Search found 74 matches

by BCaballero_4F
Sun Feb 16, 2020 8:37 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Spontaneous
Replies: 13
Views: 17

Re: Spontaneous

If delta G is negative then it is spontaneous, and if it is positive then it is not spontaneous.
by BCaballero_4F
Sun Feb 16, 2020 8:35 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Midterm Curve
Replies: 42
Views: 204

Re: Midterm Curve

I dont think he will curve the midterm considering the final grade is technically curved
by BCaballero_4F
Sun Feb 16, 2020 8:31 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies with Molecules
Replies: 4
Views: 26

Re: Bond Enthalpies with Molecules

To calculate this you would add together the bonds broken, then subtract that number by bonds formed.
by BCaballero_4F
Sun Feb 16, 2020 8:29 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: endo/exo and temp
Replies: 8
Views: 27

Re: endo/exo and temp

You can look at adding heat as adding a product or reactant depending on whether it is exothermic or endothermic. If you are adding a product, then it will shift to reactants, and vice versa.
by BCaballero_4F
Mon Feb 03, 2020 9:34 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law
Replies: 7
Views: 20

Re: Hess's Law

You basically alter the reactions to get the reaction you want, by multiplying or moving reactants to products and products to reactants
by BCaballero_4F
Mon Feb 03, 2020 9:28 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: First Law
Replies: 6
Views: 35

Re: First Law

The 1st law of thermodynamics is conservation of energy, so the energy of an isolated system must remain constant. This gives delta u = q + w = 0
by BCaballero_4F
Mon Feb 03, 2020 9:17 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: endo vs exo
Replies: 8
Views: 19

Re: endo vs exo

Delta H would be positive since breaking a bond would be considered an endothermic reaction
by BCaballero_4F
Mon Feb 03, 2020 9:15 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: reversing signs
Replies: 5
Views: 15

Re: reversing signs

Whether or not delta H is positive or negative depends on the reaction (if it is endothermic or exothermic)
by BCaballero_4F
Mon Jan 27, 2020 5:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE
Replies: 20
Views: 70

Re: ICE

You use an ICE table when you are looking for the concentration of something. Ka helps to solve for x
by BCaballero_4F
Mon Jan 27, 2020 5:57 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kp to Kc
Replies: 11
Views: 29

Re: Kp to Kc

Yes, because it is a gas and we include gases in Kc. (just depends on state given)
by BCaballero_4F
Mon Jan 27, 2020 5:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5% Rule
Replies: 9
Views: 27

Re: 5% Rule

You go back and use the quadratic formula only if it is more than 5%
by BCaballero_4F
Mon Jan 27, 2020 5:55 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Ka and Kb
Replies: 10
Views: 52

Re: Ka and Kb

It would be a strong acid instead of a weak acid
by BCaballero_4F
Mon Jan 27, 2020 5:53 pm
Forum: Phase Changes & Related Calculations
Topic: sig figs
Replies: 6
Views: 26

Re: sig figs

Moles and liters count for sig figs in this question
by BCaballero_4F
Tue Jan 21, 2020 4:13 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Gas Constant (R)
Replies: 3
Views: 17

Re: Gas Constant (R)

Which one you would use depends on the units you are initially given in the problem
by BCaballero_4F
Tue Jan 21, 2020 4:12 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: H2O in K Expressions
Replies: 6
Views: 19

Re: H2O in K Expressions

Since it is H2O as a gas, you would still include it.
by BCaballero_4F
Tue Jan 21, 2020 4:11 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5% approximation rule
Replies: 5
Views: 36

Re: 5% approximation rule

I believe it is anything less than 10^-3
by BCaballero_4F
Tue Jan 21, 2020 4:10 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE table
Replies: 5
Views: 24

Re: ICE table

You use the stoichiometric coefficients
by BCaballero_4F
Tue Jan 21, 2020 4:08 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: using K
Replies: 5
Views: 14

Re: using K

Kp is for pressure and Kc is in terms of molarity
by BCaballero_4F
Wed Jan 15, 2020 1:10 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Autoprotolysis
Replies: 8
Views: 37

Re: Autoprotolysis

Autoprotolysis can be shown using H2O and is the proton transferring of two of the same atom
by BCaballero_4F
Wed Jan 15, 2020 1:05 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction Quotient Units
Replies: 10
Views: 31

Re: Reaction Quotient Units

Q does not have specific units because it is a ratio.
by BCaballero_4F
Wed Jan 15, 2020 1:02 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Hw for next week
Replies: 19
Views: 64

Re: Hw for next week

Yes it should be okay, last quarter as long as it was recent we received credit. It is also still pretty early since it's week 2 and we went over it last week.
by BCaballero_4F
Wed Jan 15, 2020 1:01 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: equilibrium concentration with gases
Replies: 7
Views: 36

Re: equilibrium concentration with gases

Yes in this case you can ignore pressure
by BCaballero_4F
Wed Jan 15, 2020 12:59 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q=K
Replies: 14
Views: 37

Re: Q=K

Q can be calculated at any given moment, not only when the system is not at equilibrium, so Q=K is when Q is calculated when it is at equilibrium.
by BCaballero_4F
Tue Jan 07, 2020 9:04 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5G.1(d)
Replies: 3
Views: 38

Re: 5G.1(d)

Because at equilibrium the constant is consistent so if one is higher than the other would also be higher since that constant must be maintained
by BCaballero_4F
Tue Jan 07, 2020 9:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Very Large K
Replies: 12
Views: 67

Re: Very Large K

This means that at equilibrium more products are present than reactants. In this case, a lot more
by BCaballero_4F
Tue Jan 07, 2020 9:00 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Q vs K
Replies: 13
Views: 86

Re: Q vs K

K is used for when it is at equilibrium
by BCaballero_4F
Tue Jan 07, 2020 8:57 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Concentrations at Equilibrium
Replies: 6
Views: 43

Re: Concentrations at Equilibrium

No, the concentration of products and reactants are not the same but the ratio that gives the equilibrium constant is the same.
by BCaballero_4F
Tue Jan 07, 2020 8:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Question from Module Assessment Part 1A
Replies: 3
Views: 20

Re: Question from Module Assessment Part 1A

I believe the answer would be A, because the equilibrium constant gives a ratio which includes products and reactants at equilibrium. For example, when K is greater than one the reaction has mostly products and when K is less than one the reaction has mostly reactants.
by BCaballero_4F
Sat Nov 30, 2019 12:02 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Lewis Acid/Base
Replies: 5
Views: 33

Re: Lewis Acid/Base

Lewis acids accept electrons and Lewis bases donate electrons
by BCaballero_4F
Fri Nov 29, 2019 11:57 pm
Forum: Calculating the pH of Salt Solutions
Topic: pH vs. pOH
Replies: 17
Views: 127

Re: pH vs. pOH

pH measures acidity while pOH measures basicity, and you can use one to get the other
by BCaballero_4F
Fri Nov 29, 2019 11:52 pm
Forum: Resonance Structures
Topic: What is a Resonance "Structure"
Replies: 12
Views: 79

Re: What is a Resonance "Structure"

The different forms of a molecule because there can be more than one
by BCaballero_4F
Fri Nov 29, 2019 11:48 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Lewis bases vs. ligands
Replies: 3
Views: 27

Re: Lewis bases vs. ligands

Yes all ligands are basically Lewis bases
by BCaballero_4F
Fri Nov 29, 2019 11:46 pm
Forum: Conjugate Acids & Bases
Topic: NH3, acid or base?
Replies: 12
Views: 634

Re: NH3, acid or base?

In most cases Ammonia is considered a weak base
by BCaballero_4F
Mon Nov 18, 2019 11:46 pm
Forum: Hybridization
Topic: Pi and sigma bonds
Replies: 4
Views: 43

Re: Pi and sigma bonds

Because a sigma bond is stronger and more stable so there will be one of these, and pi bonds would come after the sigma bond because they are weaker.
by BCaballero_4F
Mon Nov 18, 2019 11:44 pm
Forum: Hybridization
Topic: Energy in Hybridization
Replies: 3
Views: 29

Re: Energy in Hybridization

The energy of the hybridized molecule is an average of the beginning two.
by BCaballero_4F
Mon Nov 18, 2019 11:42 pm
Forum: Hybridization
Topic: hybridization
Replies: 4
Views: 26

Re: hybridization

To explain bonds more thoroughly
by BCaballero_4F
Mon Nov 18, 2019 11:42 pm
Forum: Hybridization
Topic: hybridization
Replies: 11
Views: 57

Re: hybridization

You begin with the Lewis Structure which then allows you to use VSEPR to predict the shape, and from these two you should know the number of regions of electron density which would then allow you to derive the hybridization.
by BCaballero_4F
Mon Nov 18, 2019 11:39 pm
Forum: Hybridization
Topic: Hybridization
Replies: 6
Views: 34

Re: Hybridization

005384106 wrote:Does hybridization depend on the number of bonds between atoms?

The number of hybrid orbitals depends on the number of regions of electron density.
by BCaballero_4F
Tue Nov 12, 2019 5:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: central atoms
Replies: 7
Views: 42

Re: central atoms

Cl is the central atom because it allows for stability
by BCaballero_4F
Tue Nov 12, 2019 5:55 pm
Forum: Hybridization
Topic: Hybrid Orbitals
Replies: 6
Views: 292

Re: Hybrid Orbitals

Yes, but only sp3 + it corresponds with electron densities
by BCaballero_4F
Tue Nov 12, 2019 5:52 pm
Forum: Hybridization
Topic: Pi vs Sigma Bonds
Replies: 4
Views: 41

Re: Pi vs Sigma Bonds

The electrons in sigma bonds are very close to the nuclei, while the electrons in a pi bond are further from the nuclei so the attraction is not as strong, thus making them easier to break.
by BCaballero_4F
Tue Nov 12, 2019 5:40 pm
Forum: Hybridization
Topic: Determining how many electron densities
Replies: 5
Views: 177

Re: Determining how many electron densities

Yes they do count, so for this example it would be 4 instead of 3.
by BCaballero_4F
Tue Nov 12, 2019 5:39 pm
Forum: Hybridization
Topic: Hybridization Models
Replies: 4
Views: 40

Re: Hybridization Models

I believe we will need to know how to draw them but I am not sure, regardless it would be beneficial.
by BCaballero_4F
Sun Nov 10, 2019 4:40 pm
Forum: Octet Exceptions
Topic: Octet Exception
Replies: 8
Views: 72

Re: Octet Exception

I believe the f-block can store electrons too since the octet exception applies to those after the third period.
by BCaballero_4F
Sun Nov 10, 2019 4:37 pm
Forum: Hybridization
Topic: Noble Configuration vs. Full
Replies: 7
Views: 46

Re: Noble Configuration vs. Full

I believe it will be specified but if not the noble gas configuration should be sufficient.
by BCaballero_4F
Sun Nov 10, 2019 4:35 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Writing e- Configurations
Replies: 15
Views: 89

Re: Writing e- Configurations

Usually the question will specify whether they want the whole thing written out or not.
by BCaballero_4F
Sun Nov 10, 2019 4:34 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar v. Nonpolar
Replies: 11
Views: 646

Re: Polar v. Nonpolar

If electrons are shared equally, it is nonpolar. If electrons are shared unequally, it is polar, which you should be able to see once you calculate formal charge.
by BCaballero_4F
Sun Nov 10, 2019 4:31 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Formal Charge
Replies: 9
Views: 480

Re: Formal Charge

The most electronegative atom should have the negative charge, I think it does matter what the formal charges are on individuals which would then lead to the correct charge for the overall structure.
by BCaballero_4F
Wed Oct 30, 2019 6:36 pm
Forum: Coordinate Covalent Bonds
Topic: Coordinate covalent bond?
Replies: 12
Views: 480

Re: Coordinate covalent bond?

A coordinate covalent bond is between an acid and a base where one acts and the lone electron donor and the other acts as the lone electron acceptor.
by BCaballero_4F
Wed Oct 30, 2019 6:33 pm
Forum: Ionic & Covalent Bonds
Topic: Format of midterm?
Replies: 12
Views: 68

Re: Format of midterm?

I think the midterm will be all free-response because all of the practice problems given usually are as well.
by BCaballero_4F
Wed Oct 30, 2019 6:30 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 5
Views: 36

Re: Resonance Structures

Yes, the most stable structure will make it the most accurate so it is the one you should draw.
by BCaballero_4F
Wed Oct 30, 2019 6:27 pm
Forum: Lewis Structures
Topic: Valence Electrons from Periodic Table
Replies: 10
Views: 77

Re: Valence Electrons from Periodic Table

You get the number of valence electrons from whatever group the element is in.
by BCaballero_4F
Wed Oct 30, 2019 6:25 pm
Forum: Lewis Structures
Topic: Formal charge
Replies: 9
Views: 65

Re: Formal charge

I would recommend counting the formal charge so you have the most similar structure to what the real structure looks like.
by BCaballero_4F
Wed Oct 30, 2019 6:21 pm
Forum: Octet Exceptions
Topic: octet exceptions
Replies: 5
Views: 33

Re: octet exceptions

It may also help to understand that second row electrons can only have an octet due and count the electrons up to the 2nd row (1s^2,2s^2,2p^6) and if they are in a different row such as the third row they can take e- from the d subshell.
by BCaballero_4F
Wed Oct 30, 2019 6:16 pm
Forum: Lewis Structures
Topic: Creating Lewis Structures
Replies: 7
Views: 54

Re: Creating Lewis Structures

You would put the atom that is the least electronegative or has the lowest ionization energy in the middle.
by BCaballero_4F
Wed Oct 30, 2019 6:15 pm
Forum: Hybridization
Topic: Electrons
Replies: 13
Views: 370

Re: Electrons

It means it is moving to the next orbital because it is excited.
by BCaballero_4F
Wed Oct 30, 2019 6:13 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lewis Structure
Replies: 5
Views: 68

Re: Lewis Structure

If the negative is referring to the charge then yes you would add an electron for every negative shown and subtract an electron for every positive shown when referring to charge.
by BCaballero_4F
Tue Oct 22, 2019 12:09 pm
Forum: Trends in The Periodic Table
Topic: Ionic Radii
Replies: 10
Views: 77

Re: Ionic Radii

Anions are bigger because an electron is added. Cations are smaller because a valence electron is lost.
by BCaballero_4F
Tue Oct 22, 2019 12:03 pm
Forum: Ionic & Covalent Bonds
Topic: Week 4 Homework
Replies: 9
Views: 103

Re: Week 4 Homework

I don't think you will be penalized for moving on from Quantum World if you wanted to.
by BCaballero_4F
Tue Oct 22, 2019 11:59 am
Forum: Lewis Structures
Topic: Molecule Formulas
Replies: 5
Views: 336

Re: Molecule Formulas

For the most part I think it will be given unless it is simple for us to figure out.
by BCaballero_4F
Tue Oct 22, 2019 11:57 am
Forum: Lewis Structures
Topic: Drawing lewis structures
Replies: 5
Views: 282

Re: Drawing lewis structures

As long as the overall charge is accurate and the formal charge is matched then you should be fine.
by BCaballero_4F
Tue Oct 22, 2019 11:49 am
Forum: Lewis Structures
Topic: Central Atom
Replies: 7
Views: 290

Re: Central Atom

The central atom has to be the atom with the lowest ionization energy, so I think those can be in the middle if they have a lower ionization energy than other atoms involved.
by BCaballero_4F
Tue Oct 15, 2019 6:46 pm
Forum: *Shrodinger Equation
Topic: What is Shrodinger's for?
Replies: 6
Views: 48

Re: What is Shrodinger's for?

Schrodinger's uses a function to describe an e- in an atom and uses the concept that an e- with wavelike properties and indeterminacy in momentum and position can be described by a wave function.
by BCaballero_4F
Tue Oct 15, 2019 6:37 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 16
Views: 156

Re: Atomic Radius

The electron has to be in ground state for the radius to be measured properly, not excited.
by BCaballero_4F
Tue Oct 15, 2019 6:35 pm
Forum: Trends in The Periodic Table
Topic: Chemistry Community
Replies: 8
Views: 79

Re: Chemistry Community

They are due by Sunday, Professor Lavelle explained in an email how when discussing Chemistry Community the week "ends" on Sunday.
by BCaballero_4F
Tue Oct 15, 2019 6:32 pm
Forum: DeBroglie Equation
Topic: De Broglie's Equation
Replies: 17
Views: 106

Re: De Broglie's Equation

Light does not have mass, which is a required variable in the De Broglie equation.
by BCaballero_4F
Thu Oct 10, 2019 3:21 pm
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 169
Views: 103277

Re: Rusty on High School Chem [ENDORSED]

Definitely take advantage of all the tutoring they offer and practice as much as you can, YouTube also helps a lot.
by BCaballero_4F
Thu Oct 10, 2019 3:15 pm
Forum: Balancing Chemical Reactions
Topic: Combustion
Replies: 17
Views: 215

Re: Combustion

Combustion consists of burning, usually O^2 reacts with something else and CO^2 and H^2O are products.
by BCaballero_4F
Thu Oct 10, 2019 3:13 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Chemical Reactions
Replies: 20
Views: 211

Re: Balancing Chemical Reactions

I find it helpful to list the elements on both sides (under reactants and products) and then plug in numbers that look correct and update the numbers as I go by crossing them out and putting the new ones.
by BCaballero_4F
Thu Oct 10, 2019 3:09 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg equation [ENDORSED]
Replies: 73
Views: 1684

Re: Rydberg equation [ENDORSED]

You would use the Rydberg equation to calculate the wavelength of light when an electron moves energy levels.
by BCaballero_4F
Thu Oct 10, 2019 3:04 pm
Forum: Limiting Reactant Calculations
Topic: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
Replies: 68
Views: 1648

Re: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]

Yes, however I think it is best to show work so that in case you make a mistake you may receive partial credit.

Go to advanced search