Search found 106 matches
- Fri Mar 13, 2020 12:36 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: how to find k
- Replies: 4
- Views: 72
how to find k
how do you find k in a concentration cell?
- Fri Mar 13, 2020 12:34 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: endgame q 1d and 1e
- Replies: 1
- Views: 55
endgame q 1d and 1e
can anyone explain how they got their answer for 1d and 1e for the endgame practice problems?
- Thu Mar 12, 2020 10:45 pm
- Forum: Student Social/Study Group
- Topic: final?
- Replies: 7
- Views: 274
final?
i know that the final is a take home and open book exam now but how are we supposed to turn it and through what application? for ls30b, jukka is making us scan the test through an app and made us print out a template but does anyone know how lavelle is assigning our test? im just kind of lost...
- Wed Mar 11, 2020 1:53 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: same equation?
- Replies: 5
- Views: 87
same equation?
what's the difference between the last two equations shown on the formula sheet? when do we use which?
- Sun Mar 08, 2020 8:01 pm
- Forum: General Rate Laws
- Topic: integrated rate law vs general
- Replies: 8
- Views: 216
integrated rate law vs general
what’s the difference between the integrated rate laws vs the general rate law?
- Sun Mar 08, 2020 6:02 pm
- Forum: Zero Order Reactions
- Topic: 7A.17
- Replies: 1
- Views: 47
Re: 7A.17
you use the experiments to determine the reaction order, rate law, reaction rate, and more when asked. the experiments tell you all the information and is a method of how to solve for those things asked
- Sun Mar 08, 2020 5:56 pm
- Forum: General Rate Laws
- Topic: unique average rate vs general reaction rate
- Replies: 2
- Views: 57
unique average rate vs general reaction rate
what is the difference between the unique average rate and the general reaction rate? is it just another way of writing the general rate?
- Sun Mar 08, 2020 5:50 pm
- Forum: General Rate Laws
- Topic: negatives?
- Replies: 2
- Views: 75
negatives?
when do you add a negative when determining the rate law?
- Sun Mar 08, 2020 5:48 pm
- Forum: First Order Reactions
- Topic: question 7b.5
- Replies: 3
- Views: 60
question 7b.5
i found the half life to be 5.204 hours for part (a) but i'm not sure what i'm doing wrong for part (b). my answer is nearly identical to the initial concentration that is given for part b and i know that my answer should be smaller. can anyone that has done the problem help?
- Mon Mar 02, 2020 12:07 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Reduced/Oxidized based on Ecell
- Replies: 6
- Views: 180
Re: Reduced/Oxidized based on Ecell
is one of the E cell values under standard conditions?
- Mon Mar 02, 2020 12:06 am
- Forum: Balancing Redox Reactions
- Topic: Self Test 6L.3
- Replies: 1
- Views: 78
Re: Self Test 6L.3
the reactant side of your equation has a H but your product side doesn't. the correct chemical equation includes the H but i'm not sure how they came to that conclusion of the last molecule sorry
- Mon Mar 02, 2020 12:03 am
- Forum: Balancing Redox Reactions
- Topic: E cell and Standard
- Replies: 2
- Views: 85
Re: E cell and Standard
E is the nonstandard cell potential and the standard E is the cell potential under standard conditions
- Mon Mar 02, 2020 12:02 am
- Forum: Balancing Redox Reactions
- Topic: Left and Right
- Replies: 4
- Views: 102
Re: Left and Right
the two reactions are a redox reaction but it is easier to analyze the reaction by making them into two half-reactions
- Mon Mar 02, 2020 12:01 am
- Forum: Balancing Redox Reactions
- Topic: Cell Diagrams
- Replies: 5
- Views: 125
Re: Cell Diagrams
for cell diagrams, you're supposed to write them in the order that the reaction occurs (kinda like chronological order if that makes sense)
- Sun Feb 23, 2020 3:41 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: how to get n in equation
- Replies: 8
- Views: 175
how to get n in equation
i don’t understand how to find the n in this equation. where do you look in the given equation to find n?
- Fri Feb 21, 2020 2:43 pm
- Forum: Calculating Work of Expansion
- Topic: when work is 0
- Replies: 5
- Views: 172
when work is 0
how come work is equal to 0 in a reversible system?
- Fri Feb 21, 2020 2:30 pm
- Forum: Van't Hoff Equation
- Topic: what does it do?
- Replies: 13
- Views: 344
what does it do?
what is the difference between this equation and the other equations we know? what does it relate?
- Fri Feb 21, 2020 2:28 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: galvanic cell
- Replies: 2
- Views: 54
galvanic cell
what happens in a galvanic cell if the reaction was not spontaneous? would there be no change to the cell?
- Fri Feb 21, 2020 2:24 pm
- Forum: Balancing Redox Reactions
- Topic: oxidation
- Replies: 3
- Views: 77
oxidation
are oxidation numbers the charge of the molecule? will we be needed to calculate the oxidation numbers of larger molecules?
- Fri Feb 21, 2020 2:23 pm
- Forum: Balancing Redox Reactions
- Topic: combining redox reactions
- Replies: 2
- Views: 55
combining redox reactions
when combining redox reactions, what shouldn't be in the final equation? what should be canceled or changed?
- Wed Feb 12, 2020 2:38 pm
- Forum: Calculating Work of Expansion
- Topic: substitution
- Replies: 3
- Views: 111
substitution
when do you substitute the w=PdeltaV into the first law of thermodynamics?
- Wed Feb 12, 2020 12:10 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: change in Kc
- Replies: 5
- Views: 118
change in Kc
when there is a constant multiplied to the overall chemical equation, how does Kc change? what are the rules for Kc when there is a change to the overall reaction(s)?
- Wed Feb 12, 2020 11:33 am
- Forum: Calculating Work of Expansion
- Topic: Does the substance make a difference in expansion work?
- Replies: 2
- Views: 50
Re: Does the substance make a difference in expansion work?
im not sure if you need to use the moles of gas given in this equation because there is a change in volume and the question gives you a constant external force. since those two things are given, you can use w=-P*deltaV to calculate the work done. you would then use the conversion factor to change th...
- Wed Feb 12, 2020 11:15 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: different equation in video?
- Replies: 1
- Views: 74
different equation in video?
in one of the organic chemistry tutor's videos, the equation he uses is deltaU=q-w rather than deltaU=q+w. can someone tell me why the sign in his equation is changed?
- Sun Feb 09, 2020 10:36 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Entropy function
- Replies: 1
- Views: 28
Re: Entropy function
the standard reaction enthalpy refers to when all R and P are in their standard state at 1 atm. entropy is a state function because the properties are additive and is considered an extensive property because it depends on the number of particles (delta S= KblnW)
- Sun Feb 09, 2020 10:32 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Standard reaction enthalpy
- Replies: 2
- Views: 23
Re: Standard reaction enthalpy
those are two of the three methods we learned to calculate enthalpy. to calculate the standard reaction enthalpy, the notes say "if bond enthalpies are not available, one can calculate the standard reaction enthalpy by using the standard enthalpy of formation of all products and subtract the st...
- Sun Feb 09, 2020 10:21 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: q rev
- Replies: 4
- Views: 70
q rev
how do you know when the system is reversible?
- Wed Feb 05, 2020 12:20 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: chen discussion [ENDORSED]
- Replies: 5
- Views: 109
Re: chen discussion [ENDORSED]
the question is "calculate the change in molar entropy of carbon dioxide that is allowed to expand isothermally to 10 times its initial volume (treat carbon dioxide as an ideal gas, Cv,m=3/2R)"
- Tue Feb 04, 2020 4:26 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: chen discussion [ENDORSED]
- Replies: 5
- Views: 109
chen discussion [ENDORSED]
for #1, we used the equation delta s= nRln(V2/V1). what is n equal to in the problem? is it equal to 1 because we are calculating molar entropy?
- Mon Feb 03, 2020 11:41 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: 4F.7 - no given Cp constant?
- Replies: 3
- Views: 61
Re: 4F.7 - no given Cp constant?
i found these equations on the class website under the constants and equations tab^^
- Mon Feb 03, 2020 11:41 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: 4F.7 - no given Cp constant?
- Replies: 3
- Views: 61
Re: 4F.7 - no given Cp constant?
i think we are supposed to use the equations Cv=(3/2)R and Cp=(5/2)R to find the answer since it's not given.
- Mon Feb 03, 2020 10:54 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: overall definitions
- Replies: 4
- Views: 66
overall definitions
i'm not that good with remembering the letters that are associated with all of the terms. can anyone tell me a list of what each letter represents? like delta u, delta s, etc..
- Mon Feb 03, 2020 10:51 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: microstates
- Replies: 1
- Views: 24
microstates
how do you find the amount of microstates a molecule has and what is done with that number afterwards? i didn't understand in lecture today what he was saying about the microstates a particular molecule had was 3^avogadro's number...
- Mon Feb 03, 2020 10:48 pm
- Forum: Calculating Work of Expansion
- Topic: second equation
- Replies: 8
- Views: 65
Re: second equation
sorry the equation is -nRTln(V2/V1)*^
- Mon Feb 03, 2020 10:47 pm
- Forum: Calculating Work of Expansion
- Topic: second equation
- Replies: 8
- Views: 65
second equation
in the second equation, would we ever have to use the integral or would we just be using the equation -nRT(V2/V1)?
- Mon Feb 03, 2020 10:45 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: R vs C
- Replies: 2
- Views: 33
R vs C
what's the difference between R in the equation with volume and C in the equation with temperature? are these constants that are given?
- Mon Feb 03, 2020 10:43 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: defintion
- Replies: 6
- Views: 112
defintion
what is internal energy? i don't understand the concept of why q + w equals the change in internal energy
- Mon Feb 03, 2020 10:42 pm
- Forum: Calculating Work of Expansion
- Topic: when to use...?
- Replies: 4
- Views: 56
when to use...?
when do you use each equation and how do you know when to use it?
- Sun Jan 26, 2020 9:21 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: method 3
- Replies: 2
- Views: 26
method 3
did anyone get the last part of the last slide of friday's lecture? i didn't get the chance to write it down
- Sat Jan 25, 2020 1:15 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Pressure
- Replies: 3
- Views: 45
Re: Pressure
the notes say:
1. if V decreases and more moles of gas on the left, then reaction shifts right
2. if V decreases and more moles of gas on the right, then reaction shifts left
3. if V increases, no effect on reaction
1. if V decreases and more moles of gas on the left, then reaction shifts right
2. if V decreases and more moles of gas on the right, then reaction shifts left
3. if V increases, no effect on reaction
- Mon Jan 20, 2020 10:53 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kc to Kp conversion
- Replies: 2
- Views: 23
Kc to Kp conversion
my ta gave us an equation for the conversion but i don't get why it's different from the equation that lavelle gave in class. my ta gave us Kp=Kc(RT)^Dn where Dn is the "difference in the number of moles of gases on each side of the balanced equation for the reaction; number of moles of gaseous...
- Mon Jan 20, 2020 9:29 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: new Kc value when combining equations
- Replies: 2
- Views: 40
new Kc value when combining equations
when you add two chemical equations together, how do you figure out the new Kc value?
- Mon Jan 20, 2020 9:27 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Pressure goes to less moles of gas explaination
- Replies: 4
- Views: 45
Re: Pressure goes to less moles of gas explaination
the increasing pressure causes the side with more moles to produce more of the side with less moles. im not sure what lavelle was talking about but that's the concept of his explanation.
- Mon Jan 20, 2020 8:35 pm
- Forum: Ideal Gases
- Topic: Kc vs Kp
- Replies: 109
- Views: 989
Kc vs Kp
when a chemical equation is written and all the reactants and products are gases, do you use Kp rather than Kc? in what cases do you use Kc rather than Kp?
- Mon Jan 20, 2020 12:31 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Effect of Increasing Temperature on an Equilibrium System
- Replies: 4
- Views: 83
Re: Effect of Increasing Temperature on an Equilibrium System
an exothermic reaction releases heat which means heat is a product in a chemical reaction. when you increase the temperature, think of it like you are increasing the amount of product. when more product is added, the equilibrium shifts towards the left.
- Mon Jan 20, 2020 12:28 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ice table
- Replies: 5
- Views: 59
ice table
does an ice table only include gases and does not include solids and liquids?
- Mon Jan 20, 2020 12:27 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: q vs k
- Replies: 62
- Views: 200
q vs k
will the q value eventually reach k? is q the value that is calculated when the reaction is not at equilibrium?
- Thu Jan 16, 2020 8:42 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ice table/quadratic
- Replies: 6
- Views: 57
ice table/quadratic
will there be any situation where both values of x from the answers to the quadratic equation are positive? if so what do you do?
- Thu Jan 16, 2020 8:38 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: inert gas added
- Replies: 4
- Views: 57
inert gas added
does adding an inert gas change/shift equilibrium?
- Thu Jan 16, 2020 8:35 pm
- Forum: Ideal Gases
- Topic: partial pressure
- Replies: 1
- Views: 51
partial pressure
why does changing the amount of moles of a certain molecule not change the partial pressure of the other molecules? i thought since the total number of moles changed, the other partial pressures would change but my ta said they don't.
- Thu Jan 16, 2020 8:29 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: H3O+
- Replies: 4
- Views: 30
Re: H3O+
H3O+ refers to the released H+ ions which makes a solution acidic and water combined
- Thu Jan 16, 2020 8:27 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6C.3 Ka and pKa
- Replies: 1
- Views: 20
Re: 6C.3 Ka and pKa
when given the pKa, take the antilog of it to get the Ka value
- Thu Jan 16, 2020 8:26 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5E.2 table??
- Replies: 3
- Views: 41
Re: 5E.2 table??
i didn't find it either but maybe the book has an error and meant to refer to 5E.1 table. maybe try that? or maybe look in the back of the book?
- Thu Dec 05, 2019 11:05 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: 6D 11 E
- Replies: 1
- Views: 50
Re: 6D 11 E
i found someone else who answered the same question and this was their response: (credit to sierra cheslick 2B) "This is a salt, and it dissociates in water. Since Cl- is the conjugate base of a strong base, it is very weak and therefore considered to not affect pH and can be left out of the eq...
- Thu Dec 05, 2019 10:58 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Drawing Coordination Compounds
- Replies: 1
- Views: 67
Re: Drawing Coordination Compounds
if you're a visual learner, i would suggest just going onto youtube and looking up a video to help you because you can actually see what their process is and how they get the answer.
- Thu Dec 05, 2019 10:54 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Compounds
- Replies: 1
- Views: 49
Re: Coordination Compounds
you can go to youtube and search up your topic and there will be tons of videos that help explain the topic. "the organic chemistry tutor" on youtube has a video on coordination compounds so you can watch that and follow along
- Thu Dec 05, 2019 10:50 am
- Forum: Air Pollution & Acid Rain
- Topic: final?
- Replies: 5
- Views: 225
final?
do we need to memorize the equation for acid rain for the final or would we just need to know the concept of it?
- Wed Dec 04, 2019 4:08 pm
- Forum: Polyprotic Acids & Bases
- Topic: amphoteric
- Replies: 5
- Views: 175
Re: amphoteric
a post from chem mod answered the same question and he said, "Amphoteric is an general term for compounds that can act as an acid or a base. However, there are also compounds (like water) that gain or lose a proton to form an acid or base and this proton is where amphiprotic comes from. Therefo...
- Mon Dec 02, 2019 11:32 pm
- Forum: Conjugate Acids & Bases
- Topic: how to figure out?
- Replies: 12
- Views: 296
how to figure out?
can someone explain how to find the conjugate acid/base?
- Mon Dec 02, 2019 11:19 pm
- Forum: Amphoteric Compounds
- Topic: how to identify?
- Replies: 5
- Views: 177
how to identify?
how do you identify amphoteric compounds? are there steps to take to identify them an easy way or?
- Mon Dec 02, 2019 10:37 pm
- Forum: Bronsted Acids & Bases
- Topic: Strong Acids and Bases
- Replies: 4
- Views: 106
Re: Strong Acids and Bases
i feel like you wouldn't need to memorize all of them but knowing some of the common ones or the basic ones would be helpful.
- Mon Dec 02, 2019 10:33 pm
- Forum: Bronsted Acids & Bases
- Topic: bronsted vs lewis
- Replies: 2
- Views: 43
bronsted vs lewis
what's the difference between a bronsted acid/base and a lewis acid/base?
- Mon Dec 02, 2019 10:32 pm
- Forum: Bronsted Acids & Bases
- Topic: hw 6c.17
- Replies: 1
- Views: 38
hw 6c.17
how would you know which molecule is a stronger base, BrO- or C17H19O3N? i don't know where to even start so any help would be appreciated
- Fri Nov 22, 2019 1:28 am
- Forum: Sigma & Pi Bonds
- Topic: significance
- Replies: 2
- Views: 58
significance
what is the significance of sigma and pi bonds? i don't understand what they do for the molecular structure.
- Fri Nov 22, 2019 1:20 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: NO Shape and Polarity
- Replies: 4
- Views: 103
Re: NO Shape and Polarity
NO is a linear shaped molecule and it's polar because it's not a diatomic molecule and there is a difference in the electronegativity values of those atoms. the difference between N and O is 0.5 which makes it polar too.
- Fri Nov 22, 2019 12:36 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: london forces
- Replies: 9
- Views: 105
london forces
if two molecules have only london dispersion forces, how do you know which is stronger?
- Fri Nov 22, 2019 12:29 am
- Forum: Sigma & Pi Bonds
- Topic: More complex practice problems
- Replies: 2
- Views: 122
Re: More complex practice problems
if you go online and look up practice problems, you should be able to find some that are challenging. you could always do the examples in the book i guess. i feel like as long as you know the concept of sigma and pi bonds, you should be good for the exam.
- Fri Nov 22, 2019 12:27 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: name?
- Replies: 4
- Views: 63
name?
is bent and angular the same shape? are they just interchangeable names?
- Fri Nov 15, 2019 2:30 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: vsepr formula
- Replies: 3
- Views: 48
vsepr formula
what does the a, x, and e stand for in the vsepr formula?
- Fri Nov 15, 2019 2:28 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: polar/nonpolar
- Replies: 2
- Views: 37
polar/nonpolar
how do you know which forces are within polar/nonpolar molecules? i know that all molecules have london dispersion forces but i don't get how you know when they have dipole-dipole interactions or other forces..
- Thu Nov 14, 2019 9:15 pm
- Forum: Dipole Moments
- Topic: 3f.1
- Replies: 3
- Views: 88
3f.1
why does SO2 have dipole dipole forces? i don't really understand the concept of dipole dipole forces or how you know when a molecule exhibits it so if someone could explain that would be awesome!
- Thu Nov 14, 2019 9:07 pm
- Forum: Electronegativity
- Topic: water solubility
- Replies: 4
- Views: 148
water solubility
why is a molecule with a higher electronegativity more soluble in water?
- Thu Nov 14, 2019 2:04 pm
- Forum: Dipole Moments
- Topic: question 3f.5
- Replies: 3
- Views: 53
question 3f.5
the question says "which substance has a higher melting point: CHI3 or CHF3?" the justification in the answer key says that CHI3 has stronger london forces but i don't understand why they justified it like that. can someone explain why CHI3 has the higher melting point and explain the bond...
- Thu Nov 07, 2019 10:05 pm
- Forum: Trends in The Periodic Table
- Topic: electronegativity trend
- Replies: 3
- Views: 160
electronegativity trend
why does the trend in electronegativity increase when you go up a column and increase when you go to the right in a row?
- Thu Nov 07, 2019 10:01 pm
- Forum: Empirical & Molecular Formulas
- Topic: shortcut?
- Replies: 2
- Views: 127
shortcut?
professor lavelle did an example of one of these types of questions during the midterm review and i noticed that he did the process differently. why does it work to multiply the molar mass of the compound with the decimal of the element (like say there was 26.77% C and then you multiply the molar ma...
- Thu Nov 07, 2019 9:55 pm
- Forum: Octet Exceptions
- Topic: radicals
- Replies: 3
- Views: 114
radicals
how do you know which element in the molecular compound is the one with one lone electron? is it based on the electronegativity of the elements?
- Thu Nov 07, 2019 4:50 pm
- Forum: Electronegativity
- Topic: ionic character
- Replies: 9
- Views: 303
ionic character
in 2d.5, when it states to determine which bonds have the greater ionic character, is it asking the which has the greater difference in electronegativity?
- Tue Nov 05, 2019 9:39 pm
- Forum: Empirical & Molecular Formulas
- Topic: percent composition
- Replies: 3
- Views: 199
Re: percent composition
the problem is from the dino nuggets review problem #2 and it says "Glycogen is used as energy storage and can be broken down into glucose when needed. Glycogen’s mass composition is C 43.2% H 6.35% O 50.4% and has a molar mass of about 667 g.mol-1. What is its molecular formula?" when you...
- Tue Nov 05, 2019 6:02 pm
- Forum: Empirical & Molecular Formulas
- Topic: percent composition
- Replies: 3
- Views: 199
percent composition
what do you do when the given percents for mass composition do not add to 100%? i remember dr. lavelle saying something that you assume that the unaccounted for percent is usually oxygen but do you just add the unaccounted for percent to the percent of oxygen?
- Tue Oct 29, 2019 4:14 pm
- Forum: Ionic & Covalent Bonds
- Topic: 4f, 5f Electron Configurations
- Replies: 2
- Views: 44
Re: 4f, 5f Electron Configurations
you could think about it as f-d-s-p i guess. for ex, if you wanted the electron configuration for gold (Au), you would write it as [Xe]4f^14 5d^10 6s^1. you would do the same thing for 5f too
- Tue Oct 29, 2019 4:07 pm
- Forum: Ionic & Covalent Bonds
- Topic: Textbook question 2A.1
- Replies: 2
- Views: 34
Re: Textbook question 2A.1
the number of valence electrons is 5 because the electron configuration for Sb is [Kr]4d^10 5s^2 5p^3. there are 5 valence electrons because you would add the 2 electrons in the s orbital and the 3 electrons in the p orbital to get 5.
- Tue Oct 29, 2019 4:04 pm
- Forum: Resonance Structures
- Topic: resonance vs resonance hybrid
- Replies: 2
- Views: 51
resonance vs resonance hybrid
what is the difference between resonance and resonance hybrid? is there a difference?
- Tue Oct 29, 2019 3:59 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charges on Atoms Summed in Ions?
- Replies: 6
- Views: 73
Re: Formal Charges on Atoms Summed in Ions?
can you provide an example? if it's just adding formal charges then yes they do cancel out.
- Tue Oct 29, 2019 2:21 pm
- Forum: Ionic & Covalent Bonds
- Topic: Exceptions to the Octet
- Replies: 2
- Views: 48
Re: Exceptions to the Octet
there's not many exceptions so i think if you just memorize them, you shouldn't have a problem with it
- Wed Oct 23, 2019 9:12 pm
- Forum: Ionic & Covalent Bonds
- Topic: lewis structures for diff bonds
- Replies: 5
- Views: 95
lewis structures for diff bonds
do we draw lewis structures for both ionic and covalent bonds? how would we draw them for ionically bonded molecules?
- Wed Oct 23, 2019 9:08 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: order
- Replies: 3
- Views: 58
order
how come in some electron configurations the d-orbital comes before the s-orbital like in titanium?
- Wed Oct 23, 2019 9:00 pm
- Forum: Resonance Structures
- Topic: defintion
- Replies: 7
- Views: 121
defintion
what exactly is a resonance structure? is it a molecule that has multiple lewis structures that can be drawn for that molecule...?
- Wed Oct 23, 2019 8:59 pm
- Forum: Lewis Structures
- Topic: lewis drawings
- Replies: 8
- Views: 178
lewis drawings
do we have to know all of the different types of lewis structures for one molecule or is there a specific lewis structure that we need to know for each molecule?
- Wed Oct 23, 2019 8:57 pm
- Forum: Resonance Structures
- Topic: bond lengths
- Replies: 4
- Views: 68
bond lengths
professor lavelle said something about how double bond lengths are 1.2 A and how single bond lengths are 1.4 A. how come the bond lengths were 1.24 A for the example from today's lecture?
- Wed Oct 16, 2019 9:38 pm
- Forum: Photoelectric Effect
- Topic: relation of photoelectric effect to equations
- Replies: 2
- Views: 66
relation of photoelectric effect to equations
does the photoelectric effect prove the equations we use like E=hv? i don't get what the photoelectric effect proves?
- Wed Oct 16, 2019 9:23 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: uncertainty
- Replies: 3
- Views: 53
uncertainty
how do we calculate uncertainty and what equations do you use? i don't really understand much about the concept or what it is used or anything..
- Wed Oct 16, 2019 8:40 pm
- Forum: Einstein Equation
- Topic: why do we use these equations?
- Replies: 5
- Views: 125
Re: why do we use these equations?
also to correct myself in the first post, i meant the equation c=v*wavelength not c=v/wavelength! sorry!
- Wed Oct 16, 2019 8:40 pm
- Forum: Einstein Equation
- Topic: why do we use these equations?
- Replies: 5
- Views: 125
Re: why do we use these equations?
so if you are given frequency, then you would use the equation c=v*wavelength to find the wavelength and then use that to find the energy?
- Wed Oct 16, 2019 8:35 pm
- Forum: Photoelectric Effect
- Topic: Sodium Vapor Lamps (1.19 hw) [ENDORSED]
- Replies: 6
- Views: 10289
Re: Sodium Vapor Lamps (1.19 hw) [ENDORSED]
b) First, you convert mg to g 5.00 mg * (1g/1000mg) = 5.00 x 10^-3 g of Na Since, it's asking for the how much energy is emitted by an excited SODIUM, you use the molar mass of Na 5.00x10^-3 g Na * (1 mol Na/ 23g Na) * (6.022 x10^23 atoms Na/ 1 g Na) = 1.31 x10^20 atoms of Na (1.31 x10^20 atoms Na)...
- Wed Oct 16, 2019 8:22 pm
- Forum: Einstein Equation
- Topic: why do we use these equations?
- Replies: 5
- Views: 125
why do we use these equations?
for problem 1B.7, why do we use both c=v/wavelength and E=hv and combine it into one equation? why does using the combined equation give us the energy and not the E=hv equation?
- Wed Oct 16, 2019 6:04 pm
- Forum: Properties of Light
- Topic: homework 1A.3
- Replies: 8
- Views: 102
homework 1A.3
the question asks what happens when the frequency of electromagnetic radiation decreases. is my reasoning correct by saying when the frequency decreases, the wavelength increases which then decreases the overall speed?
- Thu Oct 10, 2019 3:55 pm
- Forum: Balancing Chemical Reactions
- Topic: compound state in chem rxn
- Replies: 3
- Views: 177
compound state in chem rxn
when forming equations, how do you know the state of each molecule/compound? is it just common knowledge to know whether it should be aqueous or in gas form?
- Thu Oct 10, 2019 3:54 pm
- Forum: Limiting Reactant Calculations
- Topic: general questions
- Replies: 11
- Views: 506
general questions
what's the purpose of finding the limiting reactant in a problem? When you find it, what's the next step you would do?
- Thu Oct 10, 2019 3:04 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: E 17
- Replies: 4
- Views: 217
Re: E 17
for part a and b, you would use the molar mass of the element to calculate the number of moles in each sample of the element. for part c, you would use avogadro's number to calculate the amount of moles in amount given.
- Thu Oct 10, 2019 2:53 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: hw question E23?
- Replies: 3
- Views: 172
hw question E23?
How do you calculate the moles of an ion in a molecular compound? What conversion factor would be used?