Search found 76 matches

by AveryAgosto
Mon Mar 02, 2020 8:51 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Kelvin or Celsius?
Replies: 47
Views: 798

Re: Kelvin or Celsius?

You should use Kelvin because R uses Kelvin.
by AveryAgosto
Mon Mar 02, 2020 8:49 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: k
Replies: 10
Views: 89

Re: k

k has no units because it is a ratio
by AveryAgosto
Mon Mar 02, 2020 8:47 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: free energy and work
Replies: 5
Views: 49

Re: free energy and work

when energy is released, that energy can be used to do work. So if the reaction has a -delta G you know that energy is being released.
by AveryAgosto
Mon Mar 02, 2020 8:46 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: Determining n
Replies: 5
Views: 65

Re: Determining n

n is the moles being transferred.
by AveryAgosto
Mon Mar 02, 2020 8:46 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: the cell diagram for 6M.5a
Replies: 2
Views: 21

Re: the cell diagram for 6M.5a

Dr. Lavelle sent an updated link for the solution manual errors. I would check that out to see if that's one of them
by AveryAgosto
Tue Feb 04, 2020 2:45 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Energy of a system
Replies: 5
Views: 42

Re: Energy of a system

When delta H is negative, the rxn is exothermic and releases heat. When delta H is positive the rxn is endothermic and absorbs heat.
by AveryAgosto
Tue Feb 04, 2020 2:43 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: C = K?
Replies: 5
Views: 36

Re: C = K?

We talked about it in discussion and it just means that it is scaled the same. If you were to add one degree to each that wouldn't change the ratio.
by AveryAgosto
Tue Feb 04, 2020 2:42 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: closed vs isolated
Replies: 14
Views: 95

Re: closed vs isolated

Closed can not interact with the environment at all. Isolated can interact slightly.
by AveryAgosto
Tue Feb 04, 2020 2:41 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm
Replies: 6
Views: 52

Re: Midterm

A lot of equations are derived from one central equation and that is typically shown on the equation sheet. As long as you are able to derive the specific equations to set it equal to the variable you are looking for than you should be fine.
by AveryAgosto
Tue Feb 04, 2020 2:40 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Topics on the Midterm
Replies: 22
Views: 185

Re: Topics on the Midterm

Everything in outlines 1-4 are covered.
by AveryAgosto
Tue Feb 04, 2020 2:39 pm
Forum: Phase Changes & Related Calculations
Topic: internal energy
Replies: 11
Views: 89

Re: internal energy

Internal energy is found using the delta U equation which will contain q.
by AveryAgosto
Tue Feb 04, 2020 2:39 pm
Forum: Calculating Work of Expansion
Topic: Calculus on The Midterm
Replies: 8
Views: 64

Re: Calculus on The Midterm

We aren't required to have previous knowledge of calculus so I don't think it will be on the exam.
by AveryAgosto
Tue Feb 04, 2020 2:38 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Equation
Replies: 2
Views: 22

Re: Equation

I think that has to do with the derivation of other equations and its more conceptual. I don't think it will be used to solve problems.
by AveryAgosto
Sun Jan 19, 2020 3:36 pm
Forum: General Science Questions
Topic: glow sticks
Replies: 1
Views: 41

Re: glow sticks

The reaction between the two chemicals in the glow stick tube is catalyzed by a base, usually sodium salicylate. The sticks consist of a tiny inner container that can be easily broken and that sits within a flexible outer container. Each container holds a different solution and when the glow stick i...
by AveryAgosto
Sun Jan 19, 2020 3:32 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Test 1 Acids and Bases Topic
Replies: 9
Views: 78

Re: Test 1 Acids and Bases Topic

There was a list of acids and bases that Lavelle made for 14A that were the ones he suggested memorizing but I can't seem to find the list.
by AveryAgosto
Sun Jan 19, 2020 3:29 pm
Forum: *Titrations & Titration Calculations
Topic: Acid/Base bonds
Replies: 3
Views: 156

Re: Acid/Base bonds

Longer bond length means that it is a weaker bond which results in it being a stronger acid.
by AveryAgosto
Sun Jan 19, 2020 3:27 pm
Forum: Student Social/Study Group
Topic: Chemistry Community
Replies: 8
Views: 610

Re: Chemistry Community

You are given credit for all posts at the end of the quarter.
by AveryAgosto
Sun Jan 19, 2020 3:25 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic and Endothermic Reactions
Replies: 5
Views: 50

Re: Exothermic and Endothermic Reactions

Every reaction is either exothermic or endothermic. You are correct about the relationship to delta H
by AveryAgosto
Sun Jan 19, 2020 3:23 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: lewis structure
Replies: 11
Views: 75

Re: lewis structure

He said that it won't be required to draw them but it is a helpful way to visualize the reaction.
by AveryAgosto
Sun Jan 12, 2020 7:00 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction Quotient Units
Replies: 10
Views: 56

Re: Reaction Quotient Units

You can determine the units by what will cancel out and if not than it can be unitless.
by AveryAgosto
Sun Jan 12, 2020 6:58 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: pressure and volume
Replies: 4
Views: 32

Re: pressure and volume

Boyle's Law states that pressure and volume have an inverse relationship when temperature is help constant. That is why double the original pressure would result in half of the original volume.
by AveryAgosto
Sun Jan 12, 2020 6:56 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: What is this?
Replies: 23
Views: 402

Re: What is this?

It is also called "The Equilibrium Law" because it states that when any system is at equilibrium for a long period of time it is subjected to change in concentration, temperature, volume, or pressure. The system changes to a new equilibrium and this change partly counteracts the applied ch...
by AveryAgosto
Sun Jan 12, 2020 6:53 pm
Forum: Ideal Gases
Topic: P=(n/v)RT
Replies: 12
Views: 83

Re: P=(n/v)RT

n/V is how concentration is calculated and the derived equation includes concentration. I believe it is written that way to show that it means concentration.
by AveryAgosto
Sun Jan 12, 2020 6:52 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Reaction Quotient Q
Replies: 6
Views: 33

Re: Reaction Quotient Q

You are usually told which variable you are looking for but I believe Q is found when the reaction is not at equilibrium and K is found when the reaction is at equilibrium.
by AveryAgosto
Sat Dec 07, 2019 9:20 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Ka. Kb, Kw
Replies: 4
Views: 57

Re: Ka. Kb, Kw

Ka refers to the pH formula and Kb refers to the pOH formula. Kw is a constant.
by AveryAgosto
Sat Dec 07, 2019 9:19 pm
Forum: Lewis Acids & Bases
Topic: Water
Replies: 7
Views: 132

Re: Water

Water can act as either an acid or a base
by AveryAgosto
Sat Dec 07, 2019 9:18 pm
Forum: Lewis Acids & Bases
Topic: neutralization
Replies: 6
Views: 152

Re: neutralization

As long as an acid and base react to form salt and water it is considered neutralization
by AveryAgosto
Sat Dec 07, 2019 9:18 pm
Forum: Hybridization
Topic: Lone pairs in hybridization
Replies: 4
Views: 86

Re: Lone pairs in hybridization

Yes. A lone pair is a region of electron density along with a bond
by AveryAgosto
Sat Dec 07, 2019 9:17 pm
Forum: Calculating the pH of Salt Solutions
Topic: pH formula?
Replies: 21
Views: 611

Re: pH formula?

-log[H+] and I think we just need to know that pH+pOH= 14
by AveryAgosto
Thu Dec 05, 2019 8:17 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Naming acids
Replies: 2
Views: 63

Re: Naming acids

Dr. Lavelle posted a chart to help but I don’t think we need to know how to name them
by AveryAgosto
Thu Dec 05, 2019 8:17 pm
Forum: Limiting Reactant Calculations
Topic: missed question test 1
Replies: 4
Views: 213

Re: missed question test 1

convert the g/mol mass to moles and multiply that by the molar ratio and then multiply by the g/mol mass of Si to get grams of Si
by AveryAgosto
Thu Dec 05, 2019 8:13 pm
Forum: Amphoteric Compounds
Topic: H2O
Replies: 8
Views: 48

Re: H2O

yes. Water can act as an acid or a base
by AveryAgosto
Thu Dec 05, 2019 8:13 pm
Forum: Bronsted Acids & Bases
Topic: Strong Bases
Replies: 3
Views: 42

Re: Strong Bases

on page F75 in the textbook there is a little chart that gives you the common strong acids and bases that are the ones we should memorize.
by AveryAgosto
Thu Dec 05, 2019 8:10 pm
Forum: Ionic & Covalent Bonds
Topic: Hydrogen bonding
Replies: 2
Views: 98

Re: Hydrogen bonding

Yes. F, O, and N are the only ones that hydrogen bond.
by AveryAgosto
Fri Nov 29, 2019 11:57 am
Forum: Lewis Acids & Bases
Topic: Bonds and pH
Replies: 4
Views: 29

Re: Bonds and pH

the longer and weaker a bond is, the more likely it is to be soluble in water and dissociate. it is the opposite for short and strong bonds
by AveryAgosto
Fri Nov 29, 2019 11:55 am
Forum: Bronsted Acids & Bases
Topic: Difference between bronsted and lewis acid/base?
Replies: 6
Views: 46

Re: Difference between bronsted and lewis acid/base?

My TA showed us in a table like this:

Acid Base

Bronsted : proton donor proton acceptor

Lewis : electron acceptor electron donor
by AveryAgosto
Fri Nov 29, 2019 11:51 am
Forum: Bronsted Acids & Bases
Topic: Bronsted Acid and base
Replies: 8
Views: 77

Re: Bronsted Acid and base

Bronsted Acid = proton donor
Bronsted Base = proton acceptor
by AveryAgosto
Fri Nov 29, 2019 11:49 am
Forum: Bronsted Acids & Bases
Topic: Naming Acids and Bases
Replies: 3
Views: 44

Re: Naming Acids and Bases

I think Lavelle emailed us a chart that is supposed to help.
by AveryAgosto
Fri Nov 29, 2019 11:46 am
Forum: Student Social/Study Group
Topic: Preparing for the final
Replies: 25
Views: 269

Re: Preparing for the final

I felt the same as you did. I did all the homework problems and still felt unprepared for the midterm. I think going to TA and peer learning workshops where extra problems are provided is another good way. Review sessions and khan academy videos can be helpful too.
by AveryAgosto
Sun Nov 17, 2019 5:57 pm
Forum: Student Social/Study Group
Topic: test 2
Replies: 8
Views: 97

Re: test 2

Homework and chemistry community responses are worth 50 points each and each test is also worth 50 points each.
by AveryAgosto
Sun Nov 17, 2019 5:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: two central atoms
Replies: 3
Views: 32

Re: two central atoms

We didn't go over this scenario in lecture so I would assume it's not something we need to know for this week. However, you could determine that the bond angle would be 180 between the central atoms and the structure around each central atom would depend on the atoms around it.
by AveryAgosto
Sun Nov 17, 2019 5:54 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: single, double, and triple bonds
Replies: 6
Views: 59

Re: single, double, and triple bonds

In regards to VSEPR I think that multiple bonds have higher electron density than a single bond, because the electrons take up more space.
by AveryAgosto
Sun Nov 17, 2019 5:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 19
Views: 207

Re: Test 2

By drawing the most stable lewis structure, you will be able to determine the correct shape.
by AveryAgosto
Sun Nov 17, 2019 5:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: repulsion strength
Replies: 5
Views: 35

Re: repulsion strength

The strength of the bonds determine the repulsion and the shape of the molecule. LP-LP has the strongest repulsion.
by AveryAgosto
Sun Nov 17, 2019 5:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Grading
Replies: 7
Views: 92

Re: Grading

I think all life science chemistry classes are curved so that the average is a B. So if the class average was a 70 than a 70 would become a B and everything else would shift as well.
by AveryAgosto
Sun Nov 17, 2019 5:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR repulsion model
Replies: 8
Views: 75

Re: VSEPR repulsion model

Repulsion helps to determine shape and bond angle. The stronger bonds must be further apart.
by AveryAgosto
Sat Nov 16, 2019 9:29 pm
Forum: General Science Questions
Topic: Midterm
Replies: 7
Views: 118

Re: Midterm

Talking to your TA or go to office hours
by AveryAgosto
Sat Nov 16, 2019 9:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Acids and Bases
Replies: 4
Views: 38

Re: Acids and Bases

This isn't anything in the homework problems so I think its not necessary to know.
by AveryAgosto
Sat Nov 16, 2019 9:24 pm
Forum: General Science Questions
Topic: Test 2
Replies: 5
Views: 51

Re: Test 2

Anything covered before the midterm that we weren't tested on and anything covered up until Friday.
by AveryAgosto
Sat Nov 16, 2019 9:20 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 8
Views: 75

Re: Bond Angles

I think memorizing them would be a good idea but he didn't specifically say we needed to memorize it.
by AveryAgosto
Sat Nov 16, 2019 9:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: What is VSPER
Replies: 14
Views: 218

Re: What is VSPER

VSEPR stands for Valence shell electron pair repulsion but he said we didn't need to memorize it.
by AveryAgosto
Sat Nov 16, 2019 9:18 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test #2
Replies: 4
Views: 41

Re: Test #2

Any points not on the midterm from Chemical Bonds section and material covered last week.
by AveryAgosto
Sat Nov 16, 2019 9:15 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Melting Points
Replies: 7
Views: 60

Re: Melting Points

Memorizing the specific melting points isn't necessary but you can assume the boiling point from the interaction.
by AveryAgosto
Sat Nov 02, 2019 1:53 pm
Forum: Dipole Moments
Topic: Induced Dipole
Replies: 5
Views: 70

Re: Induced Dipole

A dipole-induced dipole attraction is a weak attraction that happens when a polar molecule induces a dipole in an atom or in a nonpolar molecule by disturbing the arrangement of electrons in the nonpolar species.
by AveryAgosto
Sat Nov 02, 2019 1:53 pm
Forum: Photoelectric Effect
Topic: Work Function
Replies: 6
Views: 71

Re: Work Function

The work function is the required about of energy to remove an electron. It refers to the photoelectric effect.
by AveryAgosto
Sat Nov 02, 2019 1:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Midterm
Replies: 6
Views: 102

Re: Midterm

My TA didn't mention anything about it in section so I don’t think we would be tested over it unless he mentions it in class Monday before the midterm.
by AveryAgosto
Sat Nov 02, 2019 1:50 pm
Forum: Ionic & Covalent Bonds
Topic: Midterm
Replies: 28
Views: 284

Re: Midterm

fundamentals, quantum, and chemical bonds up to 2D
by AveryAgosto
Sat Nov 02, 2019 1:48 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Energy change and Energy of photon
Replies: 5
Views: 52

Re: Energy change and Energy of photon

You cant have negative energy of a photon so just because the energy change is negative it doesn't mean you have negative energy.
by AveryAgosto
Mon Oct 14, 2019 11:23 pm
Forum: Properties of Light
Topic: Wave Frequency
Replies: 9
Views: 97

Re: Wave Frequency

I think it is the amount of energy in each individual photon because of the wave model.
by AveryAgosto
Mon Oct 14, 2019 11:20 pm
Forum: Balancing Chemical Reactions
Topic: Writing Out Reactions
Replies: 6
Views: 194

Re: Writing Out Reactions

Yes eventually we will need to be able to write a chemical equation from the name of the equation.
by AveryAgosto
Mon Oct 14, 2019 11:19 pm
Forum: DeBroglie Equation
Topic: De Broglie's Equation
Replies: 13
Views: 128

Re: De Broglie's Equation

Any problem referring to wavelength, velocity, and mass.
by AveryAgosto
Mon Oct 14, 2019 11:17 pm
Forum: DeBroglie Equation
Topic: de Broglie vs Heisenberg
Replies: 2
Views: 40

Re: de Broglie vs Heisenberg

De Broglie refers to wavelength, velocity and mass whereas Heisenberg refers to position and nuclear diameter.
by AveryAgosto
Mon Oct 14, 2019 11:13 pm
Forum: Properties of Light
Topic: Angstrom
Replies: 10
Views: 89

Re: Angstrom

Most exam questions will tell you specifically what units to convert your answer to.
by AveryAgosto
Fri Oct 11, 2019 11:33 am
Forum: Balancing Chemical Reactions
Topic: Balancing Chemical Reactions
Replies: 20
Views: 474

Re: Balancing Chemical Reactions

I find that writing the amount of each reactant and each product helps me visualize what I need to add to make the equation balanced.
by AveryAgosto
Fri Oct 11, 2019 11:32 am
Forum: Empirical & Molecular Formulas
Topic: Mass Percentage Question
Replies: 9
Views: 422

Re: Mass Percentage Question

To determine mass percentage composition you find the molar mass of the compound then find the molar mass of each element in the compound and divide each elements mass by the total mass and multiply by 100 to find the percentage.
by AveryAgosto
Fri Oct 11, 2019 11:29 am
Forum: Limiting Reactant Calculations
Topic: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
Replies: 68
Views: 3176

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

You definitely receive credit for coming to the correct answer but in order to get the most partial credit possible you should write it out step by step.
by AveryAgosto
Fri Oct 11, 2019 11:27 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Wavelength Plausibility
Replies: 30
Views: 1321

Re: Wavelength Plausibility

Anything smaller than 10^-15 is not detectable.
by AveryAgosto
Fri Oct 11, 2019 11:25 am
Forum: Ideal Gases
Topic: Reading the textbook [ENDORSED]
Replies: 134
Views: 101390

Re: Reading the textbook [ENDORSED]

I would recommend reading the textbook to facilitate what is taught in lecture. If you don't feel confident about a certain topic reading the chapter and reading along with the examples in the chapter is really helpful.
by AveryAgosto
Tue Oct 08, 2019 3:49 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Test 1 [ENDORSED]
Replies: 107
Views: 4753

Re: Test 1 [ENDORSED]

It is a written exam so all questions will be answered in the test booklet you are provided in discussion.
by AveryAgosto
Sun Oct 06, 2019 11:07 pm
Forum: Balancing Chemical Reactions
Topic: Fractions
Replies: 20
Views: 438

Re: Fractions

I would assume changing the fraction to an integer is the only way you would get full credit. The purpose of making a fraction is so that it's easy to convert all of the elements coefficients to whole numbers.
by AveryAgosto
Sun Oct 06, 2019 11:05 pm
Forum: Empirical & Molecular Formulas
Topic: Writing Empirical Formulas
Replies: 8
Views: 144

Re: Writing Empirical Formulas

I think for the material we are learning in 14A, the order is not important. I think the ratio's are the important part.
by AveryAgosto
Sun Oct 06, 2019 11:03 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Reactions
Replies: 25
Views: 556

Re: Balancing Reactions

The law of conservation of mass states that mass cannot be created are destroyed and the reactants and products must have the same mass.
by AveryAgosto
Sun Oct 06, 2019 11:01 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Theoretical vs. Actual Yield
Replies: 38
Views: 1914

Re: Theoretical vs. Actual Yield

The theoretical yield is the amount produced when a reaction is completed with 100% efficiency. The actual yield is the amount that is actually produced by the reaction.
by AveryAgosto
Sun Oct 06, 2019 10:56 pm
Forum: Limiting Reactant Calculations
Topic: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
Replies: 68
Views: 3176

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

I would recommend showing all of your work regardless of the method you use. For free response tests its always better to show more work for partial credit purposes. I feel like showing that you know the process will be more important and get you more credit than getting the answer correct.

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