Search found 73 matches
- Fri Mar 15, 2019 9:54 pm
- Forum: Administrative Questions and Class Announcements
- Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
- Replies: 179
- Views: 21959
Re: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
how would you solve for worksheet 10 number 2 part c and d?
- Thu Mar 14, 2019 2:58 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Intermediate vs catalyst
- Replies: 8
- Views: 771
Intermediate vs catalyst
What are differences between intermediates and catalysts?
- Thu Mar 14, 2019 2:52 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Activated Complex Model
- Replies: 1
- Views: 211
Activated Complex Model
How does temperature affect the activated complex model?
- Thu Mar 14, 2019 2:48 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Rate laws
- Replies: 2
- Views: 306
Rate laws
Are catalysts included in the rate law of a reaction mechanism?
- Sun Mar 10, 2019 10:32 pm
- Forum: Second Order Reactions
- Topic: half-life
- Replies: 4
- Views: 347
half-life
For problems where the textbook gives us the half-life of a second order reaction of a substance and it asks us to calculate the time needed for the concentration of the substance to decrease by 1/16, why can't we just multiply the half-life by 4 to get the time needed?
- Sun Mar 10, 2019 4:54 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Slowest step
- Replies: 4
- Views: 529
Slowest step
Why does the slowest step of the reaction mechanism determine the rate of the overall reaction?
- Sun Mar 10, 2019 11:08 am
- Forum: Balancing Redox Reactions
- Topic: Reducing power?
- Replies: 3
- Views: 615
Re: Reducing power?
To rank elements by their reducing power, this means that the element itself is the one that's probably going to be oxidized in the reaction. You can think of it like the more reducing power an element has, the more likely it's going to be oxidized because it's giving up an electron to reduce anothe...
- Sun Mar 10, 2019 10:57 am
- Forum: General Rate Laws
- Topic: reaction process
- Replies: 1
- Views: 226
Re: reaction process
I think one factor is the rate constant - if the rate constant k is very small, then the reaction is going to take longer but if the rate constant k is very large, then the reaction will be faster.
- Sun Mar 10, 2019 10:44 am
- Forum: General Rate Laws
- Topic: Using Average rate of one molecule for another
- Replies: 1
- Views: 231
Re: Using Average rate of one molecule for another
To find the consumption rate of H2, you multiply the average rate of the reaction by 3/2, because the reaction rate has been based on creating 2 mols of NH3, but you need to find the consumption rate of 3 mols of H2. To find the unique reaction rate, you divide the average reaction rate (1.15) by 2 ...
- Sun Mar 03, 2019 1:16 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Setting up redox equation for Nernst
- Replies: 2
- Views: 341
Setting up redox equation for Nernst
An example in the textbook asks us to calculate the potential of a Daniell cell at 25 C in which the concentration of Zn2+ ions is 0.10 mol L 1 and that of the Cu2+ ions is 0.0010 mol L 1. How do we know if Zn2+ or Cu2+ is the product or reactant?
- Sun Mar 03, 2019 12:42 pm
- Forum: Second Order Reactions
- Topic: Reaction orders
- Replies: 3
- Views: 447
Reaction orders
What's the difference between a first and second reaction order, and how do we determine which reaction order a reaction is?
- Thu Feb 28, 2019 6:27 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Concentrations product versus reactant
- Replies: 1
- Views: 299
Concentrations product versus reactant
Calculate the molar concentration of Y3 in a saturated solution of YF3 by using a cell constructed with two yttrium electrodes. The electrolyte in one compartment is 1.0 m Y(NO3)3(aq). In the other compartment you have prepared a saturated solution of YF3. The measured cell potential is 0.34 V at 29...
- Sun Feb 24, 2019 10:05 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Problem question
- Replies: 1
- Views: 169
Problem question
For the 6th edition for problem 14-17, it says (a) Write balanced half-reactions for the redox reaction of an acidic solution of potassium permanganate and iron(II) chloride. (b) Write the balanced equation for the cell reaction and devise a galvanic cell to study the reaction (write its cell diagra...
- Sun Feb 24, 2019 10:02 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram Order
- Replies: 2
- Views: 314
Re: Cell Diagram Order
You put the substance with the highest oxidation number in the couple in the middle of the cell diagram. So, for this problem, you would do Zn/Zn+2//Ni2+/Ni
- Sun Feb 24, 2019 2:07 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs energy
- Replies: 2
- Views: 289
Gibbs energy
What's the difference between delta G and then deltaG^0?
- Fri Feb 22, 2019 2:18 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing problem
- Replies: 3
- Views: 505
Balancing problem
A question asks us to balance this skeletal equation using oxidation and reduction half-reactions, and identify the oxidizing and reducing agent. The reaction is
Cl2(g) --> HClO(aq) + Cl-(aq)
Cl2 is being reduced, so it's the oxidizing agent, but what's being oxidized in this equation?
Cl2(g) --> HClO(aq) + Cl-(aq)
Cl2 is being reduced, so it's the oxidizing agent, but what's being oxidized in this equation?
- Thu Feb 21, 2019 12:46 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: equation explanation
- Replies: 2
- Views: 238
equation explanation
Hi can someone explain the equation G = deltaG^0 + RTlnQ? I'm not sure where the RTlnQ is coming from.
- Sun Feb 17, 2019 6:09 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Delta H given
- Replies: 2
- Views: 497
Re: Delta H given
Delta H is the change in enthalpy, and the definition of enthalpy is that it is heat released or absorbed under constant pressure. So, when you're given delta H you know that there's constant pressure.
- Sun Feb 17, 2019 6:08 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: 4F17
- Replies: 1
- Views: 420
Re: 4F17
Before doing those two steps, you need to heat the water up from 85C to 100C, so you use the q=mcdeltaT formula, where you use the molar heat capacity of liquid water, plug in moles, plug in temperature difference. After this, you add the result to the other two values that you got in your two steps!
- Sun Feb 17, 2019 6:03 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs energy
- Replies: 1
- Views: 206
Gibbs energy
In lecture, professor Lavelle plugged in 0 for G in the equation deltaG=deltaH - TdeltaS to figure out at what temperature is G negative. Why does this work?
- Wed Feb 13, 2019 1:48 pm
- Forum: Administrative Questions and Class Announcements
- Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
- Replies: 179
- Views: 21959
Re: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
For worksheet 4, is the answer for 6a wrong? I did (3/2)(31.9 mol)(8.314 J/Kmol)(311.15 K) = 124 kJ. When I didn't convert the temperature from C to K I got 15.1 kJ which is the answer given in the key. We don’t have to convert it to kelvin as it is change in temperature (38-0) Don't we need to con...
- Thu Feb 07, 2019 10:51 am
- Forum: Calculating Work of Expansion
- Topic: Ideal gas expansion
- Replies: 4
- Views: 392
Ideal gas expansion
Why is the internal energy of an ideal gas equal to 0 when it expands isothermally and reversibly?
- Tue Feb 05, 2019 9:50 pm
- Forum: Phase Changes & Related Calculations
- Topic: Heating Curve
- Replies: 4
- Views: 449
Heating Curve
Why is the heating slope for a liquid less steep if it has a higher heat capacity compared to a lower heat capacity that results in a steeper slope?
- Mon Feb 04, 2019 3:24 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: residual entropy
- Replies: 3
- Views: 321
residual entropy
Can someone explain what residual entropy is and why it's important?
- Sun Feb 03, 2019 9:21 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: 7th edition 4A.3
- Replies: 1
- Views: 161
Re: 7th edition 4A.3
The change in internal energy is equal to q + w. In this problem, q is 0 because there's no heat given off or absorbed as energy, so the change in internal energy is just equal to w. From parts a and b, you know the work value so the change in internal energy will be equal to the work value you solv...
- Sun Feb 03, 2019 9:15 am
- Forum: Calculating Work of Expansion
- Topic: integral work equation
- Replies: 2
- Views: 342
Re: integral work equation
I don't know if there will be specific questions asking us to derive the work equation and explain it using the integral, but I think it's a good idea that you understand how it relates to the work equation because then you'll probably be more comfortable using the work equation to solve problems.
- Sun Feb 03, 2019 9:13 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated System Example
- Replies: 4
- Views: 996
Re: Isolated System Example
An example of an isolated system would be a thermos because no energy or heat can be exchanged with the surroundings because the walls are thermally insulated (no heat), and the volume is constant (no energy as work).
- Wed Jan 23, 2019 6:38 pm
- Forum: Phase Changes & Related Calculations
- Topic: Water heating curve
- Replies: 7
- Views: 710
Water heating curve
For the water heating curve, when water is changing from solid to liquid form and from liquid to vapor form, the temperature remains constant. Even though the extra heat is being used to break down the bonds between the molecules, why isn't there at least a slight increase in temperature?
- Mon Jan 21, 2019 2:16 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Partial pressure vs pressure
- Replies: 2
- Views: 215
Partial pressure vs pressure
Is there a difference when the question asks what happens to the equilibrium composition if the partial pressure of one reactant is increased versus if the overall pressure is increased?
- Mon Jan 21, 2019 9:55 am
- Forum: Calculating the pH of Salt Solutions
- Topic: 6th edition 12.69
- Replies: 1
- Views: 432
6th edition 12.69
The question asks us to calculate the pH of a .055 M solution of AlCl3(aq). The solutions manual shows the equation to be Al(H20)6 + H20 -- H30 + Al(H20)5OH
How do we know to use Al instead of Cl and to combine Al with H2O?
How do we know to use Al instead of Cl and to combine Al with H2O?
- Tue Jan 15, 2019 11:56 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: 11.69 (6th Edition)
- Replies: 3
- Views: 221
Re: 11.69 (6th Edition)
Changing the concentration of reactants and products don't change K because K is a constant - the ratio of products to reactants. When the concentration of the reactant is changed, then the reaction shifts in the direction of the products until the original ratio of P to R is restored. When the conc...
- Tue Jan 15, 2019 11:42 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 11.73 6th edition
- Replies: 2
- Views: 303
Re: 11.73 6th edition
I can't really tell what the equations are because it looks like the computer keyboard may have messed them up haha but I think for a it's reactants because there are more moles of gas on the right side of the reaction. In general for these problems, you can figure them out by this rule : if there a...
- Mon Jan 14, 2019 7:51 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: change in pressure
- Replies: 4
- Views: 410
change in pressure
I understand why if there are more moles of gas on the left side of a reaction, then the reactions shifts right if pressure is added. But, why does the reaction shift left if pressure is added and there are moles of gas on the right?
- Sun Jan 13, 2019 4:13 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: homework problem
- Replies: 2
- Views: 249
homework problem
For 11.43 in the 6th edition, the question says: Consider the reaction 2 NO(g) -- ∆ N2(g) + O2(g). If the initial partial pressure of NO(g) is 1.0 bar, and x is the equilibrium concentration of N2(g), what is the correct equilibrium relation? Why can't the answer be k = x^2/(1.0-x)^2, why is it k=x^...
- Wed Jan 09, 2019 1:09 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Favoring Products/Reactants
- Replies: 3
- Views: 399
Re: Favoring Products/Reactants
If K is greater than 10^3, that means the products are favored - there is a higher concentration of products compared to that of reactants at equilibrium. When K is less than 10^-3, that means the reactants are favored - there is a higher concentration of reactants compared to that of products at eq...
- Wed Jan 09, 2019 1:06 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: What does it mean when a reaction is at equilibrium?
- Replies: 4
- Views: 423
Re: What does it mean when a reaction is at equilibrium?
There's no net change in the concentration of reactants and products and the forward and reverse reactions are happening at the same rate
- Wed Jan 09, 2019 12:50 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5G 1c 7th Edition
- Replies: 1
- Views: 264
Re: 5G 1c 7th Edition
Pressure doesn't change the equilibrium constant it only changes the position of equilibrium. Temperature does affect K. When the forward reaction is endothermic, increasing the temperature increases the value of K. When the forward reaction is exothermic, increasing the temperature decreases the va...
- Fri Dec 07, 2018 5:42 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Charge versus size
- Replies: 1
- Views: 455
Charge versus size
For small, highly charged cations that have greater polarizing power, do we look at the size or the charge of the cation first to determine its polarizing power? For example, if we’re comparing Be2+ and Li+, which one has more polarizing power? Is it Li+ because it’s smaller or Be2+ because it’s mor...
- Thu Dec 06, 2018 11:46 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pKa versus pKb versus Ka versus Kb [ENDORSED]
- Replies: 2
- Views: 316
pKa versus pKb versus Ka versus Kb [ENDORSED]
what is the difference between pKa, pKb, Ka, and Kb?
- Thu Dec 06, 2018 11:40 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Problem 12.25 6th edition
- Replies: 1
- Views: 146
Problem 12.25 6th edition
Calculate the initial molarity of Ba(OH)2 and the molarities of Ba2 , OH , and H3O in an aqueous solution that contains 0.43 g of Ba(OH)2 in 0.100 L of solution.
How do you do this problem?
How do you do this problem?
- Thu Dec 06, 2018 11:38 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: strong vs weak acids
- Replies: 2
- Views: 304
strong vs weak acids
What's the difference when you're calculating the pH of a strong versus a weak acid? I'm very confused with the Ka and the pKa equilibrium and how to calculate the pH when you're given a certain number of grams of a molecule and the molarity of it in a solution.
- Mon Dec 03, 2018 11:48 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Problem 12.19 6th ed
- Replies: 3
- Views: 958
Problem 12.19 6th ed
The concentration of HCl in hydrochloric acid is reduced to 12% of its initial value by dilution. What is the difference in the pH values of the two solutions?
How do you figure out this problem?
How do you figure out this problem?
water
How do you know when to write OH2 versus H2O when writing the formula given the coordination compound?
- Sun Dec 02, 2018 11:17 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Oxidation number
- Replies: 1
- Views: 175
Oxidation number
How do you figure out the oxidation number of coordination compounds?
- Sun Dec 02, 2018 11:15 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: chelate
- Replies: 4
- Views: 439
chelate
What's the importance of a chelate and are they stronger than normal coordination compounds?
Ligands
The textbook says that if a ligand is polydentate, then use the bis, tris, and tetrakis prefixes instead. How do you know if a ligand is polydentate?
- Sat Nov 24, 2018 10:57 am
- Forum: Bond Lengths & Energies
- Topic: Determining Higher Boiling Points
- Replies: 2
- Views: 371
Determining Higher Boiling Points
Predict which would have a higher boiling point: HBr or HI. I thought HBr has higher boiling point compared to HI, because Br is smaller than I, meaning that the bond length between H and Br is shorter and stronger, so it would be harder to break this bond. But, the answer is HI. Can someone explain...
- Sat Nov 24, 2018 10:31 am
- Forum: Ionic & Covalent Bonds
- Topic: Determining the Difference between Ionic and Covalent Bonds
- Replies: 6
- Views: 656
Re: Determining the Difference between Ionic and Covalent Bonds
Will we be given the electronegativities of the two atoms so that we can calculate the difference? Or is it more of an estimate based on where the atoms are on the periodic table?
- Thu Nov 22, 2018 2:41 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: I3- ion shape
- Replies: 2
- Views: 152
I3- ion shape
Why is the shape of an i3- ion linear not angular? Don't the two lone pairs on top of the central iodine repel the other two iodine atoms from being attached in a straight line to the central iodine to bent?
- Mon Nov 19, 2018 4:11 pm
- Forum: Hybridization
- Topic: Problem 4.33
- Replies: 1
- Views: 153
Problem 4.33
State the hybridization of the atom in boldface type in each
of the following molecules: (a) BeCl2 (Be boldface); (b) BH3 (B boldface); (c) BH4 (B boldface); (d) SiF4 (Si boldface).
How do you do this problem?
of the following molecules: (a) BeCl2 (Be boldface); (b) BH3 (B boldface); (c) BH4 (B boldface); (d) SiF4 (Si boldface).
How do you do this problem?
- Sun Nov 18, 2018 9:02 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: Dipole moments
- Replies: 1
- Views: 156
Dipole moments
When you're given isomers of a compound, how do you determine which one has the largest dipole moment?
- Sun Nov 18, 2018 8:59 am
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Sigma and Pi Bonds
- Replies: 5
- Views: 664
Sigma and Pi Bonds
Which type of bond is stronger - a sigma bond or a pi bond?
Also, the textbook had this little chart:
A single bond is a sigma-bond. A double bond is a sigma-bond plus one pi-bond. A triple bond is a sigma-bond plus two pi-bonds.
Can someone explain this?
Also, the textbook had this little chart:
A single bond is a sigma-bond. A double bond is a sigma-bond plus one pi-bond. A triple bond is a sigma-bond plus two pi-bonds.
Can someone explain this?
- Sun Nov 18, 2018 8:38 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability vs Polarizing Power Trends
- Replies: 1
- Views: 1481
Re: Polarizability vs Polarizing Power Trends
Since polarizability is when atoms and ions have electron clouds that easily undergo large distortion, larger atoms are more polarizable compared to smaller atoms. So, polarizability increases going down a group, but decreases going across a period. When you go down a group, there are more shells be...
- Sun Nov 11, 2018 3:13 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape of I3-
- Replies: 1
- Views: 126
Re: Molecular Shape of I3-
I wasn't sure of this question either so as I was looking up different information I found this question was asked in an older chemistry community post! Here's the link :)
viewtopic.php?t=1248
viewtopic.php?t=1248
- Thu Nov 08, 2018 7:19 pm
- Forum: Ionic & Covalent Bonds
- Topic: HW 3.77
- Replies: 4
- Views: 331
HW 3.77
For each pair, determine which compound has bonds with greater ionic character: (a) HCl or HI; (b) CH4 or CF4;
(c) CO2 or CS2.
How do you tell which compound has greater ionic character?
(c) CO2 or CS2.
How do you tell which compound has greater ionic character?
- Thu Nov 08, 2018 7:10 pm
- Forum: Hybridization
- Topic: the ground state and ion exceptions
- Replies: 2
- Views: 281
Re: the ground state and ion exceptions
Cr and Cu are exceptions to the ground state electron configurations rules. Normally, you would expect Cr to be [Ar]3d^4s^2, but it's actually [Ar]3d^54s^1. The reason why is because the Cr is more stable having 5 electrons in its d-orbital because then it's a half-filled subshell, compared to just ...
- Thu Nov 01, 2018 8:10 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionization Energy
- Replies: 2
- Views: 82
Re: Ionization Energy
Ionization energy is the energy it takes to remove an electron from an atom. The periodic table trends are that ionization energy decreases going down a group because the electrons are farther away from the nucleus so there's less charge pulling them in and the other electrons create a shielding eff...
- Thu Nov 01, 2018 8:04 pm
- Forum: Resonance Structures
- Topic: Ground State Electron Configuration
- Replies: 1
- Views: 265
Re: Ground State Electron Configuration
Technically both ways are correct! It's just much easier to write the abbreviated version with the last noble gas filled and then the remaining orbitals because it saves space and time. It's most common to write it the second way and Lavelle usually writes electron configurations that way in lecture...
- Thu Nov 01, 2018 7:59 pm
- Forum: Resonance Structures
- Topic: Ground State Electron Configuration
- Replies: 1
- Views: 215
Re: Ground State Electron Configuration
Since the metal is M^3+ you know that the metal has lost 3 electrons which will help you when trying to figure out what the metal is. a. You're given [Ar]3d^6 after the metal has lost 3 electrons. Remember that the 4s orbital is written after the 3d orbital in electron configuration form because it ...
- Tue Oct 23, 2018 7:20 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configurations
- Replies: 2
- Views: 1936
Re: Electron Configurations
the 4f14 and the 5s4 would come before the 6s2 because they both have lower energy levels than the 6s orbital. When determining the order of the orbitals for the electron configuration think of the orbitals' energy levels. In this case, 4f14 has a lower energy level than 5s2 and 5s4 has a lower ener...
- Mon Oct 22, 2018 8:59 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Question 1.15 6th Edition
- Replies: 1
- Views: 160
Re: Question 1.15 6th Edition
The Lyman series for the hydrogen atom is known to lie in the ultraviolet spectrum and its principle quantum energy level is n1=1, so for this problem since the line is observed in the ultraviolet spectrum, you can apply the fact that the Lyman series is n1=1.
- Mon Oct 22, 2018 8:48 pm
- Forum: DeBroglie Equation
- Topic: HW Help 1.25
- Replies: 4
- Views: 527
Re: HW Help 1.25
Since you're given the amount of sodium in mg, convert this amount into moles by dividing 5.00 mg by the molar mass of sodium. Once you have the amount of sodium in moles, you can multiply this number by avogrado's number to get the number of sodium atoms in 5.00 mg. Finally, multiply your answer by...
- Sat Oct 20, 2018 9:11 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: HW problem 1.43
- Replies: 1
- Views: 152
HW problem 1.43
What is the minimum uncertainty in the speed of an electron con ned to within a lead atom of diameter 350. pm? Model the atom as a one-dimensional box with a length equal to the diameter of the actual atom. How do you model the atom? Is it just a box with a labeled length of 350.pm? Or do we add the...
- Sat Oct 20, 2018 5:38 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: HW 2.19
- Replies: 3
- Views: 364
HW 2.19
(b) How many values of ml are allowed for an electron in a 5f-subshell? (c) How many values of ml are allowed for an electron in a 2s-subshell? I don't understand the answers in the solutions manual. For part b, I thought n=5, l=3 since it's an f orbital, so then the values of ml could be -3, -2, -1...
- Thu Oct 18, 2018 8:34 pm
- Forum: Photoelectric Effect
- Topic: 1B.7
- Replies: 3
- Views: 161
Re: 1B.7
You would first find the number of moles of sodium atoms that 5.00 mg contains by dividing 5.00 mg by sodium's molar mass, then multiply that value by avogardo's number because that would transform the number of moles to the number of atoms that 5.00 mg of NA is. Finally, multiply that value by the ...
- Mon Oct 15, 2018 5:01 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Audio Visual Focus Modules
- Replies: 1
- Views: 93
Re: Audio Visual Focus Modules
I think these are the only modules that he has made. I'm not 100% sure but he probably would have put all the modules he had up on his website no matter the unit we're on. Maybe your TA knows?
- Mon Oct 15, 2018 4:59 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Module Q 23
- Replies: 1
- Views: 166
Module Q 23
23. You are caught in a radar trap and hope to show that the speed measured by the radar gun is in error due to the Heisenberg uncertainty principle. If you assume that the uncertainty in your position was +/- 5 m when your speed was measured, and that the car has a mass of 2150 kg, what is your cal...
- Thu Oct 11, 2018 9:52 am
- Forum: Molarity, Solutions, Dilutions
- Topic: Units?
- Replies: 8
- Views: 763
Re: Units?
It depends on the information given in the question. If the original or diluted solution volume is given in mL, then use mL. But, if it's given in L use L. Usually though they'll specify and if not, you can use L!
- Thu Oct 11, 2018 12:21 am
- Forum: Photoelectric Effect
- Topic: post module assessment Q35B
- Replies: 2
- Views: 306
post module assessment Q35B
Molybdenum metal must absorb radiation with a minimum frequency of 1.09 x 10^15 s-1 before it can emit an electron from its surface. If molybdenum is irradiated with 194 nm light, what is the maximum possible kinetic energy of the emitted electrons? I'm pretty sure we have to solve the problem using...
- Wed Oct 10, 2018 6:15 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Spectral line energy
- Replies: 1
- Views: 131
Spectral line energy
When an electron drops from a higher energy level to a lower energy level, why isn't the energy given off positive? Why is negative? Because wouldn't it have extra energy that can be given off now that it's going down?
- Thu Oct 04, 2018 9:18 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Polyatomic ions
- Replies: 3
- Views: 170
Polyatomic ions
How do you figure out the formulas of polyatomic ions besides memorizing them?
- Sun Sep 30, 2018 10:56 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Question E29
- Replies: 1
- Views: 412
Question E29
A chemist measured out 8.61 g of copper(II) chloride tetrahydrate, CuCl2 * 4H2O. (a). How many moles of CuCl2 * 4H2O were measured out? (b). How many moles of Cl- ions are present in the sample? (c). How many H2O molecules are present in the sample? (d). What fraction of the total mass of the sample...
- Sun Sep 30, 2018 1:34 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Solutions Manual
- Replies: 9
- Views: 1728
Re: Solutions Manual
@katie you can find a solutions manual for the 6th edition on amazon and the 7th edition on textbooks.com! Also for the module there aren't solutions but u can always ask about a specific question in the module here and people will reply with step by step solutions and help :)