Why do we use E(naught)=lnK for this problem, instead of E=E(naught)-lnQ in which Enaught would be zero (PH7)
I paraphrased the equations because I'm lazy
Search found 73 matches
- Sat Mar 17, 2018 12:18 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Chapter 14 # 107
- Replies: 1
- Views: 364
- Wed Mar 14, 2018 4:01 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Homework 8.117 [ENDORSED]
- Replies: 2
- Views: 363
Re: Homework 8.117 [ENDORSED]
Why dont you need to balance the equation before you begin solving it?
- Wed Mar 14, 2018 2:44 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Homework 8.117 [ENDORSED]
- Replies: 2
- Views: 363
Homework 8.117 [ENDORSED]
The question states that CH4 + H20 -> CO2 + 3H2, and I need to find the work done by this reaction. After balancing the equation, I found the change in N to be 1/2 with respect to 1 mol of H2 (1/4+4/4 - 2/4 -1/4), and I know that work= -nRT. What do I use for T? When I use 298K I get an incorrect an...
- Mon Mar 12, 2018 1:18 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2762262
Re: Post All Chemistry Jokes Here
What do you call the guest registry at the Annual Bovine Convention of Cows in Chemistry?
A Cattle-List!
moooo
A Cattle-List!
moooo
- Thu Mar 08, 2018 6:44 pm
- Forum: First Order Reactions
- Topic: pseudoreactions [ENDORSED]
- Replies: 2
- Views: 353
pseudoreactions [ENDORSED]
Let's say we had a second order rate law that was equal to k[A][B]. To render this a pseudo-first order reaction, one could ensure that the concentration of A was so high relative to the concentration of B (lets say .85M and .003M, respectively) that the concentration of A effectively stayed constan...
- Mon Mar 05, 2018 3:04 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2 Q8
- Replies: 2
- Views: 405
Test 2 Q8
when finding Q from the half reactions
Ag(s) + I-(aq) -> AgI(s) + e- E(anode)=-0.15V
AgCl(s) + e- -> Ag(s) + Cl- (aq) E(cathode) = 0.22V
How do you identify Cl- and I- as products or reactants?
Ag(s) + I-(aq) -> AgI(s) + e- E(anode)=-0.15V
AgCl(s) + e- -> Ag(s) + Cl- (aq) E(cathode) = 0.22V
How do you identify Cl- and I- as products or reactants?
- Mon Mar 05, 2018 2:48 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2 Q6
- Replies: 4
- Views: 543
Test 2 Q6
How do you identify the oxidizing and reducing agents for the redox couple
O3/O2 and OH- and O3, H+/02 ?
O3/O2 and OH- and O3, H+/02 ?
- Mon Mar 05, 2018 2:43 pm
- Forum: Balancing Redox Reactions
- Topic: Reducing power
- Replies: 2
- Views: 380
Reducing power
Does Br2 have a weaker reducing power compared to I2? Does this also correlate to a stronger oxidizing power for Br2 in comparison to I2?
- Fri Feb 23, 2018 10:58 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: 14.41b
- Replies: 1
- Views: 286
Re: 14.41b
Hey! To find the standard cell potential, we extrapolate oxidation and reduction half reactions from the cell diagram, from the left and right sides, respectively. Once we have these half rxns, we can use our handy dandy chart in Appendix 2B to search for standard reduction potentials (subtracting t...
- Thu Feb 22, 2018 5:51 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell diagram
- Replies: 4
- Views: 553
Cell diagram
When dealing with two compounds that are in different phases, how do you know which to list first in the cell diagram? For instance, if the two compounds on the reduction side of my diagram are Cl2(g) and Cl-, which do I put first?
- Thu Feb 22, 2018 5:42 pm
- Forum: Balancing Redox Reactions
- Topic: Cell Diagram [ENDORSED]
- Replies: 7
- Views: 837
Cell Diagram [ENDORSED]
When writing a cell diagram, why are I- ions and I2(s) separated on the oxidation side?
- Thu Feb 22, 2018 2:53 pm
- Forum: Balancing Redox Reactions
- Topic: H+ or H3O+ to balance half-rxns in acidic conditions?
- Replies: 1
- Views: 187
H+ or H3O+ to balance half-rxns in acidic conditions?
Should we use H+ or H3O+ to balance half-rxns in acidic conditions?
- Thu Feb 22, 2018 2:52 pm
- Forum: Balancing Redox Reactions
- Topic: Textbook 14.1
- Replies: 3
- Views: 473
Textbook 14.1
In 14.1 part c, why does the answer in the textbook include 14 H- in the reduction half reaction instead of 14H+?
- Wed Feb 14, 2018 1:15 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Homework Problem 9.81
- Replies: 1
- Views: 380
Re: Homework Problem 9.81
Hey Lily Fe3O4(s) + O2(g) = Fe2O3(s) This is the unbalanced equation for the oxidation of Magnetite to Hematite. If we balance the equation, we get 4Fe3O4(s) + O2(g) = 6Fe2O3(s). For your method to work, you would need to compare the deltaG of formation of six moles of Hematite to 4 moles of Magneti...
- Wed Feb 14, 2018 11:37 am
- 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: Boron Triflouride Degeneracy [ENDORSED]
- Replies: 1
- Views: 408
Boron Triflouride Degeneracy [ENDORSED]
Does Boron Triflouride have a degeneracy of one? Further implying that at T=0, it has no entropy?
- Tue Feb 13, 2018 3:15 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: 11.15
- Replies: 12
- Views: 3109
Re: 11.15
zanekoch1A wrote:I'm not sure what I am doing wrong but I keep getting an answer around 1.5kj. I am using in the Gnot part of the equation a T of 273 and a k of 6.8 and and in the G side a T of 1200 and ln(.13/.98). What am I doing wrong?
Hey Zane, I think your natural log should be of (.98)^2/(.13)
- Tue Feb 13, 2018 2:55 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Isothermal Process
- Replies: 1
- Views: 464
Re: Isothermal Process
The equation q=mCdeltaT is somewhat useless for isothermal processes because it has to do specifically with heat capacities. It's not that a substance that doesn't change in temperature has no heat capacity at all, its just that its impossible to tell what that heat capacity is when the temperature ...
- Tue Feb 13, 2018 2:29 pm
- Forum: Calculating Work of Expansion
- Topic: 8.93 Expansion?
- Replies: 4
- Views: 656
Re: 8.93 Expansion?
1) I'm not sure about this either, I know that combustion can produce water vapor when it is carried out at temperatures above 100 C, but this reaction appears to be at 25 C. 2) However, I do know that if you consider water vapor as a product instead of liquid water, you will find that the system lo...
- Tue Feb 13, 2018 1:41 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Textbook 9.67
- Replies: 1
- Views: 257
Textbook 9.67
This problem wants us to find the range over which each reaction will be spontaneous and lists a few reactions. My calculations are all slightly off for some reason; am I correct in that to solve this problem you need to use the difference in enthalpy and entropy of the products and reactants to fin...
- Mon Feb 12, 2018 12:50 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Cp vs Cv
- Replies: 1
- Views: 199
Re: Cp vs Cv
I believe constant pressure only dictates that the pressure is kept constant, not that volume and/or work are kept constant.
- Mon Feb 12, 2018 12:48 pm
- Forum: Calculating Work of Expansion
- Topic: 8.93 Expansion?
- Replies: 4
- Views: 656
Re: 8.93 Expansion?
If you write your equation with water as a gas instead of a liquid, you will find the change in moles to be +3 and you will get -3.71 KJ as the change in energy of the system due to work. If a system is losing energy due to work, that means it is performing work. Thus the work done against the atmos...
- Thu Feb 08, 2018 10:05 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Calculating entropy of vaporization
- Replies: 1
- Views: 303
Calculating entropy of vaporization
When finding entropy of vaporization from a temperature that is not the boiling point, we include the change in entropy that arises when you cool the vapor back down to original temperature. Why is this last value calculated using the heat capacity for the gaseous state? Why does cooling down a vapo...
- Thu Feb 08, 2018 9:59 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Finding entropy of vaporization from temperatures NOT = to boiling point [ENDORSED]
- Replies: 3
- Views: 1144
Finding entropy of vaporization from temperatures NOT = to boiling point [ENDORSED]
When finding the standard entropy of vaporization of water at 85 C, why do we cool the vapor back down from 100 C? I get that entropy is a state function, but enthalpy is also a state function and when finding the enthalpy of vaporization of water at 85 C, we would simply add the Hvap of water to 4....
- Thu Feb 08, 2018 3:14 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Textbook 8.89
- Replies: 1
- Views: 132
Textbook 8.89
How does one solve this problem? Is there a way to figure out the melting point of iodine or is that not needed at all?
- Tue Feb 06, 2018 7:34 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: How cold is that iced tea tho
- Replies: 1
- Views: 303
How cold is that iced tea tho
If a 50.0 g ice cube is added to 250 ml of tea at 20.0 degrees celsius, what is the final temperature at thermal equilibrium?
- Sat Feb 03, 2018 7:48 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Delta G [ENDORSED]
- Replies: 4
- Views: 482
Re: Delta G [ENDORSED]
Hey Emma, Delta G is not always negative, it is a measure of the energy available to do work in a system. For example, because the hydrolysis of ATP allows your cells to harness the energy from that spontaneous reaction and do work with it, it has a negative Delta G. A reaction that requires an net ...
- Sat Feb 03, 2018 7:42 pm
- Forum: Phase Changes & Related Calculations
- Topic: Degeneracy
- Replies: 4
- Views: 613
Degeneracy
What is degeneracy and how can we use it?
- Wed Jan 24, 2018 5:45 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Hmwk Q 8.31
- Replies: 2
- Views: 310
Re: Hmwk Q 8.31
Page 281 in the textbook tells us that
C=3/2RT for monatomic gases at constant volume, while C=5/2RT for monatomic gases at constant pressure.
C=3/2RT for monatomic gases at constant volume, while C=5/2RT for monatomic gases at constant pressure.
- Wed Jan 24, 2018 5:40 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Question regarding 8.39 homework question
- Replies: 5
- Views: 598
Re: Question regarding 8.39 homework question
Hey Michelle, You need to use the specific heat capacity of liquid water because once the ice melts, all heat being transferred will be subject to the properties and heat capacity of liquid water. This problem can be essentially be split into two parts; the first of which you use the heat capacity o...
- Wed Jan 24, 2018 5:34 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Chapter 8.7 concepts and math question
- Replies: 1
- Views: 300
Re: Chapter 8.7 concepts and math question
U=3/2RT for monatomic gases at constant volume, while U=5/2RT for monatomic gases at constant pressure. Rotational and translational contributions come into play when dealing with diatomic or polyatomic gases, for which we observe LINEAR MOLECULES- U= 5/2R, 7/2R (Constant volume, constant pressure) ...
- Wed Jan 24, 2018 5:10 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Homework Problem 8.67
- Replies: 3
- Views: 519
Homework Problem 8.67
8.67) Use the information in Tables 8.3, 8.6, 8.7 to estimate the enthalpy of formation of each of the following compounds in the liquid state. The standard enthalpy of sublimation of carbon is +717 kj/mol. b)CH3OH c)C6H6 (without resonance) d)C6H6 (with resonance) For b), I created the formation re...
- Wed Jan 24, 2018 4:46 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: homework 8.67
- Replies: 3
- Views: 466
Re: homework 8.67
Thanks Remi, one more question: Do two gases always form another gas when they react? More specifically, how did you know that H2 gas and O2 gas reacted to form H20 in its gaseous form?
- Wed Jan 24, 2018 3:59 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: homework 8.67
- Replies: 3
- Views: 466
homework 8.67
8.67) Use the information in Tables 8.3, 8.6, 8.7 to estimate the enthalpy of formation of each of the following compounds in the liquid state. The standard enthalpy of sublimation of carbon is +717 kj/mol. a)H20 b)CH3OH c)C6H6 (without resonance) d)C6H6 (with resonance) How do you find the enthalpi...
- Thu Jan 18, 2018 5:35 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 8.51 Sig Figs, Sign [ENDORSED]
- Replies: 3
- Views: 771
Re: 8.51 Sig Figs, Sign [ENDORSED]
Why is the answer to this problem written as "23.9 KJ/L x 10^3" and not "2.39 KJ/L x 10^4"?
- Tue Jan 16, 2018 3:02 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Finding change in enthalpy of a rxn
- Replies: 3
- Views: 343
Finding change in enthalpy of a rxn
When calculating the change in enthalpy of a rxn by subtracting the standard enthalpy of formation of the reactants from the standard enthalpy of the products, how do you find the enthalpies of formation for individual products/reactants? Is there a way to calculate this or is there a chart somewher...
- Mon Jan 15, 2018 1:37 pm
- Forum: Phase Changes & Related Calculations
- Topic: Types of Systems
- Replies: 10
- Views: 1406
Re: Types of Systems
An isolated system has no interaction with its surroundings whatsoever, while a closed system has a fixed amount of matter, but can exchange energy with its surroundings. A good example of a closed system is something like an ice pack, and a good example of an isolated system is something sealed off...
- Sat Jan 13, 2018 10:03 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Bomb Calorimetry
- Replies: 4
- Views: 1805
Re: Bomb Calorimetry
The main difference between a true bomb calorimeter and the coffee cup calorimeter is that the bomb is much more sophisticated and thus gives more accurate calculations. Other than that, the function of each is the same. As far as how it works, I think all we should know for this course is that a bo...
- Sat Jan 13, 2018 9:59 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: The 3 Methods for Calculating the Enthalpy of a Reaction
- Replies: 4
- Views: 567
Re: The 3 Methods for Calculating the Enthalpy of a Reaction
Hey! I know this much, rxn enthalpy is heat given off or taken up for the rxn, or just the enthalpy difference between the reactants and products. The enthalpy of formation of a compound is the enthalpy change between the reactants in their standard state and the product.
Hope that helps
Hope that helps
- Mon Jan 08, 2018 1:26 pm
- Forum: Phase Changes & Related Calculations
- Topic: Enthalpy and Temperature [ENDORSED]
- Replies: 4
- Views: 484
Enthalpy and Temperature [ENDORSED]
Can enthalpy and temperature be related?
- Sat Dec 09, 2017 9:53 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2762262
Re: Post All Chemistry Jokes Here
Which Nicki Minaj song is the best to listen to while studying Chapter 12?
Superbass!
Superbass!
- Fri Dec 08, 2017 9:58 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: 11.77 textbook problem
- Replies: 2
- Views: 366
11.77 textbook problem
Why does increasing the temperature of the rxn X2(g)<--->2X(g), where X is a halogen, favor the products? How should we know that is endothermic in the forward direction?
- Thu Dec 07, 2017 9:26 am
- Forum: Bronsted Acids & Bases
- Topic: Autoprotolysis
- Replies: 1
- Views: 219
Autoprotolysis
What is this, and why does it lead to hydronium/hydroxide ions moving through water much faster than other kinds of ions?
- Tue Dec 05, 2017 5:45 pm
- Forum: Bronsted Acids & Bases
- Topic: Net ionic equations (12.9)
- Replies: 1
- Views: 210
Net ionic equations (12.9)
When writing net ionic equations, do solid (s) or liquid (l) compounds get split into ions?
If not, why is the Bronsted Acid in the equation NH4I (s) + H20 (l) ---> NH3 (aq) + H3O+ (aq) + I- (aq)
considered to be NH4+, instead of NH4I
If not, why is the Bronsted Acid in the equation NH4I (s) + H20 (l) ---> NH3 (aq) + H3O+ (aq) + I- (aq)
considered to be NH4+, instead of NH4I
- Mon Dec 04, 2017 5:25 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Neutralization reactions
- Replies: 4
- Views: 535
Re: Neutralization reactions
Okay, thanks!
- Mon Dec 04, 2017 5:18 pm
- Forum: Administrative Questions and Class Announcements
- Topic: What is a passing grade? [ENDORSED]
- Replies: 4
- Views: 1308
Re: What is a passing grade? [ENDORSED]
The syllabus says that final grades will not be assigned until the class average score out of 500 is known, which makes me think (hope) that perhaps our grade will be out of slightly less than 500, but I am not sure
- Mon Dec 04, 2017 5:14 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Neutralization reactions
- Replies: 4
- Views: 535
Re: Neutralization reactions
How do you know that there are two hydroxide ions in Zinc Hydroxide?
- Mon Dec 04, 2017 5:11 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Proton Transfer Reactions
- Replies: 2
- Views: 440
Proton Transfer Reactions
When writing the chemical equation for the proton transfer reaction of NaC6H5O, I realized that my answer (NaC6H5O + H2O --> NaOH + C6H5OH)
differed from the textbook solution in that the solution did not include sodium at all (C6H5O- + H20 --> C6H5OH + OH-). Why is sodium left out?
differed from the textbook solution in that the solution did not include sodium at all (C6H5O- + H20 --> C6H5OH + OH-). Why is sodium left out?
- Mon Dec 04, 2017 4:33 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Zinc Nitrate
- Replies: 2
- Views: 471
Zinc Nitrate
How does one draw the lewis structure of this compound?
- Mon Dec 04, 2017 4:29 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Neutralization reactions
- Replies: 4
- Views: 535
Neutralization reactions
What would a neutralization reaction that resulted in the formation of zinc nitrite look like?
- Mon Dec 04, 2017 9:54 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: H20 Dentate [ENDORSED]
- Replies: 2
- Views: 399
H20 Dentate [ENDORSED]
If H20 has two atoms with lone pairs on them, why is it monodentate and not bidentate?
- Mon Nov 27, 2017 8:32 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 11.1 Homework
- Replies: 2
- Views: 253
11.1 Homework
"If one starts with a higher pressure of reactant, the equilibrium constant will be larger."
Why is this false? I thought K=[Products]/[Reactants]
Why is this false? I thought K=[Products]/[Reactants]
- Mon Nov 27, 2017 3:16 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: CH2Cl2
- Replies: 1
- Views: 502
CH2Cl2
Why is this molecule polar? What's stopping the chlorines from being on opposite sides of the carbon, and their dipoles canceling? Why are they adjacent to each other instead?
- Mon Nov 27, 2017 3:06 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Seesaw
- Replies: 2
- Views: 447
Seesaw
What are the different bond angles in a seesaw arrangement of atoms in a molecule?
- Mon Nov 27, 2017 11:16 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: T_shaped Molecules
- Replies: 2
- Views: 359
T_shaped Molecules
What's an example of a t-shaped molecules and how does this shape come to be? What stops the atoms attached to the central atom from getting as far away from each other as possible and forming a trigonal planar shape?
- Mon Nov 27, 2017 11:10 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pair Effect on Bond Angles [ENDORSED]
- Replies: 3
- Views: 956
Re: Lone Pair Effect on Bond Angles [ENDORSED]
Hey! Not sure about calculating the exact measure of bond angles being influenced by a lone pair, I believe that's a little above this course's pay grade, but I do know that bond angles in a molecule adjacent to the bond angle containing the lone pair will be slightly smaller than they would have be...
HCN
How does one name this molecule?
- Tue Nov 21, 2017 5:47 pm
- Forum: Hybridization
- Topic: Significance of hybridization
- Replies: 2
- Views: 2424
Re: Significance of hybridization
The necessity of the hybridization of orbitals can be traced back to Valence Bond theory, the theory that calculates covalent bonds angles and lengths. When we try to apply this theory to a compound like methane (CH4), it begins to fall apart. This is due to something called Electron Promotion, in w...
- Mon Nov 20, 2017 2:26 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Reaction progress [ENDORSED]
- Replies: 2
- Views: 549
Reaction progress [ENDORSED]
How does one depict the progress of a reaction graphically?
- Mon Nov 20, 2017 2:14 pm
- Forum: Ideal Gases
- Topic: PV=nRT [ENDORSED]
- Replies: 4
- Views: 581
PV=nRT [ENDORSED]
What do all of the different variables in the ideal gas law above represent?
- Sat Nov 11, 2017 12:47 pm
- Forum: Lewis Structures
- Topic: HOCO [ENDORSED]
- Replies: 3
- Views: 553
HOCO [ENDORSED]
What does the correct lewis structure for this molecule look like?
- Wed Nov 08, 2017 2:08 pm
- Forum: Empirical & Molecular Formulas
- Topic: Fundamentals E9
- Replies: 1
- Views: 312
Fundamentals E9
The question asks how many atoms of oxygen are in 5.15 grams of epsom salt, or magnesium sulfate heptahydrate. Firstly, are we going to need to know nomenclature like this for the midterm? Secondly, I googled the formula and got MgSO4(7H20). I am unsure of whether or not this problem would like me t...
- Tue Nov 07, 2017 8:43 am
- Forum: Ionic & Covalent Bonds
- Topic: oxidation state
- Replies: 3
- Views: 481
oxidation state
What is an oxidation state, and how can chlorine have both positive and negative oxidation states?
- Mon Oct 30, 2017 9:35 pm
- Forum: Electronegativity
- Topic: ELECTRON AFFINITY
- Replies: 7
- Views: 1515
ELECTRON AFFINITY
How are we supposed to know how electron affinity changes as you go down a group on the periodic table? I know that (generally) electron affinity increases from left to right across the table, but how should I know that Na has a lower EA than Li, for example?
- Sun Oct 29, 2017 10:50 pm
- Forum: Resonance Structures
- Topic: HOW [ENDORSED]
- Replies: 1
- Views: 275
HOW [ENDORSED]
How do we know what the most stable amount of double bonds is for a sulfur atom in a Sulfide molecule?
- Sun Oct 29, 2017 10:46 pm
- Forum: Resonance Structures
- Topic: Resonance Structures [ENDORSED]
- Replies: 3
- Views: 528
Resonance Structures [ENDORSED]
How do we draw a representation of a resonance structure? Is it just a combination of all possible configurations?
- Fri Oct 20, 2017 5:08 pm
- Forum: Properties of Light
- Topic: 1.43
- Replies: 1
- Views: 282
1.43
What is the minimum uncertainty in the speed of an electron confined to within a lead atom of diameter 350. pm?
- Fri Oct 20, 2017 5:05 pm
- Forum: SI Units, Unit Conversions
- Topic: Chemistry
- Replies: 3
- Views: 498
Chemistry
how do I convert cm-1 into meters? Thanks!
- Thu Oct 12, 2017 9:20 pm
- Forum: Properties of Light
- Topic: Question 1.33
- Replies: 1
- Views: 150
Question 1.33
Hey! I'm having trouble with part c of this problem. When I use the equation wavelength=c/frequency I get around 12 nm, but the back of the book says 8.8
- Thu Oct 12, 2017 2:18 pm
- Forum: Properties of Light
- Topic: 1.27
- Replies: 1
- Views: 241
Re: 1.27
Hey Irma! A key step of this problem is to find the energy created by one photon from this source of radiation, which we can do by using the formula E=hv, h being planck's constant (6.626x10^-34) and v being the frequency. In order to plug the frequency into the above equation we must use the formul...
- Tue Oct 10, 2017 2:49 pm
- Forum: Properties of Light
- Topic: Atomic Spectra
- Replies: 1
- Views: 230
Atomic Spectra
Using the formula
V=R(1/nsquared - 1/nsquared)
in atomic spectra problems, what does it mean when the initial n is greater than the final n (ex// n=1 transitioning to n=5) and you get a negative value for the frequency of the energy emitted?
V=R(1/nsquared - 1/nsquared)
in atomic spectra problems, what does it mean when the initial n is greater than the final n (ex// n=1 transitioning to n=5) and you get a negative value for the frequency of the energy emitted?
- Tue Oct 10, 2017 2:37 pm
- Forum: Properties of Light
- Topic: Problem 1.4
- Replies: 3
- Views: 479
Problem 1.4
The problem asks which statement is true A) x-rays travel faster than infrared radiation B) the wavelength of visible radiation decreases as its color changes from blue to green C) the frequency of infrared radiation is half that of radio waves D) the frequency of infrared radiation is twice that of...
- Mon Oct 02, 2017 1:38 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing Chemical Equations [ENDORSED]
- Replies: 1
- Views: 380
Balancing Chemical Equations [ENDORSED]
What are coefficients in chemical equations called?
- Mon Oct 02, 2017 1:37 pm
- Forum: Limiting Reactant Calculations
- Topic: % yield [ENDORSED]
- Replies: 2
- Views: 408
% yield [ENDORSED]
Hey, what is the difference between percent yield and theoretical yield?