## Search found 55 matches

Sat Mar 17, 2018 1:54 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: cell diagram
Replies: 4
Views: 250

### Re: cell diagram

When writing an oxidized and reduced species in the same phase are they always separated in the order (Oxidized, Reduced) in the cell diagram no matter what side of the cell diagram they're on?
Sat Mar 17, 2018 1:49 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram: Porous Disk and Salt Bridge
Replies: 5
Views: 338

### Re: Cell Diagram: Porous Disk and Salt Bridge

Will we be told if a porous disk or salt bridge is being used or is there a way to figure that out?
Sat Mar 17, 2018 1:45 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Rule when writing cell diagrams?
Replies: 5
Views: 335

### Re: Rule when writing cell diagrams?

How can you tell which side a cathode or anode is on in a cell diagram?
Sat Mar 17, 2018 1:41 pm
Forum: *Enzyme Kinetics
Topic: Final-Collision Theory
Replies: 3
Views: 567

### Re: Final-Collision Theory

Can someone please explain the difference between the collision theory and the transition state theory?
Sat Mar 17, 2018 1:37 pm
Forum: *Enzyme Kinetics
Topic: Enzyme
Replies: 5
Views: 1497

### Re: Enzyme

What is the difference between a homogeneous catalyst and a heterogeneous catalyst?
Sat Mar 17, 2018 1:35 pm
Forum: *Enzyme Kinetics
Topic: Two Paths
Replies: 5
Views: 787

### Re: Two Paths

When there are multiple paths, why is the faster one the one that determines the rate law? I'm still kind of confused on this concept
Sat Mar 17, 2018 1:32 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Activation Energy
Replies: 5
Views: 410

### Re: Activation Energy

How do you know which step is rate determining by looking at a graph interpretation of a reaction such as the one shown above?
Sat Mar 17, 2018 1:29 pm
Forum: *Enzyme Kinetics
Topic: Catalysts in a reaction
Replies: 10
Views: 836

### Re: Catalysts in a reaction

How can we tell if a substance is a catalyst or an intermediate?
Sat Mar 17, 2018 1:27 pm
Forum: General Rate Laws
Topic: Rate Law
Replies: 6
Views: 618

### Re: Rate Law

Just for clarification, a catalyst can appear in the rate law but an intermediate cannot?
Sat Mar 17, 2018 3:42 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Rate and equilibrium constants
Replies: 3
Views: 230

### Re: Rate and equilibrium constants

Do we use K=k/k' when there is only one step in a mechanism and K=(k1/k1') x (k2/k2') x ... when there are multiple steps?
Sat Mar 17, 2018 3:33 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Slow Step Vs. Steady State Approximation
Replies: 3
Views: 284

### Re: Slow Step Vs. Steady State Approximation

Can someone further explain when to use steady state approximation and the pre equilibrium approach please?
Sat Mar 17, 2018 3:28 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Proposing a reaction mechanism
Replies: 5
Views: 260

### Re: Proposing a reaction mechanism

Will we be told which step is the slow or fast step? If we are not told how do we find the slow step?
Sat Mar 17, 2018 3:25 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Rate Determining
Replies: 7
Views: 414

### Re: Rate Determining

Do you always ignore the reverse of the slow step? Why?
Sat Mar 17, 2018 3:21 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Fast or Slow
Replies: 8
Views: 476

### Re: Fast or Slow

I'm still sort of confused about the pre-equilibrium approach, can somebody please explain it?
Sat Mar 17, 2018 3:16 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Slow Step in Reaction Mechanisms
Replies: 7
Views: 2333

### Re: Slow Step in Reaction Mechanisms

How do we know when to use the pre-equilibrium condition?
Fri Mar 16, 2018 11:54 pm
Forum: Van't Hoff Equation
Topic: Exothermic and decrease in tempterature
Replies: 4
Views: 380

### Re: Exothermic and decrease in tempterature

Raising the temperature of an exothermic reaction favors the formation of reactants while raising the temperature of an endothermic reaction favors the formation of products.
Fri Mar 16, 2018 11:24 pm
Forum: Van't Hoff Equation
Topic: Van't Hoff
Replies: 9
Views: 638

### Re: Van't Hoff

Is this equation only used when K1 at T1 is known?
Fri Mar 16, 2018 11:16 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: reversible system
Replies: 9
Views: 579

### Re: reversible system

Does deltaS total always equal 0 in a reversible process? Is it possible for deltaS to be 0 in an irreversible system, and why or why not?
Fri Mar 16, 2018 11:11 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: State functions?
Replies: 9
Views: 588

### Re: State functions?

Why are heat and work not state functions?
Fri Mar 16, 2018 5:18 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: S=klnW
Replies: 7
Views: 1531

### Re: S=klnW

Can someone explain what residual entropy is and is it found from just using this equation?
Fri Mar 16, 2018 5:15 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: W
Replies: 3
Views: 416

### Re: W

W= (# of possible orientations)^ (# of molecules). For example if you have 3 molecules and each molecule could be arranged in 10 ways then W= 10^3. You might have to use Avogadro's number like explained above.
Fri Mar 16, 2018 5:10 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: Microstates
Replies: 2
Views: 323

### Re: Microstates

You can calculate the number of microstates by using W= (# of possible orientations)^(# of molecules)
Fri Mar 16, 2018 5:02 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: Boltzmann Equation
Replies: 3
Views: 399

### Re: Boltzmann Equation

Yes, with an increase in temperature, there is an increase in available microstates so W increases as well. Since W increases, the entropy increases as well.
Fri Mar 16, 2018 4:57 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: confused about 2nd law !!! [ENDORSED]
Replies: 3
Views: 449

### Re: confused about 2nd law !!![ENDORSED]

How do we know when to use the 2nd law or 3rd law equations? What is the main difference between these 2 laws?
Fri Mar 16, 2018 4:54 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: ΔS = q/t vs. ΔS = nCln(T2/T1) [ENDORSED]
Replies: 2
Views: 391

### Re: ΔS = q/t vs. ΔS = nCln(T2/T1)[ENDORSED]

Is Clausius' inequality, ΔS is greater than or equal to (q/T) always true or only under certain conditions?
Fri Mar 16, 2018 4:34 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: delta s surroundings
Replies: 3
Views: 336

### Re: delta s surroundings

The heat that leaves the system enters the surroundings so q(surr)= - q
Mon Mar 12, 2018 3:31 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacities of Gases
Replies: 3
Views: 367

### Re: Heat Capacities of Gases

How do we know when to use the different R values? When would 3/2R or 5/2R be used?
Mon Mar 12, 2018 3:27 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bonds formed - negative?
Replies: 3
Views: 324

### Re: Bonds formed - negative?

Just for clarification, would the bond enthalpy values in the reactants be positive and the bond enthalpy values for the products be negative?
Mon Mar 12, 2018 3:21 pm
Forum: Phase Changes & Related Calculations
Topic: Correct Answer For Test 1 Question 7
Replies: 4
Views: 424

### Re: Correct Answer For Test 1 Question 7

For the set up for this problem, how did you get 16675.91565 for the first part of the equation?
Mon Mar 12, 2018 3:14 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Heat Required to Heat a Substance
Replies: 5
Views: 326

### Re: Heat Required to Heat a Substance

For test 1 question 3, it states "when a balloon filled with gas is expanded to a larger volume and lower pressure while maintaining the same temperature," how is heat being transferred in this process?
Mon Mar 12, 2018 2:56 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Reaction enthalpy
Replies: 2
Views: 180

### Re: Reaction enthalpy

When calculating the reaction enthalpy using mean bond enthalpy values vs standard enthalpies of formation values, why is there a difference between answers?
Mon Mar 12, 2018 2:49 pm
Forum: Phase Changes & Related Calculations
Topic: The universe
Replies: 9
Views: 503

### Re: The universe

Would a 20mL vial filled with an organic solvent be open or isolated? and why?
Sat Dec 09, 2017 9:59 pm
Forum: Lewis Acids & Bases
Topic: Lewis Acids/Bases vs Bronsted Acids/Bases
Replies: 3
Views: 259

### Re: Lewis Acids/Bases vs Bronsted Acids/Bases

How can you tell between a Lewis acid and Lewis base by looking at the lewis structure?
Sat Dec 09, 2017 5:51 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Endothermic v. Exothermic Reactions
Replies: 9
Views: 1659

### Re: Endothermic v. Exothermic Reactions

How does an endothermic or exothermic reaction affect the direction of the reaction?
Sat Dec 09, 2017 5:48 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE table
Replies: 7
Views: 597

### Re: ICE table

Can somebody explain the 5% rule when approximating x please? Is K being less than 10^-3 enough to be able to approximate or does it also have to follow the 5% rule?
Sat Dec 09, 2017 1:47 am
Forum: Octet Exceptions
Topic: Beryllium exception
Replies: 4
Views: 707

### Re: Beryllium exception

Are Be and Li the only atoms that form duplets or do other atoms form duplets as well?
Sat Dec 09, 2017 12:39 am
Forum: Trends in The Periodic Table
Topic: why carbon has a higher electron affinity than nitrogen.
Replies: 5
Views: 4204

### Re: why carbon has a higher electron affinity than nitrogen.

What is the overall trend for electron affinity? And are there any exceptions to the trend?
Sat Dec 09, 2017 12:36 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 3
Views: 289

### Re: Bond Angles

Will we be required to know the bond angles on certain molecular shapes and how lone pairs affect the angles?
Sat Dec 09, 2017 12:34 am
Forum: Bond Lengths & Energies
Topic: Bond Length and Bond Strength Relationship
Replies: 5
Views: 1173

### Re: Bond Length and Bond Strength Relationship

What is the relationship between bond length and bond strength?
Fri Dec 08, 2017 9:19 pm
Forum: Bond Lengths & Energies
Topic: Double Bond vs Triple Bond
Replies: 7
Views: 782

### Re: Double Bond vs Triple Bond

Are there any restrictions to drawing double bonds or triple bonds between certain atoms in lewis structures?
Fri Dec 08, 2017 8:21 pm
Forum: Ionic & Covalent Bonds
Topic: 3.23
Replies: 3
Views: 311

### Re: 3.23

Which elements are able to exist in both positive and negative oxidation states? Is there a way to determine that or do we just have to memorize which elements this applies to?
Fri Dec 08, 2017 8:17 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Unpaired Electrons [ENDORSED]
Replies: 7
Views: 549

### Re: Unpaired Electrons[ENDORSED]

Will we only be asked to give the number of unpaired electrons for ground state configurations?
Fri Dec 08, 2017 1:07 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: unpaired electrons [ENDORSED]
Replies: 3
Views: 267

### Re: unpaired electrons[ENDORSED]

How can you tell if a an electron configuration represents the ground state or an excited state of an atom?
Fri Dec 08, 2017 1:01 am
Forum: Quantum Numbers and The H-Atom
Topic: Valence electrons [ENDORSED]
Replies: 7
Views: 600

### Re: Valence electrons[ENDORSED]

For question 2.37b, why are electrons in an s-orbital more effective than those in other orbitals at shielding electrons from nuclear charge?
Fri Dec 08, 2017 12:49 am
Forum: Quantum Numbers and The H-Atom
Topic: 2.29 parts b and d
Replies: 4
Views: 434

### Re: 2.29 parts b and d

I am still a little confused, how do you determine how many electrons can have certain quantum numbers?
In 2.29a with the quantum numbers n=2 and l=1, the answer is 6 electrons, but why is that the answer?
Wed Dec 06, 2017 9:05 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polar vs nonpolar vs ionic
Replies: 11
Views: 7798

### Re: Polar vs nonpolar vs ionic

How can we tell if the dipole moments cancel out or not? I am still a little confused about that concept.
Wed Dec 06, 2017 8:49 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Test 4 [ENDORSED]
Replies: 4
Views: 399

### Re: Test 4[ENDORSED]

How can we determine if there is a dipole moment? For example, for NO2 on Test 4 the correct answer was yes there is a dipole moment, but do we determine that by looking at the lewis structure?
Wed Dec 06, 2017 8:44 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: How to tell if bidentate, tri- etc
Replies: 5
Views: 869

### Re: How to tell if bidentate, tri- etc

How is a chelate different than a polydentate?
Wed Dec 06, 2017 8:36 pm
Forum: Naming
Topic: (en) and (EDTA)
Replies: 2
Views: 210

### Re: (en) and (EDTA)

How do we determine the coordination number of the metal ion when the complex has (en) or (edta) or (ox)?
Wed Dec 06, 2017 8:30 pm
Forum: Naming
Topic: Suffixes
Replies: 4
Views: 407

### Re: Suffixes

For prefixes, in what cases would bis- tris- and tetrakis- be used?
Wed Dec 06, 2017 8:23 pm
Forum: Naming
Topic: Naming Coordination Compounds
Replies: 8
Views: 455

### Re: Naming Coordination Compounds

Does anyone know the difference between writing CN as cyanido or cyano? The solution manual uses cyano to denote CN, but in table 17.4 it is listed as cyanido, does it matter which name is used?
Sun Oct 15, 2017 6:23 pm
Forum: Photoelectric Effect
Topic: Balmer vs Lyman [ENDORSED]
Replies: 5
Views: 425

### Re: Balmer vs Lyman[ENDORSED]

Along with the wavelengths within the Balmer and Lyman series, will we need to memorize the wavelengths in the electromagnetic spectrum? Or will they be given to us?
Sun Oct 15, 2017 6:16 pm
Forum: Properties of Light
Topic: Question about speed of light rounding
Replies: 4
Views: 370

### Re: Question about speed of light rounding

Regarding the constant for the speed of light, should we always use 2.99792 x 10^8 or is it okay to round to 3.0 x 10^8? In the lectures 3.0x10^8 is used, but on the constants and equations sheet it says 2.99792 x 10^8
Thu Oct 05, 2017 10:56 pm
Forum: Balancing Chemical Reactions
Topic: incomplete combustion
Replies: 3
Views: 733

### Re: incomplete combustion

Are we expected to know terms such as incomplete combustion and understand how that affects the chemical equation or will the problem state which compounds are involved?
Thu Oct 05, 2017 10:48 pm
Forum: Empirical & Molecular Formulas
Topic: Combustion Analysis
Replies: 5
Views: 409

### Re: Combustion Analysis

Do C, H, and O all have to be present in order for it to be a combustion analysis problem, and will the problem state which elements are involved?