Search found 100 matches
- Sat Mar 14, 2020 10:10 pm
- Forum: Ideal Gases
- Topic: T variable in pv=nrt [ENDORSED]
- Replies: 38
- Views: 1548
Re: T variable in pv=nrt [ENDORSED]
For simplicity, it would be easier to use Kelvin, especially since Kelvin is used in the constants.
- Sat Mar 14, 2020 10:06 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Printing for Final
- Replies: 9
- Views: 719
Re: Printing for Final
No need to print out anything for the final! If you feel more comfortable with the constants and equations sheet printed out, maybe that will be helpful.
- Sat Mar 14, 2020 10:02 pm
- Forum: General Rate Laws
- Topic: Factors Affecting k
- Replies: 83
- Views: 4543
Re: Factors Affecting k
k can only change when there is a temperature change.
- Sat Mar 14, 2020 10:01 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam Time
- Replies: 13
- Views: 891
Re: Final Exam Time
The final will be 3 hours and 30 mins! From 11:15AM-2:45PM
- Sat Mar 14, 2020 8:03 pm
- Forum: General Science Questions
- Topic: Final Content
- Replies: 5
- Views: 442
Re: Final Content
I feel like some questions on the final would be structured similarly to hw questions.
- Sat Mar 14, 2020 7:03 pm
- Forum: General Rate Laws
- Topic: integrals and derivatives
- Replies: 7
- Views: 564
Re: integrals and derivatives
I believe it was used to show how the equations work but would not necessarily be applied on a test.
- Sat Mar 14, 2020 5:31 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Submission
- Replies: 8
- Views: 736
Re: Final Submission
In Lavelle's email he said it would be a quiz posted on CCLE.
- Sat Mar 14, 2020 5:29 pm
- Forum: General Science Questions
- Topic: Final Overview
- Replies: 5
- Views: 468
Re: Final Overview
I would make sure you have a broad understanding of Lavelle's course outlines, but to also be mindful of kinetics since it is our most recent material!
- Sat Mar 14, 2020 5:28 pm
- Forum: General Science Questions
- Topic: Summer 14BL
- Replies: 1
- Views: 208
Re: Summer 14BL
I'll be taking 14BL this summer as well, does anyone have any experience?
- Sat Mar 14, 2020 5:28 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Grading Scale
- Replies: 16
- Views: 1029
Re: Grading Scale
I think its really similar to Chem 14A, 50% is a C-, and he will scale depending on class performance, but it will not hurt you.
- Sat Mar 14, 2020 5:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Online Final
- Replies: 3
- Views: 315
Re: Online Final
Per his last email, Lavelle said that he didnt want us to go through the trouble of scanning or using different apps. I think it will just be some multiple choice and fill in the blank questions.
- Sat Mar 14, 2020 12:33 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Constants
- Replies: 15
- Views: 862
Re: Equilibrium Constants
Yes, the coefficients in a chemical equation affect the K constant.
- Fri Mar 13, 2020 10:04 pm
- Forum: First Order Reactions
- Topic: Units for t
- Replies: 30
- Views: 1166
Re: Units for t
It honestly depends on the context of the question, but I use seconds because it is the SI unit. It also depends on your k.
- Fri Mar 13, 2020 9:11 pm
- Forum: General Rate Laws
- Topic: Temperature and kinetics
- Replies: 5
- Views: 387
Re: Temperature and kinetics
Yes, because at a higher temperature molecules move faster and have more collisions.
- Fri Mar 13, 2020 9:06 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: U vs H
- Replies: 15
- Views: 1169
Re: U vs H
Delta U is change in internal energy while delta H is a change in enthalpy.
- Fri Mar 13, 2020 9:05 pm
- Forum: Student Social/Study Group
- Topic: final?
- Replies: 7
- Views: 633
Re: final?
His last email said that he would be telling us by tomorrow the format of the final. All I know is that its open book and online.
- Fri Mar 13, 2020 9:00 pm
- Forum: Administrative Questions and Class Announcements
- Topic: take home FINAL DEADLINE
- Replies: 15
- Views: 1054
Re: take home FINAL DEADLINE
I think the take home final will be in the same time period as the regular final.
- Fri Mar 13, 2020 8:25 pm
- Forum: Balancing Redox Reactions
- Topic: intensive and extensive
- Replies: 3
- Views: 209
Re: intensive and extensive
Intensive properties are not affected by changes in matter. Extensive properties change when the amount of matter changes.
- Fri Mar 13, 2020 4:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Saying Thank You to Dr. Lavelle
- Replies: 490
- Views: 513686
Re: Saying Thank You to Dr. Lavelle
Dr. Lavelle, Thank you so much for exposing me to the world of chemistry in my short first year at UCLA. I am so grateful for the way you taught chemistry and worked so hard to coordinate office hours, step-up sessions, and workshops. To all of the TAs and UAs reading this. Thank you from the bottom...
- Fri Mar 13, 2020 4:46 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final
- Replies: 11
- Views: 702
Re: Final
The final should be up around Sunday! Lavelle has been finalizing things so be sure to check his emails.
- Fri Mar 13, 2020 4:45 pm
- Forum: Administrative Questions and Class Announcements
- Topic: "Open Book" Final?
- Replies: 30
- Views: 1951
Re: "Open Book" Final?
We can use our books in pdf or physically, as well as any notes we have prepared.
- Thu Mar 12, 2020 9:46 pm
- Forum: Administrative Questions and Class Announcements
- Topic: review session packets
- Replies: 4
- Views: 328
Re: review session packets
I think they will be posted in the same thread where the worksheet was posted.
- Thu Mar 12, 2020 9:45 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram
- Replies: 4
- Views: 386
Re: Cell Diagram
The comma is for something in the same phase, such as two aqueous. The | is used to separate substances in different phases.
- Thu Mar 12, 2020 3:19 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2 Return
- Replies: 20
- Views: 1148
Re: Test 2 Return
I would ask your TA for more information to pick up Test 2
- Thu Mar 12, 2020 3:12 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalysts and Rates
- Replies: 10
- Views: 649
Re: Catalysts and Rates
Catalysts help speed up reactions though.
- Thu Mar 12, 2020 3:10 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: salt bridge
- Replies: 11
- Views: 609
Re: salt bridge
Salt bridges help with electron flow and neutralizing the solutions in a galvanic cell.
- Thu Mar 12, 2020 3:08 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Format because I posted in 14A by accident
- Replies: 8
- Views: 566
Re: Format because I posted in 14A by accident
In the email he said that the final will be shorter and open book. My TA said that it would be collected online.
- Thu Mar 12, 2020 1:43 pm
- Forum: First Order Reactions
- Topic: equation derivations
- Replies: 9
- Views: 553
Re: equation derivations
We wouldn't necessarily use the derivations on the exam, but knowing how the derivation occurs and how it leads to a specific equation would be valuable in decoding a certain question.
- Thu Mar 12, 2020 1:42 pm
- Forum: First Order Reactions
- Topic: Half Life Equations
- Replies: 10
- Views: 554
Re: Half Life Equations
They are typically provided on the list of given equations!
- Thu Mar 12, 2020 1:41 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Take Home Final
- Replies: 16
- Views: 976
Re: Take Home Final
I feel like we would have to print the final out and scan it, I'm waiting for an update as well!
- Tue Mar 10, 2020 11:45 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Homework 10
- Replies: 11
- Views: 646
Re: Homework 10
Lavelle's email said you can send a picture to your TA.
- Mon Mar 09, 2020 1:54 pm
- Forum: General Science Questions
- Topic: Who makes the Final
- Replies: 23
- Views: 1360
Re: Who makes the Final
I think that Lavelle is in control of what goes on the final.
- Mon Mar 09, 2020 1:54 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Kelvin or Celsius?
- Replies: 86
- Views: 5176
Re: Kelvin or Celsius?
You should use Kelvin since it matches with the gas constant R to cancel out.
- Mon Mar 09, 2020 1:52 pm
- Forum: First Order Reactions
- Topic: Difference between first and second order
- Replies: 6
- Views: 492
Re: Difference between first and second order
A first order reaction depends on the concentration of one of the reactants. A second order reaction is the square of the concentration of a single reactant.
- Mon Mar 09, 2020 1:48 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Relationship Between Ecell and K
- Replies: 9
- Views: 3153
Re: Relationship Between Ecell and K
When Ecell > 0, then K>1.
When Ecell < 0, then K<1
When Ecell < 0, then K<1
- Tue Mar 03, 2020 12:30 pm
- Forum: Second Order Reactions
- Topic: [A] v. Time
- Replies: 27
- Views: 1144
Re: [A] v. Time
The graph of [A] v. Time would be linear.
- Sun Mar 01, 2020 11:44 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: intermediate
- Replies: 26
- Views: 1942
Re: intermediate
An intermediate is formed and then used up during a reaction, so it cant be used in rate law.
- Sun Mar 01, 2020 11:42 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Voltage
- Replies: 6
- Views: 390
Re: Voltage
You should use a positive sign, especially when regarding voltage because it can determine if a charge is positive or negative.
- Sun Mar 01, 2020 11:33 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Kinetics in Test 2?
- Replies: 13
- Views: 786
Re: Kinetics in Test 2?
Only the second part of thermodynamics and electrochemistry is covered in test 2.
- Sun Mar 01, 2020 11:30 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Favorability
- Replies: 4
- Views: 278
Re: Favorability
Kinetics is used to tell the rate of a reaction, instead you can use thermodynamics to determine if a rxn is favorable.
- Sun Mar 01, 2020 11:28 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: units
- Replies: 11
- Views: 706
Re: units
Typically the unit for rates is mol per liter per time unit.
- Sun Mar 01, 2020 11:20 pm
- Forum: Administrative Questions and Class Announcements
- Topic: what to know for test 2
- Replies: 10
- Views: 575
Re: what to know for test 2
I'm pretty sure that test 2 covers all of electrochemistry and the second page of the thermodynamics outline (not covered in the midterm)
- Sun Jan 19, 2020 10:14 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: pKa
- Replies: 13
- Views: 449
Re: pKa
the lower the pKa = the stronger the acid
- Sun Jan 19, 2020 9:55 pm
- Forum: Ideal Gases
- Topic: ICE Tables
- Replies: 8
- Views: 461
Re: ICE Tables
you use -x typically for the reactants and +x for the products
- Sun Jan 19, 2020 9:54 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K vs Q
- Replies: 14
- Views: 316
Re: K vs Q
k is used when at equilibrium and q is used when not in equilibrium
- Sun Jan 12, 2020 4:01 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Units for Kc and Kp
- Replies: 3
- Views: 102
Re: Units for Kc and Kp
We dont include units for Kp because its a constant.
- Sun Jan 12, 2020 3:56 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q and direction
- Replies: 4
- Views: 261
Q and direction
How does Q let us predict the direction that an equilibrium practice will go through?
- Sun Jan 12, 2020 3:55 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Difference between Kc and Kp??
- Replies: 2
- Views: 150
Difference between Kc and Kp??
Hi, I really don't get how to differentiate between Kc and Kp.
- Sun Jan 12, 2020 3:52 pm
- Forum: Ideal Gases
- Topic: R in PV=nRT
- Replies: 34
- Views: 5853
Re: R in PV=nRT
R is the gas constant, and depending on the units you have in your problem you have to choose a certain R value.
R = 8.314 J·K-1·mol-1 = 8.206 x 10-2 L·atm·K-1·mol-1 = 8.314 x 10-2 L·bar·K-1·mol-1
= 62.364 L·Torr·K-1·mol-1
R = 8.314 J·K-1·mol-1 = 8.206 x 10-2 L·atm·K-1·mol-1 = 8.314 x 10-2 L·bar·K-1·mol-1
= 62.364 L·Torr·K-1·mol-1
- Sun Jan 12, 2020 3:51 pm
- Forum: Ideal Gases
- Topic: Topics on Test 1
- Replies: 37
- Views: 1251
Re: Topics on Test 1
Most likely outline 1 and some of outline 2, whatever he covers right before the test is on the test I think.
- Sun Dec 08, 2019 12:31 am
- Forum: Biological Examples
- Topic: Important Complexes and their Biological Significance
- Replies: 2
- Views: 277
Re: Important Complexes and their Biological Significance
We went over porphyrin ligands and the effects in hemoglobin in lecture so I think its fair game for the final.
- Sun Dec 08, 2019 12:28 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: CO2 in blood
- Replies: 1
- Views: 111
Re: CO2 in blood
Well more H3O+ in the blood would lower pH not make it higher.
- Sun Dec 08, 2019 12:14 am
- Forum: Naming
- Topic: Ferrate and Cuprate? [ENDORSED]
- Replies: 5
- Views: 515
Re: Ferrate and Cuprate? [ENDORSED]
You use ferrate and cuprate when naming a coordination compound.
- Sat Dec 07, 2019 11:51 pm
- Forum: Naming
- Topic: IUPAC Name Convention
- Replies: 1
- Views: 154
Re: IUPAC Name Convention
Dr Lavelle said you can use IUPAC or the regular naming as long as you stay consistent with it.
- Sat Dec 07, 2019 11:50 pm
- Forum: Ionic & Covalent Bonds
- Topic: Coulombs equation
- Replies: 2
- Views: 197
Re: Coulombs equation
q1 and q2 stand for the charges on the interacting objects.
- Sat Dec 07, 2019 11:46 pm
- Forum: Student Social/Study Group
- Topic: Study websites besides quizlet
- Replies: 3
- Views: 325
Re: Study websites besides quizlet
I really like using adobe spark for flashcards, its really customizable.
- Sat Dec 07, 2019 11:45 pm
- Forum: Student Social/Study Group
- Topic: Equilibrium
- Replies: 3
- Views: 135
Re: Equilibrium
I dont think we need to know equilibrium that deep, but we did talk about k constants in lecture. We're only expected to do calculations on weak acids/bases though.
- Sat Dec 07, 2019 3:39 pm
- Forum: Biological Examples
- Topic: cisplatin vs transplatin?
- Replies: 2
- Views: 236
cisplatin vs transplatin?
Whats the difference between cisplatin and transplatin?
- Sat Dec 07, 2019 3:36 pm
- Forum: Naming
- Topic: Biological Functions
- Replies: 2
- Views: 147
Re: Biological Functions
Cisplatin can be used in chemotherapy treatment by stopping cell division but I'm not quite sure if it's naturally occurring...
- Sun Dec 01, 2019 6:32 pm
- Forum: Student Social/Study Group
- Topic: Final Studying
- Replies: 8
- Views: 339
Re: Final Studying
For the final, try going to as much review sessions as possible that are focused on topics that you need the most help on. I recommend looking for some of the worksheets that the UAs make they're really helpful!
- Sun Dec 01, 2019 6:30 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Relative acidity
- Replies: 7
- Views: 509
Re: Relative acidity
Bond length is a component of relative acidity. Since the bond length in HI is longer and weaker compared to the short and strong bond in HF, HI is able to dissociate much easier in a solution compared to HF.
- Sun Dec 01, 2019 6:26 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: equation breakdown
- Replies: 2
- Views: 86
Re: equation breakdown
The pH equation is on a logarithmic scale and is -log[H+]
You basically find the negative log of the concentration of H+ in a solution to find the pH in a strong acid.
You basically find the negative log of the concentration of H+ in a solution to find the pH in a strong acid.
- Sun Dec 01, 2019 6:23 pm
- Forum: Lewis Acids & Bases
- Topic: Difference between Lewis and Bronsted Acids?
- Replies: 2
- Views: 147
Difference between Lewis and Bronsted Acids?
Hi can someone tell me how Lewis and Bronsted acids are different or similar?
- Sun Dec 01, 2019 6:12 pm
- Forum: Student Social/Study Group
- Topic: Study Strategies
- Replies: 6
- Views: 440
Re: Study Strategies
I feel like you should go to the review sessions for topic that you need the most help in. Also office hours too!!
- Sun Dec 01, 2019 6:10 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Calculating pH for Weak Acids and Bases
- Replies: 1
- Views: 75
Re: Calculating pH for Weak Acids and Bases
I think we'll be going over ICE tables in 14B. Lavelle said we should know how to calculate pH for strong acids and bases, but i think we just need to know K value for weak acids and bases.
- Sun Dec 01, 2019 6:08 pm
- Forum: Biological Examples
- Topic: EDTA
- Replies: 3
- Views: 171
Re: EDTA
EDTA can remove metals from a solution. So if your blood had elevated levels of a deadly metal such as mercury, EDTA can help remove it from your bloodstream.
- Sun Nov 24, 2019 11:55 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular shape of carbon Dioxide
- Replies: 10
- Views: 579
Re: Molecular shape of carbon Dioxide
The molecular shape of carbon dioxide is linear bc there's no lone pairs and it has 2 domains.
- Sun Nov 24, 2019 11:50 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Electron pair geometry
- Replies: 1
- Views: 152
Re: Electron pair geometry
the electron pair geometry for NCl2 is tetrahedral since there are 4 domains.
the molecular geometry is bent
the molecular geometry is bent
- Sun Nov 24, 2019 11:47 pm
- Forum: Hybridization
- Topic: Hybridization Formulas
- Replies: 2
- Views: 104
Re: Hybridization Formulas
You have to count the atoms around the atom you're looking at in a molecule.
If there are 4 atoms around the central atom, you'd have sp3
If there are 3 atoms around the central atom, youd have sp2
If there are 2 atoms around the central atom, youd have sp1
If there are 4 atoms around the central atom, you'd have sp3
If there are 3 atoms around the central atom, youd have sp2
If there are 2 atoms around the central atom, youd have sp1
- Sun Nov 24, 2019 11:44 pm
- Forum: Hybridization
- Topic: Sigma and Pi Bonds
- Replies: 21
- Views: 943
Re: Sigma and Pi Bonds
Usually a sigma bond occurs in single bonds, double bonds and triple bonds.
pi bonds are found in double and triple bond.
Each bond type has a sigma bond
Ex. Double bond=one sigma, one pi
Triple bond: one sigma, two pi
pi bonds are found in double and triple bond.
Each bond type has a sigma bond
Ex. Double bond=one sigma, one pi
Triple bond: one sigma, two pi
- Sun Nov 24, 2019 11:42 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Hydrogen Bonding
- Replies: 13
- Views: 651
Re: Hydrogen Bonding
Yes, hydrogen bonding should have a partial positive or negative charge.
- Wed Nov 20, 2019 3:28 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Do we need to know the pentagonal bipyramidal model for Test 2?
- Replies: 6
- Views: 373
Re: Do we need to know the pentagonal bipyramidal model for Test 2?
I don't think you need to know pentagonal bipyramid because its not THAT common, but its nice to know more VSEPR shapes!
- Wed Nov 20, 2019 3:17 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles in Square Pyramidal and T-Shaped
- Replies: 4
- Views: 265
Re: Bond Angles in Square Pyramidal and T-Shaped
In a square pyramidal all angles are <90 degrees
In a t-shape the angles are <90 degrees
In a t-shape the angles are <90 degrees
- Wed Nov 20, 2019 3:09 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: Boiling/melting points
- Replies: 5
- Views: 264
Re: Boiling/melting points
Depending on the IMFs that the molecules have you can compare them to determine which molecule has a higher boiling or melting point.
- Wed Nov 20, 2019 12:28 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: Why is CBr2Cl2 polar?
- Replies: 7
- Views: 834
Re: Why is CBr2Cl2 polar?
isn't CBrCl2 tetrahedral so its polar??
- Sun Nov 03, 2019 11:22 pm
- Forum: Trends in The Periodic Table
- Topic: ionization energy vs electronegativity
- Replies: 4
- Views: 167
ionization energy vs electronegativity
Both have the same trend on the periodic table, but what is the difference between the two?
- Sun Nov 03, 2019 11:21 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: magnetic quantum number
- Replies: 5
- Views: 172
Re: magnetic quantum number
The magnetic quantum number, ml tells you the number of orbitals and the way its oriented in a sub shell. it ranges from -l to l.
- Sun Nov 03, 2019 11:18 pm
- Forum: Resonance Structures
- Topic: Bond lengths
- Replies: 11
- Views: 360
Bond lengths
Why is it when there is a resonance structure, all of the bond lengths are the same even though there's double and single bonds.
- Sun Nov 03, 2019 11:15 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: central atom
- Replies: 21
- Views: 909
Re: central atom
You would want the formal charge on the central atom to be closer to zero because its supposed to be the least electronegative.
- Sun Nov 03, 2019 11:13 pm
- Forum: General Science Questions
- Topic: Study Tactics
- Replies: 5
- Views: 182
Re: Study Tactics
I would focus on lewis structures and resonance because it plays a huge role in drawing a stable structure!
- Sun Oct 27, 2019 11:58 pm
- Forum: Ionic & Covalent Bonds
- Topic: Anions and Cations
- Replies: 4
- Views: 219
Anions and Cations
Why do certain elements make anions and others make cations?
- Sun Oct 27, 2019 11:40 pm
- Forum: Bond Lengths & Energies
- Topic: Double bond vs single bonds
- Replies: 4
- Views: 264
Double bond vs single bonds
Why are double bond lengths shorter than single bond lengths?
- Sun Oct 27, 2019 11:39 pm
- Forum: Electronegativity
- Topic: Fluorine's Electronegativity
- Replies: 6
- Views: 426
Fluorine's Electronegativity
Why is Fluorine touted as the most electronegative atom? What makes it so electronegative?
- Sun Oct 27, 2019 11:35 pm
- Forum: Ionic & Covalent Bonds
- Topic: Confusion with covalent
- Replies: 3
- Views: 122
Confusion with covalent
Why do shared atoms want to be at a noble gas configuration?
- Sun Oct 27, 2019 11:34 pm
- Forum: Lewis Structures
- Topic: Valence Shells
- Replies: 2
- Views: 266
Valence Shells
Why exactly can P, S, and Cl have more than 8 valence electrons?
- Sun Oct 20, 2019 10:53 pm
- Forum: Trends in The Periodic Table
- Topic: Ionization Energy
- Replies: 8
- Views: 282
Re: Ionization Energy
As you remove more electrons from an atom, the attraction between electrons and the nucleus increase because repulsion decreases. So as you go through successive ionization energies, more energy is required to remove electrons due to the lack of repulsion.
- Sun Oct 20, 2019 10:37 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Exceptions to the rules
- Replies: 3
- Views: 172
Exceptions to the rules
Why does Cr and Cu not follow the rules for electron configuration? Why isn't the s block completely filled?
- Sun Oct 20, 2019 10:32 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Spin
- Replies: 2
- Views: 93
Re: Electron Spin
We draw arrows going up first because each electron must enter an empty orbital first before going into the same orbital because of repulsion (two electrons repel). By putting the arrows up before down, it shows how we can minimize repulsion in a specific element.
- Sun Oct 20, 2019 10:27 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Writing Electron Configurations
- Replies: 2
- Views: 92
Re: Writing Electron Configurations
In some answers, the orders may be reversed due to some exceptions in the Aufbau principle in elements such as Cr and Cu.
- Sun Oct 20, 2019 10:23 pm
- Forum: DeBroglie Equation
- Topic: Conversion Units for 1B.21
- Replies: 3
- Views: 92
Re: Conversion Units for 1B.21
For ounce to grams use 1 ounce = 28.3 g
For mph to m/s use 1 mph = 0.447 m/s
For mph to m/s use 1 mph = 0.447 m/s
- Sun Oct 13, 2019 11:43 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Class example
- Replies: 2
- Views: 93
Re: Class example
The change in energy was negative because we went from a high to low energy level (n=4 to n=2). When finding the frequency, we made the energy positive because you can't have a negative value of Hertz as your answer, since a wave's frequency can not be -6.17*10^14 per second.
- Sun Oct 13, 2019 11:35 pm
- Forum: Properties of Light
- Topic: Spectroscopic Analysis
- Replies: 1
- Views: 86
Re: Spectroscopic Analysis
Spectroscopic analysis is the analysis of light emitted by a certain substance. We can use a device called a spectrometer to analyze light (it involves the use of a prism to separate different wavelengths of light). This gives us spectral lines that allow us to analyze light further.
- Sun Oct 13, 2019 9:04 pm
- Forum: Properties of Light
- Topic: Baler v. Lyman Series
- Replies: 10
- Views: 510
Re: Baler v. Lyman Series
The Balmer series is found in the visible region of the hydrogen spectral lines and goes from n=3,4,5,... to n=1
The Lyman series is found in the ultraviolet series of the hydrogen spectra and goes from n=2,3,4,... to n=2
The Lyman series is found in the ultraviolet series of the hydrogen spectra and goes from n=2,3,4,... to n=2
- Sun Oct 13, 2019 8:58 pm
- Forum: Properties of Electrons
- Topic: electron size
- Replies: 3
- Views: 90
Re: electron size
The diameter of an electron is approximately < 10−18 m.
- Sun Oct 13, 2019 8:54 pm
- Forum: Properties of Light
- Topic: Wavelength
- Replies: 3
- Views: 88
Re: Wavelength
When a wavelength is shorter, its frequency is higher therefore there is more energy. Using the equation E=hc/lambda (lambda is the wavelength), a shorter wavelength would make energy hbiggergher, and a longer wavelength would make energy smaller.
- Thu Oct 03, 2019 11:31 pm
- Forum: Significant Figures
- Topic: How would sig figs be used in a problem?
- Replies: 7
- Views: 164
Re: How would sig figs be used in a problem?
Problems usually require us to use the least amount of sig figs from the "given" in the problem. Say you get a problem that gives you the following info: 0.179 M AgNO3 and 0.50 L. You would only round your answer to the least amount of sig figs given in the problem, this being 2 sig figs f...
- Thu Oct 03, 2019 11:12 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Solutions vs. Dilutions
- Replies: 4
- Views: 234
Re: Solutions vs. Dilutions
Dilution problems typically use the term "stock solution" when one wants to dilute a certain compound. For example a problem might say you have a stock solution of 12.0 M NaOH and it would want you to figure out how much stock solution is needed to get 250. mL of 2.0 M NaOH. The word "...
- Thu Oct 03, 2019 11:04 pm
- Forum: Empirical & Molecular Formulas
- Topic: What decimal place to round to when taking masses from the Periodic Table?
- Replies: 19
- Views: 2897
Re: What decimal place to round to when taking masses from the Periodic Table?
For more accuracy, you should use all decimal places on the periodic table that is provided. Feel free to round to the amount of sig figs needed at the end of the problem.
- Thu Oct 03, 2019 11:01 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Aqueous, solid, gas
- Replies: 11
- Views: 16034
Re: Aqueous, solid, gas
You can usually tell if something is solid or gas by looking through the problem you are doing (it is normally given) and it is usually marked on the periodic table. You can determine if a solution is aqueous if you see that it is being dissolved in water or if ions/precipitates are involved in a pr...
- Thu Oct 03, 2019 8:38 pm
- Forum: Significant Figures
- Topic: Sig figs in intermediate steps??
- Replies: 5
- Views: 910
Sig figs in intermediate steps??
Hi all, It's been a long time since I've taken chem, but I was wondering if you need to keep on using sig figs on the intermediate steps of a problem. Say your answer has to be 3 sig figs, do I have to keep on using 3 sig figs for each step in the middle of the problem or implement it in the end? Th...