Search found 94 matches

by Tiffany Cao 1D
Sat Mar 17, 2018 11:32 pm
Forum: General Rate Laws
Topic: rate law
Replies: 6
Views: 495

rate law

When there are two of the same products being produced, will the rate law always have a coefficient of 2?
by Tiffany Cao 1D
Sat Mar 17, 2018 12:57 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: reversible system
Replies: 2
Views: 243

reversible system

When a system expands reversibly, does that only mean that change in entropy of the total system and surroundings is 0?
by Tiffany Cao 1D
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: 384

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?
by Tiffany Cao 1D
Sat Mar 17, 2018 12:35 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: pseudo equilibrium constants
Replies: 1
Views: 107

pseudo equilibrium constants

When calculating pseudo equilibrium constants, why do we use delta G (dagger) rather then just the usual delta G?
by Tiffany Cao 1D
Thu Mar 15, 2018 10:50 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Example 8.5
Replies: 3
Views: 220

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?
by Tiffany Cao 1D
Thu Mar 15, 2018 10:48 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: delta U
Replies: 2
Views: 231

delta U

In what cases will delta U be 0?
by Tiffany Cao 1D
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: 226

NO vs BF3

At 0 Kelvin, why does NO have a higher residual entropy then BF3?
by Tiffany Cao 1D
Tue Mar 13, 2018 9:59 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: catalysts
Replies: 5
Views: 228

catalysts

Can catalysts appear in an overall rate law?
by Tiffany Cao 1D
Tue Mar 13, 2018 9:29 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: elementary reaction
Replies: 1
Views: 93

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}?
by Tiffany Cao 1D
Mon Mar 12, 2018 11:46 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 15.89
Replies: 2
Views: 130

15.89

For #89, how do we know which step is the slow step when none of the rates match the experimental rate given?
by Tiffany Cao 1D
Mon Mar 12, 2018 11:09 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: example 15.7
Replies: 1
Views: 106

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...
by Tiffany Cao 1D
Sat Mar 10, 2018 2:15 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.85
Replies: 1
Views: 134

15.85

How do we draw the proposed structure for an activated complex, as asked in problem 15.85?
by Tiffany Cao 1D
Fri Mar 09, 2018 8:40 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.67
Replies: 1
Views: 106

15.67

For this problem, why can we assume that rate constant is directly proportional to rate?
by Tiffany Cao 1D
Fri Mar 09, 2018 8:34 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.67
Replies: 1
Views: 103

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.
by Tiffany Cao 1D
Thu Mar 08, 2018 9:50 pm
Forum: Calculating Work of Expansion
Topic: external pressure
Replies: 2
Views: 123

external pressure

Does expansion against a external pressure imply constant pressure?
by Tiffany Cao 1D
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: 369

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.
by Tiffany Cao 1D
Sun Mar 04, 2018 3:12 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: slow reaction mechanisms
Replies: 4
Views: 175

slow reaction mechanisms

Why are we allowed to assume that fast reaction mechanisms will not have an effect on the overall rate law?
by Tiffany Cao 1D
Sat Mar 03, 2018 10:45 pm
Forum: First Order Reactions
Topic: k
Replies: 16
Views: 625

k

When finding the rate constant, should we convert all time units to seconds?
by Tiffany Cao 1D
Tue Feb 20, 2018 6:01 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams
Replies: 1
Views: 104

Cell Diagrams

Does the order of the cathode and anode matter in our cell diagrams? Especially when there is an H+ present.
by Tiffany Cao 1D
Tue Feb 20, 2018 4:33 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: H+
Replies: 2
Views: 128

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?
by Tiffany Cao 1D
Mon Feb 19, 2018 10:39 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.21
Replies: 1
Views: 67

14.21

For problem 14.21, a solid electrode is not given on the electrode side. How do we go about answering this problem?
by Tiffany Cao 1D
Mon Feb 19, 2018 9:38 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell reactions
Replies: 1
Views: 80

Cell reactions

In problem 13, part d, how do we know which side is the cathode and which side is the anode?
by Tiffany Cao 1D
Sun Feb 18, 2018 5:23 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell reactions
Replies: 1
Views: 77

Cell reactions

Given a cell reaction, like in example 14.13, how do we know which is the cathode and which is the anode?
by Tiffany Cao 1D
Sun Feb 18, 2018 3:43 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell reactions
Replies: 3
Views: 150

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.
by Tiffany Cao 1D
Sun Feb 18, 2018 3:23 pm
Forum: Balancing Redox Reactions
Topic: agents
Replies: 3
Views: 141

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...
by Tiffany Cao 1D
Sun Feb 18, 2018 3:18 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams
Replies: 2
Views: 116

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?
by Tiffany Cao 1D
Sat Feb 17, 2018 11:43 am
Forum: Balancing Redox Reactions
Topic: 14.1
Replies: 3
Views: 134

14.1

When balancing charges in the half reactions, why do we not make the charges on both sides equal each to each other?
by Tiffany Cao 1D
Wed Feb 14, 2018 2:26 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isothermal system
Replies: 5
Views: 423

Isothermal system

Why delta S of the surroundings 0 in an isothermal, free expansion process?
by Tiffany Cao 1D
Wed Feb 14, 2018 10:14 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Work
Replies: 5
Views: 247

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?
by Tiffany Cao 1D
Tue Feb 13, 2018 11:07 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: reversible system
Replies: 9
Views: 432

reversible system

When a process is reversible, is deltaS of the system 0 or is delta S total 0?
by Tiffany Cao 1D
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: 91

molar heat capacity

If using molar heat capacity, do we need to convert temperature to Kelvin?
by Tiffany Cao 1D
Tue Feb 13, 2018 7:30 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible
Replies: 4
Views: 200

Re: Reversible

Is delta U also 0
by Tiffany Cao 1D
Tue Feb 13, 2018 5:33 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: irreversible system
Replies: 1
Views: 120

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?
by Tiffany Cao 1D
Tue Feb 13, 2018 5:24 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible
Replies: 4
Views: 200

Reversible

When a system is reversible, does that mean that only change in total entropy is 0? How about change in internal energy?
by Tiffany Cao 1D
Sat Feb 10, 2018 3:08 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Work
Replies: 6
Views: 462

Work

Does a system do work when a piston expands isothermally in a vacuum?
by Tiffany Cao 1D
Sat Feb 10, 2018 1:59 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: isothermal system [ENDORSED]
Replies: 3
Views: 218

isothermal system [ENDORSED]

How is heat being transferred in an isothermal system?
by Tiffany Cao 1D
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: 116

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.
by Tiffany Cao 1D
Sat Feb 10, 2018 1:48 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: delta u [ENDORSED]
Replies: 3
Views: 218

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.
by Tiffany Cao 1D
Fri Feb 09, 2018 10:52 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibb's Free Energy
Replies: 2
Views: 113

Gibb's Free Energy

In what real life scenarios would Gibb's free energy be negative?
by Tiffany Cao 1D
Sun Feb 04, 2018 2:26 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Heating Capacity
Replies: 3
Views: 135

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?
by Tiffany Cao 1D
Fri Feb 02, 2018 4:39 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Entropy [ENDORSED]
Replies: 5
Views: 305

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?
by Tiffany Cao 1D
Fri Feb 02, 2018 4:37 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible systems
Replies: 7
Views: 304

Reversible systems

If there was a there is a change in volume and pressure, would we use Cv or Cp to calculate entropy?
by Tiffany Cao 1D
Fri Feb 02, 2018 4:32 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy
Replies: 3
Views: 140

Gibbs Free Energy

What exactly does Gibbs Free Energy measure?
by Tiffany Cao 1D
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: 86

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?
by Tiffany Cao 1D
Sun Jan 28, 2018 10:09 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: 9.19
Replies: 4
Views: 230

9.19

For problem 9.19, why do we also cool the system? Aren't we just find entropy change of vaporization?
by Tiffany Cao 1D
Sun Jan 28, 2018 9:07 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Calculating Entropy Change [ENDORSED]
Replies: 2
Views: 95

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...
by Tiffany Cao 1D
Sun Jan 28, 2018 8:53 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 9.13 [ENDORSED]
Replies: 6
Views: 406

9.13 [ENDORSED]

Why do we use Cv instead of Cp when calculating entropy change in relation to temperature change?
by Tiffany Cao 1D
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: 158

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.
by Tiffany Cao 1D
Sun Jan 28, 2018 2:20 pm
Forum: Calculating Work of Expansion
Topic: irreversible system
Replies: 2
Views: 116

irreversible system

How do you find the change in entropy when dealing with an irreversible system?
by Tiffany Cao 1D
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: 88

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...
by Tiffany Cao 1D
Sun Jan 28, 2018 2:17 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: change in entropy
Replies: 2
Views: 107

Re: change in entropy

Im asking for practice example 9.5
by Tiffany Cao 1D
Sun Jan 28, 2018 1:10 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: change in entropy
Replies: 2
Views: 107

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...
by Tiffany Cao 1D
Sun Jan 28, 2018 1:06 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 9.13
Replies: 3
Views: 161

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)?
by Tiffany Cao 1D
Sat Jan 27, 2018 4:30 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: isothermal system
Replies: 4
Views: 185

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?
by Tiffany Cao 1D
Sat Jan 27, 2018 3:59 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: equations
Replies: 1
Views: 116

equations

Which equation do we use for change in volume? Change in temperature? And change in pressure?
by Tiffany Cao 1D
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: 236

Bond Enthalpies

Why is using bond enthalpies the most unreliable form of calculating reaction enthalpy?
by Tiffany Cao 1D
Tue Jan 23, 2018 4:56 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: negative vs. positive
Replies: 1
Views: 81

negative vs. positive

If asked to give the amount of heat RELEASED by a chemical reaction, would the answer be positive or negative?
by Tiffany Cao 1D
Mon Jan 22, 2018 10:40 pm
Forum: Phase Changes & Related Calculations
Topic: Heat capacities
Replies: 5
Views: 199

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?
by Tiffany Cao 1D
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: 129

Reaction Enthalpy

Is standard enthalpy of formation essentially the same as reaction enthalpy, but with molecules in their most standard form?
by Tiffany Cao 1D
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: 100

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.
by Tiffany Cao 1D
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: 102

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.
by Tiffany Cao 1D
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: 64

enthalpy of reaction

Can we assume that enthalpy of reaction(change in enthalpy) is the same as heat transferred(q)?
by Tiffany Cao 1D
Sat Jan 20, 2018 12:50 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: change in internal energy
Replies: 4
Views: 143

change in internal energy

When can change in internal energy be equaled to heat transferred? When can it be equaled to work?
by Tiffany Cao 1D
Fri Jan 19, 2018 10:52 pm
Forum: Phase Changes & Related Calculations
Topic: Change in enthalpy and change in internal energy
Replies: 2
Views: 106

Change in enthalpy and change in internal energy

What is the relation between change in enthalpy and change in internal energy?
by Tiffany Cao 1D
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: 125

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?
by Tiffany Cao 1D
Thu Jan 18, 2018 9:39 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Bond Enthalpies
Replies: 1
Views: 105

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?
by Tiffany Cao 1D
Sat Jan 13, 2018 2:13 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 8.53
Replies: 2
Views: 104

8.53

In example 8.53, why do we use q=C(change in T) rather than q=mC(change in T)?
by Tiffany Cao 1D
Fri Jan 12, 2018 2:07 pm
Forum: Phase Changes & Related Calculations
Topic: Heating Curve
Replies: 6
Views: 245

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?
by Tiffany Cao 1D
Thu Jan 11, 2018 4:52 pm
Forum: Phase Changes & Related Calculations
Topic: Temperature during phase changes [ENDORSED]
Replies: 4
Views: 275

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.
by Tiffany Cao 1D
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: 84

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?
by Tiffany Cao 1D
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: 277

Exothermic Reaction

In an exothermic reaction when temperature doubled, what happens to the K constant and why?
by Tiffany Cao 1D
Fri Dec 08, 2017 5:03 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction Quotient
Replies: 3
Views: 265

Reaction Quotient

How does the reaction quotient differ from the K constant?
by Tiffany Cao 1D
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: 146

partial pressure

How does partial pressure affect equilibrium ?
by Tiffany Cao 1D
Sat Dec 02, 2017 3:10 pm
Forum: Conjugate Acids & Bases
Topic: conjugates
Replies: 2
Views: 218

conjugates

Why do some conjugate acids gain H while others gain OH
by Tiffany Cao 1D
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: 211

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 ???
by Tiffany Cao 1D
Sat Nov 25, 2017 5:33 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: K constant
Replies: 5
Views: 370

K constant

I noticed that K was written out in brackets [X] or in parenthesis with P (Px). What is the differentiation?
by Tiffany Cao 1D
Fri Nov 24, 2017 4:44 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.75 Part a
Replies: 1
Views: 142

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...
by Tiffany Cao 1D
Fri Nov 24, 2017 4:38 pm
Forum: Naming
Topic: Polydentate
Replies: 3
Views: 192

Polydentate

What are polydentates and how are they related to ligands. How does CO3^2- in example 17.33 have polydentate ligands?
by Tiffany Cao 1D
Sun Nov 19, 2017 5:15 pm
Forum: Hybridization
Topic: bond strength
Replies: 3
Views: 172

bond strength

Why are pi bonds weaker than sigma bonds even though they make double bonds stronger?
by Tiffany Cao 1D
Sun Nov 19, 2017 5:14 pm
Forum: Hybridization
Topic: Hybrid orbitals and bonds
Replies: 3
Views: 140

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.
by Tiffany Cao 1D
Sun Nov 12, 2017 9:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape [ENDORSED]
Replies: 2
Views: 172

Molecular Shape [ENDORSED]

How do lone pairs influence the shape of the molecule?
by Tiffany Cao 1D
Sun Nov 12, 2017 9:37 pm
Forum: Octet Exceptions
Topic: Expanded Octet
Replies: 6
Views: 698

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?
by Tiffany Cao 1D
Sat Nov 04, 2017 3:28 pm
Forum: Lewis Structures
Topic: Lewis Structure
Replies: 4
Views: 518

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?
by Tiffany Cao 1D
Sat Nov 04, 2017 3:08 pm
Forum: Resonance Structures
Topic: Bonds
Replies: 4
Views: 241

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?
by Tiffany Cao 1D
Sat Nov 04, 2017 3:04 pm
Forum: Ionic & Covalent Bonds
Topic: covalent and ionic bonds
Replies: 3
Views: 193

covalent and ionic bonds

When can an element have both covalent and ionic bonds? Or is this impossible?
by Tiffany Cao 1D
Sat Oct 28, 2017 4:36 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Valence Electrons [ENDORSED]
Replies: 1
Views: 155

Valence Electrons [ENDORSED]

Do we need to include d-block elements when counting the number of valence electrons?
by Tiffany Cao 1D
Sat Oct 28, 2017 4:34 pm
Forum: *Shrodinger Equation
Topic: Concept [ENDORSED]
Replies: 1
Views: 192

Concept [ENDORSED]

What concept of the Shrodinger Equation is necessary to know for the test?
by Tiffany Cao 1D
Sat Oct 21, 2017 4:06 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 3d and 4s
Replies: 3
Views: 189

3d and 4s

When will the energy for 4s be less than 3d?
by Tiffany Cao 1D
Sat Oct 21, 2017 4:03 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: electron configurations [ENDORSED]
Replies: 2
Views: 179

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?
by Tiffany Cao 1D
Sat Oct 21, 2017 3:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Hund's Rule [ENDORSED]
Replies: 6
Views: 422

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?
by Tiffany Cao 1D
Tue Oct 10, 2017 4:40 pm
Forum: Properties of Light
Topic: photoelectric effect
Replies: 2
Views: 152

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?
by Tiffany Cao 1D
Tue Oct 10, 2017 4:30 pm
Forum: DeBroglie Equation
Topic: Deriving the function [ENDORSED]
Replies: 5
Views: 410

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?
by Tiffany Cao 1D
Wed Oct 04, 2017 12:22 pm
Forum: Empirical & Molecular Formulas
Topic: Identifying Empirical and Molecular Formulas [ENDORSED]
Replies: 13
Views: 1372

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...
by Tiffany Cao 1D
Wed Oct 04, 2017 12:12 pm
Forum: Significant Figures
Topic: Theoretical and Percentage Yield
Replies: 4
Views: 337

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?

Go to advanced search