Search found 100 matches
- Fri Mar 12, 2021 5:53 pm
- Forum: General Rate Laws
- Topic: Intermediate
- Replies: 59
- Views: 4077
Re: Intermediate
An intermediate is a substance that is produced from a reaction, but then is reacted in another reaction, so that it does not appear in the overall reaction
- Fri Mar 12, 2021 5:51 pm
- Forum: General Rate Laws
- Topic: liquids and solids
- Replies: 6
- Views: 477
Re: liquids and solids
It would largely depend on substances at hand
- Fri Mar 12, 2021 5:50 pm
- Forum: General Rate Laws
- Topic: k vs K
- Replies: 6
- Views: 449
Re: k vs K
K is the equilibrium constant while k is the rate constant.
- Fri Mar 12, 2021 5:47 pm
- Forum: Phase Changes & Related Calculations
- Topic: Vapor vs gas
- Replies: 121
- Views: 14839
Re: Vapor vs gas
Yes a vapor and a gas are the same
- Wed Mar 10, 2021 3:07 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K
- Replies: 33
- Views: 1556
Re: K
K is a variable that represents the equilibrium constant, but Kc is specifically the equilibrium constant in concentrations.
- Wed Mar 10, 2021 3:05 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: rust
- Replies: 8
- Views: 1335
Re: rust
Saltwater speeds up rusting because it allows better electricity conduction, so iron can lose protons much faster.
- Wed Mar 10, 2021 3:00 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: nernst equation
- Replies: 20
- Views: 934
Re: nernst equation
The n is the number of electrons transferred
- Sun Feb 28, 2021 10:53 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation Numbers
- Replies: 30
- Views: 1445
Re: Oxidation Numbers
I think remembering the most common element's oxidation numbers would be good, but not necessarily all of them.
- Sun Feb 28, 2021 10:32 pm
- Forum: Balancing Redox Reactions
- Topic: Determining which molecule is the oxidizing agent
- Replies: 49
- Views: 2116
Re: Determining which molecule is the oxidizing agent
Yes, the oxidizing agent is the substance that is reduced. The reducing agent is being oxidized
- Sun Feb 28, 2021 10:28 pm
- Forum: Balancing Redox Reactions
- Topic: states of matter
- Replies: 58
- Views: 2758
Re: states of matter
Yes, some problems require phases.
- Sun Feb 28, 2021 10:27 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Final
- Replies: 15
- Views: 928
Re: Final
It will be on March 14th!
- Sun Feb 28, 2021 10:19 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Moles in ΔG = -nFE
- Replies: 45
- Views: 4318
Re: Moles in ΔG = -nFE
The "n" in the formula represents moles of electrons.
- Sun Feb 28, 2021 10:18 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Anode/Cathode
- Replies: 45
- Views: 1745
Re: Anode/Cathode
Most definitely! The anode is on the left and the cathode on the right
- Sun Feb 28, 2021 12:41 am
- Forum: Balancing Redox Reactions
- Topic: Sapling #5
- Replies: 9
- Views: 606
Re: Sapling #5
I am having the same problem too. Does anyone have a fix for it?
- Sun Feb 28, 2021 12:33 am
- Forum: Balancing Redox Reactions
- Topic: Charges for balancing redox reactions
- Replies: 8
- Views: 487
Re: Charges for balancing redox reactions
Yes, it is always important to balance the reaction
- Sun Feb 21, 2021 4:45 pm
- Forum: Balancing Redox Reactions
- Topic: coefficients for oxidation number
- Replies: 22
- Views: 5055
Re: coefficients for oxidation number
Simply remember, coefficients do not affect oxidation numbers. There is no relationship with coefficients and oxidation numbers at all.
- Sun Feb 21, 2021 4:42 pm
- Forum: Balancing Redox Reactions
- Topic: Cathode v Anode
- Replies: 8
- Views: 488
Re: Cathode v Anode
I think to calculate anode is where oxidation reaction loses electrons, while the cathode is where the reduction reaction takes place.
- Sun Feb 21, 2021 4:24 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Molecular Interlude
- Replies: 3
- Views: 261
Re: Molecular Interlude
Yeah, some further knowledge about translational, rotational, and vibrational is about degrees of freedom. To calculate the degrees of freedom in a 3 dimensional space, there are some equations you can utilize depending on molecular geometry. For example, note that N = number of atoms in the molecul...
- Sun Feb 21, 2021 4:16 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: delta U=0
- Replies: 17
- Views: 2717
Re: delta U=0
Delta u = 0 because temperature is a constant meaning the change in energy will also be zero. In ideal gas law, enthalpy is a function of temperature, so in isothermal process involving only ideal gases, the change of enthalpy will also be zero.
- Sun Feb 21, 2021 4:12 pm
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 422991
Re: Final Jitters
To calm my anxiety, I use a stress ball and listen to music. Music helps calm me down, and a stress ball is used if I want to take my rage out on something, but being safe at the same time.
- Sun Feb 21, 2021 4:08 pm
- Forum: Student Social/Study Group
- Topic: Culinary Chemistry
- Replies: 239
- Views: 41511
Re: Culinary Chemistry
Yeah, learning about Chemistry definitively helped further my knowledge on cooking. I always wondered the relationship between temperature on the stove and it's effect in the food. After learning more about thermodynamics, I learned that the rate of heat transfer is proportional to the heat transfer...
- Sun Feb 14, 2021 7:33 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy vs Entropy
- Replies: 39
- Views: 3350
Re: Enthalpy vs Entropy
Entropy is the amount of disorder in a system. Enthalpy is the amount of heat released or absorbed in a given system. Temperature and phase changes affect entropy and enthalpy.
- Sun Feb 14, 2021 7:24 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Bomb Calorimeter
- Replies: 12
- Views: 636
Re: Bomb Calorimeter
A bomb calorimeter is a closed system.
- Sun Feb 14, 2021 7:20 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: q vs -q
- Replies: 9
- Views: 584
Re: q vs -q
It shows that the q of the reaction and calorimeter are directly related to each other. The heat of the reaction is the negative of that of the calorimeter.
- Sun Feb 14, 2021 7:08 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: temperature
- Replies: 32
- Views: 1468
Re: temperature
Usually, it is Kelvin that's most commonly used, but sometimes Celsius is needed for the answer.
- Sun Feb 14, 2021 7:05 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Likeliness to form products/reactants
- Replies: 27
- Views: 1049
Re: Likeliness to form products/reactants
A positive delta G means the reaction will for more reactants and a negative delta G mean it will form more products.
- Sun Feb 07, 2021 11:09 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Does phase matter in Hess's Law?
- Replies: 21
- Views: 2142
Re: Does phase matter in Hess's Law?
Phases matter in Hess's Law. Like in the sapling homework for weeks 3/4, you can use a given reaction to change the phases.
- Sun Feb 07, 2021 11:07 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Bomb calorimeter
- Replies: 7
- Views: 572
Re: Bomb calorimeter
It is a constant volume calorimeter that can measure the heat of combustion
- Sun Feb 07, 2021 11:06 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Extensive Properties
- Replies: 10
- Views: 520
Re: Extensive Properties
An extensive property is a property that changes as the amount of substance is changed. The mass, volume, etc. are all extensive.
- Sun Feb 07, 2021 11:03 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Entropy
- Replies: 27
- Views: 1246
Re: Entropy
Entropy is the measure of randomness in a system.
- Sun Feb 07, 2021 10:52 pm
- Forum: Ideal Gases
- Topic: Gas Constant Value
- Replies: 43
- Views: 1933
Re: Gas Constant Value
Hello! there are multiple forms of it depending on the units needed.
- Sun Jan 31, 2021 11:02 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: is HClO3 weak or strong? [ENDORSED]
- Replies: 49
- Views: 4798
Re: is HClO3 weak or strong? [ENDORSED]
I believe that HClO3 is a strong acid!
- Sun Jan 31, 2021 11:01 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Taking the Anti-Log
- Replies: 37
- Views: 2786
Re: Taking the Anti-Log
Since pKa = - log10 Ka, you negative both sides and base 10 both sides. -pKa = log10 Ka -> 10^(-pKa) = Ka
- Sun Jan 31, 2021 10:52 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K vs. Kc
- Replies: 36
- Views: 1537
Re: K vs. Kc
K is the equilibrium constant. Kc is the equilibrium constant for concentrations.
- Sun Jan 31, 2021 10:44 pm
- Forum: Ideal Gases
- Topic: Reversing Reactions
- Replies: 68
- Views: 2716
Re: Reversing Reactions
The K for a reverse reaction is 1/K
- Fri Jan 29, 2021 9:58 pm
- Forum: Phase Changes & Related Calculations
- Topic: endothermic/exothermic
- Replies: 43
- Views: 4951
Re: endothermic/exothermic
Any phase change to gas is considered endothermic. Any phase change to solid is exothermic. Gas to liquid is exothermic while solid to liquid is endothermic.
- Sun Jan 24, 2021 2:51 pm
- Forum: Ideal Gases
- Topic: PV=nRT
- Replies: 74
- Views: 5162
Re: PV=nRT
P stands for Pressure, V stands for Volume, n stands for number of moles, R stands for gas constant, T stands for temperature.
- Sun Jan 24, 2021 2:45 pm
- Forum: Phase Changes & Related Calculations
- Topic: Non-State Properties
- Replies: 9
- Views: 498
Re: Non-State Properties
Work is not a state property because the path in between final and initial affects the amount of work done. Heat is not a state property as the amount of heat transferred depends on the process in between.
- Sun Jan 24, 2021 2:34 pm
- Forum: Phase Changes & Related Calculations
- Topic: Define Phase Change
- Replies: 78
- Views: 5843
Re: Define Phase Change
A phase change is when a solid becomes a liquid or gas becoming a liquid or any combination of the three.
- Sun Jan 24, 2021 2:32 pm
- Forum: Phase Changes & Related Calculations
- Topic: Steam
- Replies: 33
- Views: 2087
Re: Steam
Steam burns are more severe because the energy used to break the hydrogen bonds is an endothermic reaction. When it touches your skin, it becomes a liquid, which is an exothermic reaction, so all the energy used to break the hydrogen bonds are released in heat.
- Sun Jan 17, 2021 2:48 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Using the ICE table
- Replies: 36
- Views: 1544
Re: Using the ICE table
Yes, we can use the ICE table to do problems involving partial pressures
- Sun Jan 17, 2021 2:45 pm
- Forum: Ideal Gases
- Topic: Bars to atm [ENDORSED]
- Replies: 41
- Views: 2132
Re: Bars to atm [ENDORSED]
Dr. Lavelle spoke about this in lecture and told us to approximate 1 bar to 1 atm!
- Sun Jan 17, 2021 2:44 pm
- Forum: Ideal Gases
- Topic: Does temperature matter?
- Replies: 19
- Views: 644
Re: Does temperature matter?
Temperature matters as it affects the condition the experiment is held in
- Sun Jan 17, 2021 2:40 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Heating an Exothermic Reaction
- Replies: 7
- Views: 407
Re: Heating an Exothermic Reaction
Adding heat to an exothermic reaction shifts the reaction to the left, to favor reactants. The reverse reaction of an exothermic reaction is endothermic, which requires heat to function. That is why the reaction shifts to favor reactants.
- Sun Jan 17, 2021 2:27 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling Number 2
- Replies: 2
- Views: 100
Re: Sapling Number 2
Hello Ethan, I started by converting the 0.960 moles of S03 to molarity by dividing it by 5.00 L. So you would make the ICE table with that as the initial SO3 and 0 for the product reactants. Then the change for SO3 will be -2x because of the 2 molar ratio. For 2SO2, it will be +2x. For O2, it will ...
- Sun Jan 10, 2021 3:10 pm
- Forum: Ideal Gases
- Topic: Advice on how to navigate Chem Community
- Replies: 17
- Views: 1019
Re: Advice on how to navigate Chem Community
You can go through the Board Index to find topics that correspond to each course. Clicking on a topic will lead to a subsection with many questions and answers about that topic. You can click "Post a Reply" to answer a question on a post.
- Sun Jan 10, 2021 3:08 pm
- Forum: Ideal Gases
- Topic: Bars to atm [ENDORSED]
- Replies: 41
- Views: 2132
Re: Bars to atm [ENDORSED]
We are allowed to approximate 1 bar = 1 atm! There is a very small difference, though.
- Sun Jan 10, 2021 3:03 pm
- Forum: Ideal Gases
- Topic: Non-Ideal gases?
- Replies: 26
- Views: 1098
Re: Non-Ideal gases?
I think it would be much later in the series, or in upper-division courses.
- Sun Jan 10, 2021 2:48 pm
- Forum: Ideal Gases
- Topic: value of R
- Replies: 24
- Views: 1135
Re: value of R
Each value of R is different because different units are used. Use the value of R that corresponds to your problem.
- Sun Jan 10, 2021 2:43 pm
- Forum: Ideal Gases
- Topic: Kc vs Kp
- Replies: 109
- Views: 5487
Re: Kc vs Kp
Kc is used for problems with molarity and Kp for calculating pressures of gas.
- Wed Dec 16, 2020 1:21 am
- Forum: Naming
- Topic: Ligand use -ate
- Replies: 18
- Views: 1128
Re: Ligand use -ate
Hi! -ate is used when there is an overall negative charge
- Fri Dec 11, 2020 2:27 pm
- Forum: Bronsted Acids & Bases
- Topic: HClO3 Strong Acid
- Replies: 4
- Views: 594
Re: HClO3 Strong Acid
This is really confusing. I think it is because of the three oxygens attached.
- Fri Dec 11, 2020 2:22 pm
- Forum: Bronsted Acids & Bases
- Topic: Strong and Weak Acids/Bases
- Replies: 5
- Views: 302
Re: Strong and Weak Acids/Bases
Yes, it would be best. Sapling provides a very concise list of these acids and bases.
- Fri Dec 11, 2020 2:10 pm
- Forum: Industrial Examples
- Topic: Chemotherapy
- Replies: 22
- Views: 1765
Re: Chemotherapy
As mentioned in lecture, cisplatin is one of them.
- Fri Dec 11, 2020 2:05 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Sapling Week 9 HW Question 2
- Replies: 11
- Views: 650
Re: Sapling Week 9 HW Question 2
The coordination number is the amount of atoms bonded to the transition metal atom, so in this case, it would be 4.
- Thu Dec 10, 2020 3:02 pm
- Forum: Properties of Light
- Topic: Minimum Energy
- Replies: 4
- Views: 488
Re: Minimum Energy
The work function determines the amount of energy to remove an electron from a surface. The threshold frequency is the minimum amount of radiation needed for the work function
- Thu Dec 10, 2020 2:58 pm
- Forum: General Science Questions
- Topic: Textbook Questions on the Final
- Replies: 11
- Views: 725
Re: Textbook Questions on the Final
It will most likely follow a similar format to the previous midterms
- Thu Dec 10, 2020 2:56 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Content
- Replies: 18
- Views: 1145
Re: Final Content
My TA said that there would be more of an emphasis on topics we spent more time on.
- Thu Dec 10, 2020 2:55 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Naming on Final
- Replies: 9
- Views: 689
Re: Naming on Final
Yes, memorizing them would most likely benefit greatly
- Thu Dec 10, 2020 2:54 pm
- Forum: Ionic & Covalent Bonds
- Topic: CO2 vs CS2
- Replies: 8
- Views: 1556
Re: CO2 vs CS2
It is because the oxygen is much more electronegative
- Fri Dec 04, 2020 7:50 pm
- Forum: Resonance Structures
- Topic: Resonance
- Replies: 9
- Views: 671
Re: Resonance
Resonance is where a molecule's Lewis structure could be expressed in multiple ways. This is due to interchanging double bonds or triple bonds.
- Fri Dec 04, 2020 7:30 pm
- Forum: Lewis Structures
- Topic: Lone Pair placement
- Replies: 10
- Views: 688
Re: Lone Pair placement
The lone pairs want to be in the areas where there is least electron repulsion, so the two lone pairs on H2O try to be furthest away from each other
- Fri Dec 04, 2020 5:48 pm
- Forum: Electronegativity
- Topic: Periodic Table Trend
- Replies: 40
- Views: 2662
Re: Periodic Table Trend
Electronegativity increases from the lower left side of the table to the top right and the ionization energy increases as you go from the bottom left to top right.
- Fri Dec 04, 2020 5:43 pm
- Forum: Ionic & Covalent Bonds
- Topic: Polar and Nonpolar
- Replies: 37
- Views: 2009
Re: Polar and Nonpolar
Drawing the molecule and seeing whether there is a difference in dipoles helps too
- Fri Dec 04, 2020 5:37 pm
- Forum: Bond Lengths & Energies
- Topic: London Dispersion Forces/ van der Waal forces
- Replies: 8
- Views: 794
Re: London Dispersion Forces/ van der Waal forces
The two are both essentially the same type of force!
- Fri Dec 04, 2020 3:50 pm
- Forum: Hybridization
- Topic: Sigma/pi bonds
- Replies: 6
- Views: 188
Re: Sigma/pi bonds
I don't think the order matters, as long as we can identify the bonds.
- Thu Nov 26, 2020 1:53 am
- Forum: Ionic & Covalent Bonds
- Topic: Valence in d-block
- Replies: 4
- Views: 373
Re: Valence in d-block
For most d-block elements in period 4, you would add have [Ar] 4s2 and some number of electrons in 3d orbital. As you go along the d block, add one electron to 3d. There are exceptions, such as Cr and Cu in which the 4s orbital is missing one electron. Cr is [Ar]4s1 3d5 and Cu is [Ar]4s1 3d10
- Wed Nov 25, 2020 11:20 pm
- Forum: DeBroglie Equation
- Topic: De broglie equation versus E=hv
- Replies: 10
- Views: 863
Re: De broglie equation versus E=hv
The De Broglie Equation is used to find wavelengths with a mass while E=hv finds the energy of a photon at a given wavelength
- Wed Nov 25, 2020 11:12 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Grade Adjustment after Final
- Replies: 2
- Views: 188
Re: Grade Adjustment after Final
Dr. Lavelle will hopefully curve the grades, but it would be dependent on the final grade distribution.
- Wed Nov 25, 2020 10:45 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final exam (fall 2020 quarter)
- Replies: 20
- Views: 1035
Re: Final exam (fall 2020 quarter)
Dr. Lavelle will most likely discuss it in the upcoming weeks, but I believe it is cumulative. My guess is that it might have an emphasis on material after Midterm 2
- Wed Nov 25, 2020 10:18 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 14B Enrollment [ENDORSED]
- Replies: 67
- Views: 18764
Re: 14B Enrollment [ENDORSED]
I think the lectures are recorded again because it saids "Online - Recorded"
- Wed Nov 25, 2020 10:02 pm
- Forum: Limiting Reactant Calculations
- Topic: Combustion
- Replies: 10
- Views: 636
Re: Combustion
Hi,
In combustion reactions, the Oxygen is usually in excess unless its specific amount is given
In combustion reactions, the Oxygen is usually in excess unless its specific amount is given
- Sun Nov 08, 2020 8:39 pm
- Forum: Trends in The Periodic Table
- Topic: Tips for learning the trends in the Periodic table
- Replies: 11
- Views: 755
Re: Tips for learning the trends in the Periodic table
I personally quiz myself on the trends of atomic radii, ionic radii, etc by looking at different elements. I find that it helps identifying trends after short practice.
- Sun Nov 08, 2020 8:34 pm
- Forum: Coordinate Covalent Bonds
- Topic: Group 13 Elements
- Replies: 4
- Views: 322
Re: Group 13 Elements
Many metal cations are also able to be in Lewis reactions
- Sun Nov 08, 2020 8:27 pm
- Forum: Ionic & Covalent Bonds
- Topic: Classifying Distortion
- Replies: 4
- Views: 196
Re: Classifying Distortion
I think it has to do with the charge of the cation(+1, +2, +3) and the electron density of the anion. There would be a higher distortion as the anion becomes larger as the electrons in the outer shell are held weakly compared to the inner shells. The greater the charge would mean a higher attraction...
- Sun Nov 08, 2020 8:18 pm
- Forum: Ionic & Covalent Bonds
- Topic: Extra Valence Electrons
- Replies: 10
- Views: 509
Re: Extra Valence Electrons
Those three elements are exceptions to the octet rule. It's because of their d-orbitals.
- Sun Nov 08, 2020 8:16 pm
- Forum: Ionic & Covalent Bonds
- Topic: Chemical Bonds
- Replies: 12
- Views: 599
Re: Chemical Bonds
Double bonds are stronger than single bonds, so it pulls atoms closer together
- Sun Nov 01, 2020 7:45 pm
- Forum: DeBroglie Equation
- Topic: Sapling HW (Speed of Diatomic Hydrogen Molecule)
- Replies: 2
- Views: 690
Re: Sapling HW (Speed of Diatomic Hydrogen Molecule)
Hello! I started off with De Broglie's Equation, plugging in the speed of H for v and Planck's constant. To find the mass, multiply the mass of hydrogen(1.008 g/mol) by two, as it is a diatomic. Multiply this by Avogadro's Number and divide by 1000 to get Kg.(Kg is better because Planck's Constant h...
- Sun Nov 01, 2020 7:40 pm
- Forum: DeBroglie Equation
- Topic: wrong equation?
- Replies: 6
- Views: 773
Re: wrong equation?
I believe you mistook two separate equations for De Broglie's. Lambda = h/mv would be the equation.
- Sun Nov 01, 2020 7:37 pm
- Forum: DeBroglie Equation
- Topic: Avogadro's Number
- Replies: 21
- Views: 1738
Re: Avogadro's Number
Avogadro's number is 6.02214 * 10^23 units. These units tell us the amount of "stuff" in a mole. For example, there are 6.02214 * 10^23 atoms of Nitrogen in a Mole of Nitrogen.
- Sun Nov 01, 2020 7:34 pm
- Forum: DeBroglie Equation
- Topic: Sapling HW #17
- Replies: 6
- Views: 407
Re: Sapling HW #17
For this problem, utilize the De Broglie Equation. λ = h/mv. Insert Planck's Constant and the velocity of the diatomic fluorine for h and v, respectively. Mass could be found by multiplying the atomic mass of fluorine(18.998) by 2, then multiplying that by Avogadro's number. Then you would solve for...
- Sun Nov 01, 2020 7:27 pm
- Forum: DeBroglie Equation
- Topic: energy of a photon
- Replies: 7
- Views: 488
Re: energy of a photon
Hello,
You would use the equations E = HV and c= λv. Convert the 2.4 μm to meters and insert that into c= λv for λ. Isolate for v, then use that to solve the E = HV equation
You would use the equations E = HV and c= λv. Convert the 2.4 μm to meters and insert that into c= λv for λ. Isolate for v, then use that to solve the E = HV equation
- Sun Oct 25, 2020 5:35 pm
- Forum: DeBroglie Equation
- Topic: Derivation of Equations on Midterm?
- Replies: 17
- Views: 646
Re: Derivation of Equations on Midterm?
I do not believe so as the midterm is completely MCQ.
- Sun Oct 25, 2020 5:30 pm
- Forum: Einstein Equation
- Topic: Einstein's Equation
- Replies: 7
- Views: 323
Re: Einstein's Equation
The equation Ek = HV - Φ represents the kinetic energy of the ejected electron. This is determined by finding the initial energy of the photon subtracting the threshold energy of the metal, which is the minimum energy required to eject an electron from the metal.
- Sun Oct 25, 2020 5:14 pm
- Forum: Einstein Equation
- Topic: Usage of E=hv
- Replies: 10
- Views: 546
Re: Usage of E=hv
Those equations work for photons. De Broglie's equation is for electrons.
- Sun Oct 25, 2020 5:09 pm
- Forum: Einstein Equation
- Topic: m vs nm
- Replies: 66
- Views: 4069
Re: m vs nm
The question will most likely ask for specific units. Dr Lavelle has said either is fine unless specified.
- Sun Oct 25, 2020 5:08 pm
- Forum: Einstein Equation
- Topic: Textbook Problem 1A.3
- Replies: 9
- Views: 522
Re: Textbook Problem 1A.3
Since frequency and wavelength are directly related to one another( c = λ * v ), the slope on a wave with high frequency will be more than that with a lower frequency. This means the "extent of change" (slope) decreases as frequency decreases.
- Sun Oct 25, 2020 4:43 pm
- Forum: Einstein Equation
- Topic: Scratch paper during the exam
- Replies: 19
- Views: 696
Re: Scratch paper during the exam
Yes I believe so. Run it through with the TA first ofcourse.
- Sun Oct 18, 2020 10:13 pm
- Forum: *Shrodinger Equation
- Topic: Schrodinger for exam
- Replies: 20
- Views: 915
Re: Schrodinger for exam
I don't think so. Understanding basic principles that support what we have learned is enough I think.
- Sun Oct 18, 2020 10:12 pm
- Forum: Einstein Equation
- Topic: e=hv used for particles?
- Replies: 10
- Views: 1451
Re: e=hv used for particles?
E=hv is only usable for electromagnetic radiation.
- Sun Oct 18, 2020 10:04 pm
- Forum: Properties of Electrons
- Topic: Ionizing Electrons vs Ejecting Electrons
- Replies: 6
- Views: 341
Re: Ionizing Electrons vs Ejecting Electrons
Hi! I think Professor Lavelle meant ionizing atoms, not electrons. To my understanding, ionizing atoms and electrons are different procedures.
- Sun Oct 18, 2020 9:40 pm
- Forum: Einstein Equation
- Topic: unexpected outcome of wave-particle experiment
- Replies: 8
- Views: 268
Re: unexpected outcome of wave-particle experiment
The unexpected outcome of the photoelectric experiment was that increasing the intensity of a given light would not eject electrons from a metal surface. However, increasing the wavelengths(frequency) of the light would eject electrons. This is significant because it shows the wave-particle duality ...
- Sun Oct 18, 2020 9:18 pm
- Forum: Properties of Electrons
- Topic: Electron Wave-Particle Duality
- Replies: 10
- Views: 379
Re: Electron Wave-Particle Duality
Wave-particle duality means that electronics are both waves and particles at the same time. It has properties of both. In response to your question, there would be no particle-like behavior in long wavelengths and no wave-like behaviors in short wavelengths, so it wouldn't make sense.
- Sat Oct 17, 2020 4:59 pm
- Forum: Properties of Electrons
- Topic: Work function/Threshold Energy
- Replies: 19
- Views: 795
Re: Work function/Threshold Energy
The threshold energy and the work function are the exact same, only with different names. In the photoelectric effect experiment, the threshold energy is the amount of energy required to displace an electron from the metal.
- Tue Oct 06, 2020 1:37 pm
- Forum: Balancing Chemical Reactions
- Topic: Periodic Table
- Replies: 66
- Views: 5206
Re: Periodic Table
I think a periodic table will be given during exams, but understanding certain properties and elements of the table would be beneficial.
- Mon Oct 05, 2020 9:40 pm
- Forum: SI Units, Unit Conversions
- Topic: Conversion of grams to moles and millimoles to moles.
- Replies: 9
- Views: 4099
Re: Conversion of grams to moles and millimoles to moles.
Converting from grams to moles can be done by dividing the grams of substance divided by the molar mass of the substance. For the millimoles to moles, I think multiplying by 1000 would work
- Mon Oct 05, 2020 7:37 pm
- Forum: Empirical & Molecular Formulas
- Topic: Sapling HW 9
- Replies: 21
- Views: 826
Re: Sapling HW 9
Yes, the empirical formula gives us the ratio of moles between each atom in the molecule, so converting the grams of products to moles would simplify it.
- Mon Oct 05, 2020 7:23 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Determining Molar Mass
- Replies: 19
- Views: 702
Re: Determining Molar Mass
For rough estimates, 16 is fine, but for precise calculations, 15.999 is best.
- Mon Oct 05, 2020 7:20 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: G5 Molarity of Na
- Replies: 6
- Views: 627
Re: G5 Molarity of Na
Which question in the textbook are you looking at? You could take the moles of Na divided by the final volume of the solution of sodium carbonate to find the molarity.
- Mon Oct 05, 2020 6:58 pm
- Forum: SI Units, Unit Conversions
- Topic: Chemistry 14A Exam format
- Replies: 5
- Views: 211
Re: Chemistry 14A Exam format
Dr. Lavelle spoke of partial credit for some problems during discussion, so there seems to be written and multiple choice questions for the exams.