## Search found 61 matches

Sat Mar 16, 2019 8:13 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 4c.3
Replies: 1
Views: 270

### 4c.3

What is the change in enthalpy for part b?
Sat Mar 16, 2019 11:31 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Phases Cell Diagram
Replies: 2
Views: 115

### Phases Cell Diagram

I cell diagram, what is the order you write the phases?
Sat Mar 16, 2019 11:06 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Midterm Questions
Replies: 2
Views: 261

### Midterm Questions

Why do you not use an ICE table in question 4 of the midterm?
Mon Mar 04, 2019 3:24 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Reaction order
Replies: 4
Views: 140

### Re: Reaction order

You get the total order of the reaction by adding all the individual orders of the reaction!
Mon Mar 04, 2019 3:19 pm
Forum: General Rate Laws
Topic: Derivatives
Replies: 5
Views: 191

### Re: Derivatives

I don't think you need to memorize how to derive the equations, he just shows them to us to explain how we get from each formula to the next to help us comprehend!
Mon Mar 04, 2019 3:16 pm
Forum: General Rate Laws
Topic: General Rate Law Orders
Replies: 3
Views: 126

### Re: General Rate Law Orders

the slope of a first order reaction is negative, shown as "-k" in the equation. It forms a straight line plot of ln[R] vs. Time
Mon Mar 04, 2019 3:14 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst
Replies: 6
Views: 181

### Nernst

In the Nernst equation when do you use log vs. ln?
Mon Mar 04, 2019 3:11 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: K
Replies: 5
Views: 168

### K

When K is 0, <1, and >1, what is ∆G's sign??
Mon Feb 25, 2019 2:39 pm
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: Electrolysis on Test 2
Replies: 1
Views: 245

### Electrolysis on Test 2

Is Electrolysis going to be on test 2? It's the section after Nernst so I wasn't sure since we aren't being tested on Nernst. Thanks!
Sun Feb 24, 2019 10:00 pm
Forum: Balancing Redox Reactions
Topic: Reducing and Oxidizing Agents
Replies: 3
Views: 119

### Re: Reducing and Oxidizing Agents

A reactant is both the reducing and oxidizing agent when it's used to form both products. For example, 2H2O2 -> 2H2O + O2
Sun Feb 24, 2019 9:58 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: E standard
Replies: 3
Views: 146

### E standard

Does the standard reaction potential change when you manipulate the half-reactions?
Sun Feb 24, 2019 9:57 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Maximum work
Replies: 1
Views: 85

### Maximum work

When is maximum work done?
Thu Feb 14, 2019 10:39 am
Forum: Calculating Work of Expansion
Topic: S=0
Replies: 12
Views: 688

### S=0

When is entropy equal to 0?
Thu Feb 14, 2019 10:38 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible vs. Irreversible
Replies: 5
Views: 561

### Reversible vs. Irreversible

I'm still having trouble understanding what reversible means for a reaction? What are the different equations you use for a reversible or irreversible?
Thu Feb 14, 2019 10:36 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Cp,m
Replies: 5
Views: 418

### Cp,m

When do you use Cp,m and Cv,m?
Thu Feb 14, 2019 10:35 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Cp,m
Replies: 3
Views: 351

### Cp,m

When do you use Cp,m and Cv,m?
Thu Feb 07, 2019 2:21 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: Entropy
Replies: 1
Views: 111

### Entropy

What does Dr. Lavelle mean when he says to ignore thermal energy? How does this affect the system and finding entropy?
Thu Feb 07, 2019 2:19 pm
Forum: Calculating Work of Expansion
Topic: Reversible vs. Irreversible
Replies: 2
Views: 87

### Reversible vs. Irreversible

How can you tell if a reaction is irreversible or reversible?
Thu Feb 07, 2019 2:18 pm
Forum: Calculating Work of Expansion
Topic: Constant Pressure and Temperature
Replies: 1
Views: 86

### Constant Pressure and Temperature

What's the difference in equations for when a system has constant temperature or constant pressure?
Wed Jan 30, 2019 1:21 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Homework
Replies: 9
Views: 320

### Re: Homework

I had to skip around because a lot of the homework included subjects we haven't fully covered! Also, if you read through the textbook, you'll be able to understand the processes needed for the problems we haven't gone over in class!
Wed Jan 30, 2019 1:17 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy
Replies: 4
Views: 145

### Re: Enthalpy

Enthalpy of reaction is first, and enthalpy of formation is second; Enthalpy of reaction is how much heat the reaction absorbs or gives off. Enthalpy of formation is how much heat a reaction absorbs or gives off when a compound is formed.
Mon Jan 28, 2019 8:22 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Extensive
Replies: 4
Views: 193

### Extensive

What is the difference between and extensive and state property? Thank you!
Wed Jan 23, 2019 4:19 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Acids and bases
Replies: 2
Views: 135

### Re: Acids and bases

To find the Kb, you subtract 11.86 from 14 to get 2.14 as the pOH. From there you solve for the concentration of [OH] = .0072 mol/L, which is labeled x in the ice chart. Using the ice chart, you set up Kb, putting in .0072 as x. From this you can find Kb= 5.6x10^-4 and pKb=-log(Kb)= 3.25.
Wed Jan 23, 2019 4:14 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Ka and pH
Replies: 6
Views: 192

### Ka and pH

Is there a formula that directly relations pH and Ka? or pOH and Kb?
Wed Jan 23, 2019 4:13 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Sig Figs
Replies: 3
Views: 168

### Sig Figs

What are the sig fig rules for calculating pH and pOH? thank you!
Wed Jan 16, 2019 2:32 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Conjugates
Replies: 5
Views: 205

### Conjugates

Can someone please explain the Conjugate Seesaw effect?
Wed Jan 16, 2019 2:31 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: % Ionization
Replies: 3
Views: 105

### % Ionization

How do you calculate the percent ionization of an acid?
Wed Jan 16, 2019 2:30 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Taking x away in a Ka calculation
Replies: 5
Views: 148

### Taking x away in a Ka calculation

Why are we able to disregard the -x when calculating the Ka from an ICE chart?
Thu Jan 10, 2019 9:54 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 11.1d
Replies: 2
Views: 127

### Re: 11.1d

In order for the reaction to go back to equilibrium, the reactants will react towards products (forward reaction). For example, if in A\rightleftharpoons B where K= 7/2, the initial ratio (Q) is 0/9 (A=9 and B=0). In order to go back to equilibrium, A must react towards B until equilibrium is satisf...
Thu Jan 10, 2019 9:39 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Effects on Equilibrium
Replies: 2
Views: 111

### Effects on Equilibrium

What factors can affect the equilibrium constant?
Thu Jan 10, 2019 9:37 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K
Replies: 4
Views: 203

### K

What is the difference between K[p], K[eq], and K[p]? When do you use each and what are the units?
Mon Dec 10, 2018 1:06 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acidity
Replies: 3
Views: 352

### Acidity

What are the two factors that affect the acidity of an acid?
Mon Dec 10, 2018 1:05 am
Forum: Ionic & Covalent Bonds
Topic: Ion-Dipole
Replies: 3
Views: 522

### Ion-Dipole

What exactly is an ion-dipole interaction and can you give an example?
Mon Dec 10, 2018 1:05 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: polarizability
Replies: 1
Views: 465

### polarizability

What is the difference between polarizability and polarizing power?
Mon Dec 03, 2018 4:13 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Relative Acidity
Replies: 1
Views: 105

### Relative Acidity

Why does the pKa of an acid increase as the acidity decreases?
Mon Dec 03, 2018 4:09 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pOH
Replies: 5
Views: 468

### Re: pOH

I think we need to know both because they go hand in hand! pOH = 14 - pH!
Mon Dec 03, 2018 4:07 pm
Forum: Amphoteric Compounds
Topic: Amphoteric Structure
Replies: 2
Views: 156

### Amphoteric Structure

Would a molecule with a central atom able to have an expanded octet that currently has a lone pair and room to accept another pair be considered amphoteric?
Sat Nov 24, 2018 10:47 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Pi Bond
Replies: 1
Views: 64

### Pi Bond

What happens if the 2 Carbons do rotate?
Sat Nov 24, 2018 10:45 am
Forum: Hybridization
Topic: hybridization
Replies: 1
Views: 78

### hybridization

When writing AXE of the structure, what determines the numbers following X and E?
Sat Nov 24, 2018 10:43 am
Forum: Hybridization
Topic: Writing out Hybridization
Replies: 8
Views: 258

### Re: Writing out Hybridization

I don't think the placement of the d-orbital matters when writing the hybridization!
Sun Nov 18, 2018 9:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone pairs
Replies: 5
Views: 192

### Lone pairs

I know that lone pairs influence the shape of the molecule, but do they also influence the name of the shape?
Sun Nov 18, 2018 9:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar molecules
Replies: 5
Views: 206

### Re: Polar molecules

NF4 would be polar due to the lone pair of electrons around the central atom, N.
Sun Nov 18, 2018 9:29 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Distorted Bond Angles
Replies: 3
Views: 776

### Re: Distorted Bond Angles

Lone pairs of a molecules make the structure of a molecule distorted because the lone pairs repulsions are stronger than the repulsions between bond pair repulsions. This makes the angles between the atoms slightly smaller!
Mon Nov 12, 2018 2:30 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Polydentates Ligands
Replies: 2
Views: 354

### Re: Polydentates Ligands

Polydentate Ligands contain multiple bonding atoms bonded to the central metal atom or ion.
Mon Nov 12, 2018 2:27 pm
Forum: Hybridization
Topic: Electron densisty
Replies: 5
Views: 406

### Re: Electron densisty

To find the electron density, you add up all the bonding and unshared electron pairs that are around the central atom after drawing the lewis structure, counting double and triple bonds as one region high electron density.
Mon Nov 12, 2018 2:13 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.1
Replies: 2
Views: 63

### 2E.1

2E.1. Below are ball-and-stick models of two molecules. in each case, indicate whether there must be, may be or cannot be one or more lone pairs of electrons on the central atom.
Part A shows a trigonal planar ball-and-stick model with 120˙ and Im not sure what the answer would be! Thank you!
Sat Nov 03, 2018 2:14 pm
Forum: Lewis Structures
Replies: 2
Views: 102

You can find the formal charge by using the formula:
Formal Charge = valence electrons- (number of electrons in lone pairs + 0.5(bonding electrons))
Sat Nov 03, 2018 2:10 pm
Forum: Lewis Structures
Topic: Lewis Base & Acid
Replies: 2
Views: 149

### Lewis Base & Acid

What is the difference between a Lewis Base and a Lewis Acid? Which accepts a proton and which donates a proton?
Sat Nov 03, 2018 11:20 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Nodes
Replies: 1
Views: 51

### Nodes

How do you find planar and radial nodes?
Sun Oct 28, 2018 4:19 pm
Forum: Ionic & Covalent Bonds
Replies: 5
Views: 193

### Re: Trend of Ionic Radii

The ionic radii size increases down a group and decreases across a period!
Sun Oct 28, 2018 4:15 pm
Forum: Ionic & Covalent Bonds
Replies: 4
Views: 153

### Re: Unit of Atomic Radius

It's measured in picometers, or pm!
Sun Oct 28, 2018 4:10 pm
Forum: Quantum Numbers and The H-Atom
Topic: Degeneracy
Replies: 5
Views: 247

### Degeneracy

What is degeneracy?
Sun Oct 21, 2018 5:36 pm
Forum: Quantum Numbers and The H-Atom
Topic: Spin Magnetic Quantum
Replies: 1
Views: 116

### Spin Magnetic Quantum

How can you determine if ms is +1/2 and -1/2?
Sun Oct 21, 2018 5:31 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Effective Nuclear Charge
Replies: 3
Views: 161

### Re: Effective Nuclear Charge

Zeff is the effective nuclear charge of an electron. It can be calculated with Zeff= Z-S where Z is the number of protons in the nucleus and S is the electron density between the nucleus and electron. It increases going to the right and down on the periodic table.
Sun Oct 21, 2018 5:27 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electrostatic Attraction
Replies: 5
Views: 476

### Re: Electrostatic Attraction

Electrostatic attraction is the repulsion or attraction between two particles due to their charges and distance between these two charges. This can be found by using Coulomb's Law: (q1 x q2)/(r^2) where q1 and q2 represent the two charges and r represents the distance between charges.
Sun Oct 14, 2018 2:15 pm
Forum: Trends in The Periodic Table
Topic: problem 1.13
Replies: 3
Views: 86

### Re: problem 1.13

Since nitrogen has the electron configuration of 1s^2 2s^2 2p^3, its orbitals are half filled, resulting in a stable condition. Oxygen has the electron configuration of 1s^2 2s^2 2p^4, which means it has two half filled orbitals and one orbital filled with two paired electrons. Since the atoms want ...
Sun Oct 14, 2018 2:08 pm
Forum: Properties of Light
Topic: Wave vs. Particle Behavior
Replies: 5
Views: 197

### Wave vs. Particle Behavior

Which specific characteristics of electrons distinguish if it is acting as a wave or particle?
Sun Oct 14, 2018 2:00 pm
Forum: Properties of Electrons
Topic: Wave Length Calculations
Replies: 5
Views: 171

### Wave Length Calculations

What wavelength values are measurable? For example, why is 1.64 x 10^-38 m not measurable?
Sun Oct 07, 2018 6:18 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: MOLARITY
Replies: 17
Views: 1049

### Re: MOLARITY

Molarity is the moles of solute divided by the liters of the solution. You can use it during dilution calculations!
Sun Oct 07, 2018 6:16 pm
Forum: Significant Figures
Topic: Significant Figures
Replies: 2
Views: 128

### Significant Figures

Do the zeros implied in scientific notation count as significant figures?
Sun Oct 07, 2018 6:13 pm
Forum: SI Units, Unit Conversions
Topic: formula units [ENDORSED]
Replies: 69
Views: 24657

### Re: formula units[ENDORSED]

Yes I think you just use Avogadro's number to find the number of atoms or molecules!