Search found 65 matches

by Sean Tran 2K
Sun Mar 01, 2020 11:46 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Kelvin or Celsius?
Replies: 47
Views: 500

Re: Kelvin or Celsius?

Use Kelvin, as the gas constant R includes it.
by Sean Tran 2K
Sun Mar 01, 2020 11:44 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Electrolytes vs electrodes
Replies: 5
Views: 29

Re: Electrolytes vs electrodes

Electrodes connect cells, while electrolytes are ions.
by Sean Tran 2K
Sun Mar 01, 2020 11:43 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Enzyme
Replies: 4
Views: 824

Re: Enzyme

An enzyme is a biological catalyst that allows for reactions to proceed faster.
by Sean Tran 2K
Sun Mar 01, 2020 11:42 pm
Forum: General Rate Laws
Topic: Preferred way to write reaction rate
Replies: 5
Views: 46

Re: Preferred way to write reaction rate

The way it is written does not matter, it just makes it more easily understandable.
by Sean Tran 2K
Sun Mar 01, 2020 11:40 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Kinetics in Test 2?
Replies: 13
Views: 103

Re: Kinetics in Test 2?

Kinetics is not included in Test 2, only up to Electrochemistry.
by Sean Tran 2K
Sun Feb 23, 2020 11:39 pm
Forum: Balancing Redox Reactions
Topic: Test 2 Topics
Replies: 7
Views: 49

Re: Test 2 Topics

Test 2 covers the last bit of Thermodynamics that wasn't on the midterm, as well as electrochemistry
by Sean Tran 2K
Sun Feb 23, 2020 11:38 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: STP
Replies: 13
Views: 82

Re: STP

273 K and 1atm under STP. It should be provided during tests.
by Sean Tran 2K
Sun Feb 23, 2020 11:37 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: G(not) and G
Replies: 15
Views: 109

Re: G(not) and G

G(not) represents standard Gibbs Free energy.
by Sean Tran 2K
Sun Feb 23, 2020 11:36 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Test 2
Replies: 13
Views: 81

Re: Test 2

The test should cover the end of thermo, as well as electrochemistry.
by Sean Tran 2K
Sun Feb 23, 2020 11:35 pm
Forum: Balancing Redox Reactions
Topic: Test 2
Replies: 9
Views: 68

Re: Test 2

The test will be week 9 in discussion
by Sean Tran 2K
Sun Feb 09, 2020 11:31 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: X is to small
Replies: 8
Views: 83

Re: X is to small

X is dropped when it is less than 10^-3 and the percent at the end is less than 5
by Sean Tran 2K
Sun Feb 09, 2020 11:30 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE BOX
Replies: 27
Views: 179

Re: ICE BOX

If X is less than 10^-3
by Sean Tran 2K
Sun Feb 09, 2020 11:25 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Partial Pressure
Replies: 7
Views: 80

Re: Partial Pressure

Partial pressure is based upon the pressures of the gases in a reaction.
by Sean Tran 2K
Sun Feb 09, 2020 11:13 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Le Chatelier's Principle
Replies: 5
Views: 23

Re: Le Chatelier's Principle

Increasing pressure and decreasing volume increases concentration on the side with a greater amount of moles.
by Sean Tran 2K
Sun Feb 09, 2020 11:10 pm
Forum: Ideal Gases
Topic: Gas constant
Replies: 10
Views: 57

Re: Gas constant

The value used is dependent on the units given.
by Sean Tran 2K
Sun Feb 02, 2020 11:50 pm
Forum: Phase Changes & Related Calculations
Topic: Calorimeters
Replies: 8
Views: 47

Re: Calorimeters

Bomb calorimeters are isolated systems.
by Sean Tran 2K
Sun Feb 02, 2020 11:39 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Delta q and delta h
Replies: 5
Views: 37

Re: Delta q and delta h

Q is heat transfer, while H is enthalpy.
by Sean Tran 2K
Sun Feb 02, 2020 11:36 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: H2O as a Gas
Replies: 12
Views: 90

Re: H2O as a Gas

Yes, include H2O as a gas, but not liquid.
by Sean Tran 2K
Sun Feb 02, 2020 11:32 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Temperature
Replies: 14
Views: 75

Re: Temperature

Negative delta H shows a release of energy, being exothermic
by Sean Tran 2K
Sun Feb 02, 2020 11:16 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Changing the energy of a system
Replies: 9
Views: 45

Re: Changing the energy of a system

You can change heat, mass, or do work on the system.
by Sean Tran 2K
Sun Jan 26, 2020 10:35 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Changing K
Replies: 13
Views: 79

Re: Changing K

K is changed by change in temperature.
by Sean Tran 2K
Sun Jan 26, 2020 10:34 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Gas Constant
Replies: 13
Views: 60

Re: Gas Constant

The gas constant needed will be based on the units of pressure. The constants should be on the formula sheets during tests.
by Sean Tran 2K
Sun Jan 26, 2020 10:27 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: exothermic reactions
Replies: 19
Views: 113

Re: exothermic reactions

Increasing heat in an exothermic reaction favors the reactants.
by Sean Tran 2K
Sun Jan 26, 2020 10:19 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: endothermic
Replies: 8
Views: 40

Re: endothermic

Increasing temperature in an endothermic reaction would favor the forward reaction.
by Sean Tran 2K
Sun Jan 26, 2020 10:17 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic reaction
Replies: 18
Views: 85

Re: Exothermic reaction

In an exothermic reaction, decreasing the temperature will favor the formation of products, while increasing temperature would favor formation of reactants.
by Sean Tran 2K
Sun Jan 12, 2020 11:32 pm
Forum: Ideal Gases
Topic: K and Units
Replies: 7
Views: 32

Re: K and Units

Due to K being a ratio, it does not have units.
by Sean Tran 2K
Sun Jan 12, 2020 11:27 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homogenous Equilibrium
Replies: 13
Views: 59

Re: Homogenous Equilibrium

Is there a certain significance to homogeneous and heterogeneous equilibrium? Or do we just need to know what they are?
by Sean Tran 2K
Sun Jan 12, 2020 11:25 pm
Forum: Ideal Gases
Topic: Aqueous Solutions
Replies: 4
Views: 28

Re: Aqueous Solutions

It is correct that solids and liquids are omitted from equilibrium constant concentrations. Aqueous solutions are included in the calculations.
by Sean Tran 2K
Sun Jan 12, 2020 11:23 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Types of Equilibrium Constants
Replies: 7
Views: 39

Re: Types of Equilibrium Constants

When there are gases, use Kp to show partial pressure, and when there are aqueous solutions, use Kc to show molarity.
by Sean Tran 2K
Sun Jan 12, 2020 11:21 pm
Forum: Ideal Gases
Topic: Q vs. K
Replies: 10
Views: 53

Re: Q vs. K

Q and K are both calculated similarly, but Q can be calculated at any time during the reaction and can be compared with K to determine the direction in which the reaction is favored.
by Sean Tran 2K
Sun Dec 01, 2019 8:22 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Number
Replies: 4
Views: 38

Re: Coordination Number

The coordination number of a central atom on a molecule refers to the number of bonds on it.
by Sean Tran 2K
Sun Dec 01, 2019 8:19 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 5
Views: 75

Re: Cisplatin

I thought the only thing regarding the structure of cisplatin we needed to remember was what side the Cl atoms were on.
by Sean Tran 2K
Sun Dec 01, 2019 8:13 pm
Forum: Hybridization
Topic: Writing the hydrization
Replies: 10
Views: 120

Re: Writing the hydrization

Since we’re on the topic of writing hybridization, does it matter if we write d hybridization before s and p? Or can we out it after.
by Sean Tran 2K
Sun Dec 01, 2019 8:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sigma Bond
Replies: 10
Views: 71

Re: Sigma Bond

Sigma bonds exist in single, double, and triple bonds.
by Sean Tran 2K
Sun Dec 01, 2019 8:09 pm
Forum: Lewis Acids & Bases
Topic: Proton acceptor and proton donor?
Replies: 33
Views: 208

Re: Proton acceptor and proton donor?

Acids give H+ ions (protons). Bases receive H+ ions.
by Sean Tran 2K
Sun Nov 24, 2019 10:48 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Transition Metals
Replies: 7
Views: 67

Re: Transition Metals

Yes, the transition metals in the d-block all can form coordination compounds.
by Sean Tran 2K
Sun Nov 24, 2019 10:39 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: How to draw dipoles
Replies: 7
Views: 51

Re: How to draw dipoles

You will have the arrow pointing to the more electronegative atom, as well as the slightly negative and positive symbols on the respective atoms.
by Sean Tran 2K
Sun Nov 24, 2019 10:30 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Drawing molecules
Replies: 7
Views: 63

Re: Drawing molecules

Organic molecules are covered in future Chem courses, being 14C and 14D.
by Sean Tran 2K
Sun Nov 24, 2019 10:22 pm
Forum: Biological Examples
Topic: Coordination Compounds
Replies: 2
Views: 40

Re: Coordination Compounds

I'm not too sure what exactly, so you may want to go over the examples we covered in lectures and ask your TA/Lavelle for more information.
by Sean Tran 2K
Sun Nov 24, 2019 9:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Hybridization
Replies: 7
Views: 53

Re: Hybridization

In addition to the s and p orbitals, the d orbitals can be used in hybridization as well.
by Sean Tran 2K
Sun Nov 03, 2019 8:15 pm
Forum: Octet Exceptions
Topic: Elements with Exceptions to Octet Rule
Replies: 1
Views: 24

Re: Elements with Exceptions to Octet Rule

Typically, atoms in the third period or further down are exceptions to the Octet Rule, as they can use the d-orbitals for extra valence electrons.
by Sean Tran 2K
Sun Nov 03, 2019 8:12 pm
Forum: Lewis Structures
Topic: Which element at center of the structure
Replies: 6
Views: 44

Re: Which element at center of the structure

The least electronegative atom is placed in the center of the electron structures, with the exception of Hydrogen, which will never be in the center.
by Sean Tran 2K
Sun Nov 03, 2019 8:10 pm
Forum: Octet Exceptions
Topic: Expanded Valence Shells
Replies: 6
Views: 46

Re: Expanded Valence Shells

Atoms within the third period or past that can have expanded valence shells for electrons, since they have the d-orbitals.
by Sean Tran 2K
Sun Nov 03, 2019 8:07 pm
Forum: Electronegativity
Topic: size
Replies: 8
Views: 46

Re: size

The atomic radius of an atom increases as you go down the periodic table and towards the left.
by Sean Tran 2K
Sun Nov 03, 2019 8:05 pm
Forum: Bond Lengths & Energies
Topic: Strength of Bonds
Replies: 16
Views: 110

Re: Strength of Bonds

The double and triple covalent bonds are stronger than the single bonds, as more electrons are shared. As a result, these bonds are shorter.
by Sean Tran 2K
Sun Oct 27, 2019 6:47 pm
Forum: Resonance Structures
Topic: Bond lenghts.
Replies: 11
Views: 84

Re: Bond lenghts.

If we were required to know bond lengths, I think the values would be given to us to use in whatever calculations are required.
by Sean Tran 2K
Sun Oct 27, 2019 6:43 pm
Forum: Lewis Structures
Topic: Clarification
Replies: 6
Views: 70

Re: Clarification

We are saying that there are exceptions to the octet rule, as formal charges of zero take priority, but these exceptions will still mean that the atom breaking the octet rule would have more than 8 atoms or no?
by Sean Tran 2K
Sun Oct 27, 2019 6:38 pm
Forum: Octet Exceptions
Topic: Exceeding the Octet Rule
Replies: 5
Views: 76

Re: Exceeding the Octet Rule

Central atoms in the 3rd period or further down are able to accommodate more than 8 electrons due to having the d-orbitals available, as d-orbitals start becoming available at n=3.
by Sean Tran 2K
Sun Oct 27, 2019 6:29 pm
Forum: Resonance Structures
Topic: Determining Resonance Structures
Replies: 6
Views: 63

Re: Determining Resonance Structures

I thought that resonance structures were "ideal" when the formal charges of the atoms were equal to 0? Or close to that value in some cases.
by Sean Tran 2K
Sun Oct 27, 2019 6:26 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Bonds
Replies: 11
Views: 95

Re: Covalent Bonds

Indeed, and covalent bonds are different than ionic bonds because electrons are shared between the non-metals.
by Sean Tran 2K
Sun Oct 20, 2019 11:46 pm
Forum: Trends in The Periodic Table
Topic: Electron affinity
Replies: 5
Views: 134

Re: Electron affinity

The trend for electron affinity and electronegativity is the same, but what are the differences between the two? Or rather, how similar or they?
by Sean Tran 2K
Sun Oct 20, 2019 11:45 pm
Forum: Trends in The Periodic Table
Topic: memorization
Replies: 3
Views: 49

Re: memorization

A quick tip for trends is that atomic radius increases as you go down and left, while ionization energy and electronegativity increase as you go up and to the right. In addition to these, I believe another trend is that elements as you go down and to the left on the periodic table tend to have more...
by Sean Tran 2K
Sun Oct 20, 2019 11:43 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Exceptions in Electron Configurations
Replies: 5
Views: 47

Exceptions in Electron Configurations

So in lecture, I remember there was a briefing discussion regarding the exceptions of the configurations of electrons in the groups with Chromium and Copper, taking one electron from the s orbitals to half fill their d-orbital. Is there a specific reason regarding the energy of these and why the def...
by Sean Tran 2K
Sun Oct 20, 2019 11:39 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration and orbital diagram
Replies: 1
Views: 23

Re: Electron Configuration and orbital diagram

Orbital diagrams are used to display the electrons within an atom. According to Hund's Rule, an each orbital in a subshell will have one electron in each at the ground state, and these unpaired electrons will generally be spinning up initially. When all the orbitals are filled, electrons will begin ...
by Sean Tran 2K
Sun Oct 20, 2019 11:32 pm
Forum: Trends in The Periodic Table
Topic: ionization energy
Replies: 11
Views: 419

Re: ionization energy

The first ionization energy of an electron is the energy required to remove the first electron from a ground state atom. The trend for this is seen on the periodic table as you go to the right and up.
by Sean Tran 2K
Sun Oct 13, 2019 11:11 pm
Forum: Properties of Light
Topic: Angstrom
Replies: 10
Views: 83

Re: Angstrom

I think that most questions, at least on the tests, would ask for a specific unit for the final answer to be in.
by Sean Tran 2K
Sun Oct 13, 2019 11:09 pm
Forum: Significant Figures
Topic: sig figs and periodic tables
Replies: 11
Views: 238

Re: sig figs and periodic tables

When I use the periodic table for math on problems, I take the entire number shown on it, then round off my final answer to the required number of sig figs, in hopes of retaining accuracy.
by Sean Tran 2K
Sun Oct 13, 2019 9:54 pm
Forum: Properties of Light
Topic: When to use the Planck's Constant?
Replies: 6
Views: 43

Re: When to use the Planck's Constant?

I believe that Planck's Constant (h) is also able to be used when determining the energy level of an electron.
En = -hR/n2
by Sean Tran 2K
Sun Oct 13, 2019 9:44 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Test 1 [ENDORSED]
Replies: 107
Views: 4005

Re: Test 1 [ENDORSED]

Can someone explain what Angstroms are? I was confused on the test on this question. Angstroms are a unit of length equivalent to 10^(-10) m. I was taken aback by this question on the test as I do not ever remember being told we had to memorize the quant. value of Angstroms. Did I miss that in clas...
by Sean Tran 2K
Sun Oct 13, 2019 9:43 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Test 1 [ENDORSED]
Replies: 107
Views: 4005

Re: Test 1 [ENDORSED]

I don't think sig figs were looked at too carefully for this test.

Also, I believe questions heading in the direction are given partial credit, and the grader will read through your work.
by Sean Tran 2K
Sun Oct 06, 2019 10:37 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical Ratio Rounding
Replies: 6
Views: 86

Re: Empirical Ratio Rounding

As Ami mentioned, .9 would be okay to round up for figuring out empirical formulas, but what if it is .8?
by Sean Tran 2K
Sun Oct 06, 2019 10:05 pm
Forum: SI Units, Unit Conversions
Topic: Calculators Permitted on the Test
Replies: 2
Views: 38

Re: Calculators Permitted on the Test

I believe a CASIO scientific calculator is permitted, as it meets the criteria listed on the syllabus. I will personally be using a TI-36X scientific calculator which (hopefully) should work.
by Sean Tran 2K
Sun Oct 06, 2019 10:00 pm
Forum: Significant Figures
Topic: Reviewing Sig Figs
Replies: 3
Views: 56

Re: Reviewing Sig Figs

On the class website, there is a link that will lead you to a PDF for assistance regarding sig figs. It has examples included, so it doesn't contain strictly definitions.
by Sean Tran 2K
Sun Oct 06, 2019 9:58 pm
Forum: Significant Figures
Topic: Sig Figs
Replies: 3
Views: 29

Re: Sig Figs

In addition to resources already listed, the class website for 14A has something that will help with sig figs. It provides a link to a document covering how to use sig figs.
by Sean Tran 2K
Sun Oct 06, 2019 3:04 pm
Forum: Significant Figures
Topic: Sig Fig Test Importance
Replies: 2
Views: 40

Re: Sig Fig Test Importance

Based on what I've read on other posts on this regarding the usage of sig figs, I think sig figs are required for the first test. Even if they aren't required for the first test, I'm sure that learning them now in preparation for future tests won't hurt you.

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