Search found 61 matches
- Wed Mar 13, 2019 5:24 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Pre-equilibrium approach
- Replies: 4
- Views: 435
Pre-equilibrium approach
When do we use the pre-equilibrium approach?
- Wed Mar 13, 2019 5:18 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: catalyst vs intermediate
- Replies: 3
- Views: 653
Re: catalyst vs intermediate
Intermediates are produced and then consumed, so they will be on the products side for one step and then on the reactants side for a second step. Catalysts are present in the beginning of the reaction (on the reactants for the first step) and present in the end of the reaction (on the products for t...
- Wed Mar 13, 2019 5:12 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Kinetically v. Thermodynamically Controlled Reaction
- Replies: 2
- Views: 561
Kinetically v. Thermodynamically Controlled Reaction
What does it mean for a reaction to be kinetically/thermodynamically controlled? How does temperature affect a reaction that is kinetically controlled?
- Wed Mar 06, 2019 2:07 pm
- Forum: First Order Reactions
- Topic: Pseudo-First-Order Reaction
- Replies: 5
- Views: 550
Re: Pseudo-First-Order Reaction
I think when are there are multiple reactants, we treat the reaction as a pseudo-reaction. It's difficult to study a reaction when the concentrations of multiple reactants are changing, so we let one reactant change and keep the others constant.
- Wed Mar 06, 2019 2:03 pm
- Forum: General Rate Laws
- Topic: Difference between instantaneous and unique rate
- Replies: 3
- Views: 482
Difference between instantaneous and unique rate
Other than the unique rates have coefficients in the equation, what is the difference between instantaneous and unique rate? What does it mean that the unique rate is the same for all reactants and products in that unique reaction?
- Wed Mar 06, 2019 2:00 pm
- Forum: Zero Order Reactions
- Topic: General Meaning of "Zero Order" Reactions
- Replies: 7
- Views: 753
General Meaning of "Zero Order" Reactions
What does it mean for a reaction to have zero order?
- Tue Feb 26, 2019 8:43 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Stoichiometric Coefficients in Cell Diagrams
- Replies: 2
- Views: 233
Stoichiometric Coefficients in Cell Diagrams
Are stoichiometric coefficients included in cell diagrams?
- Tue Feb 26, 2019 8:43 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: H2O and H+ in Cell Diagrams
- Replies: 1
- Views: 244
H2O and H+ in Cell Diagrams
Are H2O and H+ included in a cell diagram? In 6M.5 part c, the solutions manual contains H+ in the cell diagram.
- Tue Feb 26, 2019 2:54 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: 6M.1 7th Ed
- Replies: 1
- Views: 251
6M.1 7th Ed
Hello, I'm having trouble with this problem. It says: A student was given a standard Cu(s)|Cu2+(aq) half-cell and another half-cell containing an unknown metal M in 1.00 M M(NO3)2 (aq) and formed the cell M(s)|M+(aq)||Cu2+(aq)|Cu(s). The cell potential was found to be -0.689 V. What is the value of ...
- Wed Feb 20, 2019 4:45 pm
- Forum: Balancing Redox Reactions
- Topic: Adding Salt Bridge/Porous Disk to Reaction Beakers
- Replies: 2
- Views: 300
Adding Salt Bridge/Porous Disk to Reaction Beakers
Dr. Lavelle discussed that a salt bridge or porous disk must be added to reaction beakers to remain neutral. What is the purpose of that?
- Wed Feb 20, 2019 4:41 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Potential Difference Between Electrodes
- Replies: 1
- Views: 222
Potential Difference Between Electrodes
Why is the maximum potential difference calculated when there is very little current flow?
- Wed Feb 20, 2019 4:38 pm
- Forum: Balancing Redox Reactions
- Topic: Determining Oxidation State
- Replies: 2
- Views: 281
Determining Oxidation State
Hello, Today in lecture Dr. Lavelle discussed the chem reaction 8H+ + MnO4- + 5Fe2+ --> Mn2+ +5Fe3+ + 4H2O How did we determine that iron was oxidized and lost 5 electrons? I know that manganese was reduced because its oxidation number went from +7 to +2, and iron was oxidized because it went from 2...
- Tue Feb 12, 2019 10:15 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Extensive v. Intensive Property of Heat Capacities
- Replies: 3
- Views: 462
Extensive v. Intensive Property of Heat Capacities
Why are heat capacities extensive, but specific and molar heat capacities intensive properties?
- Tue Feb 12, 2019 10:12 pm
- Forum: Calculating Work of Expansion
- Topic: Substituting -nrT for -PΔV
- Replies: 4
- Views: 519
Substituting -nrT for -PΔV
Hello,
When substituting -nrT for -PΔV, how do you know what changing (moles or temperature)?
When substituting -nrT for -PΔV, how do you know what changing (moles or temperature)?
- Tue Feb 12, 2019 10:08 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: Entropy at 0 K
- Replies: 6
- Views: 1490
Entropy at 0 K
Hello,
Is it possible to have 0 entropy? Also, what is the difference between residual, translational, vibrational, and transitional entropy?
Thanks
Is it possible to have 0 entropy? Also, what is the difference between residual, translational, vibrational, and transitional entropy?
Thanks
- Wed Feb 06, 2019 5:15 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: U= 3/2nRT
- Replies: 2
- Views: 529
U= 3/2nRT
Hello,
When is the equation U= 3/2 nrT used? Is it only applicable when the system is isothermal? Also, for this question, is the volume constant and pressure changing?
Thanks!
When is the equation U= 3/2 nrT used? Is it only applicable when the system is isothermal? Also, for this question, is the volume constant and pressure changing?
Thanks!
- Wed Feb 06, 2019 5:00 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Determining Spontaneity of a Reaction
- Replies: 4
- Views: 551
Determining Spontaneity of a Reaction
Hello,
Why do we need to know both enthalpy and entropy to determine if the reaction will occur spontaneously? If the reaction is exothermic, won't the products be favored?
Thanks
Why do we need to know both enthalpy and entropy to determine if the reaction will occur spontaneously? If the reaction is exothermic, won't the products be favored?
Thanks
- Wed Feb 06, 2019 4:56 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Constant Pressure/Volume
- Replies: 6
- Views: 1015
Constant Pressure/Volume
Hello, Dr. Lavelle went over a question in class last week that said "an exothermic reaction occurs an open beaker producing a net 8 moles of gas at 25 C. What is the change in internal energy?" How do we know that this reaction is occurring under conditions of constant pressure? Thanks!
- Wed Jan 30, 2019 10:46 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Calculating Reaction Enthalpies
- Replies: 1
- Views: 205
Calculating Reaction Enthalpies
Hello,
When will we know when do use the different methods for calculating reaction enthalpies?
When will we know when do use the different methods for calculating reaction enthalpies?
- Wed Jan 30, 2019 10:45 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Capacity
- Replies: 5
- Views: 548
Heat Capacity
Hello,
I'm confused about the difference between an extensive property and an intensive property.What is the significance of each?
I'm confused about the difference between an extensive property and an intensive property.What is the significance of each?
- Wed Jan 30, 2019 10:43 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy of Reaction v. Enthalpy of Formation
- Replies: 1
- Views: 220
Enthalpy of Reaction v. Enthalpy of Formation
Hello,
What is the difference between the enthalpy of reaction and the enthalpy of formation? Are they calculated the same way?
Thanks
What is the difference between the enthalpy of reaction and the enthalpy of formation? Are they calculated the same way?
Thanks
- Thu Jan 24, 2019 8:32 pm
- Forum: Phase Changes & Related Calculations
- Topic: Why steam at 100 C burns more than liquid at 100 C
- Replies: 2
- Views: 589
Why steam at 100 C burns more than liquid at 100 C
Hello,
I'm still confused about why steam causes more severe burns at 100 degrees celsius compared to liquid at 100 degrees celsius. Is it because more energy is required for liquid to become gas, so it releases more energy when it touches skin (which is significantly cooler than steam)?
Thanks!
I'm still confused about why steam causes more severe burns at 100 degrees celsius compared to liquid at 100 degrees celsius. Is it because more energy is required for liquid to become gas, so it releases more energy when it touches skin (which is significantly cooler than steam)?
Thanks!
- Thu Jan 24, 2019 8:17 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Weak Acids and Bases
- Replies: 5
- Views: 705
Re: Weak Acids and Bases
Usually, if you are given a Kb value, then you know it's a weak base. Also, there are 6 strong bases: LiOH, NaOH, KOH, Ca(OH)2, Sr(OH)2, Ba(OH)2.
- Thu Jan 24, 2019 3:03 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5% Rule and % Deprotonation
- Replies: 3
- Views: 405
5% Rule and % Deprotonation
Hello,
Is the 5% rule calculated the same way as percent deprotonation/protonation?
Is the 5% rule calculated the same way as percent deprotonation/protonation?
- Wed Jan 16, 2019 5:14 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: pH of Hydronium Ion
- Replies: 1
- Views: 187
pH of Hydronium Ion
In class today, Dr. Lavelle said that if the concentration of hydronium ion is less than 10^-7, then the solution is considered neutral. I understand that it is because the pH would be greater than 7, which is considered basic, but why exactly would the concentration of hydronium ion in a solution r...
- Wed Jan 16, 2019 5:08 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Solids and liquids in K
- Replies: 6
- Views: 2196
Re: Solids and liquids in K
Solids and liquids are not included because they do not affect the reaction amount at equilibrium. Solids remain as solids, so their concentration will not change. Also, we assume that there is a large excess of solvent in the reaction, so liquids will remain at the end of the reaction (cancel out i...
- Tue Jan 15, 2019 8:02 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: HW 6B.11 7th Ed
- Replies: 1
- Views: 222
HW 6B.11 7th Ed
Hello, I'm having difficulty with this problem It says: A student added solid Na2O to a volumetric flaks of volume 200.0 mL, which was then filled with water, resulting in 200.0 mL of NaOH solution. Then 5.00 mL of the solution was transferred to another volumetric flask and diluted to 500.0 mL. The...
- Sat Jan 12, 2019 11:03 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle: Change in temperature
- Replies: 2
- Views: 256
Le Chatelier's Principle: Change in temperature
Hello, I'm a bit confused about how changing temperature changes K. I understand that if the reaction requires heat to form products, then heating will favor products and if the reaction releases heat to form products, then heating will favor reactions, but how does this affect K? Wouldn't the react...
- Thu Jan 10, 2019 2:27 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Explaining Q<K and Q>K [ENDORSED]
- Replies: 7
- Views: 2334
Re: Explaining Q<K and Q>K [ENDORSED]
If Q<K, more reactants are present in the reaction (Dr. Lavelle said that there may be some other source adding reactant) than products being removed, so in order to decrease the amount of reactant to reach equilibrium, the forward reaction is favored to produce more product. If Q>K, there is a high...
- Wed Jan 09, 2019 7:41 pm
- Forum: Ideal Gases
- Topic: Value of K
- Replies: 6
- Views: 1624
Re: Value of K
When K > 1, the equilibrium favors the formation of products. When k < 1, the equilibrium favors the decomposition back to reactants. When k=1, there is the same concentration of reactants and products.
Hope this helps!
Hope this helps!
- Fri Dec 07, 2018 10:12 pm
- Forum: Hybridization
- Topic: The purpose of hybridization
- Replies: 1
- Views: 258
Re: The purpose of hybridization
Hybridization gives the correct number of bonds. For example, using atomic orbitals, CH4 could only form two bonds, but we know that carbon forms 4 bonds. When you use hybrid orbitals, there are four hybrid orbitals (sp^3), which allows carbon to form 4 bonds. Also, the bond angles are incorrect for...
- Fri Dec 07, 2018 10:07 pm
- Forum: Amphoteric Compounds
- Topic: Recognizing Amphoteric Compounds
- Replies: 9
- Views: 785
Recognizing Amphoteric Compounds
What makes certain elements have acid or basic quality in certain compounds? Also, is there a way to know whether something is amphoteric or not, or do we just have to memorize them?
- Fri Dec 07, 2018 10:04 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: 7th edition 6B number 3
- Replies: 1
- Views: 368
Re: 7th edition 6B number 3
HCL is already in units of concentration (mol/L), so in order to find the number of moles, you would have to multiply by 200 mL (.2 L). In order to find the pH of the desired solution, you take the -log[.025 M]. In order to find the actual pH, you would need to divide the number of moles by .25 L an...
- Wed Dec 05, 2018 6:20 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Strength of Acids
- Replies: 1
- Views: 190
Strength of Acids
Why is acetic acid stronger than formic acid? The only difference between the two structures is the extra two hydrogens on acetic acid, so I'm confused to as to why it's stronger. Does it have something to do with being an oxoacid?
Thanks!
Thanks!
- Fri Nov 30, 2018 3:28 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Amines and strength of acid
- Replies: 4
- Views: 439
Re: Amines and strength of acid
Amines are bases. For example, in ammonia, NH3, the nitrogen has a lone pair, making it a base. Amines are considered weaker bases because they are not completely ionized in water.
- Fri Nov 30, 2018 3:24 pm
- Forum: Hybridization
- Topic: 2s or s?
- Replies: 7
- Views: 673
Re: 2s or s?
2s specifics the energy level and the orbital of the atom. S just refers to what type of orbital.
- Fri Nov 30, 2018 11:25 am
- Forum: Electronegativity
- Topic: 7th Edition 3F.15
- Replies: 4
- Views: 2904
Re: 7th Edition 3F.15
AsF3 is polar because it has a lone pair, so the dipoles do not completely cancel. All the dipoles in AsF5 cancel, that's why it is non polar. Because AsF3 is polar, it has dipole-dipole intermolecular forces, so its boiling point would be higher.
Hope this helps!
Hope this helps!
- Tue Nov 20, 2018 8:31 pm
- Forum: Dipole Moments
- Topic: Dipole Moment
- Replies: 1
- Views: 241
Dipole Moment
When are tetrahedrals polar and non polar? For example, a molecule like CCl4 is non polar because the atoms around Carbon are the same, but wouldn't there still be a dipole moment because of the 109.5 angle? I'm a little confused about when you know a molecule (in two planes) is polar or nonpolar.
- Tue Nov 20, 2018 8:18 pm
- Forum: Lewis Structures
- Topic: Lewis structure for POCl3
- Replies: 7
- Views: 1380
Re: Lewis structure for POCl3
I think P is in the middle because it is the least electronegative. When drawing lewis structures, the least electronegative atoms goes in the middle, which in this case, would be phosphorus because it is lower on the periodic table.
- Tue Nov 20, 2018 4:25 pm
- Forum: Hybridization
- Topic: Homework Question 7th Edition 2F.15
- Replies: 2
- Views: 308
Homework Question 7th Edition 2F.15
Hello, I'm having a little difficulty understanding this question: Noting that the bond angle of an sp3 hybridized atom is 109.5 and that of an sp2 hybridized atom is 120, do you expect the bond angle between two hybrid orbitals to increase or decrease as the s-character of the hybrids is increased?...
- Wed Nov 14, 2018 5:08 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: London Dispersion Forces
- Replies: 2
- Views: 559
London Dispersion Forces
In class, we talked about the different intermolecular forces, and Dr. Lavelle mentioned that London Dispersion Forces are the weakest. What exactly are London Dispersion Forces, and why are they much weaker?
Thanks
Thanks
- Wed Nov 14, 2018 5:03 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability v. Polarizing Power
- Replies: 2
- Views: 361
Polarizability v. Polarizing Power
Hello, I'm a little confused by the difference between polarizability and polarizing power. I know the polarizability refers to the large size of anions, and polarizing power refers to small size cations, but what exactly is the reason for how strongly a cation can polarize an anion and how easily a...
- Wed Nov 14, 2018 4:52 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: Polar v. Non Polar
- Replies: 7
- Views: 881
Re: Polar v. Non Polar
Hi! You can determine if some molecules are polar based on the difference in electronegativity of the bond (ie if the difference in electronegativity is between 0 and 0.4, the bond is non polar. If the difference is between 0.5 and 1.4, the bond is polar) . For example, N2 is non-polar because the d...
- Wed Nov 07, 2018 6:57 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: Liquid and Solid Formations for Non-polar Atoms and Molecules
- Replies: 2
- Views: 303
Liquid and Solid Formations for Non-polar Atoms and Molecules
In class today, Dr. Lavelle discussed how electron distortion and polarizability can predict states of matter for certain molecules (like methane and pentane). I'm having a little trouble understanding how the size or molar mass can predict if a molecule is a solid, liquid, or gas. If someone could ...
- Wed Nov 07, 2018 6:52 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability
- Replies: 2
- Views: 248
Polarizability
Hello,
I'm having difficulty understanding polarity. I know that it causes a separation of charge (for example, O becoming slightly negative and H becoming slight positive), but what does it mean that polarity is how easily electrons are distorted?
Thanks
I'm having difficulty understanding polarity. I know that it causes a separation of charge (for example, O becoming slightly negative and H becoming slight positive), but what does it mean that polarity is how easily electrons are distorted?
Thanks
- Tue Nov 06, 2018 7:29 pm
- Forum: Resonance Structures
- Topic: Resonance Hybrids
- Replies: 3
- Views: 406
Resonance Hybrids
Hello,
Does the octet rule have to be fulfilled for resonance hybrids? Is it possible to draw resonance for a molecule that's central atom does not have a complete octet?
Thanks
Does the octet rule have to be fulfilled for resonance hybrids? Is it possible to draw resonance for a molecule that's central atom does not have a complete octet?
Thanks
- Wed Oct 31, 2018 9:20 pm
- Forum: Lewis Structures
- Topic: Double bonds [ENDORSED]
- Replies: 3
- Views: 361
Double bonds [ENDORSED]
Hello,
I'm having troubling knowing when to add double bonds to a lewis structure. When do you know when to change a lone pair to a double bond? Also, when do you know when to stop adding doubling bonds?
Thanks
I'm having troubling knowing when to add double bonds to a lewis structure. When do you know when to change a lone pair to a double bond? Also, when do you know when to stop adding doubling bonds?
Thanks
- Wed Oct 31, 2018 9:17 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Question 2A.9 7th Edition
- Replies: 1
- Views: 146
Question 2A.9 7th Edition
Hi, I'm having difficulty with this problem from the homework: Which M3+ ions (where M is a metal) are predicted have the following ground-state electron configurations: (a) [Ar] 3d6; (b) [Ar] 3d5; (c) [Kr] 4d5; (d) 4d3. I thought you would add 3 electrons to each electron configuration, but the ans...
- Wed Oct 31, 2018 6:32 pm
- Forum: Ionic & Covalent Bonds
- Topic: Question 2A.23 7th Edition
- Replies: 1
- Views: 299
Question 2A.23 7th Edition
Hi, I'm having difficulty with solving this question from the homework: On the basis of the expected charges of the monatomic ions, give the chemical formula of each of the following compounds: a) manganese arsenide; b) indium (III) sulfide; c) aluminum hydride; (d) hydrogen telluride; e) bismuth (I...
- Wed Oct 24, 2018 10:37 pm
- Forum: *Shrodinger Equation
- Topic: Solutions to the Schrodinger Equation
- Replies: 1
- Views: 487
Solutions to the Schrodinger Equation
Hello,
In one of the workshops, we discussed that the wave function is the solution to Schrodinger's equation. What exactly does that mean?
In one of the workshops, we discussed that the wave function is the solution to Schrodinger's equation. What exactly does that mean?
- Wed Oct 24, 2018 10:35 pm
- Forum: Trends in The Periodic Table
- Topic: Ionization Energy
- Replies: 6
- Views: 1751
Ionization Energy
Why does sulfur have a higher ionization energy than oxygen?
- Wed Oct 24, 2018 10:32 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Subshells/Orbitals
- Replies: 5
- Views: 539
Subshells/Orbitals
Hi,
I know that the p subshell has 2px, 2py, and 2pz orbitals, what specific orbitals would the f subshell have?
Thanks!
I know that the p subshell has 2px, 2py, and 2pz orbitals, what specific orbitals would the f subshell have?
Thanks!
- Wed Oct 17, 2018 10:23 pm
- Forum: *Shrodinger Equation
- Topic: Schrodinger's Equation
- Replies: 2
- Views: 205
Schrodinger's Equation
Hello,
I'm having trouble understanding the significance of Schrodinger's equation. What exactly did it prove? Is there any equation related to it?
Thanks!
I'm having trouble understanding the significance of Schrodinger's equation. What exactly did it prove? Is there any equation related to it?
Thanks!
- Wed Oct 17, 2018 10:21 pm
- Forum: DeBroglie Equation
- Topic: Measurable wavelike properties?
- Replies: 2
- Views: 327
Re: Measurable wavelike properties?
Hi!
You compare the wavelength you calculated to the speed of light (3.00*10^8 m/s). If the wavelength you calculated is greater than the speed of light, then it is unrealistic.
Hope this helps!
You compare the wavelength you calculated to the speed of light (3.00*10^8 m/s). If the wavelength you calculated is greater than the speed of light, then it is unrealistic.
Hope this helps!
- Wed Oct 17, 2018 10:19 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbitals
- Replies: 3
- Views: 239
Orbitals
Hello, I'm having a little difficulty understanding orbitals, specifically nodal planes. I know that the S-orbital does not have any nodal planes because it has one orbital, the P-orbital has one nodal plane, and the D-orbital has two nodal planes, but what are the exact functions and significance o...
- Tue Oct 09, 2018 8:40 pm
- Forum: Properties of Light
- Topic: Photoelectric Effect
- Replies: 2
- Views: 135
Photoelectric Effect
Hello,
I'm a little confused about the process of the photoelectric experiment. I know that through this experiment, light was shown to be a particle, but how exactly was this experiment conducted so that the quantum mechanic description of light was proven?
Thank you!
I'm a little confused about the process of the photoelectric experiment. I know that through this experiment, light was shown to be a particle, but how exactly was this experiment conducted so that the quantum mechanic description of light was proven?
Thank you!
- Tue Oct 09, 2018 8:34 pm
- Forum: Properties of Light
- Topic: Atomic Spectra: Balmer and Lyman Series [ENDORSED]
- Replies: 1
- Views: 132
Atomic Spectra: Balmer and Lyman Series [ENDORSED]
Hello,
I'm confused about the applications of the Balmer and Lyman series. I understand that they deal with identifying spectral lines, but what exactly are they used to calculate, when do you use each of them, and how can you use both of the equations in the same problem?
Thanks!
I'm confused about the applications of the Balmer and Lyman series. I understand that they deal with identifying spectral lines, but what exactly are they used to calculate, when do you use each of them, and how can you use both of the equations in the same problem?
Thanks!
- Tue Oct 09, 2018 7:39 pm
- Forum: Properties of Light
- Topic: 1.A.11 Atomic Spectra
- Replies: 1
- Views: 130
1.A.11 Atomic Spectra
Hello, I'm having trouble with 1.A.11. The question is: In the spectrum of atomic hydrogen, several lines are generally classified together as belonging to a series (for example, Balmer series or Lyman series, as shown in Fig.1A.1). What is common to the lines within a series that makes grouping the...
- Wed Oct 03, 2018 10:42 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Fundamentals E3- 7th Edition
- Replies: 3
- Views: 273
Re: Fundamentals E3- 7th Edition
Hello! First, in order to know how many atoms of Astatine you will need, you must calculate the mass of Gallium. You use the 9 atoms from the picture and avogadro's number to convert to moles, then the molar mass of Gallium to convert from moles to grams: Mass Gallium= (9 atoms) *(1 mol Ga/6.02*10^2...
- Wed Oct 03, 2018 10:28 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: G.25 Molarity of Solution after Diluting
- Replies: 1
- Views: 120
G.25 Molarity of Solution after Diluting
I'm having difficulty understanding question G. 25. I know that after doubling the volume the first time, the concentration will decrease to 0.5 mol.L^-1, but I don't know how to double the concentration 90 times without fully writing it out. Practitioners of the branch of a alternative medicine kno...
- Tue Oct 02, 2018 5:12 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Molarity and Dilution of a Solution Post Module Assessment Question 25
- Replies: 5
- Views: 705
Re: Molarity and Dilution of a Solution Post Module Assessment Question 25
First, you would need to convert grams of KMnO4 to moles: 5g KMnO4/158.04 g/mol= 0.0316 mol Then, you would need to calculate the initial molarity of this solution by dividing by the initial volume: 0.0316 mol KMn04/ 0.15 L= 0.2109 M KMnO4 Now, you use the MinitialVinitial=MfinalVfinal equation to f...