## Search found 60 matches

Sun Mar 17, 2019 1:04 am
Forum: First Order Reactions
Topic: rate law
Replies: 2
Views: 285

### Re: rate law

you may also be given the half-life and asked to calculate k from that, but just use the equation sheet and see what variables are given.
Sun Mar 17, 2019 1:02 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst Equation Confusion
Replies: 4
Views: 363

### Re: Nernst Equation Confusion

The second equation can only be used at room temperature 298 K.
Sun Mar 17, 2019 1:01 am
Forum: *Enzyme Kinetics
Replies: 13
Views: 803

It would still appear on either side of the equation as well when it comes to rate laws.
Mon Mar 11, 2019 7:29 pm
Forum: General Rate Laws
Topic: determining rate law
Replies: 2
Views: 120

### Re: determining rate law

You should see which reactants affect the rate most of the time it will only be the slowest step, but it could also entail other steps.
Mon Mar 11, 2019 7:27 pm
Forum: General Rate Laws
Topic: units
Replies: 2
Views: 134

### Re: units

There's no real units for k it's based off what the problem entails whether given concentration or partial pressure.
Mon Mar 11, 2019 7:26 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Frequency factor A
Replies: 7
Views: 323

### Re: Frequency factor A

I'm pretty sure its the percent of successful collisions.
Sun Mar 03, 2019 4:55 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Non-Spontaneous
Replies: 3
Views: 182

### Re: Non-Spontaneous

Non-spontaneous reactions because they are adding energy to perform the reaction
Sun Mar 03, 2019 4:41 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Battery
Replies: 2
Views: 112

### Re: Battery

The most common form of Electrolytic cell is the rechargeable battery. While the battery is being used in the device it is a galvanic cell function (using the redox energy to produce electricity). While the battery is charging it is an electrolytic cell function (using outside electricity to reverse...
Sun Mar 03, 2019 4:39 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Standard G
Replies: 4
Views: 165

### Re: Standard G

delta G0 is used at equilibrium
Mon Feb 25, 2019 12:54 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Graphite
Replies: 3
Views: 119

### Re: Graphite

Graphite is what allows the electrons to flow from one solution to the next, it connects the two and it was conducts the electron transfer.
Mon Feb 25, 2019 12:53 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: ions
Replies: 2
Views: 97

### Re: ions

Ions are always aqueous and it just makes sense because they are donation or accepting an electron.
Mon Feb 25, 2019 12:52 am
Forum: Balancing Redox Reactions
Topic: Single Reactant in Redox
Replies: 2
Views: 104

### Single Reactant in Redox

If there's a single reactant, how do you know which part is the reducing agent and which is the oxidizing agent?
Sun Feb 17, 2019 11:58 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Max Work
Replies: 5
Views: 226

### Re: Max Work

Constant temperature and pressure provide the opportunity for max work
Sun Feb 17, 2019 11:56 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: K vs. Delta G
Replies: 2
Views: 128

### Re: K vs. Delta G

When K=1 delta g=0
When k<1 delta g is positive
when k>1 delta g is negative
Sun Feb 17, 2019 11:55 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy
Replies: 5
Views: 210

### Re: Gibbs Free Energy

I think it describes the overall spontaneity of the system and whether it is achieved through the delta s or delta h.
Fri Feb 08, 2019 3:02 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: q= -w
Replies: 8
Views: 255

### Re: q= -w

It is essentially saying that q and w are equal but opposite
Fri Feb 08, 2019 2:55 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Enthalpy and Hheat
Replies: 2
Views: 136

### Re: Enthalpy and Hheat

The heat given off or absorbed when a reaction is run at constant pressure is equal to the change in the enthalpy of the system.
Fri Feb 08, 2019 2:50 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs free energy
Replies: 5
Views: 199

### Re: Gibbs free energy

It tells you if the reaction is favorable which is based on spontaneity
Sun Feb 03, 2019 10:41 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Material on Midterm?
Replies: 9
Views: 388

### Re: Material on Midterm?

Last quarter he taught new material until two lectures before the midterm, so I assume that everything stated on the syllabus will be covered.
Sun Feb 03, 2019 10:38 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Delta H and q
Replies: 3
Views: 117

### Re: Delta H and q

delta h is the change in enthalpy of the system and q is the heat given off or absorbed in the system
Sun Feb 03, 2019 10:35 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: w=PdeltaV
Replies: 5
Views: 208

### Re: w=PdeltaV

If you remember the diagrams Dr. Lavelle presented to display AxD is equal to the volume since it is the area of the section of the cylinder multiplied by the distance it traveled and in this cause that represents the change in volume.
Wed Jan 23, 2019 10:54 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5% Rule
Replies: 5
Views: 267

### Re: 5% Rule

But if you do disregard x make sure to double check that it is under 5% because if not the solution is incorrect.
Wed Jan 23, 2019 10:44 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Strong Acids and Bases
Replies: 3
Views: 170

### Re: Strong Acids and Bases

Correct because it dissociates completely you assume all of the reactant is used to form the products.
Wed Jan 23, 2019 10:42 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Volume and Le Chatelier's Principle
Replies: 5
Views: 206

### Re: Volume and Le Chatelier's Principle

If an inert gas is added to the system the reaction does not shift one way or the other
Sat Jan 19, 2019 4:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K - small verses big
Replies: 4
Views: 185

### Re: K - small verses big

when Kb is larger than Ka it means that the base is stronger than its conjugate acid. Or that the acid is weaker than its conjugate base.
Sat Jan 19, 2019 4:19 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Need to always check for Q?
Replies: 2
Views: 145

### Re: Need to always check for Q?

Just to be safe and check your work you should check to see which way the reaction will move if possible.
Sat Jan 19, 2019 4:18 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatelier's Principle and Partial Pressure
Replies: 3
Views: 115

### Re: Le Chatelier's Principle and Partial Pressure

Partial pressures change when product or reactant are removed or added to the system.
Fri Jan 11, 2019 4:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Charles’s Law
Replies: 4
Views: 64

### Re: Charles’s Law

Charles' Law shows the relationship between the Temperature and Volume of a gas. Temperature and volume have a direct relationship, so if the volume goes up then the temperature goes up and if the temperature goes down then the volume goes down (and vice versa).
Fri Jan 11, 2019 4:11 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Mole Ratio with a Solid [ENDORSED]
Replies: 3
Views: 106

### Mole Ratio with a Solid[ENDORSED]

In the example,
B(g) + C(g)<-->A(s)
If volume is decreased, would I say the reaction favors products because mole ratio is (2:0)?
Fri Jan 11, 2019 4:08 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids and Liquids in Rxn
Replies: 6
Views: 287

### Re: Solids and Liquids in Rxn

I believe since solids and liquids are considered 1 in the equation K=1
Thu Dec 06, 2018 12:15 pm
Forum: Amphoteric Compounds
Topic: acidic vs. basic vs. amphoteric
Replies: 2
Views: 154

### Re: acidic vs. basic vs. amphoteric

My TA said to just memorize the amphoteric metal oxides to make your life easier.
Mon Dec 03, 2018 12:23 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: KA, KB values on final
Replies: 3
Views: 167

### KA, KB values on final

On the final we will just need to apply equilibrium constants to determine the strength of an acid or base correct.
Mon Dec 03, 2018 12:18 pm
Forum: Bronsted Acids & Bases
Topic: Comparing pH levels
Replies: 3
Views: 126

### Comparing pH levels

Will we have to compare hydronium ion concentrations for the final? For example, knowing that a pH of 3 has a hydronium concentration 100 times greater than a pH of 5.
Sun Dec 02, 2018 12:54 pm
Forum: Administrative Questions and Class Announcements
Topic: More practice
Replies: 7
Views: 431

### Re: More practice

You can always check the test bank that has past exam questions. That really helped me on the midterm!
Sun Dec 02, 2018 12:52 pm
Forum: Lewis Acids & Bases
Topic: bronsted acid vs. lewis acid
Replies: 4
Views: 211

### Re: bronsted acid vs. lewis acid

The Bronsted definition: an acid is a proton (H+ ion) donor, and a base is a proton acceptor;
The Lewis definition: an acid is an electron acceptor, and a base is an electron donor.
Sun Dec 02, 2018 12:50 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Lone pair location
Replies: 3
Views: 387

### Re: Lone pair location

If there is more than one lone pair they are located so that they are farthest away from other areas of electron density since they have the greatest repulsion.
Sun Nov 25, 2018 7:16 pm
Forum: Hybridization
Topic: Hybridization scheme
Replies: 3
Views: 124

### Re: Hybridization scheme

Also every molecular shape has a specific hybridization, so you can memorize what hybridization matches to a specific molecular shape.
Sun Nov 25, 2018 7:14 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarity
Replies: 3
Views: 142

### Re: Polarity

The easiest thing to look at is the molecules symmetry. Most of the time if it's symmetrical it will be non polar, but other than symmetry you have to determine the polarity between each bond and then observe the whole molecule.
Sun Nov 25, 2018 7:11 pm
Forum: Properties of Light
Topic: Speed of light
Replies: 13
Views: 3250

### Re: Speed of light

It depends on the sig fig in the problem stay true to that.
Mon Nov 19, 2018 3:44 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Atom Placement
Replies: 4
Views: 185

### Re: Atom Placement

I think usually it will specify if it's important, however, the arrangement does affect the polarity, so I think it depends on what the question is asking.
Mon Nov 19, 2018 3:39 pm
Forum: Sigma & Pi Bonds
Topic: Rotating Pi bonds
Replies: 3
Views: 142

### Rotating Pi bonds

Is there any time that a pi bond can rotate or does it break when it begins to rotate?
Mon Nov 19, 2018 3:37 pm
Forum: Hybridization
Topic: Molecular Shape & Hybridization
Replies: 4
Views: 178

### Molecular Shape & Hybridization

Does each molecular shape i.e. trigonal planar, tetrahedral always have the same hybridization model?
Sat Nov 10, 2018 7:15 pm
Forum: Bond Lengths & Energies
Topic: Bond Lengths
Replies: 6
Views: 229

### Re: Bond Lengths

Bond length is given unless there is resonance then you must calculate it.
Sat Nov 10, 2018 6:55 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability Trend
Replies: 6
Views: 1403

### Polarizability Trend

How would I go about predicting the polarizability of Anions and the polarizing power of Cations? Is there a periodic trend which can be used to predict such things, or another way?
Sat Nov 10, 2018 6:34 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Drawing Lewis Structures with VSPER
Replies: 5
Views: 247

### Drawing Lewis Structures with VSPER

When drawing the Lewis structure of a trigonal planar model does it matter if the spacing is 120 degrees or can you draw it how we did previously then specify that the angle is 120 degrees.
Thu Nov 01, 2018 2:57 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 5
Views: 228

### Re: Electron Affinity

The more negative the electron affinity value, the higher an atom's affinity for electrons. So the elements in the top corner (chlorine, fluorine) have a more negative value than lower down the column or left. It is more negative because the they give off energy to form an anion exothermic process.
Thu Nov 01, 2018 2:49 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge and the Octet Rule
Replies: 6
Views: 345

### Re: Formal Charge and the Octet Rule

Remember the exceptions to expanding the octet rule begin in period three because that period has the d block only then can the octet rule be altered. However, elements like B and Al can be a part of Lewis acid-base reactions and may only have 6 valence electrons.
Thu Nov 01, 2018 2:39 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: What is the notation for the valence-shell configuration?
Replies: 2
Views: 109

### Re: What is the notation for the valence-shell configuration?

It's asking for the short hand configuration where you use the noble gas and then show the valence electrons
Sat Oct 27, 2018 5:04 pm
Forum: Lewis Structures
Topic: Lewis Dot Structures
Replies: 3
Views: 176

### Re: Lewis Dot Structures

Unless it specifies which atom (usually carbon atom) the double or triple bond is on it shouldn't matter.
Sat Oct 27, 2018 5:01 pm
Forum: Lewis Structures
Topic: Order in Drawing Lewis Structures
Replies: 2
Views: 54

### Re: Order in Drawing Lewis Structures

I don't think it matters however if you are representing it next to another molecule that it could bond with I would put the unpaired one at that side for representation purposes.
Sat Oct 27, 2018 4:58 pm
Forum: Lewis Structures
Topic: When electrons do no pair in orbitals:
Replies: 2
Views: 54

### Re: When electrons do no pair in orbitals:

It also depends on the orbitals so the d orbital has 10 slots for electrons however if it is 3d^6 only one set of electrons are paired and the other 4 are not paired.
Sun Oct 21, 2018 2:04 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: What is a node?
Replies: 2
Views: 43

### Re: What is a node?

As Dr. Lavelle explained in class only p, d, & f orbitals have nodes, thus they have nodal planes in which the orbitals orient themselves. Since the s orbitals are similar to a sphere they do not contain nodes. Nodes come from the math function that give us each of the orbital shapes which we to...
Sun Oct 21, 2018 1:58 pm
Forum: Trends in The Periodic Table
Topic: Homework
Replies: 10
Views: 352

### Re: Homework

I normally do problems from the topics we cover that week. i.e. quantum numbers since we just went over that and then a review question from the previous section like a Heisenberg problem.
Mon Oct 15, 2018 3:19 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg Indeterminacy Equation Limits
Replies: 1
Views: 43

### Heisenberg Indeterminacy Equation Limits

In class Dr. Lavelle explained in his example that the velocity we calculated using the uncertainty equation must be incorrect because it was greater than the speed of light. I understand the upper bound to determining if a velocity value is realistic is the speed of light, but I was wondering if th...
Sat Oct 13, 2018 3:40 pm
Forum: Limiting Reactant Calculations
Topic: Test 1
Replies: 5
Views: 375

### Re: Test 1

My TA mentioned that even if you get the wrong answer write all the equations you're using down so that you can receive partial credit and they can see where you go wrong.
Sat Oct 13, 2018 3:37 pm
Forum: Administrative Questions and Class Announcements
Topic: Required knowledge for test/midterm [ENDORSED]
Replies: 17
Views: 645

### Re: Required knowledge for test/midterm[ENDORSED]

I assume like the last test we get all the constants and equations necessary on the cover page and would just have to derive the equations not given.
Sat Oct 13, 2018 3:34 pm
Forum: DeBroglie Equation
Topic: De Broglie wavelength - when can it be seen
Replies: 5
Views: 89

### Re: De Broglie wavelength - when can it be seen

Essentially the wavelength cannot be measured when it is smaller than 10^-18 thus it is used as the cut off point
Fri Oct 05, 2018 3:56 pm
Forum: Limiting Reactant Calculations
Topic: Limiting reagents
Replies: 12
Views: 366

### Re: Limiting reagents

There is only one limiting reactant in a single step chemical reaction. If the moles are the same for all reactants none of them are limiting the others' potential to create more product. Thus, there is a perfect amount of reactant to fully react with the others in order to form product.
Fri Oct 05, 2018 3:45 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Chemical Reactions with Heat
Replies: 6
Views: 266

### Re: Balancing Chemical Reactions with Heat

The implementation of heat basically describes the properties of the reaction further to show if its an endothermic or exothermic reaction which comes into play later with thermodynamics.
Fri Oct 05, 2018 3:39 pm
Forum: Significant Figures
Topic: Zeros in sig figs
Replies: 4
Views: 223

### Re: Zeros in sig figs

The best way to determine what zeros are included is to put the number in scientific notion and from there you will be able to determine the correct sig figs with the zeros. i.e. 0.000500 --> 5.00*10^-4 Thus, in my example there are 3 sig figs which is clear in scientific notation.