## Search found 94 matches

Sat Mar 17, 2018 11:32 pm
Forum: General Rate Laws
Topic: rate law
Replies: 6
Views: 628

### rate law

When there are two of the same products being produced, will the rate law always have a coefficient of 2?
Sat Mar 17, 2018 12:57 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: reversible system
Replies: 2
Views: 322

### reversible system

When a system expands reversibly, does that only mean that change in entropy of the total system and surroundings is 0?
Sat Mar 17, 2018 2:34 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Final 2013 #4A
Replies: 2
Views: 448

### Re: Final 2013 #4A

If we use the equation, Ecell=Ecellnaut - (RT/nF)(lnQ), for this problem, how do we solve for what n is?
Sat Mar 17, 2018 12:35 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: pseudo equilibrium constants
Replies: 1
Views: 155

### pseudo equilibrium constants

When calculating pseudo equilibrium constants, why do we use delta G (dagger) rather then just the usual delta G?
Thu Mar 15, 2018 10:50 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Example 8.5
Replies: 3
Views: 292

### Example 8.5

For practice example 8.5 on page 274, why did we assume that delta U was 0 in the second step of part B?
Thu Mar 15, 2018 10:48 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: delta U
Replies: 2
Views: 291

### delta U

In what cases will delta U be 0?
Thu Mar 15, 2018 12:19 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: NO vs BF3
Replies: 1
Views: 297

### NO vs BF3

At 0 Kelvin, why does NO have a higher residual entropy then BF3?
Tue Mar 13, 2018 9:59 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: catalysts
Replies: 5
Views: 335

### catalysts

Can catalysts appear in an overall rate law?
Tue Mar 13, 2018 9:29 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: elementary reaction
Replies: 1
Views: 145

### elementary reaction

Can we assume the rate law for individual elementary reactions? For an example, if a slow elementary reaction is 2I+H2==>2HI, is the rate law=k[I]^2[H2}?
Mon Mar 12, 2018 11:46 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 15.89
Replies: 2
Views: 204

### 15.89

For #89, how do we know which step is the slow step when none of the rates match the experimental rate given?
Mon Mar 12, 2018 11:09 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: example 15.7
Replies: 1
Views: 140

### example 15.7

In practice example 15.7, on page 636, I used the pre equilibrium concept and got a similar answer to the book, which used the steady state concept. However, I don't really understand how the 2 appeared in the overall rate of decomposition of O3. In the previous example in the book, they used the un...
Sat Mar 10, 2018 2:15 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.85
Replies: 1
Views: 187

### 15.85

How do we draw the proposed structure for an activated complex, as asked in problem 15.85?
Fri Mar 09, 2018 8:40 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.67
Replies: 1
Views: 147

### 15.67

For this problem, why can we assume that rate constant is directly proportional to rate?
Fri Mar 09, 2018 8:34 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.67
Replies: 1
Views: 150

### 15.67

For problem 15.67, is it correct to just plug in the actual rates into the equation rather than using the the relationship between Ea,cat and Ea,uncat. I just used Ae^(-75/RT)/ Ae^(-125/RT) and got the same answer.
Thu Mar 08, 2018 9:50 pm
Forum: Calculating Work of Expansion
Topic: external pressure
Replies: 2
Views: 193

### external pressure

Does expansion against a external pressure imply constant pressure?
Sun Mar 04, 2018 10:16 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: rates of reaction vs rates of consumption and formation (15.3)
Replies: 3
Views: 500

### Re: rates of reaction vs rates of consumption and formation (15.3)

The rate of a reaction can never be negative. Basically, since its a rate of consumption, the overall is negative to make the final minus initial part positive.
Sun Mar 04, 2018 3:12 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: slow reaction mechanisms
Replies: 4
Views: 267

### slow reaction mechanisms

Why are we allowed to assume that fast reaction mechanisms will not have an effect on the overall rate law?
Sat Mar 03, 2018 10:45 pm
Forum: First Order Reactions
Topic: k
Replies: 16
Views: 794

### k

When finding the rate constant, should we convert all time units to seconds?
Tue Feb 20, 2018 6:01 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams
Replies: 1
Views: 146

### Cell Diagrams

Does the order of the cathode and anode matter in our cell diagrams? Especially when there is an H+ present.
Tue Feb 20, 2018 4:33 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: H+
Replies: 2
Views: 216

### H+

When do we include H+ when writing cell diagrams? In 14.23, part a,in what order should we write the reactants in the cathode side?
Mon Feb 19, 2018 10:39 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.21
Replies: 1
Views: 103

### 14.21

For problem 14.21, a solid electrode is not given on the electrode side. How do we go about answering this problem?
Mon Feb 19, 2018 9:38 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell reactions
Replies: 1
Views: 122

### Cell reactions

In problem 13, part d, how do we know which side is the cathode and which side is the anode?
Sun Feb 18, 2018 5:23 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell reactions
Replies: 1
Views: 114

### Cell reactions

Given a cell reaction, like in example 14.13, how do we know which is the cathode and which is the anode?
Sun Feb 18, 2018 3:43 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell reactions
Replies: 3
Views: 1469

### Cell reactions

When there is no salt bridge, how do we know which element gets reduced and oxidized. In practice example 14.4 on page 576(not the actual homework problems), I don't understand how they assumed the reduction or oxidation of the half reactions.
Sun Feb 18, 2018 3:23 pm
Forum: Balancing Redox Reactions
Topic: agents
Replies: 3
Views: 229

### agents

What does it mean to say that something is an oxidizing or reducing agent. I noticed that in the first couple questions, that when electrons were added in half reactions, the solution would call that an oxidizing agents. But in later sessions, when electrons were lost, it was through an oxidation pr...
Sun Feb 18, 2018 3:18 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams
Replies: 2
Views: 193

### Cell Diagrams

I don't really understand how tot do cell diagrams. How do we know which element gets reduced and how do we organize the diagram?
Sat Feb 17, 2018 11:43 am
Forum: Balancing Redox Reactions
Topic: 14.1
Replies: 3
Views: 214

### 14.1

When balancing charges in the half reactions, why do we not make the charges on both sides equal each to each other?
Wed Feb 14, 2018 2:26 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isothermal system
Replies: 5
Views: 600

### Isothermal system

Why delta S of the surroundings 0 in an isothermal, free expansion process?
Wed Feb 14, 2018 10:14 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Work
Replies: 5
Views: 354

### Work

Am I right by saying that if volume does not change,if a gas expands in a vacuum, and if a gas undergoes free expansion, work is 0?
Tue Feb 13, 2018 11:07 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: reversible system
Replies: 9
Views: 580

### reversible system

When a process is reversible, is deltaS of the system 0 or is delta S total 0?
Tue Feb 13, 2018 9:10 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: molar heat capacity
Replies: 1
Views: 138

### molar heat capacity

If using molar heat capacity, do we need to convert temperature to Kelvin?
Tue Feb 13, 2018 7:30 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible
Replies: 4
Views: 317

### Re: Reversible

Is delta U also 0
Tue Feb 13, 2018 5:33 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: irreversible system
Replies: 1
Views: 160

### irreversible system

In an isothermal, free expansion system, work is 0. However, this is only true for the surroundings, as can be seen in practice example 9.12 on page 346. Why is work not 0 for the system too?
Tue Feb 13, 2018 5:24 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible
Replies: 4
Views: 317

### Reversible

When a system is reversible, does that mean that only change in total entropy is 0? How about change in internal energy?
Sat Feb 10, 2018 3:08 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Work
Replies: 6
Views: 580

### Work

Does a system do work when a piston expands isothermally in a vacuum?
Sat Feb 10, 2018 1:59 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: isothermal system [ENDORSED]
Replies: 3
Views: 321

### isothermal system[ENDORSED]

How is heat being transferred in an isothermal system?
Sat Feb 10, 2018 1:50 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Homework problem 9.25: orientations of a molecule
Replies: 2
Views: 174

### Re: Homework problem 9.25: orientations of a molecule

Well in order to use the formula, s=klnw, you need to know the number of orientations of a compound. To solve for degeneracy, I use # of orientations^# of molecules.
Sat Feb 10, 2018 1:48 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: delta u [ENDORSED]
Replies: 3
Views: 308

### Re: delta u[ENDORSED]

Delta U is the change in internal energy. It is calculated through the formula, DeltaU=q+w. In an isolated system, deltaU=0 and consequently, w=-q.
Fri Feb 09, 2018 10:52 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibb's Free Energy
Replies: 2
Views: 172

### Gibb's Free Energy

In what real life scenarios would Gibb's free energy be negative?
Sun Feb 04, 2018 2:26 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Heating Capacity
Replies: 3
Views: 202

### Heating Capacity

In which cases would we use 3/2*R=Cv and 5/2*R=Cp? I noticed in 9.43, the solution used the actual heating capacity of water(75.29J/Kmol), but when would we ever use the other heating capacity rules?
Fri Feb 02, 2018 4:39 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Entropy [ENDORSED]
Replies: 5
Views: 1593

### Entropy[ENDORSED]

When a system is heated, experiences an increase an volume, or a decrease in pressure, entropy increases. In what other scenarios will entropy increase?
Fri Feb 02, 2018 4:37 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible systems
Replies: 7
Views: 445

### Reversible systems

If there was a there is a change in volume and pressure, would we use Cv or Cp to calculate entropy?
Fri Feb 02, 2018 4:32 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy
Replies: 3
Views: 194

### Gibbs Free Energy

What exactly does Gibbs Free Energy measure?
Mon Jan 29, 2018 1:13 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Practice Example 9.6
Replies: 1
Views: 107

### Practice Example 9.6

On page 329, why do we use 127J/Kmol as the heating capacity for heating up liquid acetone but 133.26 J/Kmol (4R) when cooling down vapor acetone?
Sun Jan 28, 2018 10:09 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: 9.19
Replies: 4
Views: 369

### 9.19

For problem 9.19, why do we also cool the system? Aren't we just find entropy change of vaporization?
Sun Jan 28, 2018 9:07 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Calculating Entropy Change [ENDORSED]
Replies: 2
Views: 116

### Re: Calculating Entropy Change[ENDORSED]

The second law of thermodynamics states that entropy will increase when spontaneous actions occurs, such as gas expanding in a vacuum. Basically in the equation, nrln(V2/V1) and cln(T2/T1), if V2 and T2 are bigger than V1 and T1, entropy will increase. If V1 and T1 are bigger than V2 and T2,, entrop...
Sun Jan 28, 2018 8:53 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 9.13 [ENDORSED]
Replies: 6
Views: 531

### 9.13[ENDORSED]

Why do we use Cv instead of Cp when calculating entropy change in relation to temperature change?
Sun Jan 28, 2018 3:03 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy calculated from Bonds vs Enthalpy of formation
Replies: 3
Views: 248

### Re: Enthalpy calculated from Bonds vs Enthalpy of formation

Calculating enthalpies using bond enthalpy is the least accurate method since this method uses the average bond enthalpies. Because of this, bond enthalpies are not specific to certain molecules.
Sun Jan 28, 2018 2:20 pm
Forum: Calculating Work of Expansion
Topic: irreversible system
Replies: 2
Views: 137

### irreversible system

How do you find the change in entropy when dealing with an irreversible system?
Sun Jan 28, 2018 2:17 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Practice Example 9.5
Replies: 1
Views: 120

### Practice Example 9.5

When calculating total entropy change of a process, like in Practice Example 9.5 on page 325, we use the change in entropy equations of both volume and temperature changes. For the second portion, why do we use the change in entropy equation when temperature changes with heat capacity that relates t...
Sun Jan 28, 2018 2:17 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: change in entropy
Replies: 2
Views: 149

### Re: change in entropy

Im asking for practice example 9.5
Sun Jan 28, 2018 1:10 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: change in entropy
Replies: 2
Views: 149

### change in entropy

When calculating total entropy change of a process, like in example 9.5 on page 325, we use the change in entropy equations of both volume and temperature changes. For the second portion, why do we use the change in entropy equation when temperature changes with heat capacity that relates to when vo...
Sun Jan 28, 2018 1:06 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 9.13
Replies: 3
Views: 211

### 9.13

For problem 9.13, why do we use the change in entropy=nRln(T2/T1) instead of the change in entropy=nCv(T2/T1)?
Sat Jan 27, 2018 4:30 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: isothermal system
Replies: 4
Views: 235

### isothermal system

When a system is isothermal, does that mean that temperature is constant? Why does this also mean that change in internal energy is also 0?
Sat Jan 27, 2018 3:59 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: equations
Replies: 1
Views: 138

### equations

Which equation do we use for change in volume? Change in temperature? And change in pressure?
Tue Jan 23, 2018 8:25 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 5
Views: 352

### Bond Enthalpies

Why is using bond enthalpies the most unreliable form of calculating reaction enthalpy?
Tue Jan 23, 2018 4:56 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: negative vs. positive
Replies: 1
Views: 129

### negative vs. positive

If asked to give the amount of heat RELEASED by a chemical reaction, would the answer be positive or negative?
Mon Jan 22, 2018 10:40 pm
Forum: Phase Changes & Related Calculations
Topic: Heat capacities
Replies: 5
Views: 320

### Heat capacities

What if you were given the specific heating capacity which is measured in J/g*C, but asked to find final temperature in K. Are Celsius and Kelvin used interchangeably in this case?
Mon Jan 22, 2018 9:35 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Reaction Enthalpy
Replies: 2
Views: 207

### Reaction Enthalpy

Is standard enthalpy of formation essentially the same as reaction enthalpy, but with molecules in their most standard form?
Mon Jan 22, 2018 9:28 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 2
Views: 119

### Bond Enthalpies

Given the equation for a thermodynamic reaction and bond enthalpies for each bond, can we find the standard enthalpy of formation or just the reaction enthalpy. For an example, 8.67 asks for enthalpy of formation and 8.73 asks for reaction enthalpy, but they both used bond enthalpies in the same way.
Mon Jan 22, 2018 5:21 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: kj/mol vs kj
Replies: 2
Views: 139

### Re: kj/mol vs kj

Since enthalpy is essentially heat (which is measured in kJ), it doesn't really matter if you use kJ/mol or kJ for enthalpy.
Sun Jan 21, 2018 2:37 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: enthalpy of reaction
Replies: 1
Views: 90

### enthalpy of reaction

Can we assume that enthalpy of reaction(change in enthalpy) is the same as heat transferred(q)?
Sat Jan 20, 2018 12:50 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: change in internal energy
Replies: 4
Views: 193

### change in internal energy

When can change in internal energy be equaled to heat transferred? When can it be equaled to work?
Fri Jan 19, 2018 10:52 pm
Forum: Phase Changes & Related Calculations
Topic: Change in enthalpy and change in internal energy
Replies: 2
Views: 129

### Change in enthalpy and change in internal energy

What is the relation between change in enthalpy and change in internal energy?
Fri Jan 19, 2018 10:27 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpies [ENDORSED]
Replies: 3
Views: 149

### Enthalpies[ENDORSED]

When finding enthalpies of reactions, what are the indicators that will show you when to use Hess's Law, Bond Enthalpies, or Standard Enthalpies of Formation?
Thu Jan 18, 2018 9:39 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Bond Enthalpies
Replies: 1
Views: 194

### Bond Enthalpies

In example 8.13 on page 301, why is the enthalpy of vaporization of Br2 positive while enthalpy of vaporization of CH3ChBrCH2Br is negative?
Sat Jan 13, 2018 2:13 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 8.53
Replies: 2
Views: 128

### 8.53

In example 8.53, why do we use q=C(change in T) rather than q=mC(change in T)?
Fri Jan 12, 2018 2:07 pm
Forum: Phase Changes & Related Calculations
Topic: Heating Curve
Replies: 6
Views: 342

### Heating Curve

In a heating curve, the enthalpies of fusion and vaporization are depicted as straight, horizontal lines. However, which element or characteristic of the heating curve gives information about heat capacities?
Thu Jan 11, 2018 4:52 pm
Forum: Phase Changes & Related Calculations
Topic: Temperature during phase changes [ENDORSED]
Replies: 4
Views: 389

### Re: Temperature during phase changes[ENDORSED]

Temperature stays the same during phase changes, such as melting and vaporization, because all energy added is being used to break up the bonds rather increasing temperature.
Thu Jan 11, 2018 11:40 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy of vaporization
Replies: 1
Views: 99

### Enthalpy of vaporization

How do you find enthalpy of vaporization if a question does not give you the enthalpies of either vapor or liquid. In self test 8.9A on page 284, is the heat added to the system equal to the enthalpy of vaporization?
Sat Dec 09, 2017 11:42 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic Reaction
Replies: 3
Views: 354

### Exothermic Reaction

In an exothermic reaction when temperature doubled, what happens to the K constant and why?
Fri Dec 08, 2017 5:03 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction Quotient
Replies: 3
Views: 347

### Reaction Quotient

How does the reaction quotient differ from the K constant?
Fri Dec 08, 2017 4:59 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: partial pressure
Replies: 1
Views: 173

### partial pressure

How does partial pressure affect equilibrium ?
Sat Dec 02, 2017 3:10 pm
Forum: Conjugate Acids & Bases
Topic: conjugates
Replies: 2
Views: 305

### conjugates

Why do some conjugate acids gain H while others gain OH
Mon Nov 27, 2017 10:00 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: change in temperature
Replies: 4
Views: 252

### change in temperature

In an endothermic reaction, heat is required to break bonds, so endothermic reactions favor a reverse reactions. Do endothermic reactions, then, also favor the formation of reactants? In class, it was said that endothermic reactions favor product formation ???
Sat Nov 25, 2017 5:33 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: K constant
Replies: 5
Views: 560

### K constant

I noticed that K was written out in brackets [X] or in parenthesis with P (Px). What is the differentiation?
Fri Nov 24, 2017 4:44 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.75 Part a
Replies: 1
Views: 191

### Re: 4.75 Part a

In this case oxygen has a tetrahedral molecular shape, but a bent VESPR geometry. The two lone pairs aren't directly 180 degrees from each other, but 109.5, so they don't really cancel the effects of each other out. Because of this, they push the remaining bonds closer together, and thus they become...
Fri Nov 24, 2017 4:38 pm
Forum: Naming
Topic: Polydentate
Replies: 3
Views: 245

### Polydentate

What are polydentates and how are they related to ligands. How does CO3^2- in example 17.33 have polydentate ligands?
Sun Nov 19, 2017 5:15 pm
Forum: Hybridization
Topic: bond strength
Replies: 3
Views: 253

### bond strength

Why are pi bonds weaker than sigma bonds even though they make double bonds stronger?
Sun Nov 19, 2017 5:14 pm
Forum: Hybridization
Topic: Hybrid orbitals and bonds
Replies: 3
Views: 179

### Re: Hybrid orbitals and bonds

In hybridized orbitals s and p orbitals combine, or hybridize. When an element makes a single bond, that becomes a sigma bond. Every second or third bond is a pi bond.
Sun Nov 12, 2017 9:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape [ENDORSED]
Replies: 2
Views: 194

### Molecular Shape[ENDORSED]

How do lone pairs influence the shape of the molecule?
Sun Nov 12, 2017 9:37 pm
Forum: Octet Exceptions
Topic: Expanded Octet
Replies: 6
Views: 1103

### Expanded Octet

What elements can hold less or more than an octet? Do all of their orbitals need to be filled as well when drawing Lewis dot diagrams?
Sat Nov 04, 2017 3:28 pm
Forum: Lewis Structures
Topic: Lewis Structure
Replies: 4
Views: 1210

### Lewis Structure

For compounds such as ClONO2, how will we be able to determine which element is in the middle and the overall organization of the Lewis structure?
Sat Nov 04, 2017 3:08 pm
Forum: Resonance Structures
Topic: Bonds
Replies: 4
Views: 342

### Bonds

How do we know when to create a double or triple bond? Would it be okay to just leave a Lewis structure consisting of single bonded elements if all elements had an octet?
Sat Nov 04, 2017 3:04 pm
Forum: Ionic & Covalent Bonds
Topic: covalent and ionic bonds
Replies: 3
Views: 282

### covalent and ionic bonds

When can an element have both covalent and ionic bonds? Or is this impossible?
Sat Oct 28, 2017 4:36 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Valence Electrons [ENDORSED]
Replies: 1
Views: 171

### Valence Electrons[ENDORSED]

Do we need to include d-block elements when counting the number of valence electrons?
Sat Oct 28, 2017 4:34 pm
Forum: *Shrodinger Equation
Topic: Concept [ENDORSED]
Replies: 1
Views: 211

### Concept[ENDORSED]

What concept of the Shrodinger Equation is necessary to know for the test?
Sat Oct 21, 2017 4:06 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 3d and 4s
Replies: 3
Views: 228

### 3d and 4s

When will the energy for 4s be less than 3d?
Sat Oct 21, 2017 4:03 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: electron configurations [ENDORSED]
Replies: 2
Views: 206

### electron configurations[ENDORSED]

When writing out electron configurations, why can't you just write out 2p^2, instead of 2px^1 2py^1. Are they both the same configurations?
Sat Oct 21, 2017 3:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Hund's Rule [ENDORSED]
Replies: 6
Views: 599

### Hund's Rule[ENDORSED]

What is Hund's rule and how is it relevant to electron orbitals? What would happen if the orbitals had opposite spin?
Tue Oct 10, 2017 4:40 pm
Forum: Properties of Light
Topic: photoelectric effect
Replies: 2
Views: 172

### photoelectric effect

In the function, Ek=hv-(work function), how would we solve for the work function? In addition, if the work function exceeds the kinetic energy, does this mean the photon is not able to be emitted from the piece of metal?
Tue Oct 10, 2017 4:30 pm
Forum: DeBroglie Equation
Topic: Deriving the function [ENDORSED]
Replies: 5
Views: 538

### Deriving the function[ENDORSED]

I am uncertain how to derive the DeBroglie Equation from the E=mc^2 equaiton. Is it necessary to know how to derive this function?
Wed Oct 04, 2017 12:22 pm
Forum: Empirical & Molecular Formulas
Topic: Identifying Empirical and Molecular Formulas [ENDORSED]
Replies: 13
Views: 5432

### Re: Identifying Empirical and Molecular Formulas[ENDORSED]

An empirical formula is just the ratio of the atoms in a reaction, whereas an molecular formula shows the actual number of atoms in a reaction. In order to calculate a molecular formula, you first must calculate the empirical formula by dividing the given mass by the molar mass to find the amount of...
Wed Oct 04, 2017 12:12 pm
Forum: Significant Figures
Topic: Theoretical and Percentage Yield
Replies: 4
Views: 451

### Theoretical and Percentage Yield

What is the difference between theoretical and percentage yield, if there is a difference? Also, what causes the theoretical yield to be less than the actual yield?