Search found 57 matches
- Sat Mar 17, 2018 5:07 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chemical Compounds
- Replies: 1
- Views: 342
Chemical Compounds
Will we be tested on naming chemical compounds? For example, name CH3CH(CH3)CH(CH2CH3)C(CH3)3?
- Thu Mar 15, 2018 12:22 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: 14.101
- Replies: 4
- Views: 1007
Re: 14.101
Where does the 0.0257V come from? Why isn't it 0.05916V?
- Thu Mar 15, 2018 10:19 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: 8.57
- Replies: 1
- Views: 292
8.57
How do we know which balanced equations to use for the reaction given? Where do the equations from the solutions manual come from?
- Wed Mar 14, 2018 9:49 pm
- Forum: Balancing Redox Reactions
- Topic: Lecture 3/14
- Replies: 3
- Views: 503
Lecture 3/14
For the first problem that we reviewed today, how do we know which reaction to choose to be oxidizing and reducing? Do we choose our oxidizing to be the reaction with the largest cell voltage?
- Thu Mar 08, 2018 8:21 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: 15.17
- Replies: 6
- Views: 1093
Re: 15.17
How can we tell [C] is zero order?
- Tue Mar 06, 2018 10:08 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Increasing Concentration of Reactants
- Replies: 5
- Views: 771
Increasing Concentration of Reactants
Does increasing the concentration of the reactants increase the rate of the reaction?
- Tue Mar 06, 2018 3:05 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Midterm Question 5 (Step 2)
- Replies: 2
- Views: 462
Midterm Question 5 (Step 2)
Why is the internal energy positive if when we calculated it in step 1 it was negative?
- Sun Mar 04, 2018 10:40 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667791
Re: Post All Chemistry Jokes Here
I'm having such a hard time staying up late to do homework.
It's sodium hard.
It's sodium hard.
- Sun Mar 04, 2018 10:36 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667791
Re: Post All Chemistry Jokes Here
Would you like to hear a joke about sodium?
Na
Na
- Sun Mar 04, 2018 10:33 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Affects rate of chemical reactions
- Replies: 2
- Views: 454
Affects rate of chemical reactions
What affects the rate of chemical reactions?
- Thu Feb 22, 2018 8:41 am
- Forum: Balancing Redox Reactions
- Topic: 14.1 [ENDORSED]
- Replies: 1
- Views: 266
14.1 [ENDORSED]
Why is H+ included in part B? Its oxidation number stays the same?
- Tue Feb 20, 2018 8:40 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing number of electrons
- Replies: 10
- Views: 1104
Balancing number of electrons
To balance the number of electrons between the two half-reactions, we multiply each reaction by the least common multiple?
- Tue Feb 20, 2018 6:46 pm
- Forum: Balancing Redox Reactions
- Topic: Exceptions in Halogens
- Replies: 1
- Views: 229
Exceptions in Halogens
Which halogens do not have a (-1) charge?
- Sun Feb 18, 2018 8:14 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Work when pressure is constant
- Replies: 6
- Views: 1013
Work when pressure is constant
When pressure is constant, since w=-P(ext)change in v , it also can be w= -nRT?
- Sun Feb 18, 2018 8:09 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Order in Cell Diagrams
- Replies: 4
- Views: 574
Order in Cell Diagrams
Is there a specific order of the phases or does it not matter?
- Tue Feb 13, 2018 3:06 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Homework this week?
- Replies: 1
- Views: 252
Homework this week?
Is the homework for this week on Chapter 11? Since there are few questions, could we repeat the ones we did for last week?
- Sun Feb 11, 2018 8:27 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: 11.83
- Replies: 4
- Views: 634
11.83
Why do we need to find delta S?
- Sun Feb 11, 2018 11:03 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Non-spontaneous
- Replies: 4
- Views: 675
Non-spontaneous
What does it mean for a reaction to be non-spontaneous yet its reverse reaction to be spontaneous? Why is its reverse reaction spontaneous?
- Thu Feb 08, 2018 5:04 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Extensive Property?
- Replies: 3
- Views: 455
Extensive Property?
What does it mean for something to be an extensive or intensive property?
- Wed Feb 07, 2018 9:24 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bonds Broken - Bonds Formed?
- Replies: 2
- Views: 2236
Bonds Broken - Bonds Formed?
Are the bonds being added since bonds forming releases energy so it will be negative? Or is it broken- formed so it’s a double negative ?
- Tue Feb 06, 2018 8:10 pm
- Forum: Phase Changes & Related Calculations
- Topic: 8.19
- Replies: 3
- Views: 554
8.19
Does anyone know where the 0.38 J/Cg come from?
- Tue Feb 06, 2018 1:29 am
- Forum: Phase Changes & Related Calculations
- Topic: Units for Internal Energy
- Replies: 5
- Views: 724
Units for Internal Energy
Does it matter which units to use for internal energy for our final answer. Is it kJ or J?
- Sun Feb 04, 2018 11:12 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm
- Replies: 5
- Views: 746
Re: Midterm
I believe it is Chapter 8, 9 and 11? I am not too sure.
- Sun Feb 04, 2018 11:11 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Heating Capacity
- Replies: 3
- Views: 408
Re: Heating Capacity
Does it matter which equation we use to find heat capacity? Will the formula for specific heat capacity and molar heat capacity give the same thing?
- Sun Feb 04, 2018 11:08 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Calculations on Internal Energy
- Replies: 4
- Views: 700
Calculations on Internal Energy
Will calculations on internal energy and work be on the midterm?
- Thu Jan 25, 2018 1:17 am
- Forum: Phase Changes & Related Calculations
- Topic: 8.17
- Replies: 2
- Views: 275
8.17
Can anyone explain why a) is work done by the system? Wouldn’t it be on the system since it is absorbing heat? Hence solid to liquid?
- Tue Jan 23, 2018 2:34 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: How to use Hess’s Law
- Replies: 1
- Views: 187
How to use Hess’s Law
In toolbox 8.1, it says to cancel species that appear on both sides of the equation and to add substances on the opposite side of the arrow. However in the example 8.16 provides on pg. 292, it does the opposite. The O2’s are added yet are on the same side of the arrow and the CO’s are subtracted yet...
- Tue Jan 23, 2018 2:10 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Material in Book but not in Lectures
- Replies: 5
- Views: 453
Re: Material in Book but not in Lectures
Should we know how to draw the heating curves?
- Mon Jan 22, 2018 9:40 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: standard enthalpy of formation
- Replies: 3
- Views: 479
Re: standard enthalpy of formation
Standard reaction enthalpy is when the reactants and products in a reaction are in their standard state at 1 atm. Standard enthalpy of formation is the standard reaction enthalpy for the formation of one mole of a substance from its element in their most stable form.
- Mon Jan 22, 2018 9:29 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Calculations on Test 3
- Replies: 3
- Views: 332
Re: Calculations on Test 3
Yes sorry I meant Test 1.
- Sat Jan 20, 2018 3:22 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Finding change in enthalpy when given bond enthalpies
- Replies: 3
- Views: 258
Finding change in enthalpy when given bond enthalpies
Do we subtract the reactants from the products or do we add all the bond enthalpies together ?
- Sat Jan 20, 2018 1:43 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Calculations on Test 3
- Replies: 3
- Views: 332
Calculations on Test 3
So if the calculations will not be on work and internal energy, what will the calculations be on?
- Sat Jan 20, 2018 12:57 pm
- Forum: Phase Changes & Related Calculations
- Topic: Why does steam cause severe burns?
- Replies: 4
- Views: 471
Why does steam cause severe burns?
I know he covered this in class, but I still quite don’t understand. Could someone explain please?
- Sun Jan 14, 2018 11:47 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: 8.7
- Replies: 2
- Views: 351
8.7
Why is 982 delta U? Wouldn’t it be 982J- 492J? Aren’t work and delta U the same thing as according to 8.3 c?
- Sun Jan 14, 2018 9:51 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: 8.5
- Replies: 2
- Views: 310
8.5
So whenever we are trying to find the change in internal energy, we add the two energy terms?
- Sun Jan 14, 2018 8:51 pm
- Forum: Calculating Work of Expansion
- Topic: 8.3 Solution Question
- Replies: 1
- Views: 242
8.3 Solution Question
In the solutions manual, it says we use change of volume= -(pi)(r^2)(d). Why would we use the radius of the initial diameter and for d we use the second diameter?
- Fri Dec 08, 2017 7:14 pm
- Forum: Conjugate Acids & Bases
- Topic: Stabilizing Conjugate Bases
- Replies: 1
- Views: 283
Stabilizing Conjugate Bases
What can stabilize a base? How can we tell if it’s stabilized?
- Wed Dec 06, 2017 4:28 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Will we be given Table 11.2?
- Replies: 2
- Views: 297
Will we be given Table 11.2?
Will we be given table 11.2 or should we memorize some values?
- Wed Dec 06, 2017 3:33 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 11.25 [ENDORSED]
- Replies: 2
- Views: 263
11.25 [ENDORSED]
Why is the answer Kc = [HI]^2/ [H2][I2] instead of P[HI]^2/P[H2]P[I2]?
- Thu Nov 30, 2017 3:34 am
- Forum: Naming
- Topic: Homework 17.29(B)
- Replies: 1
- Views: 211
Re: Homework 17.29(B)
We determine the oxidation number of the metal with the equation (# of metals)(oxidation # of metal) + (# of ligands)(charge of each ligand) = charge of ion so for 17.29 (B) # of metals = 1 oxidation # of metal = x (what we are trying to find) # of ligands = 6 charge of ligand = 0 (which is given by...
Suffixes
What suffixes should we memorize? I understand if one of the ligands has a negative charge of one then -ate is added to the metal, but if it has a negative charge of 2, no suffix is added as demonstrated in 17.29 d)?
- Thu Nov 30, 2017 1:26 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Changes in K
- Replies: 4
- Views: 363
Changes in K
So the only thing that changes equilibrium is temperature? If a reactant is removed, the equilibrium would not change? Removing it would only change Q?
- Sun Nov 26, 2017 11:59 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Difference between molecular and electron geometry?
- Replies: 3
- Views: 55964
Difference between molecular and electron geometry?
What is the difference between electron and molecular geometry?
- Sun Nov 19, 2017 11:50 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: All bond angles
- Replies: 3
- Views: 434
All bond angles
Do we have to memorize all bond angles within each shape?
- Sun Nov 19, 2017 11:46 am
- Forum: Lewis Structures
- Topic: Best way to start Lewis Structures
- Replies: 12
- Views: 1284
Best way to start Lewis Structures
What is the best way to start a Lewis structure? Draw all the electrons on each atom, then draw the bonds or draw the bonds then assign electrons?
- Wed Nov 08, 2017 12:35 am
- Forum: Trends in The Periodic Table
- Topic: Radius
- Replies: 6
- Views: 792
Radius
What is the difference between an atomic and ionic radius?
- Wed Nov 08, 2017 12:27 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 3.5 b) [ENDORSED]
- Replies: 5
- Views: 754
3.5 b) [ENDORSED]
I still don't quite understand how we write electron configurations. The answer is [Xe] 4f^14 5d^10 6s^2 , and I understand it is in numerical order, but when we are solving it, do we solve it as [Xe] 6s^2 4f^14 5d^10 then rearrange it?
- Thu Nov 02, 2017 5:36 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Reasonable Model
- Replies: 2
- Views: 291
Reasonable Model
If the velocity in the Heisenberg's equation is slower than the speed of light, then it is a reasonable model? And if it is more than the speed of light, then it is an unrealistic model?
- Wed Nov 01, 2017 9:33 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Order of Orbitals
- Replies: 10
- Views: 2596
Order of Orbitals
Does the order of orbitals matter? For instance is it okay if we either write 4s2 3d10 or 3d10 4s2?
- Sun Oct 29, 2017 11:26 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Copper and Chromium [ENDORSED]
- Replies: 4
- Views: 1295
Copper and Chromium [ENDORSED]
What is the exception with Copper and Chromium?
- Wed Oct 25, 2017 11:19 pm
- Forum: Properties of Light
- Topic: Homework?
- Replies: 2
- Views: 424
Homework?
Is this week's homework based on Chapter 2 or the rest of Chapter 1?
- Mon Oct 16, 2017 10:46 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Question about 1.17 [ENDORSED]
- Replies: 3
- Views: 1497
Re: Question about 1.17 [ENDORSED]
Even though it is He^+ we would still make Z 2? So if it is a one-electron ion, we would use how many the element originally has?
- Mon Oct 16, 2017 9:47 pm
- Forum: Properties of Light
- Topic: Where is the page of constants?
- Replies: 1
- Views: 209
Where is the page of constants?
Does anyone know where in Dr. Lavelle's website the page of constants is? I can't seem to find it.
- Sun Oct 15, 2017 2:50 pm
- Forum: DeBroglie Equation
- Topic: 1.37 [ENDORSED]
- Replies: 5
- Views: 800
Re: 1.37 [ENDORSED]
I think the mass would be given since in Example 1.6, Self-Test 1.6A, the question mentions that the mass of an electron can be found inside the back cover of the book. There, you can also find the mass of a proton.
- Sat Oct 14, 2017 1:41 pm
- Forum: Properties of Light
- Topic: Electromagnetic Spectrum [ENDORSED]
- Replies: 2
- Views: 330
Electromagnetic Spectrum [ENDORSED]
Will the electromagnetic spectrum be given on the test? Or would we have to memorize the group the wavelength belongs to?
- Thu Oct 05, 2017 12:33 am
- Forum: Balancing Chemical Reactions
- Topic: H1 // Book Problem [ENDORSED]
- Replies: 7
- Views: 975
Re: H1 // Book Problem [ENDORSED]
By adding an O to the products, it will indicate that free range Oxygen atoms are ALSO being produced, which is not the case. So adding an O will indicate that a different reaction is occurring.
- Thu Oct 05, 2017 12:26 am
- Forum: Limiting Reactant Calculations
- Topic: Percent Yield [ENDORSED]
- Replies: 5
- Views: 6096
Percent Yield [ENDORSED]
Why is having a high percentage yield good? Around what percentage is considered good?