Search found 60 matches
- Mon Mar 11, 2019 8:38 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Finding n
- Replies: 12
- Views: 1067
Re: Finding n
n is just the number of balanced electrons
- Mon Mar 11, 2019 8:37 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation vs Reduction Half Rxn
- Replies: 9
- Views: 1021
Re: Oxidation vs Reduction Half Rxn
Oxidation loses electrons and reduction gains electrons.
- Mon Mar 11, 2019 8:36 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation number?
- Replies: 12
- Views: 7166
Re: Oxidation number?
There are certain elements that have specific charges. You need to know these to properly balance the redox equation.
- Sat Mar 02, 2019 7:08 pm
- Forum: Balancing Redox Reactions
- Topic: Creating a cell diagram
- Replies: 8
- Views: 727
Re: Creating a cell diagram
You do not need to add them to the cell diagram (-:
- Sat Mar 02, 2019 7:05 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ignoring x
- Replies: 16
- Views: 3220
Re: ignoring x
you can ignore x when youre approximating. this is when your k value is less than or equal to 10^-3
- Sat Mar 02, 2019 7:03 pm
- Forum: Ideal Gases
- Topic: pV=nRT
- Replies: 12
- Views: 2049
Re: pV=nRT
You can use pv=nrt to find one of the constants like n,t,p,or v.
- Mon Feb 25, 2019 2:49 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Solids and Liquids in K expression
- Replies: 2
- Views: 383
Re: Solids and Liquids in K expression
Balance the entire equation first, and then omit the liquids and solids. This will reduce the chance of you making an error.
- Mon Feb 25, 2019 2:47 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Increasing/Decreasing temp
- Replies: 8
- Views: 1067
Re: Increasing/Decreasing temp
It can change which way the reaction proceeds.
- Mon Feb 25, 2019 2:46 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: System vs Surroundings
- Replies: 14
- Views: 2042
Re: System vs Surroundings
The system is the thing that you're observing/looking at, while the surrounding is everything else.
- Sat Feb 23, 2019 4:07 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: When to use Quadratic equation
- Replies: 10
- Views: 6430
Re: When to use Quadratic equation
You use the quadratic equation when you can't approximate because of how large the K value is. If the K value is greater than 10^-3, then you would have to use the quadratic formula.
- Sat Feb 23, 2019 4:02 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Direction of a Reaction
- Replies: 8
- Views: 938
Re: Direction of a Reaction
They should give you the value of k or they'll give you the correct values to solve for k.
- Sat Feb 23, 2019 4:01 pm
- Forum: Ideal Gases
- Topic: Approximations for ICE
- Replies: 20
- Views: 1533
Re: Approximations for ICE
You can do this when your equilibrium constant value is less than 10^-3 because this value is extremely small.
- Sat Feb 23, 2019 3:59 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: increasing pressure, what happens to concentration?
- Replies: 10
- Views: 2427
Re: increasing pressure, what happens to concentration?
Le Chatelier's Principle for pressure: if the pressure increases, the reaction will proceed towards the side with less moles of gas. if the pressure is decreased, the reaction will proceed towards the side with more moles of gas.
- Sat Feb 23, 2019 3:57 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Reverse Reaction
- Replies: 8
- Views: 763
Re: Reverse Reaction
The reverse reaction is the inverse. so it would would 1/k
- Sat Feb 23, 2019 3:56 pm
- Forum: Ideal Gases
- Topic: ICE Table Values
- Replies: 9
- Views: 1237
Re: ICE Table Values
It's typically for moles, concentration (M), and pressure. You can also start off with moles and then convert it to molarity after. Just make sure that your units are consistent all throughout the ice table.
- Wed Feb 06, 2019 11:29 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Quiz 1 Number 3c
- Replies: 6
- Views: 623
Re: Quiz 1 Number 3c
it should be mol/L or M. This is the case when they are asking for the concentration.
- Wed Feb 06, 2019 11:28 pm
- Forum: Ideal Gases
- Topic: Ideal gas constant R
- Replies: 10
- Views: 1564
Re: Ideal gas constant R
That depends on the units that you are given and are working with.
- Wed Feb 06, 2019 11:27 pm
- Forum: Phase Changes & Related Calculations
- Topic: Negative work
- Replies: 11
- Views: 1014
Re: Negative work
yes, it is a thing. This will happen when system does work on the surrounding.
- Mon Jan 28, 2019 3:27 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Exothermic vs. Endothermic
- Replies: 10
- Views: 3140
Re: Exothermic vs. Endothermic
Endothermic: When energy is absorbed from its surroundings. delta H>0
Exothermic: When energy is released. delta H<0
Exothermic: When energy is released. delta H<0
- Mon Jan 28, 2019 3:22 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Memorizing bond enthalpies
- Replies: 5
- Views: 610
Re: Memorizing bond enthalpies
The values are usually given for the uncommon ones. Highly recommend to memorize the common ones though just to be safe!
- Mon Jan 28, 2019 3:21 pm
- Forum: Phase Changes & Related Calculations
- Topic: Heat Capacity
- Replies: 10
- Views: 917
Re: Heat Capacity
Heat capacity: amount of heat needed to raise the Temp. by 1 degree Celsius
Molar heat capacity: amount of heat needed to raise the Temp. of 1 mole of that certain substance by 1 degree Celsius
Molar heat capacity: amount of heat needed to raise the Temp. of 1 mole of that certain substance by 1 degree Celsius
- Wed Jan 23, 2019 3:37 pm
- Forum: Ideal Gases
- Topic: OH and H3O
- Replies: 10
- Views: 1264
Re: OH and H3O
You should also memorize the strong acids and bases that we had to use in 14A
- Wed Jan 23, 2019 3:36 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ice chart
- Replies: 7
- Views: 863
Re: ice chart
when they give you the initial value of a weak acid.
- Wed Jan 23, 2019 3:32 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Does [H3O+][OH-] always equal 10^-14?
- Replies: 9
- Views: 1163
Re: Does [H3O+][OH-] always equal 10^-14?
Yes, only if the temperature of the water is at a constant temperature of 25 degrees celsius.
- Wed Jan 16, 2019 9:12 pm
- Forum: Ideal Gases
- Topic: pressure [ENDORSED]
- Replies: 13
- Views: 1029
Re: pressure [ENDORSED]
You can do this by increasing the temperature.
- Wed Jan 16, 2019 9:07 pm
- Forum: Ideal Gases
- Topic: Water
- Replies: 13
- Views: 1028
Re: Water
Water can be a solid, liquid, or gas. However, it cannot be an aqueous solution.
- Wed Jan 16, 2019 9:03 pm
- Forum: Ideal Gases
- Topic: K value
- Replies: 8
- Views: 779
Re: K value
It's rare because it's not common to have an equal amount of products and reactants.
- Wed Jan 09, 2019 3:08 pm
- Forum: Ideal Gases
- Topic: Temperature in PV=nRT
- Replies: 9
- Views: 1093
Re: Temperature in PV=nRT
The unit for T in this case is always in Kelvin (K)
- Wed Jan 09, 2019 3:08 pm
- Forum: Ideal Gases
- Topic: Memorization
- Replies: 12
- Views: 1190
Re: Memorization
you should memorize and the units just in case
- Wed Jan 09, 2019 3:07 pm
- Forum: Ideal Gases
- Topic: Q and K [ENDORSED]
- Replies: 35
- Views: 3015
Re: Q and K [ENDORSED]
both of the formulas for Q and K are the same!
- Thu Dec 06, 2018 10:12 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Final Exam
- Replies: 7
- Views: 665
Re: Final Exam
I believe so. I recall my TA saying something about it during our discussion
- Thu Dec 06, 2018 10:10 pm
- Forum: Lewis Acids & Bases
- Topic: Strong Acids
- Replies: 6
- Views: 613
Re: Strong Acids
Based off of what the person above me said, the longer the bond length, the weaker it is
- Thu Dec 06, 2018 9:59 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pH calculation
- Replies: 4
- Views: 537
Re: pH calculation
This is normally given to you in the problem as a molarity
- Sun Dec 02, 2018 8:01 pm
- Forum: Resonance Structures
- Topic: Formal Charge
- Replies: 13
- Views: 1368
Re: Formal Charge
you typically want the formal charge to be 0
- Sun Dec 02, 2018 7:59 pm
- Forum: Octet Exceptions
- Topic: Octet vs formal charge
- Replies: 16
- Views: 3059
Re: Octet vs formal charge
having a formal charge of 0
- Sun Dec 02, 2018 7:58 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: 3F.5 part b (7th Ed.) Melting point
- Replies: 5
- Views: 698
Re: 3F.5 part b (7th Ed.) Melting point
it has a stronger IMF, resulting in a higher melting point
- Sun Nov 25, 2018 5:27 pm
- Forum: Hybridization
- Topic: Hybridization and molecular shape
- Replies: 3
- Views: 343
Re: Hybridization and molecular shape
lone pairs affect the shape
- Sun Nov 25, 2018 5:26 pm
- Forum: Ionic & Covalent Bonds
- Topic: Bond Lengths
- Replies: 10
- Views: 1033
Re: Bond Lengths
You can take the average of the two
- Sun Nov 25, 2018 5:24 pm
- Forum: Properties of Electrons
- Topic: Determining the Probability of Finding an Electron in an Orbital: Test 2
- Replies: 2
- Views: 552
Re: Determining the Probability of Finding an Electron in an Orbital: Test 2
I think that the probability of finding that is very low or close to 0
- Sun Nov 18, 2018 7:02 pm
- Forum: Hybridization
- Topic: Bond Angles
- Replies: 12
- Views: 1112
Re: Bond Angles
Drawing the structure is highly recommended when determining the bond angle.
- Sun Nov 18, 2018 7:00 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: lone pairs and bond angle
- Replies: 6
- Views: 669
Re: lone pairs and bond angle
This is because the lone pairs push away the other atoms resulting in a larger bond angle.
- Sun Nov 18, 2018 6:59 pm
- Forum: Trends in The Periodic Table
- Topic: Electronegativity vs. Electron Affinity?
- Replies: 11
- Views: 1618
Re: Electronegativity vs. Electron Affinity?
Electronegativity and electron affinity are different. Electronegativity is how well the electrons are attracted to an atom, and electron affinity is the amount of energy needed to release an electron.
- Wed Nov 07, 2018 9:25 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge
- Replies: 11
- Views: 1223
Re: Formal Charge
You cannot determine an element/compound just by using formal charge alone. The formal charge does not have to be zero. If it is zero, that means that it is at its most stable point.
- Wed Nov 07, 2018 9:23 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionization Energies
- Replies: 13
- Views: 3573
Re: Ionization Energies
That is correct. Helium has the highest ionization energy.
- Wed Nov 07, 2018 9:22 pm
- Forum: Resonance Structures
- Topic: bond length
- Replies: 5
- Views: 615
Re: bond length
It is because of resonance. Resonance tells us that there is more than one lewis structure for a specific compound.
- Tue Oct 30, 2018 5:25 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A.5 7th edition
- Replies: 5
- Views: 419
Re: 2A.5 7th edition
Cu and Cr are special cases which means that they have different electron configurations.
- Tue Oct 30, 2018 5:17 pm
- Forum: Resonance Structures
- Topic: Lengths of bonds
- Replies: 3
- Views: 249
Re: Lengths of bonds
Double bonds are stronger that single bonds. This means that double bonds have a stronger pull, resulting in a shorter length.
- Tue Oct 30, 2018 5:11 pm
- Forum: Lewis Structures
- Topic: Dots in Lewis Stucture
- Replies: 14
- Views: 1169
Re: Dots in Lewis Stucture
It doesn't matter as long as you put the right amount of dots and bonds.
- Fri Oct 26, 2018 2:06 am
- Forum: Properties of Light
- Topic: Test 2
- Replies: 7
- Views: 676
Re: Test 2
It'll be very helpful to go over Lavelle's "outline 2" document on his website.
- Fri Oct 26, 2018 2:06 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Equation
- Replies: 7
- Views: 674
Re: Rydberg Equation
I believe I heard during lecture that it is final - initial.
- Fri Oct 26, 2018 1:58 am
- Forum: SI Units, Unit Conversions
- Topic: Sig Figs
- Replies: 8
- Views: 930
Re: Sig Figs
Always use the amount of sig figs that they give you in the question.
- Thu Oct 18, 2018 3:02 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: What the equation is used for
- Replies: 5
- Views: 483
Re: What the equation is used for
The Heisenberg uncertainty equation is used to find a particles position and momentum.
- Thu Oct 18, 2018 3:00 pm
- Forum: Einstein Equation
- Topic: Photons and E=hv
- Replies: 5
- Views: 853
Re: Photons and E=hv
E gives the energy of one photon, v is frequency, and h is planck's constant.
- Thu Oct 18, 2018 2:58 pm
- Forum: Properties of Light
- Topic: Wave/particles
- Replies: 5
- Views: 440
Re: Wave/particles
You can see the similarities through the wave-particle duality. Light has very similar qualities of both wave and particles.
- Sat Oct 13, 2018 7:07 pm
- Forum: Properties of Light
- Topic: E=hv
- Replies: 13
- Views: 1028
Re: E=hv
The equation tells us that E is the energy of light, which is also called a photon.
- Fri Oct 12, 2018 6:18 pm
- Forum: Properties of Light
- Topic: Electromagnetic Spectrum: Colors
- Replies: 3
- Views: 262
Re: Electromagnetic Spectrum: Colors
It'll probably fall in between the colors blue and green, giving it a cyan color.
- Fri Oct 12, 2018 6:16 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student [ENDORSED]
- Replies: 297
- Views: 382915
Re: Advice from a Medical Student [ENDORSED]
Thank you for giving me the advice that I needed!
- Fri Oct 05, 2018 2:56 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Accuracy and Precision
- Replies: 4
- Views: 463
Re: Accuracy and Precision
Picture an archer doing target practice. If the archer is relatively hitting the same spot on the target, that would be considered as precise. If the archer is constantly hitting the bullseye, that would be considered as accurate.
- Fri Oct 05, 2018 2:48 am
- Forum: SI Units, Unit Conversions
- Topic: units during dimensional analysis
- Replies: 4
- Views: 436
Re: units during dimensional analysis
Writing out the units will definitely save you from making mistakes. As the problems get more detailed, writing the units down will be much more beneficial to you.
- Fri Oct 05, 2018 2:44 am
- Forum: Significant Figures
- Topic: Scientific Notation
- Replies: 7
- Views: 379
Re: Scientific Notation
I think that it's based off of personal preference. It should not matter which format you write your answer in, unless the question specifically asks you to write it a certain way.