## Search found 64 matches

Mon Mar 11, 2019 2:03 pm
Forum: First Order Reactions
Topic: First order rxn graphs [ENDORSED]
Replies: 4
Views: 195

### First order rxn graphs[ENDORSED]

How do the graphs differ among first, second, and zero order reactions?
Mon Mar 11, 2019 2:02 pm
Forum: Second Order Reactions
Topic: Units
Replies: 4
Views: 200

### Units

What units are used for second order reactions?
Mon Mar 11, 2019 2:01 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Meaning of k
Replies: 4
Views: 265

### Meaning of k

What is the difference between capital K and lowercase k in the kinetics equations?
Tue Mar 05, 2019 10:47 pm
Forum: First Order Reactions
Topic: Deriving these equations
Replies: 2
Views: 157

### Deriving these equations

Do we have to know how to derive the equations for first order reactions? Or just understand the concept/how to do calculations.
Tue Mar 05, 2019 10:43 pm
Forum: General Rate Laws
Topic: unique rate of reaction
Replies: 2
Views: 139

### Re: unique rate of reaction

The unique rate of a reaction is the rate of appearance/disappearance of any of the species in a reaction divided by their stoichiometric coefficient. Coefficients are not taken into account for an average rate.
Tue Mar 05, 2019 10:38 pm
Forum: General Rate Laws
Topic: Rate Laws
Replies: 1
Views: 103

### Rate Laws

If a reactant does not affect the rate of the reaction do you still include it in the rate law equation?
Mon Feb 25, 2019 2:05 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: What number to use for "n"
Replies: 2
Views: 121

### What number to use for "n"

What is "n" in the Nernst equation and how do we know what number to use?
Mon Feb 25, 2019 2:04 pm
Forum: Balancing Redox Reactions
Topic: Balancing redox reactions
Replies: 2
Views: 134

### Balancing redox reactions

How will we know whether to add H+ or OH- to the reaction? Will it say the rxn is done under basic/acidic conditions?
Mon Feb 25, 2019 2:02 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic vs Voltaic
Replies: 1
Views: 87

### Galvanic vs Voltaic

Is there a difference between Galvanic and Voltaic cells?
Wed Feb 20, 2019 3:34 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs and concepts
Replies: 3
Views: 150

### Gibbs and concepts

What sort of conceptual things would we have to know regarding Gibbs Free Energy? Just wondering how we may have to apply it on a test.
Wed Feb 20, 2019 3:28 pm
Forum: Balancing Redox Reactions
Topic: Separating the equation
Replies: 5
Views: 188

### Separating the equation

Today in class Dr. Lavelle discussed it may be easier to figure out redox rxns by separating the equation. Can someone explain what he meant by this I am still confused?
Wed Feb 20, 2019 3:26 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cathode vs Anode
Replies: 1
Views: 89

### Cathode vs Anode

How do you determine which container has the cathode vs the anode?
Tue Feb 12, 2019 10:27 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Applying to biological and organic examples
Replies: 2
Views: 173

### Re: Applying to biological and organic examples

We may have to apply our knowledge of thermodynamic processes to biological examples such as ATP hydrolysis or the breaking down of glucose. Just an idea because Dr. Lavelle covered these examples in class a couple times.
Tue Feb 12, 2019 10:24 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Equations for 2nd law
Replies: 1
Views: 130

### Equations for 2nd law

How does Qrev/T relate to the 2nd law of thermodynamics? I'm confused about the relationship.
Tue Feb 12, 2019 10:20 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Isochoric vs isometric
Replies: 4
Views: 769

### Isochoric vs isometric

What is an isochoric/isometric system and is there a difference between the two?
Sun Feb 10, 2019 2:29 pm
Forum: Calculating Work of Expansion
Topic: Work equations
Replies: 2
Views: 125

### Work equations

What is the difference between the capital W and lowercase w on the equation sheet?
Sat Feb 09, 2019 3:47 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: 4A.9 7th Edition
Replies: 3
Views: 194

### 4A.9 7th Edition

In question 9 where did the solution manual get the 0.38 J/C.g for the heat capacity of copper?
Sat Feb 09, 2019 2:45 pm
Forum: Phase Changes & Related Calculations
Topic: 4A3 7th Edition
Replies: 3
Views: 143

### Re: 4A3 7th Edition

I agree that you can assume that q=0 because if no heat is added/removed from the system then delta U is equal to work.
Sat Feb 09, 2019 2:43 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: 9.35 Sixth Edition
Replies: 2
Views: 160

### Re: 9.35 Sixth Edition

Container a has the least because it contains monatomic atoms and container c has the most entropy because it contains diatomic molecules that are active. Entropy is essentially the disorder of the system so if you consider all 3 containers, container a will has the least disorder because it only ha...
Sat Feb 09, 2019 2:37 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Delta S equations
Replies: 3
Views: 162

### Delta S equations

Which delta S equations do we have to know for the midterm that are not on the equation sheet?
Thu Feb 07, 2019 9:25 pm
Forum: Phase Changes & Related Calculations
Topic: Work equation
Replies: 4
Views: 227

### Work equation

Is there a constant to covert work from atm.L to J?
Mon Jan 28, 2019 3:17 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Neutralization reactions
Replies: 6
Views: 262

### Neutralization reactions

Is a neutralization reaction always exothermic?
Mon Jan 28, 2019 3:17 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Extensive vs Intensive properties
Replies: 4
Views: 159

### Extensive vs Intensive properties

What is the difference between an extensive and intensive property?
Mon Jan 28, 2019 3:13 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Memorizing bond enthalpies
Replies: 5
Views: 259

### Memorizing bond enthalpies

Which bond enthalpies do we have to memorize?
Tue Jan 22, 2019 8:32 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Q reaction quotient
Replies: 2
Views: 120

### Re: Q reaction quotient

Liquids are not included in the reaction quotient nor the equilibrium k value/expression. If the reaction contains only gases, you will find Q in terms of the partial pressures of the gases.
Tue Jan 22, 2019 8:30 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ignoring x
Replies: 16
Views: 1109

### Re: ignoring x

You can ignore x in the ice table when the K value is less than 10^-3 because it the percent ionization will be less than 5%.
Tue Jan 22, 2019 8:28 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Changing pressure
Replies: 3
Views: 170

### Re: Changing pressure

According to Le Chatelier's Principle, when the reaction undergoes a disturbance that does not involve a change in temperature, the reaction will adjust to minimize the effect of this disturbance. The reaction will move to favor the side with fewer moles of reactant/product. In this case, the moles ...
Wed Jan 16, 2019 11:30 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Test topics for next week
Replies: 3
Views: 152

### Test topics for next week

Up to what topic/section in the outlines will the test 1 cover next week?
Tue Jan 15, 2019 8:45 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Cations as acids
Replies: 2
Views: 80

### Re: Cations as acids

Cations are always going to act as acids, but as far as strength, you have to memorize the strong acids: HCl, HNO3, H2SO4, HBr, HI, HClO4, HClO3 . If you know the strong acids, the others are weak acids.
Tue Jan 15, 2019 8:40 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J.11 Part b
Replies: 2
Views: 85

### Re: 5J.11 Part b

When a reaction involves the breaking of a diatomic molecule X2, this requires energy to become 2X, so the reaction is endothermic because it takes in heat to break apart.
Tue Jan 15, 2019 8:38 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: partial pressure
Replies: 2
Views: 77

### Re: partial pressure

Just like Fiona said, K for gases and aqueous solutions are calculated the same way, just different units are used. Molarity for concentration, and generally bar for partial pressure.
Mon Jan 07, 2019 9:33 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Help on 11.13
Replies: 2
Views: 84

### Re: Help on 11.13

Since the reactants are a solid and liquid the K value will just be the concentrations of the products multiplied together. You do not include pure solids or liquids are in the equilibrium expression because their concentrations stay constant throughout the reaction. The density of a pure liquid or ...
Mon Jan 07, 2019 9:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids and Liquids and the K expression
Replies: 2
Views: 179

### Re: Solids and Liquids and the K expression

Pure solids or liquids are excluded from the equilibrium expression because their concentrations stay the same during the reaction. The density of a pure liquid or solid is the same, regardless of how much pure liquid or solid is present.
Mon Jan 07, 2019 8:17 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Concentrations of products/reactants
Replies: 6
Views: 258

### Concentrations of products/reactants

Is the equilibrium constant K the ratio of the initial or equilibrium concentrations of the products and reactants?
Thu Dec 06, 2018 1:16 pm
Forum: Polyprotic Acids & Bases
Topic: Identifying polyprotic acids and bases
Replies: 2
Views: 335

### Identifying polyprotic acids and bases

What are specific characteristics of polyprotic acids and bases? Are there any common examples that we should be familiar with?
Thu Dec 06, 2018 1:14 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Calculating pH
Replies: 2
Views: 160

### Calculating pH

How do you calculate the pH of an NaOH solution when given the molarity of the NaOH?
Thu Dec 06, 2018 1:13 pm
Forum: Amphoteric Compounds
Topic: Amphoteric vs Amphiprotic
Replies: 4
Views: 343

### Amphoteric vs Amphiprotic

what is the difference between amphoteric and amphiprotic?
Sat Dec 01, 2018 9:30 pm
Forum: Lewis Acids & Bases
Topic: Lewis/Bronsted acids and bases
Replies: 2
Views: 135

### Lewis/Bronsted acids and bases

What is the difference between Lewis and Bronsted acids and bases?
Mon Nov 26, 2018 10:47 am
Forum: Octet Exceptions
Topic: Atoms with expanded octets
Replies: 4
Views: 405

### Atoms with expanded octets

Do all atoms located in period 3 or below have expanded octets?
Mon Nov 26, 2018 10:46 am
Forum: Bond Lengths & Energies
Topic: 7th Edition 2D.13
Replies: 1
Views: 116

### 7th Edition 2D.13

How do you know the order of decreasing bond lengths for CO, CO2, and CO3 2-?
Mon Nov 26, 2018 10:45 am
Forum: Dipole Moments
Topic: Polarizability vs Polarizing power
Replies: 8
Views: 328

### Polarizability vs Polarizing power

What is the difference between polarizability and polarizing power?
Mon Nov 26, 2018 10:44 am
Forum: Formal Charge and Oxidation Numbers
Topic: Formal charge question Focus 2 (7th Edition)
Replies: 1
Views: 3315

### Formal charge question Focus 2 (7th Edition)

How do you find the formal charge of C2O4 2- from focus 2 problem 1 in the 7th edition?
Mon Nov 26, 2018 10:42 am
Forum: Hybridization
Topic: Sigma vs Pi Bonds
Replies: 2
Views: 72

### Sigma vs Pi Bonds

Can someone explain the difference between sigma and pi bonds and how they relate to resonance?
Thu Nov 15, 2018 1:44 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: HW 2E3 PART B (7TH EDITION)
Replies: 4
Views: 216

### Re: HW 2E3 PART B (7TH EDITION)

Only lone pairs around the central atom affect the shape of the molecule because they repel the electrons from the other atoms.
Thu Nov 15, 2018 1:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Coordination Numbers
Replies: 1
Views: 65

### Coordination Numbers

What are coordination numbers and an example of when we would need to know them?
Thu Nov 15, 2018 1:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Structure of xenon trioxide
Replies: 1
Views: 62

### Structure of xenon trioxide

For problem 2E.11 part d in the 7th Edition textbook, why is Xenon double bonded with each oxygen instead of single bonded?
Fri Nov 09, 2018 2:15 pm
Forum: Dipole Moments
Topic: Dipole induced-dipole
Replies: 2
Views: 131

### Dipole induced-dipole

What exactly is a dipole induced-dipole and how do they happen?
Fri Nov 09, 2018 2:13 pm
Forum: Ionic & Covalent Bonds
Topic: HW 3.77
Replies: 4
Views: 164

### Re: HW 3.77

The greater the electronegativity difference, the greater the ionic character.
Fri Nov 09, 2018 2:12 pm
Forum: Lewis Structures
Topic: Atoms with 8+ valence e-
Replies: 6
Views: 491

### Atoms with 8+ valence e-

Why can some atoms have more than an octet for their Lewis structure? I know it has something to do with the period they are in but I am still confused about it.
Fri Nov 02, 2018 10:15 pm
Forum: Bond Lengths & Energies
Topic: Bond length energies
Replies: 3
Views: 135

### Bond length energies

Why do double and triple bonds have more energy and are shorter than single bonds?
Fri Nov 02, 2018 10:14 pm
Forum: Resonance Structures
Topic: 6th Edition 3.21
Replies: 2
Views: 151

### Re: 6th Edition 3.21

You can just write [Ar] that is acceptable notation for an ion like that.
Fri Nov 02, 2018 10:13 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic and Covalent bonds with covalent/ionic characteristics
Replies: 3
Views: 162

### Ionic and Covalent bonds with covalent/ionic characteristics

I don't really understand what it means when an ionic bond has covalent character and vice versa?
Sat Oct 27, 2018 9:45 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Writing electron configurations [ENDORSED]
Replies: 5
Views: 114

### Re: Writing electron configurations[ENDORSED]

I think it will always be spin up. When writing the electron configurations we always go through and do the spin up electrons first and fill in the spin down electrons after all the spin up are full.
Sat Oct 27, 2018 9:44 am
Forum: Trends in The Periodic Table
Replies: 8
Views: 350

You only will know the atomic radius if it is experimentally determined. For the purposes in our class, we only have to know the general trend.
Sat Oct 27, 2018 9:43 am
Forum: Trends in The Periodic Table
Topic: Trends in the periodic table & electron configuration
Replies: 5
Views: 241

### Trends in the periodic table & electron configuration

How do trends in the periodic table affect electron configurations? Is there a relationship between the two concepts?
Sat Oct 20, 2018 9:35 am
Forum: *Shrodinger Equation
Topic: Test 2 and Shrodinger Equation
Replies: 3
Views: 326

### Test 2 and Shrodinger Equation

I don't understand what the Shrodinger Equation is actually calculating. Will we have to use it on the upcoming test?
Sat Oct 20, 2018 9:33 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Symmetric vs. Non symmetric orbitals
Replies: 4
Views: 574

### Symmetric vs. Non symmetric orbitals

I know s-orbitals are the only ones without a nodal plane so the electron density is symmetric but I don't really understand the significance of this or what it really means when applying this information?
Sat Oct 20, 2018 9:30 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 4th quantum number question [ENDORSED]
Replies: 3
Views: 180

### 4th quantum number question[ENDORSED]

I'm confused about the 4th quantum number and the significance of it? What does it mean for an electron to be spin up or spin down? How do you figure out if an atom is +1/2 or -1/2?
Fri Oct 12, 2018 1:53 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Wavelike properties
Replies: 7
Views: 211

### Re: Wavelike properties

I think for this type of example, since the value is so small you just don't consider the object to have wave-like properties. Dr. Lavelle mentioned in class that it would be pretty clear if something had wave-like properties because the value would be like 3.46 x 10^-10 for example.
Fri Oct 12, 2018 1:49 pm
Forum: Properties of Light
Replies: 4
Views: 216

### Re: Explaining answer for 1.3

So when the wavelength increases, the frequency decreases so the slope is flatter. When the wavelength decreases, the frequency increases so the slope is steeper. So in this example, when the frequency decreases, the slope becomes flatter and the extent of change is lesser.
Fri Oct 12, 2018 1:44 pm
Forum: Properties of Electrons
Topic: Energy emitted by electrons
Replies: 6
Views: 248

### Energy emitted by electrons

I'm kind of confused about the explanation of electrons moving from one energy state to another. If free electrons has higher energy than atom bound electron, then where does the energy that was lost go?
Fri Oct 12, 2018 1:35 pm
Forum: DeBroglie Equation
Topic: Measurable wavelengths
Replies: 3
Views: 99

### Measurable wavelengths

In class, some of the examples asked if the calculated wavelengths could be detected in a lab experiment but what value can actually be classified as a measurable wavelength to have wave properties?
Fri Oct 12, 2018 1:32 pm
Forum: DeBroglie Equation
Replies: 2
Views: 163