Search found 101 matches
- Mon Mar 16, 2020 6:18 pm
- Forum: General Rate Laws
- Topic: rate laws
- Replies: 8
- Views: 697
Re: rate laws
Yes, rate is determine by the slowest step.
- Mon Mar 16, 2020 6:16 pm
- Forum: *Free Energy of Activation vs Activation Energy
- Topic: Temperature vs. activation energy
- Replies: 33
- Views: 2575
Re: Temperature vs. activation energy
More T, more activation energy because more collisions.
- Mon Mar 16, 2020 6:13 pm
- Forum: Phase Changes & Related Calculations
- Topic: state functions
- Replies: 13
- Views: 1413
Re: state functions
State functions are path-independent.
- Mon Mar 16, 2020 6:12 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Exothermic rxns and heat
- Replies: 9
- Views: 625
Re: Exothermic rxns and heat
Q is negative as heat is being released.
- Mon Mar 16, 2020 6:12 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Final Exam #15
- Replies: 3
- Views: 542
Re: Final Exam #15
You use the van't hoff equation.
- Mon Mar 16, 2020 6:10 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Kelvin or Celsius?
- Replies: 86
- Views: 5905
Re: Kelvin or Celsius?
Kelvin is always the unit for such equations.
- Mon Mar 16, 2020 6:09 pm
- Forum: Van't Hoff Equation
- Topic: Entropy
- Replies: 18
- Views: 1014
Re: Entropy
I would calculate deltaH and then use deltaG = deltaH - TdeltaS to find entropy.
- Mon Mar 16, 2020 6:08 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Delta U
- Replies: 6
- Views: 487
Re: Delta U
Depends on whether work is done or work is being done on the system.
- Mon Mar 16, 2020 6:07 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: pH of acids
- Replies: 13
- Views: 1083
Re: pH of acids
Strong acids dissociate completely, while weak acids don't which affects the ph.
- Mon Mar 16, 2020 6:06 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Approximating X
- Replies: 13
- Views: 858
Re: Approximating X
Use the 5% rule, if X is less than that then we can approximate.
- Mon Mar 16, 2020 6:06 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ATP QUESTION ON FINAL
- Replies: 9
- Views: 918
Re: ATP QUESTION ON FINAL
K depended on ADP, basically the same as ADP.
- Mon Mar 16, 2020 6:05 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: method
- Replies: 4
- Views: 454
Re: method
Pre equilibrium is probably the method i would use.
- Mon Mar 16, 2020 6:04 pm
- Forum: Second Order Reactions
- Topic: 2nd order
- Replies: 6
- Views: 591
Re: 2nd order
When the rate is affected by the concentration of two first-order reactants, it is a second order reaction.
- Mon Mar 16, 2020 6:03 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Catalyst
- Replies: 9
- Views: 612
Re: Catalyst
A catalyst will first appear to the left as a reactant, and then as a product in the following reactions because it speeds up the reaction but doesn't get used up.
- Mon Mar 16, 2020 6:02 pm
- Forum: First Order Reactions
- Topic: size
- Replies: 6
- Views: 520
Re: size
No, only stoichiometric coeffecients affect the rate of a reaction, not the size of the reactant molecules.
- Mon Mar 16, 2020 6:00 pm
- Forum: Zero Order Reactions
- Topic: 0 order
- Replies: 7
- Views: 693
Re: 0 order
It is independent of the concentration of the reactants.
- Mon Mar 16, 2020 6:00 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Glass Electrode
- Replies: 5
- Views: 417
Re: Glass Electrode
A ph meter is a glass electrode, it is an ion-selective electrode.
- Mon Mar 16, 2020 5:59 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: calculating standard cell potential
- Replies: 6
- Views: 561
Re: calculating standard cell potential
You would do standard potential of cathode minus the standard potential of anode.
- Mon Mar 16, 2020 5:58 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst K vs Q
- Replies: 14
- Views: 1021
Re: Nernst K vs Q
You use K when the reaction is at equilibrium, and Q when the reaction is not.
- Sat Mar 14, 2020 3:59 pm
- Forum: Phase Changes & Related Calculations
- Topic: Negative Work
- Replies: 18
- Views: 1500
Re: Negative Work
When a system does work, the value of work is negative.
- Sat Mar 14, 2020 3:57 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Gibbs free energy
- Replies: 9
- Views: 737
Re: Gibbs free energy
G* means a substance is in its standard state.
- Sat Mar 14, 2020 3:54 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Steps to solve calorimeter problem
- Replies: 3
- Views: 981
Re: Steps to solve calorimeter problem
Use q=mcdeltaT for these problems. Take into account phase changes as well.
- Sat Mar 14, 2020 3:18 pm
- Forum: Van't Hoff Equation
- Topic: what does it do?
- Replies: 13
- Views: 1019
Re: what does it do?
It relates equilibrium constant to temperature.
- Sat Mar 14, 2020 3:09 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: predicting entropy
- Replies: 3
- Views: 402
Re: predicting entropy
More the disorganization, more is the entropy which is why COF2 will have more entropy compared to BF3.
- Sat Mar 14, 2020 3:08 pm
- Forum: *Nucleophiles
- Topic: FInal
- Replies: 11
- Views: 1747
Re: FInal
Do try and read and understand what the textbook says.
- Sat Mar 14, 2020 2:54 pm
- Forum: General Rate Laws
- Topic: Hw 7A.13
- Replies: 9
- Views: 698
Re: Hw 7A.13
Yes, because the power will be 1, making it a first order reaction.
- Sat Mar 14, 2020 2:49 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Textbook question 7.17
- Replies: 4
- Views: 362
Re: Textbook question 7.17
The slowest step is the rate determining step, if the catalyst doesn't affect this step, the rate of reaction doesn't change.
- Sat Mar 14, 2020 1:43 pm
- Forum: Second Order Reactions
- Topic: does the order determine molecularity?
- Replies: 7
- Views: 952
- Sat Mar 14, 2020 1:42 pm
- Forum: General Rate Laws
- Topic: Rate-determining step
- Replies: 7
- Views: 594
Re: Rate-determining step
They usually tell us which is the slow and fast step.
- Sat Mar 14, 2020 1:41 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalysts
- Replies: 7
- Views: 488
Re: Catalysts
It is introduced as a reactant, and then produced as a product in the following equations showing that it remains unconsumed in the reaction.
- Sat Mar 14, 2020 1:40 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Activation energy
- Replies: 7
- Views: 480
Re: Activation energy
Since its energy, its unit can be Joules or kJ.
- Sat Mar 14, 2020 1:39 pm
- Forum: Zero Order Reactions
- Topic: zero order reactions
- Replies: 5
- Views: 405
Re: zero order reactions
A zero order reaction is independent of concentration and only depends on the rate constant.
- Thu Jan 30, 2020 4:01 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Kw Equations
- Replies: 10
- Views: 553
Re: Kw Equations
[h3O+] + [OH-] = kw = 1x10^-14
- Thu Jan 30, 2020 3:59 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ka and Kb
- Replies: 10
- Views: 379
Re: Ka and Kb
Greater than 10^3 is a strong acid.
- Thu Jan 30, 2020 3:57 pm
- Forum: Phase Changes & Related Calculations
- Topic: Molar Heat Capacity at Cp s. Cv
- Replies: 4
- Views: 227
Re: Molar Heat Capacity at Cp s. Cv
P is the constant pressure and V indicates temperature.
- Thu Jan 30, 2020 3:56 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Equilibrium shift by pressure
- Replies: 7
- Views: 271
Re: Equilibrium shift by pressure
If the system is compressed, the reaction proceeds in the direction with the least moles of the gas, which can be either reactants or products.
- Thu Jan 30, 2020 3:54 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Negative pH
- Replies: 9
- Views: 329
Re: Negative pH
Very strong acids have extremely low PH, sometimes it can be negative.
- Thu Jan 30, 2020 3:52 pm
- Forum: Ideal Gases
- Topic: Inert Gas
- Replies: 12
- Views: 712
Re: Inert Gas
Inert gases won't cause any change in the chemical equilibrium (equilibrium constant) since they are unreactive.
- Thu Jan 30, 2020 3:51 pm
- Forum: Phase Changes & Related Calculations
- Topic: Units
- Replies: 16
- Views: 870
Re: Units
We record temperature in terms of how it changes, change in a celsius is same as a change in a kelvin.
- Thu Jan 30, 2020 3:50 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond enthalpies
- Replies: 4
- Views: 245
Re: Bond enthalpies
Breaking a bond is endothermic and forming one is exothermic, so it can be either.
- Fri Jan 24, 2020 12:24 pm
- Forum: Ideal Gases
- Topic: ICE table approximation
- Replies: 10
- Views: 419
Re: ICE table approximation
If K value is very small, we can approximate.
- Fri Jan 24, 2020 12:21 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: pKa and pKb
- Replies: 17
- Views: 932
Re: pKa and pKb
when you are given Ka and Kb, you take -log of that to find pka and pkb. Pka + Pkb = 14
- Fri Jan 24, 2020 12:20 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Ka and Kb
- Replies: 10
- Views: 532
Re: Ka and Kb
Strong acids and bases do have Ka and Kb.
- Fri Jan 24, 2020 12:19 pm
- Forum: Phase Changes & Related Calculations
- Topic: Steam vs. Boiling Water
- Replies: 10
- Views: 509
Re: Steam vs. Boiling Water
To put it in simpler terms, changing the state of a substance releases a lot more energy than the substance remaining in the same state. Water at 100C releases less heat than steam because the change in state from water to steam (vaporisation), releases more energy.
- Fri Jan 24, 2020 12:17 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Changes in Pressure
- Replies: 9
- Views: 413
Re: Changes in Pressure
Increasing pressure shifts the reaction to the side with the fewer moles of gas according to Le Chatelier's principle.
- Fri Jan 24, 2020 12:15 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Molar concentration of H3O
- Replies: 6
- Views: 578
Re: Molar concentration of H3O
If we assume that the concentrations of h3o+ and oh- is the same, the answer will be square root of kw which is 10^-7.
- Fri Jan 24, 2020 12:13 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: solvent
- Replies: 10
- Views: 416
Re: solvent
Only gaseous and aqueous substances will be included in the equilibrium constant equations.
- Sun Jan 12, 2020 8:01 am
- Forum: Ideal Gases
- Topic: PV = nRT
- Replies: 16
- Views: 1986
Re: PV = nRT
P stands for pressure, V is volume, n is number of moles, R is ideal gas constant, T is temperature,
- Sun Jan 12, 2020 8:00 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle
- Replies: 19
- Views: 1726
Re: Le Chatelier's Principle
The principle states that every time there is a shift from equilibrium, the effect of the shift will be counteracted to maintain equilibrium.
- Sun Jan 12, 2020 7:58 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Different K's
- Replies: 5
- Views: 304
Re: Different K's
Kp is equilibrium constant for pressure whereas Kc is for concentrations.
- Sun Dec 08, 2019 1:13 am
- Forum: Sigma & Pi Bonds
- Topic: Ionic bond --> sigma and pi bonds
- Replies: 8
- Views: 1548
Re: Ionic bond --> sigma and pi bonds
Ionic bonds don't form sigma bonds, it is only for shared electrons.
- Sun Dec 08, 2019 1:10 am
- Forum: Sigma & Pi Bonds
- Topic: Hybridization for p
- Replies: 4
- Views: 277
Re: Hybridization for p
Pi bonds only use unhybridized p orbitals.
- Sun Dec 08, 2019 1:09 am
- Forum: Dipole Moments
- Topic: Melting and Boiling Points
- Replies: 9
- Views: 713
Re: Melting and Boiling Points
ionic dipole is stronger than hydrogen bonding, so needs a higher melting point in order to break the bonds.
- Sun Dec 08, 2019 1:08 am
- Forum: Electronegativity
- Topic: Electronegativity of Atoms We Should Know About
- Replies: 4
- Views: 371
Re: Electronegativity of Atoms We Should Know About
The trend is that electronegativity increases as we move across the period and decreases as we move down the group.
- Sun Dec 08, 2019 1:06 am
- Forum: Amphoteric Compounds
- Topic: 6A.17
- Replies: 4
- Views: 397
Re: 6A.17
Non metal oxides generally form acids and metal oxides form strong bases.
- Fri Dec 06, 2019 3:41 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Periodic Trends
- Replies: 8
- Views: 697
Re: Periodic Trends
smaller cations with less electron cloud have higher polarising power whereas larger anions with a large electron cloud and distortion have more polarizability.
- Fri Dec 06, 2019 3:39 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Resonance
- Replies: 3
- Views: 350
Re: Resonance
I don't think resonance has got to do with strength per se. It is more about stabilizing the atom by delocalising the electrons. it also maintains a constant bond length in the compound.
- Fri Dec 06, 2019 3:37 pm
- Forum: Lewis Acids & Bases
- Topic: electron withdrawing
- Replies: 2
- Views: 199
Re: electron withdrawing
Higher the electronegativity of an atom, the more electron it draws, making the acid stronger.
- Fri Dec 06, 2019 3:35 pm
- Forum: Hybridization
- Topic: hybridization of lone pairs
- Replies: 4
- Views: 308
Re: hybridization of lone pairs
We mainly look at regions of electron density rather than bonding or lone pairs, in case of hybridization.
- Fri Dec 06, 2019 3:34 pm
- Forum: Dipole Moments
- Topic: Melting and Boiling Points
- Replies: 9
- Views: 713
Re: Melting and Boiling Points
I think the hierarchy is ionic>ionic-dipole>hydrogen>dipole-dipole>london forces (in terms of strength of interaction). Higher the strength, higher the temperature it needs to break the bond so higher melting point.
- Fri Dec 06, 2019 3:32 pm
- Forum: Resonance Structures
- Topic: Resonance
- Replies: 3
- Views: 354
Re: Resonance
I believe resonance stabilises a compound. Strength depends on the length of the bond, and other factors like electron repulsion, radius etc.
- Fri Dec 06, 2019 3:30 pm
- Forum: Ionic & Covalent Bonds
- Topic: intermolecular vs intramolecular
- Replies: 17
- Views: 1972
Re: intermolecular vs intramolecular
inter is between two molecules and intra is within the same molecule.
- Sun Nov 17, 2019 4:28 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: lone pairs
- Replies: 3
- Views: 204
Re: lone pairs
Lone pair-lone pair electron repulsion is the highest, so they need to be placed away from each other as we want minimum repulsion for most stability.
- Sun Nov 17, 2019 4:27 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Do we have to memorize the names of shapes and/or the bond angles?
- Replies: 7
- Views: 527
Re: Do we have to memorize the names of shapes and/or the bond angles?
I think we memorise shapes and bond angles relative to each other, like why would a particular bond angle be smaller than another etc.
- Sun Nov 17, 2019 4:26 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: regions of electron density
- Replies: 10
- Views: 531
Re: regions of electron density
Regions where electrons are found, as the name suggests, the region where the electrons are most dense around an atom.
- Sun Nov 17, 2019 4:25 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR on the test or final
- Replies: 4
- Views: 298
Re: VSEPR on the test or final
It covers both, whatever covered after midterm!
- Sun Nov 17, 2019 4:24 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Repulsion
- Replies: 6
- Views: 332
Re: Repulsion
Bonding pairs have least repulsion, then lone pairs with bonding pairs, and lone pairs with each other have the highest repulsion.
- Sun Nov 17, 2019 4:23 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone pairs and bond angles
- Replies: 4
- Views: 246
Re: Lone pairs and bond angles
Lone pair decreases bond angle because it causes repulsion with other lone pairs and bonding pairs.
- Sun Nov 17, 2019 4:22 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Dipole moments
- Replies: 4
- Views: 207
Re: Dipole moments
The arrow points to the atom that pulls electrons towards itself, so the most electronegative one.
- Sun Nov 17, 2019 4:21 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Do we name things by their electron geometry or molecular geometry?
- Replies: 2
- Views: 213
Re: Do we name things by their electron geometry or molecular geometry?
We name things according to molecular geometry because electron geometry takes into account lone pairs. We don't take lone pairs into account while writing the structure, just to find out how to minimize repulsion.
- Sun Nov 17, 2019 4:19 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR repulsion model
- Replies: 8
- Views: 626
Re: VSEPR repulsion model
If there is repulsion between lone pairs, it would change the structure of the atom. We need to figure out how the lone pairs need to be arranged in each structure to minimise repulsion and find most stability.
- Sun Nov 17, 2019 4:17 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: AXE formula
- Replies: 32
- Views: 12264
Re: AXE formula
This notation lets us know the number of bonding pairs and lone pairs which makes it easier to draw structures.
- Sun Nov 03, 2019 5:49 pm
- Forum: Einstein Equation
- Topic: eV
- Replies: 4
- Views: 344
Re: eV
M stands for mega with value 10^6.
- Sun Nov 03, 2019 5:48 pm
- Forum: *Black Body Radiation
- Topic: Info for Midterm
- Replies: 13
- Views: 1146
Re: Info for Midterm
Won't be tested on the midterm.
- Sun Nov 03, 2019 5:47 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: What are the octet exceptions?
- Replies: 11
- Views: 536
Re: What are the octet exceptions?
Generally d-block elements because the d-orbital can accommodate more valence electrons.
- Sun Nov 03, 2019 5:46 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: When would 3d orbital be filled before the 4s orbital?
- Replies: 8
- Views: 531
Re: When would 3d orbital be filled before the 4s orbital?
4s is lower in energy than 3d, causing it to get filled up first.
- Sun Nov 03, 2019 5:40 pm
- Forum: DeBroglie Equation
- Topic: When to use the DeBroglie equation?
- Replies: 6
- Views: 376
Re: When to use the DeBroglie equation?
Any particle with wavelike properties that has momentum. They will give us the mass and velocity.
- Sun Nov 03, 2019 5:39 pm
- Forum: Lewis Structures
- Topic: Dino Nuggets - 12C
- Replies: 3
- Views: 296
Re: Dino Nuggets - 12C
We always want to put the least electronegative atom in the center.
- Sun Oct 27, 2019 10:17 am
- Forum: Trends in The Periodic Table
- Topic: atomic Radii
- Replies: 11
- Views: 446
Re: atomic Radii
Adding more electrons would definitely increase the atomic radius because the electrons keep getting added to the outermost shell.
- Sun Oct 27, 2019 10:14 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbitals in relation to arrows
- Replies: 10
- Views: 679
Re: Orbitals in relation to arrows
A spin quantum number of +1/2 means the spin is in the upward direction, and vice versa for -1/2. Two electrons of opposite spin are always placed in one orbital
(by Hund's rule)
(by Hund's rule)
- Sat Oct 26, 2019 8:46 pm
- Forum: Trends in The Periodic Table
- Topic: Stable Structures
- Replies: 5
- Views: 377
Re: Stable Structures
Formal charge needs to be calculated. If the formal charge of the central atom is 0, the atom is stable.
- Sat Oct 26, 2019 8:45 pm
- Forum: Properties of Electrons
- Topic: Mass of an Electron
- Replies: 14
- Views: 570
Re: Mass of an Electron
The mass of an electron will always be given to us, because it is a set mass.
- Sat Oct 26, 2019 8:44 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: Polar v nonPolar
- Replies: 4
- Views: 1075
Re: Polar v nonPolar
You can also determine polarity from structure. If the structure of the compound is symmetric in terms of distribution of elements around the central atom, it is non polar. If the compound has a charge and is asymmetric, it is polar.
- Thu Oct 17, 2019 3:58 pm
- Forum: Photoelectric Effect
- Topic: Unit of measurements for E=hv
- Replies: 6
- Views: 259
Re: Unit of measurements for E=hv
The unit is Joules, but in relation to photoelectric effect it is Joules per photon, since that is the particle whose energy we're trying to calculate.
- Thu Oct 17, 2019 3:56 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Atomic Radius
- Replies: 18
- Views: 672
Re: Atomic Radius
The value of atomic radius will always be given to us.
- Thu Oct 17, 2019 3:55 pm
- Forum: DeBroglie Equation
- Topic: DeBroglie Equation Use
- Replies: 5
- Views: 267
Re: DeBroglie Equation Use
The equation is used to calculate wavelength of a particle with linear momentum. The equation is wavelength(lambda) = h/m*v where h is Planck's constant (6.626*10^-34 Js) , m = mass of particle, v = velocity with which the particle is moving. the formula could also be lambda = h/p(momentum) as momen...
- Thu Oct 17, 2019 3:51 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Ryberg's Constant
- Replies: 7
- Views: 345
Re: Ryberg's Constant
Do use the one given by Dr. Lavelle. Since Rydberg's constant is frequency, the unit is s^-1 or Hz.
- Thu Oct 17, 2019 3:51 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Ryberg's Constant
- Replies: 7
- Views: 345
Re: Ryberg's Constant
Do use the one given by Dr. Lavelle. Since Rydberg's constant is frequency, the unit is s^-1 or Hz.
- Thu Oct 17, 2019 3:49 pm
- Forum: Einstein Equation
- Topic: unit of energy
- Replies: 7
- Views: 1035
Re: unit of energy
It is a unit of energy. 1keV = 1.602 * 10^-16 J. Normally an eV = 1.602 *n10^-19 J but since this is Kilo electron volt, the power to 10 is raised to -16.
- Thu Oct 17, 2019 3:47 pm
- Forum: Properties of Light
- Topic: EM Spectrum
- Replies: 3
- Views: 204
Re: EM Spectrum
I think you need to know which series corresponds to which energy level and region (UV, infrared, etc). It might help to go over wavelengths of some of the regions as well.
- Thu Oct 10, 2019 11:44 pm
- Forum: Balancing Chemical Reactions
- Topic: Importance of the State of Molecules
- Replies: 6
- Views: 654
Re: Importance of the State of Molecules
Doesn't hurt to write it down because its just additional helpful information!
- Thu Oct 10, 2019 11:33 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Test 1 Grading
- Replies: 12
- Views: 966
Re: Test 1 Grading
I had no idea we get 10 points for just being there!
- Thu Oct 10, 2019 11:31 pm
- Forum: Limiting Reactant Calculations
- Topic: Can't Find Limiting Reactant
- Replies: 4
- Views: 357
Re: Can't Find Limiting Reactant
hey! You first have to balance the equation = 2AL + 6HCL --> 2ALCL3 + 3H2. You then calculate how many grams of product does each reactant give by calculating molar masses and using molecular weights of each. Using Al, we get: (5.43gAl/26.981g/molAl)*(2mol/2mol)*133.481g/molAlCl3 = 26.86g of AlCl3 D...
- Thu Oct 10, 2019 11:16 pm
- Forum: Empirical & Molecular Formulas
- Topic: Mass Percentage Question
- Replies: 9
- Views: 885
Re: Mass Percentage Question
I'd start by first finding the how many elements are there in the compound, and then find the molecular mass of the compound. Since we know the number of elements, we divide the molecular mass of each element by the total mass of the compound we just found, to get mass percentage.
- Wed Oct 09, 2019 6:18 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 2 Homework Problems [ENDORSED]
- Replies: 67
- Views: 7961
Re: Week 2 Homework Problems [ENDORSED]
You can do either! I did both just to review all topics.
- Sat Oct 05, 2019 3:53 pm
- Forum: Limiting Reactant Calculations
- Topic: M5
- Replies: 2
- Views: 127
M5
Could someone explain how to find the excess reactant in M5? I'm slightly confused.
- Sat Oct 05, 2019 3:52 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 2 Homework Problems [ENDORSED]
- Replies: 67
- Views: 7961
Re: Week 2 Homework Problems [ENDORSED]
He specified to do either fundamentals or quantum world or both for Homework 2!
- Sat Oct 05, 2019 3:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 2 Homework Problems [ENDORSED]
- Replies: 67
- Views: 7961
Re: Week 2 Homework Problems [ENDORSED]
He specified to do either fundamentals or quantum world or both for Homework 2!
- Thu Oct 03, 2019 11:17 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: E 27
- Replies: 6
- Views: 1289
Re: E 27
For part b, I'd find the moles of a kilogram of water which is 1000g/(18.02g/mol) which is 55.49 moles. Since 1 mole has 6.022x10^23 molecules, 55.49 moles will have 55.49x(6.023x10^23)molecules which is 3.34x10^25 molecules.
- Thu Oct 03, 2019 4:04 pm
- Forum: Empirical & Molecular Formulas
- Topic: Tips for Finding Which Number to Multiply a Decimal By to Get a Whole Number
- Replies: 10
- Views: 1205
Re: Tips for Finding Which Number to Multiply a Decimal By to Get a Whole Number
What generally works for me is trial and error. I sort of keep multiplying low value numbers until I find one that converts all the decimals into whole numbers, or at least close. It may not be the most efficient way but it definitely does give me the right answer.