Search found 55 matches
- Thu Mar 07, 2019 9:57 pm
- Forum: Second Order Reactions
- Topic: Half life of a second order reaction
- Replies: 1
- Views: 273
Half life of a second order reaction
Is the half life of a second order reaction affected by the initial concentration?
- Thu Mar 07, 2019 9:56 pm
- Forum: First Order Reactions
- Topic: Half life of a first order reaction
- Replies: 3
- Views: 388
Half life of a first order reaction
Does the concentration of a first order reaction not affect the half life?
- Thu Mar 07, 2019 9:55 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Reaction Rate Orders
- Replies: 4
- Views: 434
Reaction Rate Orders
Is the order of a reaction determined by the highest order of a reactant or the combined orders of the reactants?
- Mon Mar 04, 2019 8:19 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Enot
- Replies: 2
- Views: 307
Enot
Why can Enot values of a cell be added together even though they are not state functions?
- Mon Mar 04, 2019 8:18 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Concentration cells
- Replies: 6
- Views: 1422
Concentration cells
What defines a concentration cell?
- Mon Mar 04, 2019 7:42 pm
- Forum: Zero Order Reactions
- Topic: 7A 15
- Replies: 4
- Views: 502
7A 15
How do you know that molecule C is a zero order reaction? Also how do you calculate the degree for each reaction?
- Mon Feb 25, 2019 11:25 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Standard Gibbs free energy
- Replies: 1
- Views: 203
Standard Gibbs free energy
Does standard Gibbs free energy correlate to Delta G over moles?
- Mon Feb 25, 2019 11:24 am
- Forum: Calculating Work of Expansion
- Topic: -DeltanRT
- Replies: 2
- Views: 535
-DeltanRT
can - delta n RT be used to replace -PDeltaV
- Mon Feb 25, 2019 11:22 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Negative Delta G
- Replies: 2
- Views: 301
Negative Delta G
Why does a negative Delta G correlate to a spontaneous reaction?
- Mon Feb 25, 2019 11:10 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: salt bridge vs porous disk
- Replies: 2
- Views: 259
salt bridge vs porous disk
What is the difference between a salt bridge and a porous disk?
- Mon Feb 25, 2019 11:09 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Delta G
- Replies: 2
- Views: 272
Delta G
In the equation DeltaG= -nFE does the n refer to delta n of a reaction?
- Mon Feb 25, 2019 11:05 am
- Forum: Balancing Redox Reactions
- Topic: Redox in Basic compounds
- Replies: 2
- Views: 357
Redox in Basic compounds
What extra steps do we have to take to balance redox reactions in basic solutions?
- Sun Feb 10, 2019 10:38 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Isochoric
- Replies: 3
- Views: 412
Isochoric
If a reaction is isochoric is the work 0
- Sun Feb 10, 2019 10:29 pm
- Forum: Calculating Work of Expansion
- Topic: Pv=nrT
- Replies: 2
- Views: 317
Pv=nrT
can the equation w=PdeltaV be replaced with deltaNrt?
- Sun Feb 10, 2019 10:25 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Capacity
- Replies: 4
- Views: 407
Heat Capacity
With the equation q=mcDeltaT be replaced with q=ncDeltaT simply by replacing grams with moles?
- Sun Feb 03, 2019 10:50 pm
- Forum: Calculating Work of Expansion
- Topic: Different ways to derive work
- Replies: 3
- Views: 258
Different ways to derive work
Will we only need to calculate problems with work using the Pressure*change in volume definition of work, or will we ever need to calculate using force*distance?
- Sun Feb 03, 2019 10:44 pm
- Forum: Calculating Work of Expansion
- Topic: Different types of pressure
- Replies: 1
- Views: 225
Different types of pressure
Do we need to memorize the constants to convert between Torr, Atm, and Bar?
- Sun Feb 03, 2019 10:38 pm
- Forum: Calculating Work of Expansion
- Topic: L*atm
- Replies: 2
- Views: 291
L*atm
Normally when calculating work we end up with the unit L*atm and then to convert it to Joules we use a constant 101.325. Do we need to memorize this constant?
- Sun Jan 27, 2019 9:04 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed vs isolated
- Replies: 14
- Views: 1002
closed vs isolated
What is the difference between a closed and an isolated system? Is an isolated system just sealed?
- Sun Jan 27, 2019 8:58 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Delta U vs Delta H
- Replies: 6
- Views: 1537
Delta U vs Delta H
What is the difference between Delta U and Delta H?
- Sun Jan 27, 2019 8:56 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Question 4D 15 7th edition
- Replies: 1
- Views: 244
Question 4D 15 7th edition
Why is the answer -312 instead of +312? Does it have to do with that we were given the entropy of combustion instead of the entropy of formation?
- Sun Jan 20, 2019 10:34 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: Identifying which part of the salt does not affect PH
- Replies: 1
- Views: 373
Identifying which part of the salt does not affect PH
When looking at the chemical formula of a salt is there any quick way to tell which part of the salt is not present in the chemical reaction and therefore does not affect PH.
- Sun Jan 20, 2019 10:28 pm
- Forum: Polyprotic Acids & Bases
- Topic: Question 6E.3 7th edition
- Replies: 2
- Views: 543
Question 6E.3 7th edition
The question states "ignoring second deprotonations only when the approximation is justified. How do we know when its justified?
- Sun Jan 20, 2019 10:26 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Quadratic method for weak acids and bases
- Replies: 1
- Views: 206
Quadratic method for weak acids and bases
The quadratic method only has to be used if the Ke value is less than 10^-3, but if the Ka value is greater than 10^-3 then we just assume the acid is a strong acid and is completely dissociated. Therefore is there ever a time we have to use the quadratic method for weak acids and bases?
- Sun Jan 13, 2019 9:17 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Question 5I 19
- Replies: 2
- Views: 242
Question 5I 19
How do you calculate how many moles of I2 and HI are left over from the information given about 60% of H2 being used up in the reaction?
- Sun Jan 13, 2019 9:13 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium composition, estimation method vs quadratic method
- Replies: 1
- Views: 88
Equilibrium composition, estimation method vs quadratic method
Is there any way to know when we can use the estimation method to calculate equilibrium composition?
- Sun Jan 13, 2019 9:10 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Question 5G
- Replies: 3
- Views: 622
Question 5G
How do you calculate the partial pressure of the reactants and products at equilibrium for part c?
- Sun Dec 09, 2018 8:08 pm
- Forum: Biological Examples
- Topic: Iron in myoglobin [ENDORSED]
- Replies: 2
- Views: 2295
Iron in myoglobin [ENDORSED]
Why does the iron in myoglobin only bond to one O atom and not 2?
- Sun Dec 09, 2018 8:01 pm
- Forum: Naming
- Topic: naming polydentate ligands
- Replies: 2
- Views: 532
naming polydentate ligands
Do all polydentate ligands use the prefixes bis, tris, etc or just the ones that already have di or tri in their name?
- Sun Dec 09, 2018 7:59 pm
- Forum: Resonance Structures
- Topic: Resonance of CH3COOH
- Replies: 1
- Views: 2288
Resonance of CH3COOH
Does the structure CH3COOH have resonance because there are two Lewis structures that are correct, but the H atom can only be on one O atom at a time?
- Sun Dec 02, 2018 9:47 pm
- Forum: Properties & Structures of Inorganic & Organic Bases
- Topic: Bases for final
- Replies: 1
- Views: 284
Bases for final
Are there any common bases that need to be memorized for the final?
- Sun Dec 02, 2018 9:45 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acids for final
- Replies: 2
- Views: 213
Acids for final
Are there any common Acids that need to be memorized for the final?
- Sun Dec 02, 2018 9:40 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligand names
- Replies: 7
- Views: 750
Ligand names
For the final do we have to memorize all of the common ligand names?
- Sun Nov 18, 2018 7:54 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecules with more than 2 different elements
- Replies: 3
- Views: 320
Molecules with more than 2 different elements
Is there a rule that states when a molecule has more than 2 elements in it the molecule becomes polar?
- Sun Nov 18, 2018 7:48 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: polar molecules
- Replies: 2
- Views: 291
polar molecules
Why do some molecules such as AX3E molecules only have polar forms?
- Sun Nov 18, 2018 7:42 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Model formation
- Replies: 2
- Views: 222
Model formation
Are there any VESPER shapes that can form from two different types of Lewis structures? For instance is it possible for Ax3 E1 and AX5 E2 to form the same shape?
- Sun Nov 11, 2018 8:49 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Difference in models
- Replies: 2
- Views: 283
Difference in models
What causes a molecule to either form into a Trigonal planar, Trigonal pyramid, or a T-shape?
- Sun Nov 11, 2018 8:44 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarization of cation's
- Replies: 2
- Views: 210
Polarization of cation's
Do cations become more polarization power with a higher positive charge and smaller atom? Basically in the opposite way of an anion.
- Sun Nov 11, 2018 8:41 pm
- Forum: Resonance Structures
- Topic: Bond lengths
- Replies: 1
- Views: 312
Bond lengths
If a molecule has a 130pm bond length and a 150pm bond length and has resonance is the total bond length 140pm?
- Sun Nov 04, 2018 8:49 pm
- Forum: Resonance Structures
- Topic: Resonance with formal charge
- Replies: 6
- Views: 591
Resonance with formal charge
If a molecule has a formal charge that favors one form of a Lewis structure over another does the molecule still have resonance?
- Sun Nov 04, 2018 8:46 pm
- Forum: Ionic & Covalent Bonds
- Topic: Identifying ionic compounds
- Replies: 1
- Views: 200
Identifying ionic compounds
Some molecules such as (NH4)OH look like a covalent molecule but are actually an ionic molecule. How do you identify this as an ionic compound?
- Sun Nov 04, 2018 8:37 pm
- Forum: Octet Exceptions
- Topic: Radicals
- Replies: 16
- Views: 1665
Radicals
In a molecule with a radical how do you identify which element the radical is on?
- Sun Oct 28, 2018 11:41 pm
- Forum: Ionic & Covalent Bonds
- Topic: Question 2B.11
- Replies: 1
- Views: 182
Question 2B.11
How do you determine the central atoms and the order of the atoms in general?
- Sun Oct 28, 2018 11:39 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2B.7
- Replies: 3
- Views: 402
2B.7
How does the element E have 10 valence electrons?
- Sun Oct 28, 2018 11:36 pm
- Forum: Ionic & Covalent Bonds
- Topic: Question 2B.3 part d
- Replies: 2
- Views: 190
Question 2B.3 part d
For the BrF3 molecule Br has more than 8 valence electrons. I was wondering why this occurs
- Sun Oct 21, 2018 12:20 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Atomic number and orbitals [ENDORSED]
- Replies: 1
- Views: 243
Atomic number and orbitals [ENDORSED]
On the perodic table the elemtents all fit togeter into s orbital, p orbital, and d orbital sections. I was wondering is this in anyway to do with the atomic number of the atoms and the number of valence electrons?
- Sun Oct 21, 2018 12:17 am
- Forum: Photoelectric Effect
- Topic: spectral lines
- Replies: 6
- Views: 603
spectral lines
I've seen two versions of the same formula: one is v = R(1/n1^2 -1/n2^2). The other is 1/wavelength = R(1/n1^2 -1/n2^2). I was just wondering which of these two equations is correct and what's its main use is for
- Sun Oct 21, 2018 12:13 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbitals and periodic table
- Replies: 1
- Views: 135
Orbitals and periodic table
So on the periodic table I noticed that the elements all line nicely into groups that share the same sub shells. I was wondering why this occurs and about how this affects the elements properties
- Sun Oct 21, 2018 12:13 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbitals and periodic table
- Replies: 1
- Views: 284
Orbitals and periodic table
So on the periodic table I noticed that the elements all line nicely into groups that share the same sub shells. I was wondering why this occurs and about how this affects the elements properties
- Sun Oct 14, 2018 10:02 pm
- Forum: Photoelectric Effect
- Topic: 1B.7
- Replies: 2
- Views: 348
1B.7
Sodium vapor lamps, used for public lighting, emit yellow light of wavelength 589nm. How much energy is emitted by 5.00 mg of sodium atom emitting this wavelength?
- Sun Oct 14, 2018 9:53 pm
- Forum: DeBroglie Equation
- Topic: 1B.15
- Replies: 4
- Views: 249
1B.15
The velocity of an electron that is emitted from a metallic surface by a photon is 3.6*10^3 kn/s. How do you find the wavelength of the electron?
- Sun Oct 14, 2018 9:50 pm
- Forum: DeBroglie Equation
- Topic: 1B.9
- Replies: 3
- Views: 264
1B.9
A lamp is rated at 32W emits violet light of wavelength 420nm. How many photons of violet light can the lamp generate in 2.0s? How many moles of photons are emitted in that time interval?
How do you find the amount of moles using Watts?
How do you find the amount of moles using Watts?
- Sun Oct 07, 2018 8:56 pm
- Forum: Limiting Reactant Calculations
- Topic: Question M 9 and net ionic equations
- Replies: 1
- Views: 121
Question M 9 and net ionic equations
Copper (II) nitrate reacts with sodium hydroxide to produce a precipitate of light blue copper(II) hydroxide. (a) Write the net ionic equation for the reaction. I was just wondering if anyone knows how to create net ionic equations because I am very rusty with them. If anyone could explain how to in...
- Sun Oct 07, 2018 8:44 pm
- Forum: Limiting Reactant Calculations
- Topic: Question M11
- Replies: 2
- Views: 344
Question M11
I understand how to do the first reaction P4 + 3O2 = P4O6. I found the limiting reactant to be P4. I was just wondering how I calculate how much oxygen is left for the second reaction
- Sun Oct 07, 2018 8:39 pm
- Forum: Properties of Light
- Topic: Question 1A3.
- Replies: 1
- Views: 108
Question 1A3.
"What happens when the frequency of electromagnetic radiation decreases? " The answer is C "The extent of the change in the electrical field at a given point decreases.". I do not understand why c is correct. I thought the answer was A. Answer A says the "speed of radiation ...