Search found 100 matches
- Thu Mar 12, 2020 1:39 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Take Home Final
- Replies: 16
- Views: 1044
Re: Take Home Final
I am guessing it will be more than the three hour period because we will most likely need to print out a sheet and upload it and everything.
- Tue Mar 10, 2020 9:49 pm
- Forum: Administrative Questions and Class Announcements
- Topic: ENDGAME Review Session
- Replies: 71
- Views: 5724
Re: ENDGAME Review Session
Are all review sessions going to be cancelled?
- Tue Mar 10, 2020 9:48 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Email Announcement
- Replies: 8
- Views: 725
Re: Email Announcement
Is it possible he will have us take the final in small group settings on campus or are we okay to go home and assume everything for the rest of the quarter can be completed online?
- Tue Mar 10, 2020 9:46 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2 Return
- Replies: 20
- Views: 1226
Re: Test 2 Return
Will there be a way for us to get them back and review them before the final?
- Wed Mar 04, 2020 7:26 pm
- Forum: Balancing Redox Reactions
- Topic: Physical state
- Replies: 6
- Views: 447
Re: Physical state
I think the states would be the same you are just balancing the coefficients based on the number of electrons transferred so the electrons are equal in each reaction.
- Wed Mar 04, 2020 7:25 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst
- Replies: 10
- Views: 770
Re: Nernst
If you are using the shortcut E=E(naught)-(0.05916/n)logQ, you need to use log. I think there is another number shortcut if you are using the equation with natural log.
- Wed Mar 04, 2020 7:21 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic Cell
- Replies: 2
- Views: 284
Re: Galvanic Cell
How do you know when an inert electrode is needed in a galvanic cell?
- Wed Mar 04, 2020 7:20 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Variables
- Replies: 3
- Views: 250
Re: Variables
In the equation lnK=nFE/RT, which value do you use for R and how do the units cancel out?
- Wed Mar 04, 2020 7:18 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Concentration Cell
- Replies: 7
- Views: 515
Re: Concentration Cell
The standard cell potential in a concentration cell is zero because the two half cells would be identical under standard conditions.
- Tue Feb 25, 2020 7:19 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Test 2
- Replies: 13
- Views: 703
Re: Test 2
Will the first page of thermodynamics not be on test 2?
- Tue Feb 25, 2020 7:17 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Recharging Batteries [ENDORSED]
- Replies: 10
- Views: 1429
Re: Recharging Batteries [ENDORSED]
A battery dying or being used is releasing energy and therefore favorable, so the reverse reaction (charging the battery) would not be favorable.
- Tue Feb 25, 2020 7:16 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Porous Disk and Salt Bridge
- Replies: 13
- Views: 1216
Re: Porous Disk and Salt Bridge
In lecture didn't Lavelle say that the voltage is typically lower with the porous disk in a concentration cell?
- Tue Feb 25, 2020 7:15 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: G(not) and G
- Replies: 15
- Views: 750
Re: G(not) and G
In problem 5G.13 you calculate the delta G of the reaction at equilibrium and then use whether that value is positive or negative to see which way the reaction will proceed (towards reactants or products), but if the reaction is at equilibrium doesn't that mean the reaction is going both ways at the...
- Thu Feb 20, 2020 4:00 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2 [ENDORSED]
- Replies: 12
- Views: 733
Re: Test 2 [ENDORSED]
Does this mean that material covered before the midterm will not be on test 2 at all?
- Thu Feb 20, 2020 4:00 pm
- Forum: Balancing Redox Reactions
- Topic: oxidation numbers
- Replies: 8
- Views: 589
Re: oxidation numbers
The charge of a molecule is always equal to the sum of the oxidation numbers multiplied by the amount of each element, so you can use the net charge to determine oxidation numbers.
- Thu Feb 20, 2020 3:57 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Extensive and Intensive Properties
- Replies: 12
- Views: 1062
Re: Extensive and Intensive Properties
Extensive properties include volume, mass, and weight. Intensive properties include temperature, boiling point, and color.
- Thu Feb 20, 2020 3:55 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Adiabatic systems
- Replies: 14
- Views: 831
Re: Adiabatic systems
An adiabatic system is defined as a system in which no heat transfer can take place so q is zero.
- Thu Feb 20, 2020 3:53 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation Numbers
- Replies: 5
- Views: 339
Re: Oxidation Numbers
The sum of the oxidation numbers in a molecule must equal the overall charge.
- Thu Feb 13, 2020 10:47 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: adiabatic
- Replies: 19
- Views: 1078
Re: adiabatic
Would this mean that the change in enthalpy for an adiabtic process is also zero?
- Thu Feb 13, 2020 10:46 am
- Forum: Student Social/Study Group
- Topic: Number of Chemistry Community Posts
- Replies: 45
- Views: 2657
Re: Number of Chemistry Community Posts
When are the posts due every week? Is it Friday or Sunday?
- Thu Feb 13, 2020 10:45 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Spontaneous
- Replies: 23
- Views: 1250
Re: Spontaneous
It delta G is positive it means the reaction is spontaneous in the reverse direction.
- Thu Feb 13, 2020 10:44 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Why are exothermic reactions generally spontaneous?
- Replies: 16
- Views: 1254
Re: Why are exothermic reactions generally spontaneous?
A very general explanation is that systems tend to want to be in the lowest energy state and when a reaction is exothermic it loses energy as heat.
- Thu Feb 13, 2020 10:42 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Isobaric systems
- Replies: 16
- Views: 851
Re: Isobaric systems
Isobaric is constant pressure, isochoric is constant volume, and isothermal is constant temperature.
- Tue Feb 04, 2020 10:49 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Extensive Property
- Replies: 4
- Views: 320
Re: Extensive Property
You can tell that heat capacity is an extensive property because the units are Joule/Kelvin. Because there is no mass value in the units, it is not dependent on the amount of substance present. The units for specific heat are Joule/gram*Kelvin which do include mass values and are therefore dependent...
- Tue Feb 04, 2020 10:45 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: 4D.7
- Replies: 2
- Views: 146
4D.7
My solutions manual shows the way to solve this problem is by using the equation U=H+nRT, but no value for temperature is given in the problem. The solutions guide uses the value of 298 K for the temperature. Will there ever be an instances on the midterm where we will need to assume standard temper...
- Tue Feb 04, 2020 10:41 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy
- Replies: 7
- Views: 405
Re: Enthalpy
Do we need to memorize the table in the textbook that tells you which fraction to multiply R by based on if the reactant is an atom or molecule and so forth?
- Tue Feb 04, 2020 10:39 am
- Forum: Phase Changes & Related Calculations
- Topic: supercooling
- Replies: 3
- Views: 175
supercooling
Why does supercooling and superheating occur and will we need to be able to explain it on the midterm?
- Tue Feb 04, 2020 10:39 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: reversible v irreversible work
- Replies: 3
- Views: 226
reversible v irreversible work
What is the difference between reversible and irreversible work and how can you tell by looking at an experiment whether it is reversible or not?
- Wed Jan 29, 2020 3:38 pm
- Forum: Ideal Gases
- Topic: non ideal gases
- Replies: 8
- Views: 478
Re: non ideal gases
Almost all gases that you use in an experiment would be non-ideal, but it is easier to do calculations with ideal gases.
- Wed Jan 29, 2020 3:37 pm
- Forum: Phase Changes & Related Calculations
- Topic: Why does steam cause burns?
- Replies: 29
- Views: 1280
Re: Why does steam cause burns?
Why is the enthalpy larger? Aren't the same type of bonds being broken?
- Wed Jan 29, 2020 3:36 pm
- Forum: Phase Changes & Related Calculations
- Topic: sig figs
- Replies: 6
- Views: 246
Re: sig figs
When adding and subtracting you round to the value place of whichever component has the largest value for it's significant figures, where in multiplication and division you count the number of significant figures and ignore their place values.
- Wed Jan 29, 2020 3:34 pm
- Forum: Phase Changes & Related Calculations
- Topic: Calorimeter
- Replies: 5
- Views: 276
Re: Calorimeter
A bomb calorimeter is an example of an isolated system because no energy or matter can be lost or gained.
- Wed Jan 29, 2020 3:33 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Temperature
- Replies: 6
- Views: 398
Re: Temperature
So is an ice cube melting an example of an exothermic or endothermic reaction? Because the temperature of the water final is greater than the initial temperature and the difference would therefore be positive is it an endothermic reaction?
- Thu Jan 23, 2020 9:04 am
- Forum: Ideal Gases
- Topic: Inert Gases and Equilibrium
- Replies: 6
- Views: 294
Re: Inert Gases and Equilibrium
Inert gases are inert and thereby do not react with any of the other gases in solution.
- Thu Jan 23, 2020 9:03 am
- Forum: Phase Changes & Related Calculations
- Topic: State Property
- Replies: 6
- Views: 390
Re: State Property
Something is a state property if the value can be obtained just by looking at the final and initial conditions.
- Thu Jan 23, 2020 9:02 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: X was ignored
- Replies: 27
- Views: 1158
Re: X was ignored
If you were unsure as to if x is a small enough value to ignore you could also just solve the problem as you usually would and get a correct answer it would just be more work.
- Thu Jan 23, 2020 8:59 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Prep for Test 1
- Replies: 16
- Views: 683
Re: Prep for Test 1
You should also know how to convert between pKa, Ka, pKb, and Kb.
- Thu Jan 23, 2020 8:58 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Changes in pressure
- Replies: 5
- Views: 154
Re: Changes in pressure
Increasing the pressure of a system by adding an inert gas would not shift the reaction either way because the gas is inert and therefore does not react with anything else.
- Thu Jan 16, 2020 1:32 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: How to make ICE box
- Replies: 17
- Views: 1272
Re: How to make ICE box
Are pure liquids and pure solids always left out of the ICE box equations?
- Thu Jan 16, 2020 1:31 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Factors
- Replies: 7
- Views: 265
Re: Factors
A change in temperature is the only factor that can change K, but a change in concentration or pressure will shift Q.
- Thu Jan 16, 2020 1:29 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Inert Gas
- Replies: 5
- Views: 162
Re: Inert Gas
Are noble gases the only inert gases?
- Thu Jan 16, 2020 1:28 pm
- Forum: Ideal Gases
- Topic: Topics for Test 1
- Replies: 17
- Views: 711
Re: Topics for Test 1
Will we be done with acid/base equilibrium by the end of Friday's lecture and will that whole section be covered on the test?
- Thu Jan 16, 2020 1:27 pm
- Forum: Ideal Gases
- Topic: ICE tables
- Replies: 9
- Views: 1511
Re: ICE tables
In lecture on Wednesday Lavelle showed us how to approximate when using ICE tables so you do not have to use the quadratic equation. Are we allowed to use this approximation on a test assuming it is less then 5% the initial value or would we need to use the quadratic equation to receive full credit?
- Tue Jan 07, 2020 2:16 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Keq vs Kc
- Replies: 6
- Views: 447
Re: Keq vs Kc
When would we need to specify and use Kc as opposed to just using Keq?
- Tue Jan 07, 2020 2:15 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Very Large K
- Replies: 12
- Views: 2737
Re: Very Large K
Would a solution that is just a solute in water have a K value?
- Tue Jan 07, 2020 2:12 pm
- Forum: Administrative Questions and Class Announcements
- Topic: posting on chemistry community
- Replies: 11
- Views: 752
Re: posting on chemistry community
My TA confirmed that posts are due by Sunday night.
- Tue Jan 07, 2020 2:11 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Constant
- Replies: 4
- Views: 189
Re: Equilibrium Constant
What is the difference between the reaction quotient and the equilibrium constant?
- Tue Jan 07, 2020 2:10 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: HW Problem 5G.7
- Replies: 4
- Views: 153
Re: HW Problem 5G.7
Do we have to write Kp or can we just write K? My solutions manual only writes K.
- Tue Dec 03, 2019 12:42 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Grades
- Replies: 15
- Views: 1069
Re: Grades
Would it be possible that the final curve of the overall class would make it so you need higher than a 93% to get an A? Would he curve the class up?
- Tue Dec 03, 2019 12:40 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Studying for the Final [ENDORSED]
- Replies: 11
- Views: 770
Re: Studying for the Final [ENDORSED]
I would recommend taking notes from the textbook on sections you have trouble doing the practice problems from as well.
- Tue Dec 03, 2019 12:36 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polydentate
- Replies: 3
- Views: 286
Re: Polydentate
Does a double bond mean that the atom double bonded in a ligand cannot be the atom bonded to the central atom in a coordination complex because it can't rotate?
- Tue Dec 03, 2019 12:34 pm
- Forum: Naming
- Topic: Table 9C.1
- Replies: 6
- Views: 375
Re: Table 9C.1
Do we need to have the full name of edta memorized or can we just remember the abreviation?
- Tue Dec 03, 2019 12:33 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Oxalate and CO3 2- as a polydentate
- Replies: 3
- Views: 320
Re: Oxalate and CO3 2- as a polydentate
Would it always be the two single bonded oxygens that bond to the central atom? Could it be one of the double bonded oxygens and one of the single bonded ones?
- Mon Nov 25, 2019 5:59 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bent vs linear
- Replies: 56
- Views: 4321
Re: Bent vs linear
Does bent mean the same thing as angular? In the textbook they use the term angular and I was sure what that meant.
- Mon Nov 25, 2019 5:58 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Cis and Trans
- Replies: 6
- Views: 499
Re: Cis and Trans
I think if this were to be on a test it would most likely ask you to identify if the molecule is cis or trans and the effect that would have on the bonding/function of the molecule.
- Mon Nov 25, 2019 5:57 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2.27b
- Replies: 4
- Views: 295
Re: 2.27b
To clarify, that would mean there are four regions of electron density making the electron arrangement of the central atom tetrahedral.
- Mon Nov 25, 2019 5:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2.27b
- Replies: 4
- Views: 295
Re: 2.27b
In the textbook it says to treat the single electron on a radical as a region of electron density. The single electron would be less repulsive than two electrons in a lone pair and would effect bond angles less because of that. Still it would count as a single region of electron density.
- Mon Nov 25, 2019 5:52 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2.57
- Replies: 4
- Views: 324
Re: 2.57
Yes, since the molecule has two regions of electron density the electron arrangement would be linear as would the shape.
- Tue Nov 19, 2019 2:51 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: polarity
- Replies: 5
- Views: 480
Re: polarity
How do you know if they Cl atoms are across from each other or each across from a hydrogen atom when drawing the Lewis structure? Wouldn't this effect polarity?
- Tue Nov 19, 2019 2:49 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.15
- Replies: 1
- Views: 123
2E.15
In part b of homework problem 2E.15 how do you determine the bond angles in the see-saw structure?
- Tue Nov 19, 2019 2:47 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: bent v. angular
- Replies: 27
- Views: 1531
Re: bent v. angular
If there is a central atom with two bonding regions and one lone pair what shape is it?
- Tue Nov 19, 2019 2:47 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: bent v. angular
- Replies: 27
- Views: 1531
bent v. angular
What qualifies as the shape bent and what is angular? Are they the same thing?
I think in lecture Lavelle referred to a central atom with two bonding domains and two lone pairs as bent, but in the textbook they've been using angular as the shape name.
I think in lecture Lavelle referred to a central atom with two bonding domains and two lone pairs as bent, but in the textbook they've been using angular as the shape name.
- Tue Nov 19, 2019 2:45 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: electron arrangement and structure
- Replies: 1
- Views: 134
electron arrangement and structure
What are the different synonyms for electron arrangement v. the molecular domains? If a question just asked for structure/shape should you only give the molecular domain name as opposed to the electron arrangement?
- Wed Nov 13, 2019 4:53 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Week 9 homework
- Replies: 11
- Views: 752
Re: Week 9 homework
Do we still have our discussion sections on week 9 if they are earlier in the week like Tuesday or Wednesday?
- Wed Nov 13, 2019 4:52 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Exam 2
- Replies: 3
- Views: 191
Re: Exam 2
I believe exam 2 will cover everything Lavelle has covered since the material which was included on the midterm. I think it begins with correcting the ionic and covalent models with polarizability and dipole moments and also includes the intermolecular forces we have been going over such as London f...
- Wed Nov 13, 2019 4:48 pm
- Forum: Ionic & Covalent Bonds
- Topic: Bond Strength
- Replies: 8
- Views: 511
Re: Bond Strength
A general pattern for bond strength from strongest to weakest is ion-ion interactions (ionic bonds), ion-dipole interactions, dipole-dipole interactions, dipole-induced dipole interactions, induced dipole-induced dipole interactions.
- Wed Nov 13, 2019 4:45 pm
- Forum: Ionic & Covalent Bonds
- Topic: Solid v. Liquid v. Gas
- Replies: 8
- Views: 452
Re: Solid v. Liquid v. Gas
In terms of bonding, the stronger the bonds between molecules the more solid a structure it will form, meaning stronger bonds are created in the formation of solids than liquids and liquids than gases. Varying viscosity in liquids is also caused by bond strength.
- Wed Nov 13, 2019 4:42 pm
- Forum: Ionic & Covalent Bonds
- Topic: Exam 2 & Homework
- Replies: 5
- Views: 317
Re: Exam 2 & Homework
Chemical bonding will be covered in test 2 so I'm sure it is okay to include them in week 7 homework.
- Tue Nov 05, 2019 3:28 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Format
- Replies: 4
- Views: 237
Re: Midterm Format
In lecture on Monday he said he doesn't use multiple choice problems because there is no partial credit so I believe it will all be free response.
- Tue Nov 05, 2019 3:25 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Exam [ENDORSED]
- Replies: 1
- Views: 153
Re: Midterm Exam [ENDORSED]
On Professor Lavelle's website it says to bring a pen, scientific calculator, and your student ID and nothing else. I believe it will be on regular printer paper like test one was as opposed to in a blue book or on a scantron so you shouldn't need either of those.
- Tue Nov 05, 2019 3:23 pm
- Forum: Dipole Moments
- Topic: Induced dipole induced dipole interaction
- Replies: 2
- Views: 153
Re: Induced dipole induced dipole interaction
What is the difference between an instantaneous dipole moment and a dipole-induced-dipole interaction?
- Tue Nov 05, 2019 3:21 pm
- Forum: Resonance Structures
- Topic: Resonance Structures
- Replies: 2
- Views: 157
Re: Resonance Structures
How many resonance structures would be be required to draw on a test like in the instance where a molecule has four or more possible resonance structures? Would we get credit if we identified the majority of them?
- Tue Nov 05, 2019 3:19 pm
- Forum: Resonance Structures
- Topic: 2C.5 c
- Replies: 1
- Views: 108
2C.5 c
In homework problem 2C.5 part c you are told to draw the structure of ClONO2 and determine or not if it is a radical. In my structure I have the Cl, O, N, and O atoms bonded in a chain with all single bonds and the last O atom bonded to the N with a double bond. This is the answer given in the book,...
- Tue Nov 05, 2019 3:19 pm
- Forum: Resonance Structures
- Topic: 2C.5 c
- Replies: 1
- Views: 141
2C.5 c
In homework problem 2C.5 part c you are told to draw the structure of ClONO2 and determine or not if it is a radical. In my structure I have the Cl, O, N, and O atoms bonded in a chain with all single bonds and the last O atom bonded to the N with a double bond. This is the answer given in the book,...
- Tue Nov 05, 2019 3:15 pm
- Forum: Lewis Structures
- Topic: Radicals
- Replies: 2
- Views: 187
Radicals
Will radicals be covered on the midterm? Also, in homework problem 2C.5 you are asked to draw the Lewis Structure and determine is the molecule is a radical. For part a ClO-, how would you know that the one unpaired electron would be on the oxygen atom as opposed to the chlorine? Is there any way to...
- Mon Oct 28, 2019 11:01 am
- Forum: Ionic & Covalent Bonds
- Topic: Ground State
- Replies: 11
- Views: 562
Re: Ground State
Ions can be in ground state too even though they have a net charge. It just means that all of the electrons on the atom are in the lowest possible energy state for that number of electrons.
- Mon Oct 28, 2019 10:58 am
- Forum: Ionic & Covalent Bonds
- Topic: Homework prob 2A.19
- Replies: 1
- Views: 108
Homework prob 2A.19
For part e of this problem, why is the ground state electron configuration [Ar]3d8 as opposed to [Ar]3d64s2? If an element is in the d block, is the (n-1)d shell always filled before the ns shell?
- Mon Oct 28, 2019 10:56 am
- Forum: Ionic & Covalent Bonds
- Topic: 2A.23 question
- Replies: 8
- Views: 421
Re: 2A.23 question
This question asks you to determine the empirical formula of the ionic compound that would be formed if these two elements were to form an ionic bond. To do this you should find each element on the periodic table and determine the charge that element usually assumes based on it's valence electrons. ...
- Mon Oct 28, 2019 10:54 am
- Forum: Ionic & Covalent Bonds
- Topic: 2A. 13 Question
- Replies: 5
- Views: 182
Re: 2A. 13 Question
For part d of this problem, why would an electron be removed from the 4s subshell as opposed to the 3d subshell? Wouldn't it be more stable to remove and electron from the subshell that is already only partially filled as opposed to removing an electron from the filled 4s shell?
- Mon Oct 28, 2019 10:52 am
- Forum: Ionic & Covalent Bonds
- Topic: 2A. 13 Question
- Replies: 5
- Views: 182
Re: 2A. 13 Question
It helps me to think of which block on the periodic table the element sits in. If the element is in the third row of the p block, the valence electron will generally be removed from the 3p shell.
- Tue Oct 22, 2019 3:46 pm
- Forum: Properties of Light
- Topic: Combining Different Equations
- Replies: 8
- Views: 280
Re: Combining Different Equations
In class I think he mentioned that you can't use electromagnetic radiation equations on electrons. What exactly does this mean?
- Tue Oct 22, 2019 3:44 pm
- Forum: Properties of Light
- Topic: Homework due Next Week
- Replies: 9
- Views: 372
Re: Homework due Next Week
Is this the last homework we will turn in under the quantum unit?
- Tue Oct 22, 2019 3:39 pm
- Forum: DeBroglie Equation
- Topic: Velocity
- Replies: 13
- Views: 957
Re: Velocity
In problem 1B.21 you must know the conversion between miles per hour and meters per second. Are these conversion factors something we must memorize or will test problems always be given in SI units?
- Tue Oct 22, 2019 3:37 pm
- Forum: DeBroglie Equation
- Topic: DeBroglie Equation
- Replies: 11
- Views: 377
Re: DeBroglie Equation
In some of the homework problems you need to know the mass of an electron, neutron, or proton to use the DeBroglie equation and find wavelength. Do we need to have these masses memorized or would they be given on a test?
- Tue Oct 22, 2019 3:36 pm
- Forum: Einstein Equation
- Topic: 1B.15)
- Replies: 4
- Views: 215
Re: 1B.15)
What is an eV and are we required to know the conversion between that and a Joule?
- Tue Oct 15, 2019 11:39 am
- Forum: Properties of Electrons
- Topic: 1A 15
- Replies: 4
- Views: 368
Re: 1A 15
102.6 nm is part of the UV spectrum so you know you are using the Lyman series. You first divide the speed of light by the wavelength given to get frequency. You then rearrange the Rydberg Equation and use your calculated frequency to determine n2 is 3.
- Tue Oct 15, 2019 11:35 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Test 1 [ENDORSED]
- Replies: 107
- Views: 23370
Re: Test 1 [ENDORSED]
I think we will be getting graded tests back in our discussion sections on week 3.
- Tue Oct 15, 2019 11:34 am
- Forum: Properties of Light
- Topic: 1A.11
- Replies: 2
- Views: 116
Re: 1A.11
What does it mean that the principle quantum number for the lowest energy level is the same for each series?
- Tue Oct 15, 2019 11:32 am
- Forum: Properties of Light
- Topic: Wave Frequency
- Replies: 9
- Views: 508
Re: Wave Frequency
What is the relationship between the amplitude of a wave and the frequency? Or the relationship between amplitude and wavelength? What does amplitude tell us exactly?
- Tue Oct 15, 2019 11:30 am
- Forum: Properties of Light
- Topic: 1.A.3
- Replies: 2
- Views: 112
1.A.3
In homework problem 1.A.3 it asks if the extent of change in the electrical field at a given point decreases as the frequency of electromagnetic radiation decreases. I understand that as the frequency decreases the slope of the wave also decreases, but what roles does amplitude play in the extent of...
- Thu Oct 10, 2019 8:27 am
- Forum: Balancing Chemical Reactions
- Topic: Combustion
- Replies: 17
- Views: 1061
Re: Combustion
If in a problem it says it is a combustion reaction, that is how you know the products will be water and carbon dioxide. Often in combustion reactions the question will not give that information directly.
- Thu Oct 10, 2019 8:26 am
- Forum: Significant Figures
- Topic: Are we allowed to round when showing work?
- Replies: 7
- Views: 529
Re: Are we allowed to round when showing work?
When using dimensional analysis, when you round it in the end make sure you round it to the same amount of significant figures as the value with the least amount of significant figures that you used in you calculations.
- Thu Oct 10, 2019 8:23 am
- Forum: Administrative Questions and Class Announcements
- Topic: Week 2 Homework Problems [ENDORSED]
- Replies: 67
- Views: 7955
Re: Week 2 Homework Problems [ENDORSED]
Does it matter which subsection the homework problems we are doing are from as long as they are within the quantum mechanics section (like 1A v. 1B v. 1D etc.)?
- Thu Oct 10, 2019 8:21 am
- Forum: Administrative Questions and Class Announcements
- Topic: Week 2 Homework Problems [ENDORSED]
- Replies: 67
- Views: 7955
Re: Week 2 Homework Problems [ENDORSED]
Since the Quantum Unit is more than a week long does it mean we just hand in five homework problems from that section every week until we are done with the unit?
- Thu Oct 10, 2019 8:18 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Test 1 [ENDORSED]
- Replies: 107
- Views: 23370
Re: Test 1 [ENDORSED]
Are we really only allowed to use pen on the test? What happens if we make a mistake on the paper, can we get scratch paper or extra pieces of paper? There is plenty of room on the test to solve the problems. You are allotted at least half a sheet per problem which I found to be enough even with so...
- Thu Oct 03, 2019 11:36 am
- Forum: SI Units, Unit Conversions
- Topic: Scientific Notation (general requirement for the course)
- Replies: 5
- Views: 350
Re: Scientific Notation (general requirement for the course)
You could also write it as 12000 because that also uses only 2 significant figures. Any zeros to the right of a whole number are not considered significant figures.
- Thu Oct 03, 2019 11:34 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Tips on how to write a formula out from the name
- Replies: 9
- Views: 702
Re: Tips on how to write a formula out from the name
Do we need to have the formulas and charges of polyatomic ions and their charges memorized or will they be given on a test? For example in textbook problem G.5 you are unable to solve the problem unless you know the molecular formula of sodium carbonate. Will there be problems like this on the test?
- Thu Oct 03, 2019 11:31 am
- Forum: Empirical & Molecular Formulas
- Topic: Naming Molecular Compounds
- Replies: 6
- Views: 471
Re: Naming Molecular Compounds
When would you need to specify a molecule as anhydrous? I know most often that is the state molecules are in, but when naming compounds when must you include anhydrous in the written name?
- Thu Oct 03, 2019 11:30 am
- Forum: Balancing Chemical Reactions
- Topic: States of Matter in a Chemical Equation [ENDORSED]
- Replies: 11
- Views: 933
Re: States of Matter in a Chemical Equation [ENDORSED]
In what instances would a molecule be liquid as opposed to aqueous? What are some examples of molecules besides water that are in the state of pure liquid and not aqueous?
- Wed Oct 02, 2019 2:27 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Naming Compounds (F13)
- Replies: 7
- Views: 542
Re: Naming Compounds (F13)
How many of the naming rules do we need to know for the test next week? Do we need to have the names and charges of polyatomic ions memorized or will they be given if needed to solve a problem?