Search found 71 matches
- Sun Mar 17, 2019 11:03 pm
- Forum: Balancing Redox Reactions
- Topic: Triprotic
- Replies: 7
- Views: 3697
Re: Triprotic
Hehe, I remember this problem. I just sat there and then finally remembered the chemical notation for phosphoric acid.
- Sun Mar 17, 2019 11:02 pm
- Forum: *Enzyme Kinetics
- Topic: How do you tell if something is a catalyst vs an intermediate?
- Replies: 16
- Views: 5615
Re: How do you tell if something is a catalyst vs an intermediate?
A cool note I found while surfing the web was that a catalyst first shows up as a reactant and reappears as a product whereas an intermediate first shows up as a product and is cancelled out when it appears as a reactant in the next step.
- Sun Mar 17, 2019 11:01 pm
- Forum: Experimental Details
- Topic: Psuedo First Order
- Replies: 7
- Views: 1408
Re: Psuedo First Order
A pseudo rate is considered when there are too many changing concentrations. For instance, it is difficult to calculate the rate when you have k[A][B], and both A and B are changing. As such, you make one significantly larger so that the rate becomes dependent on only the other. For this example, le...
- Sun Mar 17, 2019 10:58 pm
- Forum: First Order Reactions
- Topic: Slopes of a plot
- Replies: 7
- Views: 1185
Re: Slopes of a plot
Yes, both zero and first order reactions' linear plots have slope as -k.
- Sat Mar 16, 2019 10:42 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: q and delta H
- Replies: 6
- Views: 907
Re: q and delta H
q is equal to delta H when pressure is constant.
This gives you:
delta U = delta H - P(delta V)
This gives you:
delta U = delta H - P(delta V)
- Sat Mar 16, 2019 10:40 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: elementary steps
- Replies: 3
- Views: 653
Re: elementary steps
We can use the stoichiometric coefficients when writing the rate law for elementary steps but not for the overall reaction. Given the overall reaction, the exponents on the concentrations for the rate law do not necessarily have to match the coefficients.
- Sat Mar 16, 2019 10:38 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: adiabatic systems
- Replies: 10
- Views: 919
Re: adiabatic systems
No heat is gained or lost by the system, so q=o and delta U = w.
- Sun Mar 10, 2019 10:09 am
- Forum: Zero Order Reactions
- Topic: Half-life
- Replies: 6
- Views: 887
Re: Half-life
Half-life is the amount of time it takes for a species to be reduced to half of its concentration!
- Sun Mar 10, 2019 10:07 am
- Forum: Balancing Redox Reactions
- Topic: Reducing power?
- Replies: 3
- Views: 615
Re: Reducing power?
To determine to order of increasing reducing power, you can reference the standard reduction potential sheet that is given during the test (or in the textbook in appendix 2B). Standard reduction potential is an element's/compound's inclination to be reduced, and the more positive the potential, the ...
- Sat Mar 09, 2019 10:00 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Injecting noble gasses
- Replies: 7
- Views: 733
Re: Injecting noble gasses
Injecting an inert gas will change the total pressure of the system, but it will not change the partial pressures of the other compounds/elements. As such, the equilibrium constant doesn't change!
- Mon Mar 04, 2019 5:39 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: electrolytic cell
- Replies: 4
- Views: 784
Re: electrolytic cell
In an eletrolytic cell, you're converting electrical energy into chemical energy, and in a galvanic cell, you're converting chemical energy into electrical energy!
- Thu Feb 28, 2019 6:07 am
- Forum: Student Social/Study Group
- Topic: Electrochemistry Outline
- Replies: 1
- Views: 506
Electrochemistry Outline
Since test 2 only covers material up to the Nernst equation, which homework problems (6th edition) from the outline should be practiced? (number 1-?)
- Thu Feb 28, 2019 5:50 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Order of Aqueous
- Replies: 2
- Views: 256
Order of Aqueous
In the instance that you have two ions both aqueous both in the same cell, what order would you write them?
ex:
Pt(s) I Ti(3+)(aq), Ti(2+)(aq) II....
or
Pt(s) I Ti(2+)(aq), Ti(3+)(aq) II....
ex:
Pt(s) I Ti(3+)(aq), Ti(2+)(aq) II....
or
Pt(s) I Ti(2+)(aq), Ti(3+)(aq) II....
- Sun Feb 24, 2019 8:22 pm
- Forum: Student Social/Study Group
- Topic: Test #2
- Replies: 7
- Views: 634
Re: Test #2
Definitely electrochemistry because I struggled more with the electrochem homework problems in comparison to Gibbs Free Energy.
- Sun Feb 24, 2019 8:21 pm
- Forum: Student Social/Study Group
- Topic: How are you guys going to study for Test 2?
- Replies: 10
- Views: 915
Re: How are you guys going to study for Test 2?
Going over the homework problems to ensure that I know the key concepts, reviewing the notes, and if time permits, check out the worksheets that UAs post on C. Community.
bless you for this question
bless you for this question
- Sun Feb 24, 2019 8:18 pm
- Forum: Balancing Redox Reactions
- Topic: Including H2O, H+, and OH- in balanced redox reactions
- Replies: 2
- Views: 271
Re: Including H2O, H+, and OH- in balanced redox reactions
In the instance that they cancel out, you do not include them. If they do not completely cancel each other out, include them.
- Sat Feb 23, 2019 11:25 pm
- Forum: Balancing Redox Reactions
- Topic: 14.5d
- Replies: 2
- Views: 229
14.5d
What are the steps you take to balance this reduction reaction?
P4(s) -> H2PO2(-) +PH3(g)
I have:
12e- + P4(s) -> 4PH3(g)
and then:
12e- + P4(s) + 6 H2O -> 4PH3(g) + 6 OH-
but the solutions manual indicates that the reduction reaction requires 12 water and 12 hydroxide ions.
P4(s) -> H2PO2(-) +PH3(g)
I have:
12e- + P4(s) -> 4PH3(g)
and then:
12e- + P4(s) + 6 H2O -> 4PH3(g) + 6 OH-
but the solutions manual indicates that the reduction reaction requires 12 water and 12 hydroxide ions.
- Sun Feb 17, 2019 6:40 pm
- Forum: Phase Changes & Related Calculations
- Topic: Chapter 8 number 21
- Replies: 4
- Views: 462
Re: Chapter 8 number 21
The question is just testing your knowledge that q(sys)=-q(surr). It doesn't matter where the negative sign goes.
- Sun Feb 17, 2019 6:38 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2761537
Re: Post All Chemistry Jokes Here
I tell biology jokes because all of the chemistry ones argon!
- Sun Feb 17, 2019 6:34 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Midterm Grades
- Replies: 35
- Views: 2481
Re: Midterm Grades
Edgar Olivera, the TA for 2J, said that we may receive our midterms back by Wednesday of this week and Friday at the latest.
- Sat Feb 09, 2019 10:09 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Ideal Gas, U(tot)
- Replies: 1
- Views: 234
Ideal Gas, U(tot)
What is U(tot)=(3/2)nRT refer to?
- Sat Feb 09, 2019 12:38 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Molar entropy
- Replies: 2
- Views: 298
Re: Molar entropy
In that instance, you can determine which has a higher molar entropy with which one has greater mass, and since it has greater mass, it also has more elementary particles!
- Fri Feb 08, 2019 11:51 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Motion and Entropy/Enthalpy
- Replies: 3
- Views: 420
Motion and Entropy/Enthalpy
How do vibrational, translational, and vibrational motion relate to entropy and enthalpy?
- Fri Feb 08, 2019 9:44 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: 9.25, Calculation
- Replies: 1
- Views: 234
9.25, Calculation
"9.25 If SO2F2 adopts a positionally disordered arrangement in its crystal form, what might its residual molar entropy be?" When calculating entropy using S=k(b)lnW, the solutions manual states that W is 6^(6.02214*10^23). Is the exponent just based on the number of molecules/units involve...
- Thu Feb 07, 2019 9:29 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Cv,m and CP,m
- Replies: 3
- Views: 709
Cv,m and CP,m
What is the difference between CV,m and CP,m? What do they signify aside from being the heat capacity of gasses?
- Thu Jan 31, 2019 4:38 pm
- Forum: Phase Changes & Related Calculations
- Topic: What Does U and q stand for?
- Replies: 9
- Views: 2205
Re: What Does U and q stand for?
Delta U signifies the change in internal energy.
q refers to the energy transferred by heating.
w is the energy transferred by compression.
q refers to the energy transferred by heating.
w is the energy transferred by compression.
- Thu Jan 31, 2019 4:19 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: 6th Edition, 8.9
- Replies: 1
- Views: 199
6th Edition, 8.9
8.9 "An ideal gas in a cylinder was placed in a heater and gained 5.50 kJ of energy as heat. If the cylinder increased in volume from 345 mL to 1846 mL against an atmospheric pressure of 750. Torr during this process, what is the change in internal energy of the gas in the cylinder?" For t...
- Thu Jan 31, 2019 3:51 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Work Done By vs. On
- Replies: 4
- Views: 273
Work Done By vs. On
What's the difference between "work done by" and "work done on a system"?
- Thu Jan 24, 2019 8:01 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Test 1
- Replies: 9
- Views: 694
Re: Test 1
You can consult the Constants and Equations sheet on Dr. Lavelle's website too! It's pretty handy to use while you do your homework so that you're used to it when taking tests:
https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf
https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf
- Thu Jan 24, 2019 7:56 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 11.57 6th Edition
- Replies: 2
- Views: 274
Re: 11.57 6th Edition
The CH4 isn't placed in the vessel but rather is produced through the chemical reaction involving CO and H2.
- Thu Jan 24, 2019 7:54 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Acid and bases
- Replies: 1
- Views: 137
Re: Acid and bases
Acids and bases are subject to chemical equilibrium in that under certain conditions, acids and bases produce a discrete amount of hydronium or hydroxide ions.
- Sat Jan 19, 2019 8:21 am
- Forum: Significant Figures
- Topic: SigFig: 12.59
- Replies: 1
- Views: 511
SigFig: 12.59
The initial values given for the question were 0.0073 M of codeine and pKa of conjugate acid was 8.21. With that, I assumed there were 2 significant figures (0.0073). The answer was: 1.5%, 3.96, 10.04 For 10.04, does ".04" count as two significant figures since it's after the decimal point...
- Fri Jan 18, 2019 5:05 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: 12.39 and 12.41
- Replies: 1
- Views: 221
12.39 and 12.41
12.39: Using data in Tables 12.1 and 12.2, place the following acids in order of increasing strength: HNO2, HClO2, +NH3OH, (CH3)2NH2+" How would you go about solving this problem? I referred to the table in the textbook and got the values for HNO2 and HClO2, but the last two aren't listed. What...
- Thu Jan 17, 2019 10:41 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Acids and Bases
- Replies: 2
- Views: 1942
Re: Acids and Bases
A strong acid will dissociate completely whereas a weak acid will not. Weak acids have a K constant <10^-3.
- Thu Jan 17, 2019 8:33 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Autoprotolysis
- Replies: 2
- Views: 291
Autoprotolysis
Is autoprotolysis a process that is exclusive to water or can other molecules perform autoprotolysis?
- Thu Jan 17, 2019 5:30 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: 6th Edition, 12.23
- Replies: 2
- Views: 431
6th Edition, 12.23
12.23: The value of Kw for water at body temperature (37 C) is 2.1*10^(-14) mol*L-1. (a) What is the molarity of H3O+ ions and the pH of neutral water at 37 C? I calculated the pH, and I got 6.838890353; when rounding, I should get 6.83, but the textbook says the answer is 6.80. Can someone please e...
- Thu Jan 10, 2019 9:48 pm
- Forum: Student Social/Study Group
- Topic: Outlines Included in Test 1
- Replies: 2
- Views: 171
Outlines Included in Test 1
Which outlines will be on test 1? Just trying to mentally and physically prepare myself
- Thu Jan 10, 2019 9:35 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Clarification from lecture 1 - Jan 7th
- Replies: 2
- Views: 161
Re: Clarification from lecture 1 - Jan 7th
The 1 and the 61.0 are because it is a reversible reaction. 61.0 is the equilibrium constant of the forward reaction, and the reverse reaction's equilibrium constant is just the inverse of the forward reaction's equilbrium constant.
Forward reaction: 61.0; reverse reaction: 1/61.0
Forward reaction: 61.0; reverse reaction: 1/61.0
- Thu Jan 10, 2019 9:09 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: 11.13
- Replies: 1
- Views: 154
11.13
For the answers in question 11.13, is there a particular reason as to why for parts a and c are written using partial pressures and part b is written with molar concentrations?
11.13: "Write the reaction quotient Q for..."
11.13: "Write the reaction quotient Q for..."
- Sat Dec 08, 2018 10:18 am
- Forum: Significant Figures
- Topic: Quantum World, Test 2: SigFigs
- Replies: 1
- Views: 411
Quantum World, Test 2: SigFigs
On question 2 of the quantum world exam, the question asks: "The uncertainty in the momentum (delta p) of a cricket ball which is traveling at 150 km/hr is 2 x 10(-6) times its momentum. Its mass is 0.160 kg. Calculate its minimum delta x." How many significant figures should the answer ha...
- Sat Dec 08, 2018 10:02 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: boiling point
- Replies: 5
- Views: 1160
Re: boiling point
NH3 will have a greater boiling point than PH3 because of hydrogen bonding. NH3 is capable of having hydrogen bonds and PH3 is not because nitrogen is significantly more electronegative, thus creating a dipole moment with a partial positive charge on the hydrogens and a partial negative charge on th...
- Sat Dec 08, 2018 9:57 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: sig figs
- Replies: 1
- Views: 228
Re: sig figs
I would say they're pretty important seeing as points have been deducted on exams for incorrect significant figures. Reference guides on how to calculate significant figures are on Professor Lavelle's website.
- Sat Dec 08, 2018 9:55 am
- Forum: Biological Examples
- Topic: naming
- Replies: 1
- Views: 402
Re: naming
Polydentate means that a ligand is able to occupy multiple bonding sites at once because it has lone pairs. So applying the Greek prefixes, a monodentate binds to one bonding site, and bidentate bonds to two.
- Sat Dec 01, 2018 11:24 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final
- Replies: 5
- Views: 556
Re: Final
Friday, December 7th is exclusively for past exam questions. Dr. Lavelle told lecture 1 that the last day of instruction covering new material would be the Wednesday of that week.
Happy studying! :)(((
Happy studying! :)(((
- Sat Dec 01, 2018 11:00 pm
- Forum: Naming
- Topic: Toolbox 17.1
- Replies: 1
- Views: 75
Toolbox 17.1
In the 6th edition on page 741, the textbook names [FeCl(OH2)5)+ as pentaaquachlridoiron(II) ion and [Fe(NCS)(OH2)5]2+ as thiocynato(kN)pentaaqua(III) iron. What is the reasoning behind placing the oxidation number after the name in the former and before the TM in the latter? Is it because the forme...
- Sat Dec 01, 2018 6:57 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordinate Covalent Bonds
- Replies: 1
- Views: 241
Coordinate Covalent Bonds
How are coordinate covalent bonds formed?
- Sun Nov 25, 2018 5:12 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 3
- Replies: 6
- Views: 539
Re: Test 3
MMoreno3K wrote:Does anyone know the specific topics that will be on the test?
On the class website, it is written that "Test 3 covers: End of Bonding from 3.12 (6 Ed.) and from 2D (7 Ed.); and all of Molecular Shape and Structure (see Syllabus and Outlines for details)."
Good luck with your studies!
- Sun Nov 25, 2018 5:11 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Dipole
- Replies: 2
- Views: 277
Re: Dipole
Can someone please explain to me what exactly dipole means? A dipole moment is an electrical movement from one atom toward one adjacent atom. Dipole moments do not occur with diatomic molecules because the two atoms have the same electronegativity. Dipole moments also determine covalent bond disass...
- Sun Nov 25, 2018 12:55 pm
- Forum: Ionic & Covalent Bonds
- Topic: Bond Strengths
- Replies: 1
- Views: 181
Bond Strengths
"On a plot of the potential energy of a diatomic molecule as a function of the internuclear distance, the dissociation energy is the distance between the bottom of the energy well and the energy of the separated atoms" (93, 6th E.). Would someone be able to explain this to me in layman ter...
- Sat Nov 17, 2018 7:28 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Radicals in Molecular Structure Notation
- Replies: 2
- Views: 123
Re: Radicals in Molecular Structure Notation
LOL I cannot do math. I'm leaving this school.
- Sat Nov 17, 2018 5:35 pm
- Forum: Octet Exceptions
- Topic: Tin with only 6 electrons
- Replies: 4
- Views: 845
Tin with only 6 electrons
"4.19 Predict the shapes and estimate the bond angles of...(d) SnCl2."
In the Lewis dot structure for SnCl2, tin is drawn to only have 6 electrons. Why is it that tin is an exception to the octet rule?
In the Lewis dot structure for SnCl2, tin is drawn to only have 6 electrons. Why is it that tin is an exception to the octet rule?
- Sat Nov 17, 2018 5:24 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Radicals in Molecular Structure Notation
- Replies: 2
- Views: 123
Radicals in Molecular Structure Notation
For the "ABE" notation (A being the central atom, B being atoms bonded to the central atom, and E being lone electron pairs around the central atom), how is it written for radicals? ex: "4.19 Predict the shapes and estimate the bond angles of...(c) BH(2)-" BH(2)- has only 5 elect...
- Sat Nov 17, 2018 5:01 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 4.17d
- Replies: 2
- Views: 461
4.17d
"Predict the bond angles at the central atom of the following molecules and ions:...d) hydronium ion, H3O+."
I was able to understand that the shape of this molecule is a tetrahedral, but why is it that the bond angle is "slightly less than 109.5" rather than 109.5?
I was able to understand that the shape of this molecule is a tetrahedral, but why is it that the bond angle is "slightly less than 109.5" rather than 109.5?
- Mon Nov 12, 2018 1:51 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Why do the orbitals of an atom only hold a certain amount of electrons?
- Replies: 7
- Views: 972
Re: Why do the orbitals of an atom only hold a certain amount of electrons?
we know that orbitals are given by s, p, d, and f subshells, and we know that each of these can hold 2, 6, 10, and 14 electrons, respectively. But where do those numbers come from? Each orbital is capable of holding 2 electrons. The magnetic quantum number (m(l)) depicts the orientation/# of orbita...
- Mon Nov 12, 2018 1:34 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Cations and polarizing power
- Replies: 3
- Views: 253
Re: Cations and polarizing power
Can someone explain to me why smaller and more highly charged cations have more polarizing power? Smaller, more highly charged cations have more polarizing power because these cations cause larger distortions since the more highly charged the cation, the greater the electrostatic attraction is exhi...
- Mon Nov 12, 2018 1:24 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Energy of Bonds
- Replies: 3
- Views: 349
Re: Energy of Bonds
How do we determine the energy of each bond? For example when we did the Lewis structure of Benzene in one of the double bonds we put it was 1.34 A and the single bond was 1.54 A. The energy of a bond is equal to the energy needed to break it due to the conservation of energy. The energy of a bond ...
- Sat Nov 03, 2018 9:22 am
- Forum: Trends in The Periodic Table
- Topic: Ionic Radius
- Replies: 3
- Views: 319
Re: Ionic Radius
Why is it that a Ca^2+ ion is smaller than a Na+ ion? An [Na]+ ion has 11 protons and 10 electrons whereas [Ca]2+ has 20 protons and 18 electrons. Although the periodic trends dictate that as you go down a group, the atomic radius increases due to increased shielding and energy levels, the Z-effect...
- Sat Nov 03, 2018 9:08 am
- Forum: Trends in The Periodic Table
- Topic: Ionization energy and electronegativity
- Replies: 1
- Views: 202
Re: Ionization energy and electronegativity
Since both ionization energy and electronegativity are the energies to remove an electron, then what is the difference between them? Does ionization energy refer only to ionic bonds and electronegativity refers to covalent bonds? Both of them follow the same trend on the periodic table: both increa...
- Sat Nov 03, 2018 9:03 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: En Equation - Why the Negative?
- Replies: 2
- Views: 971
Re: En Equation - Why the Negative?
Hello! I thought energy could only be positive, why does the equation for energy at a specific principle quantum number have a negative sign in front of it? Is this applied to find change in energy? En = -hR/n^2 Because when applied to delta E=E(final)-E(initial), delta E is energy emitted. It is u...
- Fri Oct 26, 2018 8:16 pm
- Forum: Lewis Structures
- Topic: writing the structure
- Replies: 5
- Views: 528
Re: writing the structure
There is no particular order by which you should draw your Lewis dot structure; a rule you should be wary of is Hund's rule, which states that due to e- repulsion, e- in same subshell will occupy different orbitals and with parallel spin because it gives the lowest energy.
- Fri Oct 26, 2018 8:08 pm
- Forum: Ionic & Covalent Bonds
- Topic: Valence Electrons
- Replies: 4
- Views: 675
Re: Valence Electrons
A good reminder of how many valence electrons is to look at the group number, which is typically indicated above the top element of each column. Group 1 has 1 valence electron, 2 has 2 electrons, 13 has 3, 14 has 4, 15 has 5....18 has 8. Groups 3-12, which are the transition metals, behave different...
- Fri Oct 26, 2018 8:01 pm
- Forum: Properties of Light
- Topic: Speed of Light
- Replies: 12
- Views: 911
Re: Speed of Light
To add a note to the previous comments, it's beneficial to acknowledge that the formula "c=lambda*frequency" is only applicable to photons because only light can travel at that speed. You shouldn't apply that formula to particles that aren't photons.
- Thu Oct 18, 2018 6:14 pm
- Forum: DeBroglie Equation
- Topic: units
- Replies: 3
- Views: 244
Re: units
When using DeBroglie's equation do you have to calculate given values into certain units before putting them into the equation? DeBroglie's wavelength formula is lambda=h/mv. Lambda (wavelength) must be in meters but can be converted after the calculation if the question asks for a different unit.P...
- Tue Oct 16, 2018 2:58 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Bohr Formula
- Replies: 4
- Views: 425
Re: Bohr Formula
Could someone explain to me when I would use hR/n^2? You would use the that formula, which is exclusive to hydrogen atoms, when attempting to calculate energy levels or energy output. A few of the questions in the textbook use this formula as a means to eventually find the energy to find the wavele...
- Sun Oct 14, 2018 12:34 pm
- Forum: SI Units, Unit Conversions
- Topic: Kiloelectron volt to Joule
- Replies: 5
- Views: 937
Kiloelectron volt to Joule
1.23 asks "The gamma-ray photons emitted by the nuclear decay of a technetium-99 atom used in radio-pharmaceuticals have an energy of 140.511 keV. Calculate the wavelength of these gamma-rays."
What is the conversion from an electron volt to a Joule?
What is the conversion from an electron volt to a Joule?
- Thu Oct 11, 2018 10:53 pm
- Forum: Limiting Reactant Calculations
- Topic: Photoelectric Effect [ENDORSED]
- Replies: 2
- Views: 477
Re: Photoelectric Effect [ENDORSED]
"I understand that Dr. Lavelle explained this during lecture, however, I am still a bit confused. Can someone please explain how an electron is able to reach the detector if there is 0 Kinetic energy. Is there an attractive force of some sort?" As Dr. Lavelle explained, this experiment wou...
- Thu Oct 11, 2018 10:51 pm
- Forum: Properties of Light
- Topic: How light behaves
- Replies: 8
- Views: 509
Re: How light behaves
"I cannot conceptualize light being both photon (PACKETS) of energy and wavelengths. I find it difficult to exercise this into equations when I do not understand how it can be both and have one number. Please explain and possibly use equations in your explanation if possible. If not that is oka...
- Thu Oct 11, 2018 10:45 pm
- Forum: Photoelectric Effect
- Topic: Confused conceptually with photoelectric effect
- Replies: 3
- Views: 207
Re: Confused conceptually with photoelectric effect
For the photoelectric effect, a shorter wavelength means a higher frequency. Higher frequency equates to a greater amount of energy in the photon, and thus, an electron is ejected because sufficient energy was provided. E=hv
- Mon Oct 01, 2018 1:00 pm
- Forum: Significant Figures
- Topic: Significant Figures [ENDORSED]
- Replies: 6
- Views: 409
Re: Significant Figures [ENDORSED]
Because without significant figures, the equipment we use to make measurements would appear to be more accurate than they truly are.
- Mon Oct 01, 2018 12:16 pm
- Forum: Empirical & Molecular Formulas
- Topic: Tin (IV) Dioxide [ENDORSED]
- Replies: 1
- Views: 233
Tin (IV) Dioxide [ENDORSED]
In Fundamentals L, question 39 is as follows: "A 1.50-g sample of metallic tin was placed in a 26.45-g crucible and heated until all the tin had reacted with the oxygen in air to form an oxide. The crucible and product together were found to weigh 28.35 g. (a) What is the empirical formula of t...
- Mon Oct 01, 2018 11:38 am
- Forum: SI Units, Unit Conversions
- Topic: Unit "t"
- Replies: 2
- Views: 177
Unit "t"
In Fundamentals L, question 35 asks "What mass of iron, in kilograms, is needed to produce 2.50 t of NaBR?"
My question is what unit of mass is "t" shorthand for?
My question is what unit of mass is "t" shorthand for?