W (1 W 1 J .s-'). (a)At what rate does your body heat generate entropy in your surroundings, taken to be at 20.0 C? (b)How much entropy do you generate each day? (c)Would the entropy generated be greater or less if you were in a room kept at ...
by Grace Ramey 2K
Wed Jan 24, 2018 8:08 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.101e
Replies: 2
Views: 102

8.101e

If the standard reaction enthalpy for a certain reaction is negative, does that mean that energy leaves or enters the system? I ask this with regard to question 8.101e, which is as follows: E. How much enthalpy is exchanged, and does it leave or enter the system? The answer is -3.0 kJ. Thank you for...
by Grace Ramey 2K
Mon Jan 22, 2018 9:12 am
Forum: Phase Changes & Related Calculations
Topic: 8.87 Standard enthalpy of vaporization of water
Replies: 2
Views: 135

8.87 Standard enthalpy of vaporization of water

In the second to last step of solving question 8.87, the enthalpy of vaporization of water is required. In the solutions manual, however, 40.7 kJ/mol is used rather than 44.0 kJ/mol. Does anyone know why this is? Can someone explain when to use 40.7 vs 44.0? Here is the question: How much heat is re...
by Grace Ramey 2K
Wed Jan 17, 2018 11:45 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.75 part a [ENDORSED]
Replies: 1
Views: 78

8.75 part a [ENDORSED]

8.75a
Use bond enthalpies to estimate the reaction enthalpy for
N2 (g) + 3F2 (g) ——> 2NF3

The answer is -202 kJ/mol, but I was wondering why it is kJ/mol and not just kJ when 2 mol NF3 are involved in the equation.

Thank you for your help!
by Grace Ramey 2K
Wed Jan 17, 2018 9:25 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.51 energy "released"
Replies: 4
Views: 147

8.51 energy "released"

In the solutions manual for this problem, the enthalpy of the reaction is -13168 kJ/mol, which correpsonds to 4 mol of TNT. So I understand why you would divide this number by 4 to get the enthalpy per one mole of TNT, but I don't understand why the solutions manual makes that answer positive (+3292...
by Grace Ramey 2K
Tue Jan 16, 2018 9:02 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.67 part a
Replies: 1
Views: 54

8.67 part a

For 8.67 part a, how do you know that -242 kJ/mol corresponds to the gaseous phase of water and not the liquid phase? The equation for part a is H2 (g) + (1/2)O2 (g) ——> H2O (l). Where does the water vapor come from?

Thanks for your help!
by Grace Ramey 2K
Sun Jan 14, 2018 8:05 pm
Forum: Phase Changes & Related Calculations
Topic: Heating Curve Question
Replies: 2
Views: 140

Heating Curve Question

Why is it that on heating curves, higher heat capacities have less steep slopes?
by Grace Ramey 2K
Sun Jan 14, 2018 8:03 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 3 Different Methods
Replies: 2
Views: 89

Re: 3 Different Methods

It is determined by what information is given to you in the problem. For example, if you were given a chemical equation along with a list of bond enthalpies for the different bonds involved in that chemical reaction, you would use the bond enthalpy method. If you were given a number of chemical equa...
by Grace Ramey 2K
Sun Jan 14, 2018 7:37 pm
Forum: Phase Changes & Related Calculations
Topic: Another 8.41 Question
Replies: 3
Views: 186

Another 8.41 Question

I have a follow-up question for 8.41: The solutions manual, when setting the heat change of the ice cube and the heat change of the water equal, puts a negative sign in front of the heat change for the water (which is on the left side of the equals sign in the equation below). The equation comes out...
by Grace Ramey 2K
Mon Jan 08, 2018 4:01 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 1 HW
Replies: 3
Views: 156

Re: Week 1 HW

I believe so! I think we can just turn in 14 homework problems during Week 2's discussion section.
by Grace Ramey 2K
Sat Dec 09, 2017 6:32 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.23 [ENDORSED]
Replies: 7
Views: 354

Re: 12.23 [ENDORSED]

[H3O+] = [OH-] when a solution is neutral, so if you set [H3O+] = x, then [OH-] = x. Therefore, if [H3O+][OH-] = 2.1 x 10^-14, then x^2 = 2.1 x 10^-14.

Hope this helps!
by Grace Ramey 2K
Fri Dec 08, 2017 4:43 pm
Forum: Trends in The Periodic Table
Topic: Smaller First Ionization Energy: Sr or Ru
Replies: 1
Views: 96

Smaller First Ionization Energy: Sr or Ru

I recall coming across a question that asked which element has the smaller first ionization energy, Sr or Ru. For some reason, the answer was Ru, which doesn't follow the periodic trend we learned about. Why is this an exception?

Thanks for your help!
by Grace Ramey 2K
Mon Dec 04, 2017 9:30 pm
Forum: Amphoteric Compounds
Topic: 12.17 part b
Replies: 3
Views: 296

12.17 part b

Can someone specifically explain why SO3 is an acidic compound? I am confused because it doesn't have any protons (H+ atoms) to give off. Also, when I drew out the Lewis structure, it appears like a relatively stable molecule.

Thank you for your help!
by Grace Ramey 2K
Mon Dec 04, 2017 9:22 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Ignoring very small quantities of "x" in equilibrium calculations
Replies: 1
Views: 174

Ignoring very small quantities of "x" in equilibrium calculations

Hi! In class today, Dr. Lavelle stated that if the equilibrium constant is less than 10^-3, then any change to the initial concentrations of the reactants can be mostly ignored (e.g. calculating ((x^2)/(.765)) = 2.0 x 10^-5 instead of (x^2)/(.765-x)) = 2.0 x 10^-5). What is the reasoning behind this...
by Grace Ramey 2K
Mon Nov 27, 2017 10:30 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW Question 11.53
Replies: 1
Views: 102

HW Question 11.53

53. A reaction mixture that consisted of .0400 mol H2 and 1.60 mol I2 was introduced into a 3.00-L flask and heated. At equilibrium, 60.0% of the hydrogen gas had reacted. What is the equilibrium constant K for the reaction H2 (g) + I2 (g) <===> 2 HI (g) at this temperature? I wrote out the ICE box,...
by Grace Ramey 2K
Mon Nov 27, 2017 10:22 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelates [ENDORSED]
Replies: 1
Views: 104

Re: Chelates [ENDORSED]

A chelate is a complex comprised of a central metal atom attached to at least one ligand that "forms a ring" with the metal atom. This most often occurs when the ligand is polydentate, so it can bind to the metal atom in more than one place, and form the ring complex that way. I believe in...
by Grace Ramey 2K
Mon Nov 27, 2017 8:54 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW Question 11.43 and general question
Replies: 1
Views: 102

HW Question 11.43 and general question

Can someone please explain question 43 from chapter 11 to me? I tried to use the ice box to figure out the relative concentrations of N2 and O2, but I am not sure I am doing it correctly. Also, as a more general question, how do you handle stoichiometric coefficients in the ice box? I believe the on...
by Grace Ramey 2K
Mon Nov 20, 2017 10:52 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Another Polydentate Question [ENDORSED]
Replies: 1
Views: 106

Another Polydentate Question [ENDORSED]

I know that for a ligand to be polydentate it has to be able to bind to a transition metal cation in more than one spot, but for this to occur, does the ligand have to have a specific shape?
by Grace Ramey 2K
Mon Nov 20, 2017 10:18 am
Forum: Naming
Topic: Anionic Ligand Naming
Replies: 2
Views: 111

Anionic Ligand Naming

For anionic ligand naming, I was confused which convention is correct. For example, in class we learned that when a chloride ion is a ligand, we drop -ide and add -o to make it chloro-. However, in the book "chlorido" is used quite frequently. Are both types of naming correct? Thanks for t...
by Grace Ramey 2K
Sun Nov 19, 2017 5:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pairs
Replies: 4
Views: 171

Re: Lone Pairs

Lone pairs change bond angles because they often have no nucleus (besides the nucleus of the atom they are a part of) pulling them in, and so they sort of "fan out" in a larger electron cloud than if electrons were shared between two different atoms. This larger cloud of electron density r...
by Grace Ramey 2K
Sun Nov 19, 2017 5:21 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: HW Question 4.27
Replies: 4
Views: 139

HW Question 4.27

Can someone explain why 4.27 part A is polar molecule? It is similar to benzene (which I believe is a nonpolar molecule), except that one CH group is exchanged for a nitrogen. But why would one nitrogen atom cause the whole molecule to become polar?

Thanks for the help!
by Grace Ramey 2K
Sun Nov 12, 2017 6:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Electronic Geometry vs. Molecular Geometry
Replies: 1
Views: 231

Re: Electronic Geometry vs. Molecular Geometry

I believe that electronic geometry, or "electronic arrangement", refers to the shape of the molecule regarding the positions of electron density, while molecular geometry or shape only takes actual atoms into account (not the electron density of a lone pair, for example). As an example, a ...
by Grace Ramey 2K
Sun Nov 12, 2017 5:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: ICl3 shape
Replies: 1
Views: 242

ICl3 shape

Are lone pairs that are right next to each other treated as one or two regions of electron density? I was looking at the Lewis Structure for ICl3, and the iodine atom has two lone pairs in the same general area. Would that be counted as one or two regions?

Thank you so much for the help!
by Grace Ramey 2K
Sat Nov 04, 2017 8:47 pm
Forum: Lewis Structures
Topic: S2F2 Isomers Question
Replies: 1
Views: 289

S2F2 Isomers Question

Hi, Would someone mind helping me with this question?: Two structural isomers of disulfur difluoride, S2 F2 are known. In each, the two S atoms are bonded to each other. In one isomer, each of the S atoms is bonded to an F atom. In the other isomer, both F atoms are attached to one of the S atoms. D...
by Grace Ramey 2K
Thu Nov 02, 2017 6:34 pm
Forum: Lewis Structures
Topic: Expanded Octet
Replies: 3
Views: 136

Expanded Octet

Hi! I'm having a lot of trouble writing the electron configuration for atoms that could possibly have an expanded octet (e.g. for atoms like sulfur). Do all atoms with electrons in the 3d subshell have the potential for an expanded octet? If so, how do you determine when an atom that could possibly ...
by Grace Ramey 2K
Thu Nov 02, 2017 6:29 pm
Forum: Lewis Structures
Topic: Valence Electrons for transition metals
Replies: 1
Views: 88

Re: Valence Electrons for transition metals

I'm kind of confused about the same thing, given that the definition of "valence electrons" is the electrons in the outermost shell, which I interpret to mean the electrons within the highest quantum number of "n". With regard to transition metals, though, after searching online ...
by Grace Ramey 2K
Wed Oct 25, 2017 6:42 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Valence Electrons (2.55)
Replies: 2
Views: 112

Valence Electrons (2.55)

Can someone explain how we determine which electrons of an atom are valence-shell electrons? I was doing homework problem number 55 from Ch. 2, and some of the answers to the question include electrons in different shells ((n-1)d^10 ns^1 for part d). Wouldn't the valence-shell configuration require ...
by Grace Ramey 2K
Wed Oct 25, 2017 11:10 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: HW Question 2.37
Replies: 2
Views: 99

HW Question 2.37

I am slightly confused by homework problem 37 in Chapter 2. The solutions manual says that (b) is one of the answers that is true. "(b)" is as follows: "Electrons in an s-orbital are more effective than those in other orbitals at shielding other electrons from the nuclear charge becau...
by Grace Ramey 2K
Sun Oct 22, 2017 2:51 pm
Forum: Trends in The Periodic Table
Topic: Atomic Size Trend [ENDORSED]
Replies: 4
Views: 209

Atomic Size Trend [ENDORSED]

Can someone explain the trend in the periodic table that relates to atomic size again? I just want to make sure that I understand it correctly. I believe that as you go to the right on the periodic table, the atomic size gets smaller. Why is this?
by Grace Ramey 2K
Sun Oct 22, 2017 2:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Electron Spin Quantum Number [ENDORSED]
Replies: 12
Views: 661

Re: Electron Spin Quantum Number [ENDORSED]

I have a follow-up question. How is the spin of an electron (either +1/2 or -1/2) determined? Does the first electron to fill an orbital automatically have a +1/2 spin since we always represent it using an upwards arrow when writing out the electron configuration? Or is there no way to tell the exac...
by Grace Ramey 2K
Thu Oct 12, 2017 9:07 pm
Forum: Properties of Light
Topic: Hw #1.67
Replies: 1
Views: 151

Re: Hw #1.67

For part a, you would use the equation c=λv, and rearrange the equation to give you λ (wavelength) = c (speed of light)/ v (frequency). λ = (3.00 x 10^8 m/s)/(6.27 x 10^14 Hz) = 4.78 x 10^-7 m or 478 nm For part b, use the same equation (c=λv), but rearrange it so that frequency is on one side of th...
by Grace Ramey 2K
Thu Oct 12, 2017 2:15 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Uncertainty in Kinetic Energy
Replies: 2
Views: 148

Uncertainty in Kinetic Energy

If a problem asks you to calculate the uncertainty in kinetic energy, would you just calculate it normally using the equation ((1/2)m(v^2)), and then using the uncertainty in velocity for v? I know this is a very simple question, but I've tried with some problems and I keep getting weird answers! I'...
by Grace Ramey 2K
Wed Oct 04, 2017 10:14 am
Forum: Molarity, Solutions, Dilutions
Topic: HW Problem E35
Replies: 5
Views: 395

Re: HW Problem E35

As a follow-up question for Problem E35, I was wondering how you know the conversion of 1 mol Ca5((PO4)3)OH is exactly 1 mol Ca5((PO4)3)F ? Is it assumed since the problem doesn't state otherwise?
by Grace Ramey 2K
Tue Oct 03, 2017 2:05 pm
Forum: Balancing Chemical Reactions
Topic: Combustion Question
Replies: 9
Views: 447

Combustion Question

Just a quick question about a trend I have noticed in some of the homework problems. Does combustion of a substance always result in the product of CO2 and water (among other compounds that correspond with elements in the reactants)?

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