Search found 100 matches
- Fri Mar 13, 2020 9:17 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Homework 7E1
- Replies: 4
- Views: 266
Re: Homework 7E1
Just because the speed of the reaction is different doesn't mean the reaction itself is. It will still have the same enthalpy value.
- Fri Mar 13, 2020 9:15 am
- Forum: Administrative Questions and Class Announcements
- Topic: "Open Book" Final?
- Replies: 30
- Views: 1948
Re: "Open Book" Final?
Any resource should be up for use except for chemistry community just because he said we can use it up to the day of the final.
- Fri Mar 13, 2020 9:11 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: how to find pkb
- Replies: 2
- Views: 327
Re: how to find pkb
In the scope of this class, you should not need to know to find pKb for pOH
- Fri Mar 13, 2020 9:01 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Using Steady State Approx/Pre-Equilibrium Approx
- Replies: 2
- Views: 210
Re: Using Steady State Approx/Pre-Equilibrium Approx
You don't need to know steady state for this class
- Fri Mar 13, 2020 8:59 am
- Forum: Administrative Questions and Class Announcements
- Topic: Partial Credit
- Replies: 8
- Views: 520
Re: Partial Credit
My hope is we will do the work ourselves and then submit it as a PDF electronically so it can be graded for partial credit.
- Thu Mar 05, 2020 3:41 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Combustion of gas
- Replies: 6
- Views: 515
Re: Combustion of gas
Hard to say something is always spontaneous but most of the time it will be
- Thu Mar 05, 2020 3:25 pm
- Forum: Balancing Redox Reactions
- Topic: oxidizing and reducing agents
- Replies: 10
- Views: 754
Re: oxidizing and reducing agents
Use the oxidation numbers to determine which is oxidized and reduced. Then whatever one is oxidized is the reducing agent and the one being reduced is the oxidizing agent.
- Thu Mar 05, 2020 3:22 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6.M.13 part b
- Replies: 2
- Views: 206
Re: 6.M.13 part b
The Mn is actually being reduced because it is going from a charge of +7 to +2 so that would be your cathode.
- Thu Mar 05, 2020 3:19 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: 6N.15
- Replies: 2
- Views: 123
Re: 6N.15
You set up the concentration cell and then use the Nernst equation to solve for potential.
- Thu Mar 05, 2020 3:15 pm
- Forum: Balancing Redox Reactions
- Topic: Half reactions
- Replies: 6
- Views: 442
Re: Half reactions
Water first for the oxygens and then the H+ for the hydrogen difference.
- Fri Feb 28, 2020 10:34 pm
- Forum: Balancing Redox Reactions
- Topic: balancing redox reactions
- Replies: 3
- Views: 354
Re: balancing redox reactions
First, you start with just the oxidation of the reduction reaction with nothing else. You balance the things that are not oxygens or hydrogens first with a coefficient. Then you balance the oxygens by adding water to whatever side that needs it (Only worry about the oxygens at this point). Then you ...
- Fri Feb 28, 2020 10:16 pm
- Forum: Balancing Redox Reactions
- Topic: Writing half reactions
- Replies: 9
- Views: 627
Re: Writing half reactions
It's better to keep oxidation on the left and reduction on the right for cell diagrams or not. It says so in the textbook
- Fri Feb 28, 2020 10:13 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2
- Replies: 10
- Views: 680
Re: Test 2
Rest of outline 4 and outline 5
- Fri Feb 28, 2020 10:05 pm
- Forum: Balancing Redox Reactions
- Topic: Acidic and Basic solutions
- Replies: 11
- Views: 670
Re: Acidic and Basic solutions
The only difference is acidic solutions you at H+ with the waters and for basic solutions, you add OH-
- Fri Feb 28, 2020 10:04 pm
- Forum: Balancing Redox Reactions
- Topic: REDOX Agents
- Replies: 9
- Views: 728
Re: REDOX Agents
The thing that takes the electrons is being reduced while at the same time it is oxidizing the other compound to get those electrons. Then the other situation is true, the thing that loses the electrons is being oxidized but also it is in a way giving those electrons to another compound which then r...
- Fri Feb 21, 2020 4:00 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation Numbers
- Replies: 9
- Views: 624
Re: Oxidation Numbers
Break the molecule into each of its elements. Then use a periodic table to find the normal charge of each element. Then combine those to find the oxidation number.
- Fri Feb 21, 2020 3:55 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Electrode
- Replies: 4
- Views: 285
Re: Electrode
The Pt is more of a bridge for the electron that allows it to get from one side to the other so it can reduce.
- Fri Feb 21, 2020 3:53 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Standards
- Replies: 2
- Views: 193
Re: Standards
Standard points are your references that you would use if specified. Otherwise you will use the non standard value in a problem.
- Fri Feb 21, 2020 3:46 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: E v E(standard)
- Replies: 4
- Views: 284
Re: E v E(standard)
Anything standard is just that variable at standard conditions
- Fri Feb 21, 2020 3:35 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: E
- Replies: 5
- Views: 322
Re: E
Positive E means negative Delta G
- Tue Feb 11, 2020 10:13 pm
- Forum: Calculating Work of Expansion
- Topic: A system doing no work
- Replies: 4
- Views: 244
Re: A system doing no work
The systems we deal with now only have work when they expand or get compressed.
- Tue Feb 11, 2020 10:11 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: 4G.5
- Replies: 3
- Views: 224
Re: 4G.5
The Cis has more because each atom can be present in each plane while the trans structure only allows a certain atom in each plane which restricts the possible states.
- Tue Feb 11, 2020 10:09 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Pizza Rolls 3B
- Replies: 2
- Views: 300
Re: Pizza Rolls 3B
The formula for the phase change is Energy = mass*entalpy of fusion. You are given that half of the original 125g melts so you have 62.5g and then that the total energy is 234 KJ. Plug those in and solve for enthalpy of fusion.
- Tue Feb 11, 2020 10:04 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Entropy of the System for irreversible expansions
- Replies: 8
- Views: 525
Re: Entropy of the System for irreversible expansions
State functions means that the path doesn't matter so it is the same.
- Tue Feb 11, 2020 12:21 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Pizza Rolls REVIEW Session DOWNLOAD HERE
- Replies: 67
- Views: 5499
Re: Pizza Rolls REVIEW Session DOWNLOAD HERE
ShastaB4C wrote:What did I do wrong? The answer is supposed to be 16 degrees Celsius
The ice goes through a phase change so you need to add that heat to the equation on the side of the ice.
- Fri Feb 07, 2020 9:23 am
- Forum: Phase Changes & Related Calculations
- Topic: Heating Curve Phase Changes
- Replies: 11
- Views: 579
Re: Heating Curve Phase Changes
It's flat when the energy in changes from being used to heat the substance to changing the phase of the substance
- Fri Feb 07, 2020 9:17 am
- Forum: Calculating Work of Expansion
- Topic: Reversible process and greatest work
- Replies: 5
- Views: 160
Re: Reversible process and greatest work
In a reversible reaction, the countless amount of small movements lead to more work being done when compared to an irreversible reaction where one big action is done causing there to be less overall work
- Fri Feb 07, 2020 9:11 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Combustion Reactions
- Replies: 4
- Views: 116
Re: Combustion Reactions
A combustion reaction always consist of the hydrocarbon plus O2 equaling CO2 plus H20 and in some cases nitrogen gas as well if it was present in the hydrocarbon
- Fri Feb 07, 2020 9:07 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: First Law
- Replies: 6
- Views: 139
Re: First Law
Energy is never destroyed in an isolated system just changes form. So the energy you begin with will be there in the end in some form or another.
- Fri Feb 07, 2020 9:05 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: reversible vs irreversible work
- Replies: 7
- Views: 434
Re: reversible vs irreversible work
In a problem, the big difference you need to spot is if the system is pushing against constant pressure or not. If it is it's irreversible but if the pressure changes its reversible.
- Fri Jan 31, 2020 4:32 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Test 1 # 4
- Replies: 10
- Views: 313
Re: Test 1 # 4
Ideal gas law but make sure you use the value of R that allows you to cancel your units correctly.
- Fri Jan 31, 2020 4:06 pm
- Forum: General Science Questions
- Topic: Extra Credit
- Replies: 19
- Views: 744
Re: Extra Credit
He has never mentioned extra credit so I wouldn't get your hopes up.
- Fri Jan 31, 2020 4:05 pm
- Forum: General Science Questions
- Topic: Midterms
- Replies: 22
- Views: 864
Re: Midterms
The midterm will cover everything before it. Test 2 will cover everything after the midterm to the test and then the final covers it all.
- Fri Jan 31, 2020 3:57 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Math Resources
- Replies: 8
- Views: 230
Re: Math Resources
He post everything to the class website
- Wed Jan 29, 2020 5:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 4 Homework
- Replies: 3
- Views: 166
Re: Week 4 Homework
Both should be ok just stay close to the lectures.
- Thu Jan 23, 2020 12:59 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Test 1
- Replies: 4
- Views: 191
Re: Test 1
Outlines 1 and 2 are very important and make sure to know the relation between pH and concentration.
- Thu Jan 23, 2020 12:58 pm
- Forum: Student Social/Study Group
- Topic: midterm/final
- Replies: 12
- Views: 2183
Re: midterm/final
The final in particular features overall concepts not just problems so while the test is pretty straight forward in their content the final is much more tricky.
- Thu Jan 23, 2020 12:56 pm
- Forum: Phase Changes & Related Calculations
- Topic: Calories vs calories
- Replies: 5
- Views: 100
Re: Calories vs calories
There are 1000 little calories in 1 Calorie. We use Calories when it comes to diet and calories when it comes to heat and energy.
- Thu Jan 23, 2020 12:53 pm
- Forum: Phase Changes & Related Calculations
- Topic: removing heat from system
- Replies: 6
- Views: 679
Re: removing heat from system
Exothermic means it releases heat so yes it will mean the temperature of the system decreases
- Thu Jan 23, 2020 12:42 pm
- Forum: Ideal Gases
- Topic: ICE table approximation
- Replies: 10
- Views: 357
Re: ICE table approximation
If the K value is less than 10^-3 and then if the percent protonation is less than 5% it is ok to take the shortcut.
- Thu Jan 16, 2020 3:41 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: How to make ICE box
- Replies: 17
- Views: 1218
Re: How to make ICE box
Always leave out the solids and bases they will not be changed enough to be included.
- Thu Jan 16, 2020 2:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Approximation
- Replies: 8
- Views: 269
Re: Approximation
Ice tables seem to be useful only when it comes to calculating the number of products and reactants are present at equilibrium for a reaction.
- Thu Jan 16, 2020 2:32 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Protonation & Deprotonation
- Replies: 9
- Views: 319
Re: Protonation & Deprotonation
When referring to acids and bases protonation is gaining a proton so this usually refers to a base as they are the ones that gain an electron and deprotonation refers to the acid because they are the ones giving up a proton.
- Wed Jan 15, 2020 10:28 am
- Forum: Administrative Questions and Class Announcements
- Topic: Test 1
- Replies: 7
- Views: 200
Re: Test 1
Jasmine Vallarta 2L wrote:when is test 1?
It's in your week three discussion section
- Wed Jan 15, 2020 10:25 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE charts on tests/exams
- Replies: 8
- Views: 236
Re: ICE charts on tests/exams
You will have plenty of time on the test so you might as well.
- Thu Jan 09, 2020 3:21 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q
- Replies: 10
- Views: 430
Re: Q
Q is basically the same thing as K but the reaction is not at equilibrium, so yes it can.
- Thu Jan 09, 2020 3:17 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Q vs K
- Replies: 7
- Views: 226
Re: Q vs K
K is the ratio of products over reactants at equilibrium, Q is the same thing not at equilibrium
- Thu Jan 09, 2020 2:46 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Q versus K
- Replies: 4
- Views: 152
Re: Q versus K
K can only be taken when the reaction is at equilibrium while Q can be taken at any point and through comparing them we can see where the reaction is overall. Other than that they use the same formula and rules.
- Thu Jan 09, 2020 2:30 pm
- Forum: Ideal Gases
- Topic: K value
- Replies: 14
- Views: 1087
Re: K value
The K value gives you the ratio of the products over the reactants so it being bigger or smaller tells you about the total concentration of each side of the ratio
- Wed Jan 08, 2020 3:19 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Re: Q and Ke: Small K value and Large K value
- Replies: 7
- Views: 258
Re: Q and Ke: Small K value and Large K value
The reaction quotient or Q is the ratio of the products over the reactants at whatever time you calculated the concentrations at. We then compare this ratio to the known K value or equilibrium constant to see if the reaction is still going and in what direction.
- Thu Dec 05, 2019 5:07 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: -ate
- Replies: 11
- Views: 685
Re: -ate
The metal has the -ate ending when the compound is the anion and has an overall negative charge
- Thu Dec 05, 2019 4:51 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: What is this?
- Replies: 5
- Views: 335
Re: What is this?
I would make sure to know the chart that he has posted on the website when it comes to naming
- Thu Dec 05, 2019 4:50 pm
- Forum: Biological Examples
- Topic: What specific compounds/ligands do we need to know for the final?
- Replies: 7
- Views: 477
Re: What specific compounds/ligands do we need to know for the final?
Know the chart he posted
- Thu Dec 05, 2019 4:47 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final exam
- Replies: 17
- Views: 871
Re: Final exam
The questions will most likely look like the ones we had on the midterms and the two quizzes so it would be beneficial to look back over those.
- Thu Dec 05, 2019 4:45 pm
- Forum: *Titrations & Titration Calculations
- Topic: Wednesday Lecture
- Replies: 3
- Views: 485
Re: Wednesday Lecture
I think it was more something to think about when it comes to future classes but if you want to be safe you could make sure to know the overall points he is making in case they come up
- Mon Nov 25, 2019 5:52 pm
- Forum: Naming
- Topic: OH2 naming
- Replies: 4
- Views: 504
Re: OH2 naming
(OH2) is aqua
- Mon Nov 25, 2019 5:50 pm
- Forum: Hybridization
- Topic: Sigma and Pi Bonds
- Replies: 21
- Views: 942
Re: Sigma and Pi Bonds
Pi bonds only occur as the other bonds in double and triple bonds. For example, a double has one sigma and one pi bond and a triple bond has one sigma and two pi bonds.
Re: ferrate
Ferrum refers to the latin name for iron and then the compound has an overall negative charge so you add ate to make it ferrate
- Mon Nov 25, 2019 4:18 pm
- Forum: Hybridization
- Topic: Bond angle/s character
- Replies: 3
- Views: 261
Re: Bond angle/s character
I understood this question as from sp3 to sp2 the bond angles increase from 109.5 to 120 so if it goes from sp2 to sp you would expect bond angles of 180 as it would be in a linear arrangement
- Mon Nov 25, 2019 4:08 pm
- Forum: Air Pollution & Acid Rain
- Topic: Clean Coal vs Dirty Coal?
- Replies: 16
- Views: 1385
Re: Clean Coal vs Dirty Coal?
Dirty coal has more sulfur which then leads to acid rain vs clean coal which contains much less sulfur and contributes to acid rain less.
- Wed Nov 20, 2019 5:08 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: 3F.5 part c)
- Replies: 2
- Views: 133
Re: 3F.5 part c)
Both size means more electrons which means more polarizability which then leads to stronger London forces
- Wed Nov 20, 2019 5:07 pm
- Forum: Dipole Moments
- Topic: Hydrogen Bonds
- Replies: 2
- Views: 93
Re: Hydrogen Bonds
For a hydrogen bond to occur the N, O, and F also has to have a lone pair
- Wed Nov 20, 2019 5:02 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: T-Shaped ??
- Replies: 9
- Views: 735
Re: T-Shaped ??
AX3E2 is the only formula that leads to T-shaped as trigonal bipyramidal is the only shape that has those flat 90-degree equatorial bonds.
- Wed Nov 20, 2019 10:26 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Problem 3F.3c
- Replies: 2
- Views: 95
Re: Problem 3F.3c
The arrangement really doesn't matter in this case as all you would need to get from the lewis structure is that there are 4 areas of electron density around the central atom and that would make it have a tetrahedral shape and all the characteristics that come with it.
- Tue Nov 19, 2019 8:06 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 3
- Views: 1164
Re: Bond Angles
Yes, bonds are calculated with the electron pairs added in so even though there is a certain amount of density spots some are electron pairs that repel the actual bonds off of there new position.
- Tue Nov 19, 2019 8:01 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Why T-shape?
- Replies: 4
- Views: 281
Re: Why T-shape?
It is T-shaped as you are having the electron pairs occupy the equatorial spots in order to reduce the effect they will have on the bonds. In doing this you are left with one equatorial and the top and bottom leading to T-shaped.
- Tue Nov 19, 2019 6:13 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Drawing dipoles
- Replies: 3
- Views: 241
Re: Drawing dipoles
The book brings up two methods one with the arrow pointing towards the negative and the other pointing towards the positive but Lavelle always has it point towards the negative so I would do that.
- Tue Nov 12, 2019 5:27 pm
- Forum: DeBroglie Equation
- Topic: When to Use
- Replies: 8
- Views: 467
Re: When to Use
If the problem says something about radiation, don't use DeBroglie as this does not have a mass, but anything else including an electron has mass and you will use this formula.
- Tue Nov 12, 2019 3:03 pm
- Forum: Empirical & Molecular Formulas
- Topic: Answering a Question without amount of elements
- Replies: 1
- Views: 205
Re: Answering a Question without amount of elements
You find the moles of the whole substance they are involved in and then multiply by the total number of the element is in the compound for example if its H2O and you want to get grams of hydrogen you find the moles of H2O and then multiply by 2 because 2 hydrogens are in H2O and then multiply by the...
- Tue Nov 12, 2019 2:38 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Writing full electron configuration
- Replies: 3
- Views: 349
Re: Writing full electron configuration
It seems like the only time 2Px, 2Py, 2Pz are ever important is just to understand the three shells in the p and how 6 valence electrons fit there, or to understand how the configuration is supposed to look.
- Sun Nov 10, 2019 5:33 pm
- Forum: Electronegativity
- Topic: Differences in Electronegativity
- Replies: 5
- Views: 360
Re: Differences in Electronegativity
The trend in the periodic table should be good enough as usually, the difference is pretty apparent and doesn't require actually knowing the values.
- Sun Nov 10, 2019 5:24 pm
- Forum: Student Social/Study Group
- Topic: midterm grades
- Replies: 8
- Views: 481
Re: midterm grades
Midterms back after the lecture on Wednesday and I'm guessing he will put out the key on the class website for the test that night.
- Sun Nov 10, 2019 11:04 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 Arrows
- Replies: 2
- Views: 83
Re: Dipole Arrows
Lavelle has only mentioned the original convention with the arrow pointing towards the negative charge in class so I would say it's safe to stick with that one.
- Thu Nov 07, 2019 6:23 pm
- Forum: Properties of Light
- Topic: Speed of Light
- Replies: 7
- Views: 602
Re: Speed of Light
The value is given in normal meters/second fashion and you can convert it beyond that.
- Thu Nov 07, 2019 6:21 pm
- Forum: General Science Questions
- Topic: Week 6 homework problems
- Replies: 7
- Views: 497
Re: Week 6 homework problems
My guess is chemical bonds because it is the most recent focus we have gone through.
- Fri Nov 01, 2019 10:11 am
- Forum: Lewis Structures
- Topic: Identifying an element from a given Lewis Structure (3.37)
- Replies: 4
- Views: 2393
Re: Identifying an element from a given Lewis Structure (3.37)
You don't need to use the formal charge equation for this problem just the total number of valence electrons. By finding the that that element accounts for five total valence electrons it points you to group 15 and the problem tells you it's in the third period so you go over to group 15 down to per...
- Fri Nov 01, 2019 10:01 am
- Forum: Student Social/Study Group
- Topic: Midterm question
- Replies: 3
- Views: 138
Re: Midterm question
I'm pretty sure he said the midterm is eight questions so my guess is that each outline is going to have 3 questions except for one and because we already had a test on the fundamentals I would think that would be the section to only have two questions, but that is all speculation.
- Wed Oct 30, 2019 4:32 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm
- Replies: 4
- Views: 233
Re: Midterm
We need to know all of outlines 1 and 2 and most of outline 3.
- Wed Oct 30, 2019 4:25 pm
- Forum: Lewis Structures
- Topic: Valence Electrons from Periodic Table
- Replies: 10
- Views: 645
Re: Valence Electrons from Periodic Table
The number of valence electrons for an element is equal to its group number starting at one on the left and moving to eight on the far right.
- Wed Oct 30, 2019 4:21 pm
- Forum: Trends in The Periodic Table
- Topic: Electron Affinity
- Replies: 8
- Views: 239
Re: Electron Affinity
It increases as you move left to right across the periodic table and up groups meaning elements such as Fluorine have very high electron affinity.
- Fri Oct 25, 2019 3:05 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 1E. 7 Ground state vs. Excited State
- Replies: 2
- Views: 138
Re: 1E. 7 Ground state vs. Excited State
The excited state of an atom is going to be a state where the electrons are arranged in a way that is not energy efficient meaning the only way it is possible is if there is extra energy present. For example, in part A of 1E.7 this represents an excited state of carbon because the last electron shou...
- Thu Oct 24, 2019 4:54 pm
- Forum: Properties of Electrons
- Topic: hw
- Replies: 6
- Views: 342
Re: hw
I think you can because we just started chemical bonds, next homework is probably going to be the first no Quantum World assignment.
- Thu Oct 24, 2019 4:43 pm
- Forum: Ionic & Covalent Bonds
- Topic: valence electrons
- Replies: 6
- Views: 423
Re: valence electrons
I think it comes from the element's unfilled outer orbital as it only has 5s2 and 5p3 which in total adds up to 5 valence electrons.
- Thu Oct 24, 2019 4:12 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: HW 1E.23
- Replies: 4
- Views: 238
Re: HW 1E.23
Finding unpaired electrons is easiest if you draw out the electron configuration first and then if done correctly the unpaired valence electrons are just the electrons don't have a pair in the configuration.
- Thu Oct 24, 2019 3:53 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configurations of ions
- Replies: 4
- Views: 113
Re: Electron Configurations of ions
You would start in the outermost shell as well because it is easier to remove electrons from there rather than spend the energy to remove it from an orbital closer to the nucleus.
- Sat Oct 19, 2019 4:45 pm
- Forum: Properties of Electrons
- Topic: Textbook 1B.21
- Replies: 2
- Views: 104
Re: Textbook 1B.21
You need to change the weight from ounces to kg and the velocity from miles per hour to m/s. Then just use the de Broglie relationship lamba= h/p or h/mv.
- Sat Oct 19, 2019 4:09 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Aufbau
- Replies: 3
- Views: 185
Re: Aufbau
The Aufbau principle states that you start filling the lower energy subshells before continuing on to the ones with the higher energy. So for example you wouldn't start filling up 2p before filling 2s
- Sat Oct 19, 2019 4:05 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Correlation Between n and l
- Replies: 6
- Views: 243
Re: Correlation Between n and l
The different values of l indicate which orbitals the electron can be on with l=0 meaning s-orbital l=1 meaning p-orbital l=2 meaning d-orbital l=3 meaning f orbital and so on.
- Sat Oct 19, 2019 3:59 pm
- Forum: SI Units, Unit Conversions
- Topic: midterm/final
- Replies: 18
- Views: 1413
Re: midterm/final
Just going off test 1 and how that was all calculations I feel like all the test including the midterm and final are going to be calculated based and will not feature any short answer or essay questions.
- Thu Oct 17, 2019 10:10 am
- Forum: General Science Questions
- Topic: Pre-Calc and Calculus
- Replies: 3
- Views: 176
Re: Pre-Calc and Calculus
It doesn't seem like a big background in calculus is really needed for the class as all the math is usually done through plugging in values into many different equations, so as long as you understand how to work the equations and what values are what you should be fine without any additional math pr...
- Sun Oct 13, 2019 2:53 pm
- Forum: Properties of Light
- Topic: Photon Model
- Replies: 3
- Views: 169
Re: Photon Model
I like to think of them as little pieces of an overall bigger wave. It's like if you are looking at a group of birds flying the sky, you see the overall shape of them but that is made of each bird. Photons are like that as they form this overall wave but when it comes to the photoelectric test they ...
- Sun Oct 13, 2019 2:51 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Advice
- Replies: 6
- Views: 335
Re: Advice
I would say to pay attention to the outlines that are on the class website when it comes to concepts you may need to know for test and then I would make sure you have an understanding on how to do all the hw problems on the syllabus especially the ones towards the end as they are usually the hardest...
- Sun Oct 13, 2019 2:38 pm
- Forum: Properties of Light
- Topic: Speed of Light
- Replies: 3
- Views: 108
Re: Speed of Light
The constant for speed of light as (3.00 x 10^8 m/s) refers to the fastest light can travel as it is measured in a vacuum but as stated before it can slow down when it goes through different thicker mediums.
- Sun Oct 13, 2019 2:17 pm
- Forum: Photoelectric Effect
- Topic: #1B.3
- Replies: 1
- Views: 92
Re: #1B.3
I think it is D because of the behavior of the EMR that then leads to the emission of a particle. The idea that increasing the overall intensity of the light not leading to more electrons creates this idea that the light itself is acting as Einstein put it "packets of energy" as if it was ...
- Sat Oct 12, 2019 11:34 am
- Forum: Significant Figures
- Topic: Balancing Equations
- Replies: 4
- Views: 371
Re: Balancing Equations
Tips that have helped me in the past: 1. Save the molecules that are just one element until the end as they are very easy to deal with due to the singular element making them very helpful when it comes to making sure the final count is balanced. 2. Try and balance the elements that only appear in th...
- Sun Oct 06, 2019 3:13 pm
- Forum: Administrative Questions and Class Announcements
- Topic: powers of 10 in answers
- Replies: 2
- Views: 105
Re: powers of 10 in answers
I wouldn't think you would lose points if you don't go out of your way to use scientific notation, but if there are some problems that ask for the answer in grams but your answer came out in kilograms it would make sense to use scientific notion to switch the units over in the clearest way. If anyth...
- Sun Oct 06, 2019 2:58 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Homework Grading
- Replies: 1
- Views: 85
Re: Homework Grading
I don't know if different TAs have different grading policies but my TA made it sound like the HW problems are just graded quickly on a credit no credit basis because we already have the solution manual so I doubt we would get them back with any comments.
- Sun Oct 06, 2019 10:25 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Naming Formulas
- Replies: 3
- Views: 235
Re: Naming Formulas
I'm pretty sure in a lecture he touched on the fact that we don't know enough yet to write out the formulas for the chemical equations ourselves so he would give us the individual compounds next to their name and then you put it together.
- Sun Oct 06, 2019 10:19 am
- Forum: Balancing Chemical Reactions
- Topic: Advice for Test 1
- Replies: 7
- Views: 409
Re: Advice for Test 1
The email says its seven questions in 50 minutes and the first one is only on the review of high school topics. I would say the best way to prepare is just to go through all the problems on the syllabus in the first section and make sure you grasp the key concepts.
- Thu Oct 03, 2019 9:29 pm
- Forum: SI Units, Unit Conversions
- Topic: How many Sig Figs are necessary?
- Replies: 4
- Views: 213
How many Sig Figs are necessary?
If I am doing a problem and the answer needs to have 5 Sig Figs and the answer comes out to 0.001295 would you round and put a zero after the 9 (that becomes a 0 when you round up), leave it unrounded, or round without the zero?