## Search found 58 matches

Sat Mar 17, 2018 9:13 pm
Forum: Phase Changes & Related Calculations
Topic: carbon
Replies: 4
Views: 357

### carbon

when would you have to atomize or sublimize carbon. lets say you had 3c(gr)+4H2(g)->C3H8(g) and I was trying to calculate enthalpy of formation- do I have to sublimize carbon? I'm confused as to when all the elements need to be in gas form vs their most stable state.
Sat Mar 17, 2018 7:56 pm
Forum: Administrative Questions and Class Announcements
Topic: Answers to red panda practice exam?
Replies: 1
Views: 273

### Re: Answers to red panda practice exam?

are they not in the thread??
Sat Mar 17, 2018 7:53 pm
Forum: General Rate Laws
Topic: Test 3 Q1- Friday discussion
Replies: 2
Views: 326

### Re: Test 3 Q1- Friday discussion

okay so I usually solve for it
you know that rate is mol*L^-1*s^-1
so what I always do is this:
mol*L^-1*s^-1=k [A]/[C]
you know the units of A and C are mol*L^-1 so you can divide the other side and find the units for k
its always a good idea to go back and test your units of k out to make sure
Sat Mar 17, 2018 7:52 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: chapter 15 #109
Replies: 1
Views: 251

### Re: chapter 15 #109

I don't know if this is right or not but I just treated it like k2 and got the right answer I think they just wrote it a different way, its just a different notation
Sat Mar 17, 2018 7:51 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: how to find Q given molarity
Replies: 1
Views: 213

### Re: how to find Q given molarity

yes
Sat Mar 17, 2018 7:50 pm
Forum: Balancing Redox Reactions
Topic: Test 2 Question 1 Part B
Replies: 2
Views: 190

### Re: Test 1 Question 1 Part B

are you sure this was test one?? we hadn't gotten to reduction in test one yet, it was only chapter 8 and reduction stuff is in chapter 14
Sat Mar 17, 2018 7:47 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Test 2 Question 4
Replies: 2
Views: 169

### Re: Test 2 Question 4

I think where you're getting confused is E standard= Ecathode-Eanode so if you "flip" the sign you wouldn't subtract again, you'd add
Sat Mar 17, 2018 7:44 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Test 2 #7
Replies: 3
Views: 222

### Re: Test 2 #7

sorry thats super confusing basically in steps:
find two half rxns that'll add up to desired overall
find delta g using delta g=-(n)(f)(E) for both
use that to find the final E cell-- delta g(you added to get this)=(-n)(F)(E) so E=deltaG/(-n)(F)
Sat Mar 17, 2018 7:42 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Test 2 #7
Replies: 3
Views: 222

### Re: Test 2 #7

correct me if I'm wrong but you probably did two half equations and added the cell potential. what you have to do instead is find the two half equations that'll give you an overall desired equation, calculate E for both then calculate delta G for both, add those up and have it equal delta g of the f...
Sat Mar 17, 2018 7:40 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Test 2 #7
Replies: 3
Views: 222

### Re: Test 2 #7

sure! what about it??
Sat Mar 17, 2018 7:39 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.93
Replies: 1
Views: 224

### 8.93

are we just assuming benzene with resonance?? on the final would we do the same thing?
Sat Mar 17, 2018 7:37 pm
Forum: General Rate Laws
Topic: general calc
Replies: 1
Views: 329

### general calc

does anyone have any general tricks for inputting exponents into calculators, I keep getting the right numbers kind of but wrong exponents
Sat Mar 17, 2018 7:36 pm
Forum: General Rate Laws
Topic: 15.13
Replies: 1
Views: 317

### 15.13

can someone explain why instead of [H2]^2 its just [H2]
Sat Mar 17, 2018 7:33 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: plotting
Replies: 1
Views: 271

### plotting

will we ever have to plot ln k against 1/T to find if its a straight line and therefore Arrhenius?
Sat Mar 17, 2018 5:13 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.69
Replies: 1
Views: 212

### 15.69

Sat Mar 17, 2018 4:41 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 15.51
Replies: 2
Views: 329

### 15.51

Is rate of formation always the concentrations of the reactants of the rate determining step times k. also I didn't get what the solution was saying about second order
Sat Mar 17, 2018 12:51 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.33
Replies: 1
Views: 146

### 14.33

where are they finding the equation they used? where would I find that value/ is there a way to figure it out??
Sat Mar 17, 2018 12:45 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.31
Replies: 1
Views: 151

### 14.31

I don't understand for part c why they didn't flip pb^4/pb^2 to match the given equation they end up using a positive 1.67, why?
Sun Feb 11, 2018 4:44 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
Replies: 1
Views: 134

Im unsure as to when to use avogadros number in the exponent of W in the Boltzmann equation for entropy
Sun Feb 11, 2018 4:43 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: 9.25
Replies: 2
Views: 197

### 9.25

to figure out residual molar entropy do you have to draw out the lewis structure to solve the problem or any other problem like this or is there an easier way?
Sun Feb 11, 2018 4:30 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: signs
Replies: 3
Views: 193

### signs

When do we need to put a + in front of values to show that it is a positive value and when can we just leave it?
Mon Feb 05, 2018 4:25 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: Example problem 9.7
Replies: 1
Views: 158

### Example problem 9.7

When do you know to multiply by Avogadro’s number?
Mon Feb 05, 2018 2:47 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Irreversible vs. Reversible
Replies: 2
Views: 201

### Irreversible vs. Reversible

Can someone explain when it’s okay to use the same equation for reversible and irreversible reactions expansion and when it’s not, also how does the characteristics of idek gases factor in?
Mon Feb 05, 2018 2:26 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: In chapter 9.2 example [ENDORSED]
Replies: 1
Views: 140

### In chapter 9.2 example[ENDORSED]

I’m confused on the in chapter blue box example problem 9.2 b. In the back of the book it uses the specific heat in kelvin but it’s given to you in Celsius in the problem- is it okay to convert then specific heat from $\frac{J}{g\cdot C}$ to $\frac{J}{g\cdot K}$ without doing anything to it??
Wed Jan 24, 2018 5:53 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.73
Replies: 1
Views: 138

### 8.73

is the best way to do this question to draw out lewis structures and just know whats going to break and whats going to form?
Wed Jan 24, 2018 5:13 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.65
Replies: 6
Views: 323

### Re: 8.65

from what it looks like in the solution manual you're trying to achieve 5 moles of o2 and 2 moles n on the reactants and the same for products so its the best way to manipulate the two equations to cancel out different reactants and products to end up with 1 mole of n2o5 for your product
Sat Jan 20, 2018 1:50 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.51
Replies: 5
Views: 230

### Re: 8.51

thank you! my only other question is what are the step by steps for calculating enthalpy density, what would you do to solve this problem?
Sat Jan 20, 2018 1:48 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.57
Replies: 3
Views: 270

### 8.57

Can someone do this question step by step? should I just know what hydrogenation means or is there another way to figure out initial reactants and products?
Sat Jan 20, 2018 1:35 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Ch 8 #53 Part b
Replies: 7
Views: 499

### Re: Ch 8 #53 Part b

why is it c(deltaT) divided by moles and not c(deltaT)(moles)
Sat Jan 20, 2018 1:08 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.51
Replies: 5
Views: 230

### 8.51

can someone explain why you only use the enthalpies of formation for two of the products in the reaction not all the products? and also just like the whole question, help
Sat Jan 20, 2018 11:31 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.37
Replies: 1
Views: 114

### 8.37

will someone explain the logic behind 8.37, why do you calculate delta h by dividing joules by moles?
Wed Jan 17, 2018 3:26 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: calculating specific heat
Replies: 5
Views: 319

### calculating specific heat

so does volume not matter when calculating specific heat? for questions involving q and qcal they keep giving me the liters of whatever molecule but I never end up using it in the calculations
Wed Jan 10, 2018 6:11 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: reaction enthalpy vs reaction internal energy [ENDORSED]
Replies: 1
Views: 140

### reaction enthalpy vs reaction internal energy[ENDORSED]

I don't understand the difference between reaction enthalpy and reaction internal energy. can someone lay out the definitions, also how does that correspond to H and U
Wed Jan 10, 2018 6:10 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: relation between delta H and delta U [ENDORSED]
Replies: 1
Views: 939

### relation between delta H and delta U[ENDORSED]

I'm confused by a part in the textbook that says "delta H is less negative(more positive) than delta U for reactions that generate gases:less energy can be obtained from a reaction as heat at constant pressure than at constant volume, because the system must use some energy to expand to make ro...
Sat Dec 09, 2017 6:44 pm
Forum: Lewis Structures
Topic: resonance and delocalization
Replies: 2
Views: 269

### resonance and delocalization

does having resonance mean that there are also delocalized electrons?
Sat Dec 09, 2017 6:21 pm
Forum: Lewis Structures
Replies: 1
Views: 195

where are radicals found? on the least electronegative element in the lewis structure?
Fri Dec 08, 2017 7:50 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.55/57
Replies: 2
Views: 253

### 12.55/57

when do you know when you need to use an ice table or when you can go straight to the equilibrium constant
Fri Dec 08, 2017 7:50 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.45
Replies: 1
Views: 184

### 12.45

can someone break down this problem- what is the main takeaway? are they trying to say more bonds is connected to acidity/basicity strength
Fri Dec 08, 2017 7:49 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.33
Replies: 1
Views: 225

### 12.33

can someone go through this problem step by step?
Fri Dec 08, 2017 7:48 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: 12.29
Replies: 1
Views: 244

### 12.29

do you know if you are calculating OH or H30 by whether or not you get pkb/pka or kb/ka or you're using a base/acid
Fri Dec 08, 2017 7:47 pm
Forum: Bronsted Acids & Bases
Topic: 12.27
Replies: 1
Views: 159

### 12.27

can someone explain part b to me?
Fri Dec 08, 2017 12:38 am
Forum: Amphoteric Compounds
Topic: 12.17 [ENDORSED]
Replies: 9
Views: 1095

### Re: 12.17[ENDORSED]

Julia Meno 1D wrote:Can someone explain why Bi2O3 is amphoteric? It's technically not listed as a metalloid on the periodic table.

draw out the lewis structure
Fri Dec 08, 2017 12:35 am
Forum: Conjugate Acids & Bases
Topic: 12.17
Replies: 1
Views: 212

### 12.17

how can you tell if an oxide is acidic, basic, or amphoteric
Thu Dec 07, 2017 11:57 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: 12.7
Replies: 2
Views: 303

### 12.7

Hey! Can someone help me figure out how to draw the conjugate base, also is naming oxoacids in the fundamental J?
Thu Dec 07, 2017 12:45 pm
Forum: Lewis Acids & Bases
Topic: lewis vs. bronsted
Replies: 1
Views: 193

### lewis vs. bronsted

I'm still a little unclear on the difference in less vs bronsted acids and bases, what is the distinction and what does it have to do with H+ protons specifically?
Wed Nov 29, 2017 5:04 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: dentates [ENDORSED]
Replies: 1
Views: 169

### dentates[ENDORSED]

Is there a way to know dentate/mono/bi if you're just given the formula? like CN-?
Tue Nov 28, 2017 10:12 pm
Forum: Naming
Topic: 17.31 a
Replies: 1
Views: 195

### 17.31 a

Hi can someone walk through the charges and how to identify them going from the name to the formula, I'm confused because to my understanding Chromate implies it has a negative one charge because of the "ate" at the end, cyano is a negative one charge and there's 6, and I don't know if the...
Sun Nov 26, 2017 10:57 am
Forum: Naming
Topic: naming order of things outside the bracket
Replies: 2
Views: 203

### naming order of things outside the bracket

How do you know to name the compounds outside the bracket before the compound or after? I've seen it vary with different examples and Im wondering if there is a rule or not
Sun Nov 26, 2017 10:48 am
Forum: Naming
Topic: Naming (steps)
Replies: 6
Views: 453

### Re: Naming (steps)

at what point should you figure out cations versus anions and is there an easy way to do that?
Sun Nov 26, 2017 10:46 am
Forum: Naming
Topic: 17.1
Replies: 1
Views: 179

### 17.1

Can someone please go through the problem 17.1 in the book? I'm getting confused on where to start, everytime we name a compound do we basically have to do lewis structures to find the charges for every part of the compound?
Thu Nov 09, 2017 10:33 am
Forum: Ionic & Covalent Bonds
Topic: 3.25
Replies: 6
Views: 507

### Re: 3.25

what happens when there is a number in parentheses for example Bismuth(III)?
Sat Oct 28, 2017 4:59 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: orbitals [ENDORSED]
Replies: 5
Views: 338

### orbitals[ENDORSED]

are orbitals the same thing as the amount of electrons in a sub shell?
Sat Oct 28, 2017 3:04 pm
Forum: *Shrodinger Equation
Topic: Node
Replies: 3
Views: 449

### Node

Im a little confused with what the book means when it says that a node is when the wave function passes through 0. What is the "passing through" referring to?
Wed Oct 18, 2017 6:29 pm
Forum: Properties of Light
Topic: Homework 1.9
Replies: 2
Views: 242

### Homework 1.9

how do you know which radiation corresponds to which frequency? Will we have to know that for the test?
Fri Oct 13, 2017 12:22 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: lines in electromagnetic spectrum
Replies: 3
Views: 316

### lines in electromagnetic spectrum

can someone explain the diagram from class today where lines in the EM Spectrum corresponded to a jump/drop in an energy level, I was confused on how to figure out from what energy level we are coming from or going to simply by a line in the EM Spectrum
Fri Oct 13, 2017 12:20 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: lines in electromagnetic spectrum
Replies: 1
Views: 185

### lines in electromagnetic spectrum

I was a little confused about what prof. Lavelle was saying today about how an electron when it falls or jumps an energy level has its energy emitted as a photon
Thu Oct 05, 2017 7:58 pm
Forum: Molarity, Solutions, Dilutions
Topic: G17
Replies: 2
Views: 303

### G17

im confused on the rounding of the question and when to do it
Thu Oct 05, 2017 7:47 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: E7 [ENDORSED]
Replies: 9
Views: 708

### E7[ENDORSED]

how do I know at what step in the problem to start rounding my sig figs to the given value?

Go to advanced search