## Search found 57 matches

Wed Mar 13, 2019 12:43 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Arrhenius Equation
Replies: 2
Views: 153

### 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: 141

### 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: 152

### 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: 183

### 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: 177

### 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: 381

### 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: 350

### 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
Replies: 73
Views: 4242

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: 188

### 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: 144

### 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: 96

### 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: 120

### 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: 156

### 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: 481

### 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: 105

### 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: 2391

### 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: 696

### 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: 318

### 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: 186

### 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: 128

### Re: Standard Enthalpy of Formation

This is the equation to find the standard enthalpy change of formation

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: 181

### 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: 165

### 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: 1961

### 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: 408

### 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: 61

### 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: 254

### 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: 400

### 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: 432

### Re: Amphiprotic vs Amphoteric

amphiprotic can donate and accept protons
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: 524

### 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: 490

### 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: 359

### 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: 300

### 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: 160

### 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: 151

### 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: 103

### 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: 859

### 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: 140

### 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: 50

### 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: 112

### 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: 128

### 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: 284

### 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: 226

### 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: 315

### 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: 160

### 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: 2143

### 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: 103

### 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: 165

### 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: 151

### 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: 154

### 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: 436

### 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: 147

### 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: 51

### 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
Topic: Stefan-Boltzmann and Wien's law
Replies: 2
Views: 551

### 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: 180

### 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: 125

### Re: diatomic molecules

There is an acronym :

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: 171

### 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: 265

### 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.