## Search found 53 matches

Sat Mar 17, 2018 9:15 pm
Forum: Calculating Work of Expansion
Topic: Spontaneity and Work
Replies: 1
Views: 252

### Spontaneity and Work

Can a nonspontaneous reaction do work?
Sat Mar 17, 2018 8:51 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.61
Replies: 1
Views: 239

### 15.61

When solving for this problem why is the answer book says to utilize the form ln(k'/k), but why is k' on the numerator when it is normally depicted as being place on the denominator, such as K=k/k' ?
Thu Mar 15, 2018 7:42 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Equations for different types of reactions
Replies: 1
Views: 244

### Equations for different types of reactions

What the equations and rules for delta s, w, and q are associated with reversible processes? And what are the ones associated with irreversible processes?
Thu Mar 15, 2018 3:47 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: determining sign for delta s
Replies: 1
Views: 976

### determining sign for delta s

When the number of moles of gas are the same for both the reactants and products side of a chemical equation and each species has the same amount of molecules, how can you determine whether or not the delta S of the reaction will be positive or negative?
Thu Mar 15, 2018 2:39 pm
Forum: Calculating Work of Expansion
Topic: Irreversible and Reversible Expansion
Replies: 1
Views: 135

### Irreversible and Reversible Expansion

What are the properties of irreversible expansion? reversible expansion?
Fri Mar 09, 2018 1:03 pm
Forum: Second Order Reactions
Topic: Units [ENDORSED]
Replies: 5
Views: 469

### Units[ENDORSED]

What are the units for zero, first, and second-order reactions?
Thu Mar 08, 2018 6:06 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: activation energy [ENDORSED]
Replies: 3
Views: 379

### activation energy[ENDORSED]

Does activation energy play a role in determining whether or not a reaction is controlled through kinetics or thermodynamics? If so, how?
Thu Mar 08, 2018 5:16 pm
Forum: Experimental Details
Topic: 15.19c
Replies: 2
Views: 563

### 15.19c

For this portion of the problem, I solved for the rate constant by plugging in the values into the rate law and converting from mmol to mol at the very end, however doing so gave me a completely different answer. So I tried converting all the values from mmol to mol before plugging them into the rat...
Mon Mar 05, 2018 11:48 pm
Forum: Experimental Details
Topic: 15.17a
Replies: 1
Views: 480

### 15.17a

How do you know that a reactant's concentration is independent of the rate (such as [C])? Is it because the initial rate is the same in both experiments 1 and 4?
Mon Mar 05, 2018 11:26 pm
Forum: First Order Reactions
Topic: When to use rate equations
Replies: 3
Views: 224

### When to use rate equations

How can you determine whether or not you need to use a regular rate law equation versus an integrated rate law equation when given certain values?
Mon Mar 05, 2018 10:55 pm
Forum: General Rate Laws
Topic: 15.3
Replies: 3
Views: 234

### 15.3

In this problem in the textbook part c asks for the "unique rate of the reaction"? Is that just another way of asking what the overall rate of the reaction would be (aka the slowest rate)?
Thu Feb 22, 2018 9:53 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Homework 14.13 part c
Replies: 1
Views: 135

### Homework 14.13 part c

For this problem, given the reaction Cl2(g) + H2(g) --> HCL(aq), how do you know which species will be in the cathode and which will be in the anode seeing as neither of Cl's and H's oxidation numbers change?
Thu Feb 22, 2018 9:28 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Homework 14.11 part d
Replies: 1
Views: 163

### Homework 14.11 part d

For this problem how do you know which species will go on the reactants side when writing the half-reaction for the cathode and anode? Because in the answer book it shows that O2 appears on the reactant side for both, but how can you decipher where it goes?
Thu Feb 22, 2018 6:14 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Homework 14.9
Replies: 1
Views: 155

### Homework 14.9

When solving for this problem how do you find n? Are you supposed to calculate it based on individual oxidation numbers or from the overall charges on either sides of the equations?
Sun Feb 18, 2018 9:27 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Standard Cell Potentials
Replies: 5
Views: 218

### Re: Standard Cell Potentials

No, multiplying a half-reaction by a factor does not affect the Standard Cell Potential value
Sun Feb 18, 2018 9:19 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram [ENDORSED]
Replies: 5
Views: 313

### Re: Cell Diagram[ENDORSED]

Visually, at the cathode, since the metal ions are being reduced, there will be an increase in the solid metal, that's how you know that the solid metal at the cathode is a product, and the metal ions are the reactants. In the anode, the opposite process occurs making the metal ions at the anode the...
Sun Feb 18, 2018 9:09 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Anodes vs. Cathodes
Replies: 3
Views: 197

### Re: Anodes vs. Cathodes

The reaction that is being reduced usually has the higher, more positive voltage, while the reaction that is being oxidized has the lower, more negative voltage
Sun Feb 11, 2018 3:20 pm
Forum: Balancing Redox Reactions
Topic: Nature
Replies: 5
Views: 284

### Nature

In nature, are things more commonly reduced or oxidized? or is it an equal occurrence?
Sun Feb 11, 2018 3:17 pm
Forum: Balancing Redox Reactions
Topic: Reduction and Oxidation
Replies: 4
Views: 203

### Reduction and Oxidation

When an oxidation of an element increases is it oxidized or reduced?
Sun Feb 11, 2018 3:13 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Potential
Replies: 2
Views: 132

### Cell Potential

What does the large/small cell potential tell us?
Thu Feb 01, 2018 6:19 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Reversible vs. Irreversible reactions
Replies: 2
Views: 181

### Reversible vs. Irreversible reactions

How does temperature, pressure, and volume differ with reversible and irreversible reactions/pathways?
Thu Feb 01, 2018 6:16 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Negative delta s value
Replies: 4
Views: 4110

### Negative delta s value

Why does a negative delta s value correspond to a spontaneous process?
Thu Feb 01, 2018 6:13 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Spontaneous
Replies: 14
Views: 816

### Spontaneous

I'm having a hard time trying to conceptually understand when reactions are considered spontaneous, can anyone clarify?
Wed Jan 24, 2018 12:16 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Degeneracy
Replies: 4
Views: 276

### Degeneracy

I'm having trouble with conceptually understanding what degeneracy is
Wed Jan 24, 2018 12:12 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Closed vs. Isolated
Replies: 8
Views: 573

### Closed vs. Isolated

What is the difference between a closed system and an isolated system?
Wed Jan 24, 2018 12:11 am
Forum: Calculating Work of Expansion
Topic: Calculating work with integral
Replies: 1
Views: 98

### Calculating work with integral

In preparation of the test, do we need to solve an integral in order to calculate the work of a system?
Wed Jan 24, 2018 12:07 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Energy of systems
Replies: 4
Views: 274

### Energy of systems

How can you change the energy of a system?
Wed Jan 24, 2018 12:06 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy changes
Replies: 1
Views: 92

### Enthalpy changes

What is the most accurate method of calculating enthalpy change of a reaction?
Wed Jan 24, 2018 12:03 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Heat vs. Temp
Replies: 9
Views: 457

### Heat vs. Temp

What is the difference between heat and temperature?
Sat Jan 13, 2018 8:21 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Delta values
Replies: 3
Views: 152

### Delta values

What is the conceptual difference between delta h and delta u?
Sat Jan 13, 2018 8:20 pm
Forum: Phase Changes & Related Calculations
Topic: Constant temp
Replies: 3
Views: 206

### Constant temp

Why does temperature stay constant during a phase change?
Sat Jan 13, 2018 8:16 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Differences between properties
Replies: 1
Views: 83

### Differences between properties

What is the main difference between intensive properties and extensive properties?
Sat Dec 09, 2017 2:05 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Ka and pKa
Replies: 1
Views: 255

### Ka and pKa

What do the Ka and the pKa values tell us? Is there a conceptual difference or is it purely just mathematical differences?
Thu Dec 07, 2017 3:57 am
Forum: Bronsted Acids & Bases
Topic: Neutralization reactions
Replies: 2
Views: 245

### Neutralization reactions

What constitutes a neutralization reaction? Is there any specific characteristics that classify a reaction as a neutralization reaction?
Sat Dec 02, 2017 9:02 pm
Forum: Amphoteric Compounds
Topic: Amphiprotic compounds
Replies: 3
Views: 1894

### Amphiprotic compounds

What are the general properties of amphiprotic compounds?
Sat Dec 02, 2017 9:01 pm
Forum: Amphoteric Compounds
Topic: amphoteric properties
Replies: 3
Views: 244

### amphoteric properties

What are the general properties of amphoteric compounds?
Fri Nov 24, 2017 1:44 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Value of K
Replies: 1
Views: 118

### Value of K

Does a small value for K favor reactants? or products? Why?
Fri Nov 24, 2017 1:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Knowing VSEPR Shapes
Replies: 3
Views: 349

### Knowing VSEPR Shapes

Does anyone know up to which VSEPR shapes would we need to know by memory? And does anyone have a good method to help remember those shapes?
Fri Nov 17, 2017 1:25 am
Forum: Hybridization
Topic: Triple bond sigma vs. pi
Replies: 3
Views: 222

### Triple bond sigma vs. pi

Why does a triple bond contain only one sigma bond, yet two pi bonds?
Fri Nov 17, 2017 1:21 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Electron Density
Replies: 3
Views: 261

### Electron Density

In terms of labeling based on electron density, why do we call a molecule with 6 e- densities an octahedral?
Sat Nov 11, 2017 12:30 am
Forum: Ionic & Covalent Bonds
Topic: Differences in polarity [ENDORSED]
Replies: 1
Views: 208

### Differences in polarity[ENDORSED]

Can a molecule's overall polarity be different from the polarity of its bonds? If so, how can you tell if they are different?
Mon Nov 06, 2017 2:54 pm
Forum: Resonance Structures
Topic: Determining Resonance Structures
Replies: 3
Views: 412

### Determining Resonance Structures

When solving for resonance structures, is there any way of knowing how many resonance structures a molecule has? Or are we supposed to find as many as possible?
Sat Nov 04, 2017 5:50 pm
Forum: Ionic & Covalent Bonds
Topic: covalent and ionic bonds
Replies: 3
Views: 282

### Re: covalent and ionic bonds

The types of bonds that elements have is dependent on the other element it is bonding with. For instance, two nonmetals have a covalent bond while a non mental bonded with a metal has an ionic bond.
Wed Nov 01, 2017 3:45 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Exceptions to the Configuration Rules
Replies: 3
Views: 262

### Exceptions to the Configuration Rules

Can someone clarify why there are certain exceptions to the rules of electron configuration when dealing with elements such as Copper and Chromium?
Wed Nov 01, 2017 3:40 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Spin of electron [ENDORSED]
Replies: 2
Views: 205

### Re: Spin of electron[ENDORSED]

The spin of the electron typically doesn't matter unless you are given a problem with the ms value. And depending on whether or not the ms value is +1/2 or -1/2 will determine the spin of the electron. For instance, if ms=+1/2 then it spins upwards (counterclockwise) and if ms=-1/2 it spins downward...
Sun Oct 29, 2017 4:36 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Determining Formal Charge [ENDORSED]
Replies: 3
Views: 308

### Determining Formal Charge[ENDORSED]

When determining the best structure of a molecule why does the formal charge have to be 0?
Sun Oct 29, 2017 4:31 pm
Forum: Trends in The Periodic Table
Topic: Ionization Energy [ENDORSED]
Replies: 5
Views: 399

### Ionization Energy[ENDORSED]

Why does the trend of ionization energy decrease going down a group and increase going across a period?
Wed Oct 18, 2017 11:36 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Schrodinger's Wave Function Equation [ENDORSED]
Replies: 1
Views: 114

### Schrodinger's Wave Function Equation[ENDORSED]

I'm just confused as to what this equation exactly tells us? What does it mean when it says it finds the height of a wave at position x, y, z?
Wed Oct 18, 2017 12:17 am
Forum: Photoelectric Effect
Topic: Energy of Photon [ENDORSED]
Replies: 9
Views: 1954

### Energy of Photon[ENDORSED]

I know that the energy of a photon has to be greater than the energy to remove an electron in order for light to be absorbed, but what happens when the energies are equal to each other? Is there a difference in outcome or in the values of the velocity of the electron?
Fri Oct 13, 2017 11:28 am
Forum: Quantum Numbers and The H-Atom
Topic: Quantized Energy
Replies: 5
Views: 605

### Quantized Energy

Can someone clarify what it means conceptually when energy is quantized?
Mon Oct 09, 2017 10:28 pm
Forum: Properties of Light
Topic: Converting to Different Units
Replies: 3
Views: 330

### Converting to Different Units

When problems, such as Question 1.7 (b), ask for an answer in specific units (in this case wavelength in picometers) will we have to memorize the various numbers needed to convert to different types of units, such as micro-, nano-, giga-, mega-, etc., or will that information be provided for us in t...
Thu Oct 05, 2017 10:09 pm
Forum: Significant Figures
Topic: Clarification
Replies: 4
Views: 354

### Re: Clarification

I remember in my TA Discussion that when working on a math problem you want to keep the numbers as long as possible until you reach the final answer value, and it's that final value where you apply the rules of significant figures so that the answer is the most accurate.
Thu Oct 05, 2017 10:02 pm
Forum: Balancing Chemical Reactions
Topic: Writing chemical formulas [ENDORSED]
Replies: 5
Views: 579

### Writing chemical formulas[ENDORSED]

For questions when we are given the name of a compound, how can we write a chemical formula for it without the molecular formula of the compound being given?