## Search found 96 matches

Wed Mar 11, 2020 6:04 pm
Forum: Administrative Questions and Class Announcements
Topic: final
Replies: 14
Views: 219

### Re: final

I agree I think we just have to wait for more information, but I assume it will still be 3 hours.
Tue Mar 10, 2020 8:05 pm
Forum: Second Order Reactions
Topic: 7B.13 Numerator
Replies: 2
Views: 49

### 7B.13 Numerator

For this problem, when it asks for one sixteenth or one fourth, we change the numerator (e.g. to 16/[A]o).
What's the math behind this?
Sun Mar 01, 2020 11:57 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Corrosion
Replies: 5
Views: 54

### Re: Corrosion

I think we need to know about rust for the corrosion section
Sun Mar 01, 2020 11:56 pm
Forum: Balancing Redox Reactions
Topic: Determining direction of flow
Replies: 15
Views: 178

### Re: Determining direction of flow

The cell diagram always has the anode on the left and the cathode to the right to demonstrate this, so the electrons would move from the anode to the cathode
Sun Mar 01, 2020 11:55 pm
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: rust
Replies: 9
Views: 143

### Re: rust

I think we just need to know the half reaction for rust.
Sun Mar 01, 2020 11:54 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: n value
Replies: 9
Views: 141

### Re: n value

Both the oxidation and reduction half reaction would have the same number of electrons transferred between them, so this would be your n.
Sun Mar 01, 2020 11:53 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: n in Equation
Replies: 6
Views: 56

### Re: n in Equation

Look for the number of electrons being transferred between the half reactions
Sun Mar 01, 2020 11:53 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: anodes and cathodes
Replies: 1
Views: 14

### Re: anodes and cathodes

cathode is where reduction occurs and the anode is where oxidation occurs

In a cell diagram, the anode is on the left side while the cathode is on the right.
Wed Feb 26, 2020 1:42 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6M.5
Replies: 1
Views: 60

### 6M.5

For each reaction that is spontaneous under standard conditions (that is, K . 1), write a cell diagram, determine the standard cell potential, and calculate deltaG for the reaction: (a) 2NO32(aq)18H1(aq)16Hg(l)S ~~For the cell diagram, why would the right side only be balanced with Platinum vs the l...
Sun Feb 23, 2020 6:11 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Boltzmann Formula
Replies: 11
Views: 193

### Re: Boltzmann Formula

w refers to the number of possible states/possible orientations
Sun Feb 23, 2020 6:10 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Spontaneous
Replies: 23
Views: 367

### Re: Spontaneous

Gibbs Free Energy being at zero signals that the reaction is at equilibrium
Sun Feb 23, 2020 6:09 pm
Forum: Van't Hoff Equation
Topic: Significance of Van't Hoff Equation
Replies: 8
Views: 106

### Re: Significance of Van't Hoff Equation

My TA said that something like this equation was just a way of mathematically showing that heating an endothermic reaction favors products vs heating an exothermic favors reactants
Sun Feb 23, 2020 6:08 pm
Forum: Balancing Redox Reactions
Topic: Flow of electrons
Replies: 11
Views: 91

### Re: Flow of electrons

Electrons flow from the anode to cathode usually so I don't think there's an exception
Sun Feb 23, 2020 6:06 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: neg vs pos
Replies: 9
Views: 58

### Re: neg vs pos

Positive voltage = spontaneous reaction
Negative voltage = nonspontaneous reaction
Sun Feb 23, 2020 6:05 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Anode & cathode
Replies: 5
Views: 71

### Re: Anode & cathode

My TA mentioned how oxidation is related to the anode because both started with vowels while the cathode is with reduction because both started with consonants.
Sun Feb 23, 2020 6:04 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: chemistry community posts
Replies: 12
Views: 80

### Re: chemistry community posts

5 posts constitute one week
Sun Feb 23, 2020 6:03 pm
Forum: Van't Hoff Equation
Topic: Significance of Van't Hoff Equation
Replies: 8
Views: 106

### Re: Significance of Van't Hoff Equation

Van't Hoff allows us to find K at different temperatures from Gibb's since K changes when the temperature does
Sun Feb 23, 2020 5:58 pm
Forum: Balancing Redox Reactions
Topic: Identifying Half Reactions
Replies: 4
Views: 70

### Re: Identifying Half Reactions

Gaining electrons is reduction (going for negative) and losing electrons is oxidation (going for positive)
Mon Feb 17, 2020 5:37 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Is spontaneity determined by entropy or free energy?
Replies: 9
Views: 638

### Re: Is spontaneity determined by entropy or free energy?

Spotaneity is determined by both as presented in the chart above, but either could be used in order to see whether a reaction is spontaneous or not
Mon Feb 17, 2020 5:35 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Constant R
Replies: 15
Views: 274

### Re: Constant R

You can find the units used on the equation sheet

Just look for what units the problem gives you and what you are trying to get. Using R with the right units allows you to cancel out the things you don't need in order to get what you want
Mon Feb 17, 2020 5:33 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible vs Irreversible
Replies: 7
Views: 139

### Re: Reversible vs Irreversible

It's also important to note that reversible does the most amount of work.
Mon Feb 17, 2020 5:32 pm
Forum: Calculating Work of Expansion
Topic: Work Equation
Replies: 6
Views: 180

### Re: Work Equation

Irreversible uses w=-Pex * deltaV

Reversible uses w=-nRTln(V2/V1) (Does the most work)

Usually the problem will be explicit in whether a reaction is reversible or irreversible
Mon Feb 17, 2020 5:27 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: isothermal reactions
Replies: 8
Views: 204

### Re: isothermal reactions

For isothermal, there is no change in temperature therefore there is no change in internal energy
Mon Feb 17, 2020 5:25 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Cv vs Cp
Replies: 17
Views: 282

### Re: Cv vs Cp

Cv is constant volume and Cp is constant pressure
Mon Feb 17, 2020 5:24 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Midterm Curve
Replies: 45
Views: 517

### Re: Midterm Curve

I don't think the midterm itself is curved
Sun Feb 09, 2020 11:45 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: DeltaH
Replies: 2
Views: 32

### Re: DeltaH

Delta H stands for Change in Enthalpy

H - Enthalpy
Delta - Change in
Sun Feb 09, 2020 11:43 pm
Forum: Ideal Gases
Topic: Gas constant
Replies: 10
Views: 129

### Re: Gas constant

Choosing which R to use depends on what units you are trying to cancel out in order to solve for your specific answer.
Sun Feb 09, 2020 9:02 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Constant T,P,V
Replies: 4
Views: 52

### Re: Constant T,P,V

Most of these variables will be given in the question in order to solve.

There was also a list put up with some useful terms that describe whether some things are constant, like "isothermal" for constant temperature or "isochoric" for constant volume.
Sun Feb 09, 2020 9:00 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: First Law of Themordynamics
Replies: 4
Views: 51

### Re: First Law of Themordynamics

I think for all intents and purposes they represent the same idea.
Sun Feb 09, 2020 8:59 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Useful Summary of Thermodynamic Definitions
Replies: 34
Views: 14699

### Re: Useful Summary of Thermodynamic Definitions

Thank you!

I think we will need to know these terms for the test in order to interpret problems
Sun Feb 09, 2020 8:57 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Difference between Cv and Cp?
Replies: 8
Views: 79

### Difference between Cv and Cp?

Do they represent the same value or no?

I looked some stuff up and what I've seen has varied
Wed Jan 29, 2020 5:36 pm
Forum: Calculating Work of Expansion
Topic: Converting gas volume to mols
Replies: 2
Views: 29

### Converting gas volume to mols

When you convert a gas to mols, they said you turn it from Liters to Mols through the conversion factor of:

1mol/22.4

but I'm not entirely certain if this is accurate or not
Fri Jan 24, 2020 9:47 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: pKa and pKb
Replies: 17
Views: 206

### Re: pKa and pKb

pKa + pKa = Kw (autoprotolysis constant) = 14

This equation can be flipped around respectively to find a value you need.
Fri Jan 24, 2020 9:45 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatelier's Principle
Replies: 19
Views: 247

### Re: Le Chatelier's Principle

Le Chatelier's Principle applies whenever a system is "disturbed" in the sense that reactants or products are added/removed.
Fri Jan 24, 2020 9:44 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Temperature
Replies: 6
Views: 78

### Re: Temperature

Increasing and decreasing temperature changes the value of K because it acts as either a product or reactant (exothermic or endothermic respectively)
Fri Jan 24, 2020 9:43 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: exothermic reactions
Replies: 19
Views: 203

### Re: exothermic reactions

Adding heat to an exothermic reaction favors reactants because heat is a product, so thereby increasing the product, it favors the formation of reactants
Fri Jan 24, 2020 9:41 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: definition of a buffer
Replies: 8
Views: 126

### Re: definition of a buffer

A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is added to it.
Fri Jan 24, 2020 9:39 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: solvent
Replies: 10
Views: 57

### Re: solvent

Only include (aq) and (g) in your equilibrium, as solids and liquids/solvents like H2O are not.
Fri Jan 24, 2020 9:36 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: suggestions
Replies: 16
Views: 154

### Re: suggestions

Fri Jan 24, 2020 9:35 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Q and K
Replies: 4
Views: 57

### Re: Q and K

K the point of equilibrium while Q is a reaction quotient by which the reaction is not at equilibrium yet

The value of Q relative to K can give you clues towards which way the reaction is going
Fri Jan 24, 2020 9:33 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: k<10^-3
Replies: 9
Views: 106

### Re: k<10^-3

I think it's just a given concept but not necessarily set in stone for identification purposes
Fri Jan 24, 2020 9:32 pm
Forum: Ideal Gases
Topic: Kc vs Kp
Replies: 43
Views: 520

### Re: Kc vs Kp

You use Kp unless it specifically asks for Kc
Sun Jan 12, 2020 4:53 pm
Forum: Ideal Gases
Topic: Kc and Kp
Replies: 8
Views: 65

### Re: Kc and Kp

I believe Kc deals with Equilibrium Constant concentrations while Kp deals with Equilibrium Constant partial pressures
Sun Jan 12, 2020 4:51 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc vs Kp
Replies: 10
Views: 73

### Re: Kc vs Kp

Tanmay Singhal 1H wrote:I'm confused on why water isn't counted in the K/Q equation.

Water is not counted because water is a liquid

Solids and liquids are not included in the equilibrium constant expressions (K=P/R)
Sun Jan 12, 2020 4:50 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Situations in which Q=K
Replies: 7
Views: 66

### Re: Situations in which Q=K

When Q=K, then the reaction is at equilibrium
Sun Jan 12, 2020 4:49 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Different types of K
Replies: 9
Views: 68

### Re: Different types of K

K = Kc = Kp

They are just different notations for whatever phase your equation is dealing with (e.g. gas w/ pressure)

Similarly, K = Q = Qc = Qp
Sun Jan 12, 2020 4:47 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Equilibrium vs. Non-Equilibrium
Replies: 4
Views: 33

### Re: Equilibrium vs. Non-Equilibrium

If Q does not equal K or vice versa, then I believe you would have to solve for either respectively. If Q is the same value calculated, then the reaction is at equilibrium
Sun Jan 12, 2020 4:45 pm
Forum: Ideal Gases
Topic: Conditions for Ideal Gases
Replies: 5
Views: 68

### Re: Conditions for Ideal Gases

The ideal gas law assumes that conditions of measurement are perfect, but in the experimental sense, they aren't.
Sun Jan 12, 2020 4:43 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Finding K: liquids and aqueous
Replies: 7
Views: 78

### Re: Finding K: liquids and aqueous

While liquids do not have a defined concentration (molarity), aqueous solutions do.
Sun Jan 12, 2020 4:40 pm
Forum: Ideal Gases
Topic: Bars vs atmospheres
Replies: 13
Views: 90

### Re: Bars vs atmospheres

Both work as their respective units of measurement, mostly dealing with gasses and pressure
Sun Jan 12, 2020 4:38 pm
Forum: Ideal Gases
Topic: R in PV=nRT
Replies: 34
Views: 693

### Re: R in PV=nRT

R is the gas constant, should be found on the equations sheet
Sun Nov 17, 2019 6:02 pm
Forum: Ionic & Covalent Bonds
Topic: Character of Bonds
Replies: 7
Views: 93

### Re: Character of Bonds

Maddie wrote:Will he give us the actual electronegativity values on the tests though?

We won't be getting electronegativity values, so we have to know the trend on the periodic table.
Sun Nov 17, 2019 6:01 pm
Forum: Ionic & Covalent Bonds
Topic: London Dispersion
Replies: 13
Views: 148

### Re: London Dispersion

Anokhi Patel 4G wrote:what exactly is london dispersion?

London dispersion is another name for Van der Waals forces, which is essentially really weak and temporary polarizations occurring due to the random movement of electrons in a molecule. It is the weakest intermolecular force and may occur on all molecules.
Sun Nov 17, 2019 5:59 pm
Forum: Lewis Structures
Topic: Carbon Monoxide
Replies: 4
Views: 54

### Re: Carbon Monoxide

Having a triple bond in CO fulfills the octet rule for Carbon has Carbon would want to have an octet.

Satisfying the octet rule precedes Formal charges
Sun Nov 17, 2019 5:56 pm
Forum: Bond Lengths & Energies
Topic: Strongest Bonds
Replies: 11
Views: 326

### Re: Strongest Bonds

Intermolecular strengths are: Ion-dipole, H-bond, Dipole-Dipole, Ion-induced dipole, Dipole-induced dipole, and London Forces
Sun Nov 17, 2019 5:54 pm
Forum: Octet Exceptions
Topic: Octet expansion
Replies: 6
Views: 180

### Re: Octet expansion

Elements after the 3rd period may have expanded octets due to their access to the 3d subshell.
Sun Nov 17, 2019 5:52 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Calculating formal charge
Replies: 8
Views: 211

### Re: Calculating formal charge

Doesn't matter where you start as long as the overall FC of the molecule matches what is given or is at the most favorable FC which is 0.
Sat Nov 09, 2019 10:17 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 9
Views: 104

### Re: Formal Charge

You try to make the formal charge 0 where possible as long as the octet rule is satisfied. If not, you aim for the lowest energy structure possible that satisfies the octet rule, which involves having the lowest number of formal charges, especially with the central atom.
Sat Nov 09, 2019 10:16 pm
Forum: Octet Exceptions
Topic: octet exceptions
Replies: 11
Views: 182

### Re: octet exceptions

Usually any element under the 3rd period may have an expanded octet due to having the whole of the d-block possible in their electron configuration
Sat Nov 09, 2019 10:14 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 18
Views: 394

### Re: Resonance Structures

Resonance structures essentially combine into a resonance hybrid. Each resonance structure describes how possible delocalized electrons may form bonds.
Sat Nov 09, 2019 10:11 pm
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 18
Views: 206

### Re: Drawing Lewis Structures

When you draw Lewis structures, you just try to get the lowest energy structure possible, typically with a 0 formal charge where possible. If not, I think you just make the entire charge of the atom match what is given.
Sat Nov 09, 2019 10:09 pm
Forum: Ionic & Covalent Bonds
Topic: C, N, O, and F
Replies: 13
Views: 180

### Re: C, N, O, and F

These four elements C, N, O, F follow the Octet guideline as they do not have access to the expanded octets found with the d block
Sun Nov 03, 2019 11:23 pm
Forum: DeBroglie Equation
Topic: When to use the DeBroglie equation?
Replies: 6
Views: 95

### Re: When to use the DeBroglie equation?

I think you use De Broglie's for any time you are given any values toward the variables for conversions between them.
Sun Nov 03, 2019 11:21 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Order of removing electrons
Replies: 4
Views: 62

### Re: Order of removing electrons

Once 4s is filled, it has a higher energy than the 3d orbital, so the electrons removed are from 4s, the outermost shell.
Sun Nov 03, 2019 11:20 pm
Forum: Trends in The Periodic Table
Topic: Midterm Question Regarding Metals, Nonmetals, etc
Replies: 2
Views: 39

### Re: Midterm Question Regarding Metals, Nonmetals, etc

I think we just need to know how the concept relates to whatever question is being asked as opposed to actually naming them.
Sun Nov 03, 2019 11:17 pm
Forum: Trends in The Periodic Table
Topic: Does H have the highest ionization energy?
Replies: 4
Views: 57

### Re: Does H have the highest ionization energy?

Flourine has the highest ionization energy, as it requires the most energy in order to lose an electron.

I believe Noble gases are excluded in this case but I'm not too sure.
Sun Nov 03, 2019 11:14 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Degenerate orbitals
Replies: 4
Views: 72

### Re: Degenerate orbitals

"Degenerate" is just a term used to describe the spdf orbitals having the same energy; This applies to a single-electron atom like Hydrogen.

I'm not sure if this was mentioned in lecture but I know for sure that it was mentioned at a review session
Sun Nov 03, 2019 11:11 pm
Forum: Properties of Electrons
Topic: Photoelectric effect
Replies: 5
Views: 239

### Re: Photoelectric effect

Khan Academy and the module were extremely helpful in understanding the topic!
Sun Oct 27, 2019 9:05 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Replies: 6
Views: 110

Sun Oct 27, 2019 9:03 pm
Forum: Trends in The Periodic Table
Topic: Ionization energy
Replies: 12
Views: 206

### Re: Ionization energy

I don't think we have to know the actual equation but rather just the general trend of Ionization Energy in the periodic table.
Sun Oct 27, 2019 12:21 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: HW 1D.23
Replies: 4
Views: 142

### Re: HW 1D.23

For part c, when n=2, it has 2s and 2p are valid orbitals

in which 2s contains 1 subshell orbital (mL=0) and 2p contains 3 subshell orbitals (mL=-1,0,+1)
Sun Oct 20, 2019 11:06 pm
Forum: Einstein Equation
Topic: When do we use the Einstein Equation?
Replies: 14
Views: 417

### Re: When do we use the Einstein Equation?

E = hv is used to solve for the energy of an electron.

Sometimes you are not given v (frequency) therefore you must use c = λν, substituting the v in E=hv for v = c/ λ:

so E = hc/ λ
Sun Oct 20, 2019 11:04 pm
Forum: Photoelectric Effect
Topic: Speed of Light
Replies: 29
Views: 326

### Re: Speed of Light

The speed of light is constant at 2.998x10^8 m.s^-1
Sun Oct 20, 2019 11:03 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: What does the H mean?
Replies: 9
Views: 89

### Re: What does the H mean?

h is Planck's constant but h-bar is h/2pi
Sun Oct 20, 2019 4:23 pm
Forum: Properties of Light
Topic: N levels
Replies: 8
Views: 103

### Re: N levels

n levels are just the levels of energy for an electron in which n is a quantum number (n=1,2,3, etc.). When electrons increase in energy, the n increases.
Sun Oct 20, 2019 4:20 pm
Forum: Properties of Electrons
Topic: Equations for Test
Replies: 9
Views: 133

### Re: Equations for Test

I think all the equations are given to us, but we just have to know when to use them.
Sun Oct 20, 2019 4:19 pm
Forum: DeBroglie Equation
Topic: De Broglie's Equation
Replies: 17
Views: 262

### Re: De Broglie's Equation

Photons do not have mass, only momentum.
Sat Oct 19, 2019 6:30 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Homework Problem 1B.27
Replies: 6
Views: 90

### Re: Homework Problem 1B.27

We use 10 for delta V
Sat Oct 19, 2019 6:26 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: HW 1B #27
Replies: 2
Views: 51

### Re: HW 1B #27

I used 5.00 value for delta v

Edit: Do not use 5.00 value for delta V:

Lavelle addressed this in his solution manual so we use 10 as delta v
https://lavelle.chem.ucla.edu/wp-conten ... rs_7Ed.pdf
Wed Oct 16, 2019 9:19 am
Forum: Properties of Light
Topic: Next test
Replies: 23
Views: 393

### Re: Next test

I think we get an equation sheet
Sat Oct 12, 2019 9:18 pm
Forum: Einstein Equation
Topic: Numbers to memorize [ENDORSED]
Replies: 37
Views: 1763

### Re: Numbers to memorize[ENDORSED]

Helps a lot to memorize when you're doing practice problems but if you forget, there's always a cheat sheet he puts on the test for us to look at with all the constants!
Sat Oct 12, 2019 9:17 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8047
Views: 1413203

### Re: Post All Chemistry Jokes Here

Studying chem has shown me a lot of funny jokes

He He He
Sat Oct 12, 2019 9:15 pm
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 198
Views: 140496

### Re: Rusty on High School Chem[ENDORSED]

I'm also really rusty but so far I think doing the practice problems he has on his Course Outlines (from the 14A website) have been extremely helpful in getting exposed to practice problems. His modules have also helped me a ton in understanding some things I haven't touched up on since 4 years ago!
Sat Oct 12, 2019 9:12 pm
Forum: Properties of Light
Topic: Quantum Levels
Replies: 9
Views: 111

### Re: Quantum Levels

I think there's a limit to how far an atom can be from the nucleus before it is lost as a "free electron."
I'm honestly not entirely sure though.
Sat Oct 12, 2019 9:10 pm
Forum: Photoelectric Effect
Topic: Planck's Constant
Replies: 4
Views: 89

### Re: Planck's Constant

Online it says that he was able to derive this constant from experimental measurements from black-body radiation.
Sat Oct 12, 2019 9:05 pm
Forum: Einstein Equation
Topic: E=hv
Replies: 8
Views: 120

### Re: E=hv

h = Planck's constant (6.626*10^-34 J*s)

It'll be given to us on the front sheet of a test with all the constants, I think
Sat Oct 12, 2019 9:00 pm
Forum: Properties of Light
Topic: Speed of Light
Replies: 41
Views: 1426

### Re: Speed of Light

The speed of light (3. 10^8 m/s) will always be a constant.
Sat Oct 12, 2019 8:59 pm
Forum: Properties of Electrons
Topic: wavelike properties of an electron
Replies: 4
Views: 79

### Re: wavelike properties of an electron

The detectors sense that the electrons had shifted to other points as opposed to a single point due to diffraction, which is demonstrated through the electron's wave-like properties.
Sat Oct 12, 2019 8:56 pm
Forum: DeBroglie Equation
Topic: Concept of a wave
Replies: 7
Views: 135

### Re: Concept of a wave

Also I believe wavelike properties are only demonstrated by objects that are extremely small.

While light does exhibit wavelike properties, the equation cannot be applied towards it.
Sat Oct 12, 2019 8:53 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Test 1 [ENDORSED]
Replies: 107
Views: 5119

### Re: Test 1[ENDORSED]

My TA said the test would be graded the same day so the grades might be up on ccle?
Thu Oct 10, 2019 12:01 am
Forum: Molarity, Solutions, Dilutions
Topic: L37
Replies: 3
Views: 437

### L37

(a) How would you prepare 1.00 L of 0.50 M HNO3 (aq) from “concentrated” (16 M) HNO3 (aq)?

(b) How many milliliters of 0.20 M NaOH(aq) could be neutralized by 100. mL of the diluted solution?

I'm not entirely sure how to begin solving this problem
Thu Oct 03, 2019 11:27 pm
Forum: SI Units, Unit Conversions
Topic: Sig Fig Mistakes
Replies: 17
Views: 312

### Re: Sig Fig Mistakes

I think you round the answer's sig fig to the smallest number at the calculation
Thu Oct 03, 2019 11:23 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Replies: 16
Views: 367

Do you think we will have to memorize the Avogadro's Number for test? I am wondering if I will be given the Avogadro's Number when I get the questions that ask for atoms' number. I don't think we need to memorize the number for the test, I think Lavelle mentioned having a front sheet on tests with ...
Thu Oct 03, 2019 11:19 pm
Forum: Empirical & Molecular Formulas
Topic: What decimal place to round to when taking masses from the Periodic Table?
Replies: 19
Views: 420

### Re: What decimal place to round to when taking masses from the Periodic Table?

Personally I use two to three decimal places but I feel like in test, we should use all of the decimals for extra accuracy in our calculation
Thu Oct 03, 2019 11:17 pm
Forum: Significant Figures
Topic: How would sig figs be used in a problem?
Replies: 7
Views: 70

### How would sig figs be used in a problem?

Would they ask "How many significant figures are in this number?"

I think I'm just confused about how this would be used practically in a problem?
Thu Oct 03, 2019 11:13 pm
Forum: SI Units, Unit Conversions
Topic: which unit to use
Replies: 9
Views: 204

### Re: which unit to use

I think we just use the ones called for by the problem