Search found 57 matches
- Wed Mar 13, 2019 12:43 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Arrhenius Equation
- Replies: 2
- Views: 329
Arrhenius Equation
So I was watching an example using the Arrhenius Equation and in their equation, it is 1/T2-(1/T1) but in the textbook, it is the reverse. The answer is going to be different depending on which order you place them in so which one should I use?
- Tue Mar 12, 2019 11:53 pm
- Forum: General Rate Laws
- Topic: writing rate law
- Replies: 2
- Views: 352
writing rate law
why do we only look at the reactants when writing a rate law from a mechanism?
- Sun Mar 10, 2019 6:48 pm
- Forum: First Order Reactions
- Topic: first order reactions examples
- Replies: 3
- Views: 407
first order reactions examples
What are some real life examples of 1st order reactions?
- Sun Mar 10, 2019 6:47 pm
- Forum: Second Order Reactions
- Topic: Second order reactions
- Replies: 2
- Views: 331
Second order reactions
What are some real life examples of second order reactions?
- Sun Mar 10, 2019 6:19 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Microscopic reversibility
- Replies: 3
- Views: 413
Re: Microscopic reversibility
I can second that, I do remember Lavelle saying we could assume microscopic reversibility
- Sun Mar 10, 2019 5:48 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalysts
- Replies: 6
- Views: 774
Re: Catalysts
does having more catalyst change the order of a reaction?
- Sun Mar 10, 2019 5:43 pm
- Forum: Zero Order Reactions
- Topic: Zero Order Reactions
- Replies: 3
- Views: 569
Re: Zero Order Reactions
the haber process is a good example of this if you look it up. it is a way of producing ammonia from hydrogen and nitrogen gas.
- Tue Mar 05, 2019 1:31 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Study Advice
- Replies: 73
- Views: 7202
Re: Study Advice
sometimes even just doing the more of the tricky questions really helps too
- Tue Mar 05, 2019 1:25 pm
- Forum: Balancing Redox Reactions
- Topic: reduction potentials at pH =7
- Replies: 2
- Views: 413
Re: reduction potentials at pH =7
Usually any constants that are needed will be given in the question details
- Sun Feb 24, 2019 9:33 pm
- Forum: Balancing Redox Reactions
- Topic: Reducing and Oxidizing Agents
- Replies: 3
- Views: 407
Reducing and Oxidizing Agents
How can something be both the Reducing and Oxidizing agent?
- Sun Feb 24, 2019 9:14 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Conc. and Gibbs Free Energy
- Replies: 1
- Views: 256
Conc. and Gibbs Free Energy
How does the conc. of a substance affect the gibbs free energy?
- Sun Feb 24, 2019 9:10 pm
- Forum: Balancing Redox Reactions
- Topic: Skeleton Equations
- Replies: 3
- Views: 325
Skeleton Equations
When it asks for a skeleton equation how do we know to include water vs just showing the transfer of electrons?
- Wed Feb 20, 2019 11:31 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Indications
- Replies: 3
- Views: 390
Re: Indications
if you look in the txtbook there is a chart that does a good job of outlining this
- Wed Feb 20, 2019 11:26 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Test 3
- Replies: 10
- Views: 986
Re: Test 3
how much of electrochemistry do you think it will include?
- Wed Feb 20, 2019 11:26 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: 9.61
- Replies: 1
- Views: 223
9.61
So if the the rxn that we are trying to find the delta G for has two products o we just add their enthalpies and entropies together and then solve for delta G?
- Sun Feb 10, 2019 10:59 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Midterm [ENDORSED]
- Replies: 49
- Views: 4921
Re: Midterm [ENDORSED]
highly recommend youtube videos too, sometimes just watching someone do the problem and seeing how they lay it out really helps
- Sun Feb 10, 2019 10:56 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: deltaS=nCvln(t2/t1) what is Cv?
- Replies: 7
- Views: 2819
Re: deltaS=nCvln(t2/t1) what is Cv?
where does the 3/2 come from?
- Sun Feb 10, 2019 10:54 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: Reversible vs. Irreversible
- Replies: 6
- Views: 596
Re: Reversible vs. Irreversible
W(reversible) will always be higher than irreversible because work is being done by the system, whereas with W(irreversible) work is being done on the system thus it is losing heat.
- Sun Jan 27, 2019 12:08 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: method 1
- Replies: 4
- Views: 435
Re: method 1
if they are not in the same state does the molecule just get brought down into the final equation?
- Sun Jan 27, 2019 12:04 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Standard Enthalpy of Formation
- Replies: 2
- Views: 263
Re: Standard Enthalpy of Formation
This is the equation to find the standard enthalpy change of formation
ΔHoreaction=∑ΔHof(products)−∑ΔHof(Reactants)
ΔHoreaction=∑ΔHof(products)−∑ΔHof(Reactants)
- Thu Jan 24, 2019 4:06 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Hmwrk 11.57 6th edition
- Replies: 2
- Views: 377
Re: Hmwrk 11.57 6th edition
how do you find the number of moles of H2O ?
- Sun Jan 20, 2019 5:18 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Salt formation
- Replies: 3
- Views: 338
Re: Salt formation
generally in a neutralization reaction and an acid and a base react the products are a salt and water. For example when you mix NaOH+HCl=H20+NaCl thus forming a salt.
- Sun Jan 20, 2019 5:15 pm
- Forum: Ideal Gases
- Topic: 5% rule
- Replies: 12
- Views: 3470
Re: 5% rule
if the approximation is above 5% then is the complete answer void?
- Sun Jan 20, 2019 5:10 pm
- Forum: Ideal Gases
- Topic: Concentration or Partial Pressure
- Replies: 13
- Views: 1011
Re: Concentration or Partial Pressure
if you are given one value in a concentration and one in partial pressure you should use the equation to get them all in the same units
- Sun Jan 13, 2019 5:47 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: affect change in pressure has on concentration
- Replies: 2
- Views: 152
affect change in pressure has on concentration
I don't quite understand why it is a change in concentration instead of a change in pressure.
- Sun Jan 13, 2019 5:42 pm
- Forum: Ideal Gases
- Topic: When is pv=nrt used? [ENDORSED]
- Replies: 5
- Views: 557
Re: When is pv=nrt used? [ENDORSED]
and the concentration is the number of moles over the volume
- Sun Jan 13, 2019 5:40 pm
- Forum: Ideal Gases
- Topic: Pv=nRT [ENDORSED]
- Replies: 12
- Views: 791
Re: Pv=nRT [ENDORSED]
we only use this equation to convert from partial pressure to concentration and vice versa rt?
- Sun Dec 09, 2018 10:33 am
- Forum: Amphoteric Compounds
- Topic: Amphiprotic vs Amphoteric
- Replies: 5
- Views: 744
Re: Amphiprotic vs Amphoteric
amphiprotic can donate and accept protons
amphoteric react as both acids and bases
amphoteric react as both acids and bases
- Sun Dec 09, 2018 9:24 am
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Boiling point
- Replies: 4
- Views: 810
Re: Boiling point
less distorted electron cloud that is larger
- Mon Dec 03, 2018 12:18 am
- Forum: Naming
- Topic: With Respect to the Final
- Replies: 9
- Views: 985
Re: With Respect to the Final
I think since it is in the hw problems, it would probably be a safe bet to know them.
- Mon Dec 03, 2018 12:14 am
- Forum: Lewis Acids & Bases
- Topic: acid names
- Replies: 8
- Views: 764
Re: acid names
I would know all the strong acids and some of the weak acids too. Especially some of the ones used in biological models.
- Mon Dec 03, 2018 12:13 am
- Forum: Naming
- Topic: drawing ligands
- Replies: 6
- Views: 562
Re: drawing ligands
I think he just wanted to show the structure of the molecule more than the actual accuracy of the order of the elements.
- Fri Nov 23, 2018 9:09 pm
- Forum: Hybridization
- Topic: Number of Hybrid Orbitals
- Replies: 3
- Views: 316
Re: Number of Hybrid Orbitals
Because the hybridization of the model is based on the number of regions of electron density around the central atom
- Fri Nov 23, 2018 9:03 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Difference Between Position and Shape
- Replies: 2
- Views: 309
Re: Difference Between Position and Shape
The shape is determined by the position of the nucleus and its electrons. Position or geometry does not take into account the additional areas of electron density that are pushing the electrons in the ideal structure. The position does, however, take into account the electron affinity of different e...
- Fri Nov 23, 2018 8:55 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.25 7th Edition
- Replies: 1
- Views: 221
Re: 2E.25 7th Edition
It has to do with the periodic trends and how they affect bonding. Chlorine has a stronger electron affinity than hydrogen, therefore, will be unbalanced and have a charge if both chlorines or both hydrogens are on the same side. However, if they are equally distributed so is the charge.
- Fri Nov 16, 2018 5:35 pm
- Forum: Octet Exceptions
- Topic: Exceptions
- Replies: 10
- Views: 1381
Re: Exceptions
In addition to this Xenon also has an expanded octet
- Fri Nov 16, 2018 5:19 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: cis and trans prefix's to molecules
- Replies: 2
- Views: 335
cis and trans prefix's to molecules
How do you know when to use the cis and trans prefixes?
- Fri Nov 16, 2018 5:19 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: cis and trans prefix's to molecules
- Replies: 2
- Views: 174
cis and trans prefix's to molecules
How do you know when to use the cis and trans prefixes?
- Fri Nov 16, 2018 5:04 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: sigma bonds
- Replies: 1
- Views: 215
sigma bonds
Can someone explain to me why you can have multiple pi bonds in a molecule but only 1sigma bond?
- Sun Nov 11, 2018 8:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR
- Replies: 2
- Views: 265
VSEPR
How are double and triple bonds represented in the VSEPR models?
- Sun Nov 11, 2018 8:51 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: determining VSEPR models
- Replies: 6
- Views: 557
determining VSEPR models
I understand that regions of high electron concentrations repel one another but, how do you know how much they repel one another? For example, the seesaw, tetrahedral, and square planar shapes have the same number of bonds, yet they have very different models.
- Sun Nov 11, 2018 8:40 pm
- Forum: Octet Exceptions
- Topic: learning octet excptions
- Replies: 4
- Views: 385
learning octet excptions
are there any tricks to learning the octet exceptions and knowing how many bonds each element usually wants?
- Sun Nov 04, 2018 9:22 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Fundamental and Quantum Review #6 [ENDORSED]
- Replies: 1
- Views: 427
Re: Fundamental and Quantum Review #6 [ENDORSED]
So we are solving for the final energy level. We know the initial value is in the ultraviolet region, therefore n=1 initially. the final value must be greater than n=1 and if we use En=-hR/n^2 Because we know the wavelength of the final observed hydrogen line we can find the change in energy and the...
- Sun Nov 04, 2018 8:58 pm
- Forum: Trends in The Periodic Table
- Topic: 6th Edition 2.71
- Replies: 4
- Views: 357
Re: 6th Edition 2.71
So, basically what the book is saying is that groups of atoms on the periodic table tend to show similar characteristics and react with similar compounds. The example the book gives is that both lithium and magnesium react directly with nitrogen to form nitrides.
- Sun Nov 04, 2018 8:51 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Ideal lewis structure with Formal Charge
- Replies: 4
- Views: 2359
Re: Ideal lewis structure with Formal Charge
It all depends on what combination you can create with the lowest formal charge. If you have a lewis dot structure that should have a neutral charge and each atom has a negative 1 charge and a positive 1 charge that is not going to be as ideal as a lewis structure that has all neutral charges.
- Sat Oct 27, 2018 3:30 pm
- Forum: Lewis Structures
- Topic: Drawing lewis structures with molecules
- Replies: 1
- Views: 203
Drawing lewis structures with molecules
How do you connect Lewis dot structures of molecules, i.e. molecules like Nitrate and Ammonium?
- Sat Oct 27, 2018 2:56 pm
- Forum: Ionic & Covalent Bonds
- Topic: formal charges
- Replies: 4
- Views: 366
formal charges
How do we know the formal charge of a transition metal since it is not given?
- Sat Oct 27, 2018 2:48 pm
- Forum: Ionic & Covalent Bonds
- Topic: Lowest Energy
- Replies: 4
- Views: 338
Re: Lowest Energy
When referring to the lowest energy it means that the molecule wants to have a full octet in the valence electrons. Therefore they have no electronegative energy.
- Sun Oct 21, 2018 2:52 pm
- Forum: Properties of Electrons
- Topic: Exercise 1.64 esu
- Replies: 1
- Views: 243
Exercise 1.64 esu
What is the conversion for electrostatic units (esu)?
- Sun Oct 21, 2018 2:40 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: real life application of using the uncertainty principle
- Replies: 1
- Views: 616
real life application of using the uncertainty principle
Can someone explain to me a real life application when we would be looking for the position and the momentum at the subatomic level?
- Sun Oct 21, 2018 2:33 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Electron configurations
- Replies: 2
- Views: 289
Re: Electron configurations
Noble gases all have full shells therefore you can assume that it will have the maximum number of electrons in its outer shell. Generally this will end with p^6 except for helium in the 1s^2. Otherwise they will go through the usual sequence depending on which one you are trying to find the electron...
- Fri Oct 12, 2018 5:32 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: spherical polar coordinates
- Replies: 1
- Views: 142
spherical polar coordinates
So, I understand that there are three points of r, theta, and phi in a wave function but what exactly do these tell us about the orbital?
- Fri Oct 12, 2018 5:18 pm
- Forum: *Black Body Radiation
- Topic: Stefan-Boltzmann and Wien's law
- Replies: 2
- Views: 810
Stefan-Boltzmann and Wien's law
Both Boltzmann's and Wien's law have to do with wavelength corresponding to intensity as the temperature increase so in what instances would you use the equations that correspond to the laws?
- Fri Oct 12, 2018 5:13 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Solving for frequency
- Replies: 3
- Views: 401
Solving for frequency
So, when you're trying to find the frequency of a wavelength why would you want to convert the units from s^-1 to Hz?
- Thu Oct 04, 2018 4:43 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: diatomic molecules
- Replies: 5
- Views: 398
Re: diatomic molecules
There is an acronym :
HNOFClBrI usually pronounced H nofclbri and those are all the diatomic molecules
HNOFClBrI usually pronounced H nofclbri and those are all the diatomic molecules
- Thu Oct 04, 2018 4:39 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Finding remaining mass of hydrate
- Replies: 1
- Views: 347
Finding remaining mass of hydrate
So if your given an Anhydrous copper (II) sulfate what amount would would remain after removing 90% of the water from 360 g of CuSO4.5H2O?
- Wed Oct 03, 2018 11:40 am
- Forum: SI Units, Unit Conversions
- Topic: Converting between Temperatures (K,C,F)
- Replies: 4
- Views: 439
Re: Converting between Temperatures (K,C,F)
To go from F to K you just need to subtract 32 from your initial temp, multiply the number by 5 and divide by 9 . Then you add 273.15 to your answer. This can be reversed to go from Kelvin to F too.