Search found 97 matches
- Sun Mar 08, 2020 7:56 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: galvanic vs electrolytic
- Replies: 12
- Views: 909
galvanic vs electrolytic
What's the difference between galvanic and electrolytic cells?
- Sun Mar 08, 2020 7:54 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: The Third Law
- Replies: 3
- Views: 321
Re: The Third Law
The third law of thermodynamics is basically as the temperature reaches absolute zero (0 Kelvin) then entropy will also decrease to zero.
- Sun Mar 08, 2020 7:27 pm
- Forum: First Order Reactions
- Topic: Graphing 1st order reaction rates
- Replies: 6
- Views: 406
Graphing 1st order reaction rates
Why do we graph ln[A] against time instead of just [A] against time?
- Sun Mar 08, 2020 7:14 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Slow step
- Replies: 2
- Views: 202
Re: Slow step
I'd think that if they propose certain mechanisms then one of them would have to match the given rate law?
- Sun Mar 08, 2020 7:08 pm
- Forum: Zero Order Reactions
- Topic: examples of zero order reactions?
- Replies: 6
- Views: 544
examples of zero order reactions?
What's an example of a zero order reaction? I still don't completely understand how they would work
- Sun Mar 01, 2020 9:16 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Standard Cell Potential for Oxidation Half-Reactions
- Replies: 3
- Views: 230
Re: Standard Cell Potential for Oxidation Half-Reactions
I think so yeah
- Sun Mar 01, 2020 9:15 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: initial reaction rates
- Replies: 2
- Views: 194
Re: initial reaction rates
We work with initial reaction rates because they're more clear and easier to measure.
- Sun Mar 01, 2020 9:13 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Kinetics vs. thermodynamics
- Replies: 4
- Views: 308
Re: Kinetics vs. thermodynamics
Thermodynamics tells us whether the forward or reverse process is favored. Kinetics touches more on the energy during the reaction itself.
- Sun Mar 01, 2020 9:09 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: kinetically stable?
- Replies: 10
- Views: 767
Re: kinetically stable?
Basically the activation energy (the hump part of the graph) is high enough so that under normal conditions the reaction won't proceed.
- Sun Mar 01, 2020 9:08 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: order of reactions
- Replies: 7
- Views: 517
Re: order of reactions
it tells you how the concentration of the reactants affects the rate.
- Sun Mar 01, 2020 9:06 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: first order
- Replies: 8
- Views: 654
Re: first order
It has a linear rate
- Sun Feb 23, 2020 1:46 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic cell vs battery system
- Replies: 3
- Views: 328
Re: Galvanic cell vs battery system
I think a galvanic cell just has a negative Gibbs free energy value.
- Sun Feb 23, 2020 1:42 pm
- Forum: Balancing Redox Reactions
- Topic: Acidic vs Basic
- Replies: 4
- Views: 383
Re: Acidic vs Basic
If they occur in basic solutions, the steps are the same, except for when you balance one side with H+ you need to balance both sides with the same amount of OH-, so that there is H20 on one side and OH- on the other side.
- Sun Feb 23, 2020 1:36 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Notation of Species
- Replies: 3
- Views: 227
Re: Notation of Species
You use a single line to differentiate between phases. If they're both in the same phase then you list them using a comma.
- Sat Feb 22, 2020 9:57 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Writing half-rxn
- Replies: 3
- Views: 272
Re: Writing half-rxn
I think we might be provided with half reactions but also it would be good to practice coming up with them on our own?
- Sat Feb 22, 2020 9:28 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: 5G.15
- Replies: 3
- Views: 238
Re: 5G.15
I also keep getting the same as you so it might be an error
- Sun Feb 16, 2020 11:19 pm
- Forum: Balancing Redox Reactions
- Topic: Whats the difference between oxidizing agent and oxiadation
- Replies: 6
- Views: 340
Re: Whats the difference between oxidizing agent and oxiadation
Oxidation is the transfer of electrons in a reaction; the oxidizing agent is the reactant that is reduced.
- Sun Feb 16, 2020 11:10 pm
- Forum: Balancing Redox Reactions
- Topic: How do you combine half reactions together?
- Replies: 2
- Views: 162
Re: How do you combine half reactions together?
If a reactant in one reaction is the same as a product in the other then you can cancel them both. For example if 5O2 is a reactant in the first and 3O2 is a product in the second then you can subtract the difference so that in the final reaction there is 2O2 on the reactant side.
- Sun Feb 16, 2020 11:06 pm
- Forum: Van't Hoff Equation
- Topic: Significance of Van't Hoff Equation
- Replies: 8
- Views: 607
Re: Significance of Van't Hoff Equation
I think the point was to relate K to the temperature? I might be wrong
- Sun Feb 16, 2020 11:05 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: standard entropies vs. entropies
- Replies: 5
- Views: 577
Re: standard entropies vs. entropies
The standard entropy of a reaction is found in lab conditions.
- Sun Feb 16, 2020 11:02 pm
- Forum: Balancing Redox Reactions
- Topic: Why do we split equations?
- Replies: 12
- Views: 814
Re: Why do we split equations?
It's just easier to understand what's happening; you don't really need to if you don't want to.
- Mon Feb 10, 2020 2:15 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: 4A13
- Replies: 1
- Views: 121
Re: 4A13
I'm pretty sure the heat released is measured by the calorimeter as the surroundings rather than the system. So since it's exothermic, Q is negative and heat is released into the surroundings, raising the temperature.
- Mon Feb 10, 2020 2:00 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 4.17E
- Replies: 1
- Views: 118
Re: 4.17E
Since they give you the specific amount of moles then you're able to find the specific reaction enthalpy.
- Mon Feb 10, 2020 1:58 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Determining what’s thermodynamically more stable
- Replies: 1
- Views: 154
Re: Determining what’s thermodynamically more stable
If F2 dissociates more then Cl2 would be more stable
- Mon Feb 10, 2020 1:49 am
- Forum: Phase Changes & Related Calculations
- Topic: 4.5
- Replies: 1
- Views: 111
Re: 4.5
It's mentioned that the ice took 10.5 (10 hours and 30 minutes) hours to reach 5.00 degrees. If it takes 30 minutes for water to increase five degrees in temperature, it's safe to say that the ice took ten hours to melt, and as water also took thirty minutes to reach 5.00 degrees.
- Mon Feb 10, 2020 1:37 am
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Conversion
- Replies: 3
- Views: 239
Re: Midterm Conversion
I'm sure that if that's something we need on the test then they'll provide it
- Thu Jan 30, 2020 7:04 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Homework question 4B.13
- Replies: 5
- Views: 288
Re: Homework question 4B.13
Pretty sure the manual's solution is correct. Did you use w=-nRTln(V2/V1)? Or maybe make sure you're using the right units?
- Thu Jan 30, 2020 5:46 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Solids and Liquids not in K
- Replies: 1
- Views: 120
Re: Solids and Liquids not in K
With gas you can compress or expand the volume which changes the concentration, and with aqueous solutions the concentration of dissolved molecules can also increase or decrease. However, for the most part it's extremely difficult for the concentration of solids and liquids to change so it remains c...
- Thu Jan 30, 2020 5:39 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Closed and Isolated
- Replies: 5
- Views: 248
Re: Closed and Isolated
I'm pretty sure there's technically no such thing as a completely isolated system. However, some experimental systems are close enough to be considered isolated since the changes are negligible.
- Thu Jan 30, 2020 5:36 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: Textbook problem 6b.3
- Replies: 1
- Views: 183
Re: Textbook problem 6b.3
I think what the question is saying is that the technician meant to produce 200 ml of a .025M HCl solution, but since he accidentally used a 250mL flask he added 50mL more water than he meant to. So he didn't actually produce a .025M HCl solution. If he made it right you would just find -log(.025) =...
- Thu Jan 30, 2020 5:24 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Test #1// #6
- Replies: 2
- Views: 117
Re: Test #1// #6
To find Ka, you find the concentration of the products and divide that by the concentration of the reactants. They gave you .10 M for the initial concentration of HF. pH is -log[H3O+] = 2.63, so [H3O+] = 2.34 x 10^-3. Since one mole of HF dissociates into one mole of H30+ and one mole of F-, you kno...
- Sun Jan 26, 2020 7:47 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Weak acid/base
- Replies: 14
- Views: 692
Re: Weak acid/base
If the acid or base isn't completely dissociated then it's probably weak.
- Sun Jan 26, 2020 7:43 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: H2O as a Gas
- Replies: 69
- Views: 6793
Re: H2O as a Gas
Yeah you'd include it if it was a gas.
- Sun Jan 26, 2020 7:39 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Predicting Molar Heat Capacity
- Replies: 3
- Views: 228
Re: Predicting Molar Heat Capacity
I think that in general the more complex a molecule is the higher the capacity will be, because more energy would go into the bonds. So I think NO2 would have a higher capacity?
- Sun Jan 26, 2020 7:32 pm
- Forum: Ideal Gases
- Topic: Determining N
- Replies: 9
- Views: 426
Re: Determining N
It's the ideal gas law so you just use it for gases.
- Sat Jan 25, 2020 3:34 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: bomb calorimeter
- Replies: 5
- Views: 322
Re: bomb calorimeter
It measures the heat of chemical reactions
- Sun Jan 19, 2020 3:59 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6B.11B
- Replies: 2
- Views: 128
Re: 6B.11B
For part a, since M is moles per liter, the [OH-] of the original solution would be 100 times stronger, since the 5.0 mL solution was diluted to 500 mL. So the original [OH-] would be 18M. For part b, you use the equation you have to convert the 18M OH- to grams of Na2O. 18 mol/L x .2 L x 1 mol Na2O...
- Sun Jan 19, 2020 3:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6D.13
- Replies: 1
- Views: 83
Re: 6D.13
a) pH = 5.00
b) pH = 5.63
c) pH = 2.72
d) pH = 8.97
b) pH = 5.63
c) pH = 2.72
d) pH = 8.97
- Sun Jan 19, 2020 12:21 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6D.3 part B
- Replies: 1
- Views: 98
Re: 6D.3 part B
So ultimately we're trying to get from pH to pKb. Since propylamine is a base we know it's best to deal in terms of OH-, so we should convert the pH to pOH (2.14). Since pOH is just -log[OH-], we can find [OH-] through 10^-2.14, which comes out to be 7.2 x 10^-3. We know that Kb is the molarity of t...
- Sat Jan 18, 2020 11:55 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6D13 part d
- Replies: 2
- Views: 111
Re: 6D13 part d
So I think you might have tried to find the concentration of H30+ by setting up the equation x^2/.2 = Ka? I don't think that would work out because the reactant is a base? If you wanted to find and use the concentration of H30+, you would need to first find the concentration of OH- by using Kb. Once...
- Sat Jan 18, 2020 11:16 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6D7
- Replies: 1
- Views: 122
Re: 6D7
I'm pretty sure it's just a typo, and should just be in the denominator. If you carry out the problem as normal without the typo, you get the same answer it provides.
- Sun Jan 12, 2020 9:25 pm
- Forum: General Science Questions
- Topic: Proton and Electron attraction
- Replies: 5
- Views: 190
Re: Proton and Electron attraction
Opposite charges attract!
- Sun Jan 12, 2020 8:29 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Reaction Quotient
- Replies: 11
- Views: 328
Re: Reaction Quotient
The reaction quotient is the proportion of the molarity of the products to the reactants at any given time of the reaction. It's pretty much the same as Kc and Kp but those two are measured specifically at equilibrium.
- Sun Jan 12, 2020 8:24 pm
- Forum: Ideal Gases
- Topic: PV=nRT
- Replies: 3
- Views: 113
Re: PV=nRT
R is a constant used in the ideal gas law, 8.314 J/(K.mol)
- Sun Jan 12, 2020 5:29 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Units and Conversions of Kp
- Replies: 3
- Views: 115
Re: Units and Conversions of Kp
Not sure which is the default but 1 bar = 10^5 Pa (1 kilopascal is 1,000 pascals).
- Sun Jan 12, 2020 5:26 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: the "quick way"
- Replies: 4
- Views: 300
Re: the "quick way"
I think what you're talking about is whether the reaction shifts left or right? If the volume decreases and more moles of gas are added to the reactants, then the reaction shifts right. If the volume decreases and more moles of gas are added to the products, then the reaction shifts left.
- Sat Dec 07, 2019 2:16 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Carbonato
- Replies: 1
- Views: 110
Re: Carbonato
Yeah I think it could be bidentate
- Sat Dec 07, 2019 2:14 pm
- Forum: Lewis Acids & Bases
- Topic: Water
- Replies: 63
- Views: 2990
Re: Water
Water can act as an acid in the presence of a base, and can act as a base in the presence of an acid.
- Sat Dec 07, 2019 1:58 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: 6B.1
- Replies: 1
- Views: 198
Re: 6B.1
The pH scale is a log scale, so if you reduce the molar concentration to .1, or 10% of the original concentration then the resulting pH will raise by 1; -Log(.1) = 1. So if molarity of HCl is reduced to 12% of the original concentration, then -log(.12) = .92. So all you need to know is the differenc...
- Sat Dec 07, 2019 1:35 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: chelating vs. polydentate?
- Replies: 2
- Views: 174
Re: chelating vs. polydentate?
I think it's just that polydentate ligands happen to form a chelate with the central atom.
- Sat Dec 07, 2019 1:32 pm
- Forum: Hybridization
- Topic: double and triple bonds
- Replies: 6
- Views: 527
Re: double and triple bonds
I'm pretty sure the pi bonds in double and triple bonds aren't hybridized.
- Sat Dec 07, 2019 1:24 pm
- Forum: Ionic & Covalent Bonds
- Topic: Hydrogen bonds
- Replies: 4
- Views: 291
Hydrogen bonds
For a dipole bond to be considered a hydrogen bond, does the hydrogen atom have to be both bonded to a N, O, or F atom within the same molecule, and then form the hydrogen bond itself with a N, O, or F atom with a lone pair in another molecule?
- Sun Dec 01, 2019 7:31 pm
- Forum: Dipole Moments
- Topic: dipole moments
- Replies: 6
- Views: 430
Re: dipole moments
Yep. Nonpolar molecules could have dipole moments as well that happen to cancel each other out.
- Sun Dec 01, 2019 7:28 pm
- Forum: Naming
- Topic: cis and trans
- Replies: 1
- Views: 90
Re: cis and trans
I would think so because they make kind of a big difference in many cases.
- Sun Dec 01, 2019 7:27 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Weak vs. Strong Acids
- Replies: 3
- Views: 102
Weak vs. Strong Acids
At what point is an acid (or base) weak or solid? Where do you draw the line?
- Sun Dec 01, 2019 7:21 pm
- Forum: Hybridization
- Topic: Order When Writing
- Replies: 5
- Views: 315
Re: Order When Writing
I think either would be fine since they're both correct.
- Sun Dec 01, 2019 7:19 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Difference in Concentrations
- Replies: 3
- Views: 167
Re: Difference in Concentrations
Acids release H+ ions in water, while bases release OH- ions in water.
Prefixes
In lecture today Dr. Lavelle mentioned something about the prefixes bis-, tris-, tetrakis-, and pentakis-... can someone explain what he was talking about?
- Fri Nov 22, 2019 2:39 pm
- Forum: Lewis Acids & Bases
- Topic: Lewis & Bronsted
- Replies: 3
- Views: 256
Lewis & Bronsted
What's the difference between a Lewis and Bronsted acid and base?
- Fri Nov 22, 2019 2:36 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 9 Homework
- Replies: 2
- Views: 203
Re: Week 9 Homework
I think it depends on your TA but you could probably just turn it in the week after
- Fri Nov 22, 2019 2:31 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Definition of a Ligand
- Replies: 4
- Views: 252
Re: Definition of a Ligand
I'm pretty sure it's just a molecule attached to a central metal ion.
- Fri Nov 22, 2019 2:29 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Sphere
- Replies: 6
- Views: 324
Re: Coordination Sphere
It's the central metal atom and the ligands attached to it.
- Fri Nov 15, 2019 5:22 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.19 b
- Replies: 1
- Views: 114
Re: 2E.19 b
The Be atom is central, forming a 180 degree angle with the two bonded C atoms. But there are also three H atoms bonded to each C atom. Because of this there are four regions of e- density around the C atoms, so they are the center of a tetrahedral structure. The structure of the entire molecule is ...
- Fri Nov 15, 2019 5:17 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.17 B
- Replies: 2
- Views: 109
Re: 2E.17 B
I'm pretty sure there should be two lone pairs on each of the bonded nitrogen atoms while the central nitrogen has a formal charge of +1. The overall charge is still -1 and that way the angle would be 180.
- Fri Nov 15, 2019 4:56 pm
- Forum: Ionic & Covalent Bonds
- Topic: Types of Covalent Bonds
- Replies: 4
- Views: 311
Types of Covalent Bonds
Which type of bond is strongest, between polar, non-polar, and coordinate covalent bonds?
- Fri Nov 15, 2019 4:51 pm
- Forum: Dipole Moments
- Topic: Xenon
- Replies: 4
- Views: 352
Re: Xenon
I think he mentioned something about how since xenon has a low electronegativity, its electrons are more easily distorted by atoms with stronger electronegativity, like fluorine.
- Fri Nov 15, 2019 4:47 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Formula Exceptions
- Replies: 6
- Views: 450
VSEPR Formula Exceptions
Are there ever any exceptions to the VSEPR formula? Or can we always rely on it?
- Wed Nov 06, 2019 11:30 pm
- Forum: SI Units, Unit Conversions
- Topic: Kg
- Replies: 4
- Views: 521
Kg
Why is the SI unit of mass kg, not g?
- Wed Nov 06, 2019 11:26 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Rydberg equation
- Replies: 9
- Views: 555
Re: Rydberg equation
Why is that preferred?
- Wed Nov 06, 2019 9:25 pm
- Forum: Dipole Moments
- Topic: Ionic bonds
- Replies: 5
- Views: 307
Ionic bonds
Do ionic bonds ever have dipole moments?
- Wed Nov 06, 2019 9:23 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Solving with velocity
- Replies: 3
- Views: 325
Solving with velocity
When given the velocity, is the actual velocity important at all or just the change of velocity?
- Wed Nov 06, 2019 9:15 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: orbitals past f
- Replies: 5
- Views: 323
orbitals past f
When would we ever see l>3?
- Wed Oct 30, 2019 4:23 pm
- Forum: Octet Exceptions
- Topic: expanded valence shells
- Replies: 2
- Views: 150
expanded valence shells
Are atoms with expanded valence shells stable?
- Wed Oct 30, 2019 4:12 pm
- Forum: Ionic & Covalent Bonds
- Topic: Partial charge
- Replies: 4
- Views: 140
Partial charge
Are partial charges found only in covalent bonds or also in ionic bonds?
- Wed Oct 30, 2019 3:56 pm
- Forum: Ionic & Covalent Bonds
- Topic: ionic vs covalent bonds
- Replies: 6
- Views: 277
ionic vs covalent bonds
So basically, whether a bond is ionic or covalent depends on the difference of the electronegativities of the atoms involved?
- Wed Oct 30, 2019 3:40 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A 1c
- Replies: 1
- Views: 95
Re: 2A 1c
I asked my TA about the valence electrons of elements in the d-block, and the short answer was that any electrons in shells that aren't included in the noble gas notation would be considered valence electrons. So for Mn, after [Ar] there are seven electrons. Hope that helps
- Wed Oct 30, 2019 3:33 pm
- Forum: Electronegativity
- Topic: Electronegativity trends
- Replies: 5
- Views: 265
Electronegativity trends
Are we expected to know specific values or just the general trends?
- Wed Oct 23, 2019 6:25 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: General Terminology for Electron Configuration
- Replies: 2
- Views: 96
Re: General Terminology for Electron Configuration
I'm pretty sure the energy shell is the principle quantum number (n), the orbital is the angular momentum quantum number (l), and the subshell is the magnetic quantum number (ml).
- Wed Oct 23, 2019 6:05 pm
- Forum: Lewis Structures
- Topic: Number of valence electrons
- Replies: 3
- Views: 179
Number of valence electrons
Is it ever possible to have more than 8 valence electrons?
- Wed Oct 23, 2019 6:03 pm
- Forum: Lewis Structures
- Topic: Valence e in d block
- Replies: 5
- Views: 351
Re: Valence e in d block
So do most d-block elements have only a couple of valence electrons?
- Wed Oct 23, 2019 5:50 pm
- Forum: Lewis Structures
- Topic: chemical formulas
- Replies: 3
- Views: 157
chemical formulas
Are we going to need to know the chemical formulas of compounds in order to create the lewis structure, or will they be given?
- Wed Oct 23, 2019 2:58 pm
- Forum: Ionic & Covalent Bonds
- Topic: octet rule
- Replies: 6
- Views: 271
octet rule
Are there any exceptions to the octet rule besides H, He, Li, & Be?
- Wed Oct 16, 2019 8:22 pm
- Forum: Properties of Electrons
- Topic: 1B.15
- Replies: 4
- Views: 149
Re: 1B.15
You can use De Broglie's equation : λ=h/p (p=mv).
- Wed Oct 16, 2019 8:15 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbitals
- Replies: 4
- Views: 162
Re: Orbitals
That helps! What I don't understand is if it's arbitrary, why did Dr. Lavelle say in his lecture today that when n=2, l=1, and ml=-1, the e- is in the 2Px state?
- Wed Oct 16, 2019 7:04 pm
- Forum: Properties of Electrons
- Topic: Question About Electron State
- Replies: 3
- Views: 116
Re: Question About Electron State
It means the electron is located in the p orbital of the second energy level, and is located somewhere along the x plane.
- Wed Oct 16, 2019 6:58 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbitals
- Replies: 4
- Views: 162
Orbitals
How are we able to determine whether a p orbital is px, py, or pz?
- Wed Oct 16, 2019 6:44 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Homework Problem Help
- Replies: 5
- Views: 243
Re: Homework Problem Help
For a, you know it's the second period and a p orbital. There's six elements in the second period with a p orbital, so there's six possible orbitals. That's how I'd go about each question.
- Wed Oct 09, 2019 4:40 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Fundamentals G21 [ENDORSED]
- Replies: 2
- Views: 248
Re: Fundamentals G21 [ENDORSED]
Ashley explained it well, here's part a written out. .5 grams KCl x (1 mole KCl)/(74.55 g KCl) = .0067 moles of KCl. For every molecule of KCl, there is one K atom. So there are .0067 moles of K. .5 grams K2S x (1 mole K2S)/(110.27 g K2S) = .0045 moles of K2S For every molecule of K2S, there are two...
- Wed Oct 09, 2019 4:01 pm
- Forum: Properties of Electrons
- Topic: Energy
- Replies: 6
- Views: 341
Re: Energy
Yep, electrons will only move up an energy level if that specific requirement is met. That's why there's distinct spectral lines on an atomic spectrum.
- Wed Oct 09, 2019 3:38 pm
- Forum: Properties of Electrons
- Topic: wave/particle properties of mass
- Replies: 3
- Views: 135
wave/particle properties of mass
So if electrons have both wave and particle properties, does that mean that anything with mass have both wave and particle properties as well?
- Wed Oct 09, 2019 3:32 pm
- Forum: Properties of Electrons
- Topic: Energy of Electron
- Replies: 10
- Views: 423
Re: Energy of Electron
He means that each electron can only hold specific amounts of energy. That's why the energy levels are n=1, n=2, n=3,... instead of any random number like n=1.74.
- Wed Oct 09, 2019 3:25 pm
- Forum: Properties of Light
- Topic: Kinetic Energy
- Replies: 2
- Views: 192
Re: Kinetic Energy
If you look at electromagnetic radiation as individual photons, a higher intensity basically increases the number of photons - each photon still contains the same amount of energy.
- Thu Oct 03, 2019 5:32 pm
- Forum: Limiting Reactant Calculations
- Topic: Percent yields/error
- Replies: 3
- Views: 2068
Percent yields/error
What's the difference between percent yield and percent error?
- Thu Oct 03, 2019 5:27 pm
- Forum: Properties of Light
- Topic: What does μm mean?
- Replies: 4
- Views: 478
Re: What does μm mean?
It's a unit of measurement (micrometer) which is 10^-6 of a meter.
- Thu Oct 03, 2019 5:19 pm
- Forum: Significant Figures
- Topic: Sig Figs in Mulitstep Problems
- Replies: 10
- Views: 326
Re: Sig Figs in Mulitstep Problems
I think it's best to round throughout the steps to an extent; we should round enough so that it's easier to keep track of the numbers but not so much that it'll affect the final answer. Maybe around four sig figs?
- Thu Oct 03, 2019 5:06 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Lab experiments- accuracy vs precision
- Replies: 7
- Views: 638
Re: Lab experiments- accuracy vs precision
Even if it isn't accurate, precision can be helpful because you know that at least your calculations are consistent. It can then be easier to fix any errors.
- Thu Oct 03, 2019 4:54 pm
- Forum: General Science Questions
- Topic: Naming compounds
- Replies: 6
- Views: 295
Re: Naming compounds
Later in the course we'll need to, but for now anything uncommon will be provided for.