Search found 59 matches

by Nicole Jacobs 1C
Sat Mar 17, 2018 11:13 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 2008 Practice Final Q3D
Replies: 1
Views: 160

Re: 2008 Practice Final Q3D

it is given that 1E-16 is the molarity of cu2+ in the question and since cu2+ is the reactant, you put its concentration in the denominator
by Nicole Jacobs 1C
Sat Mar 17, 2018 10:53 am
Forum: First Order Reactions
Topic: Slope of 1st order RXNs
Replies: 9
Views: 319

Re: Slope of 1st order RXNs

remember only the second order has a positive k slope
by Nicole Jacobs 1C
Sat Mar 17, 2018 10:51 am
Forum: Phase Changes & Related Calculations
Topic: Test #1
Replies: 4
Views: 226

Re: Test #1

if you were going from gas to liquid, then it would be exothermic because phase changes of vaporization and condensation are the opposite
by Nicole Jacobs 1C
Mon Mar 12, 2018 8:51 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Functional Groups
Replies: 7
Views: 245

Re: Functional Groups

you should be able to look at a complex molecule and identify which functional groups are in it
by Nicole Jacobs 1C
Mon Mar 12, 2018 8:47 pm
Forum: First Order Reactions
Topic: Pseudo First Order Reaction
Replies: 7
Views: 387

Re: Pseudo First Order Reaction

do we have to know how to apply a psuedo first order reaction or just understand it conceptually?
by Nicole Jacobs 1C
Mon Mar 12, 2018 8:44 pm
Forum: *Enzyme Kinetics
Topic: Catalyst
Replies: 6
Views: 352

Re: Catalyst

the catalyst is in the reactant side of the first step and in one of the other steps it is on the reactant side, so it is used
by Nicole Jacobs 1C
Wed Mar 07, 2018 9:26 pm
Forum: General Rate Laws
Topic: 15.13
Replies: 4
Views: 119

Re: 15.13

the reaction vessel is 750 mL so use this to find the molarity of H2 and I2 to find moles per liter
by Nicole Jacobs 1C
Wed Mar 07, 2018 9:22 pm
Forum: General Rate Laws
Topic: Units
Replies: 11
Views: 471

Re: Units

use the units for k requested in the question because sometimes it asks per second and sometime it asks per minute
by Nicole Jacobs 1C
Wed Mar 07, 2018 9:21 pm
Forum: First Order Reactions
Topic: half-lives of first order versus second order
Replies: 3
Views: 199

Re: half-lives of first order versus second order

for ln(1/2) and ln(2/1), they give the same value, just one is negative and one is positive, if that helps
by Nicole Jacobs 1C
Fri Mar 02, 2018 9:17 pm
Forum: Zero Order Reactions
Topic: Difference between zero, first, second [ENDORSED]
Replies: 3
Views: 106

Difference between zero, first, second [ENDORSED]

What is the difference between the zero, first, and second reactions? i still dont really get it
by Nicole Jacobs 1C
Fri Mar 02, 2018 5:35 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Quiz 3
Replies: 6
Views: 182

Quiz 3

Are we only being tested on problems that have to do with material up to #39 for quiz 3?
by Nicole Jacobs 1C
Fri Mar 02, 2018 5:33 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: How to tell difference btwn thermo and kinetics [ENDORSED]
Replies: 7
Views: 238

How to tell difference btwn thermo and kinetics [ENDORSED]

How do you tell if the reaction is controlled by thermodynamics? by kinetics?
by Nicole Jacobs 1C
Thu Feb 22, 2018 10:02 am
Forum: Balancing Redox Reactions
Topic: Balancing REDOX reactions
Replies: 5
Views: 165

Re: Balancing REDOX reactions

remember not to multiply E by a factor when you are balancing the equations. Unlike H and S, you do not multiply E by the coefficients you use to balance the equations, since E is intensive.
by Nicole Jacobs 1C
Mon Feb 19, 2018 4:53 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: how to write a cell diagram [ENDORSED]
Replies: 6
Views: 258

how to write a cell diagram [ENDORSED]

what is the order in which we are supposed to write the cell diagram? Our TA told us to write reactants first then products but that doesnt seem to match the solution manual
by Nicole Jacobs 1C
Mon Feb 19, 2018 4:51 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Word equations
Replies: 2
Views: 127

Word equations

Will we be expected to write the whole cell reaction and use nerst equations for word equations? like without the elements and compounds explicitly written in their molecular formulas?
by Nicole Jacobs 1C
Mon Feb 12, 2018 10:29 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Internal Energy State Function
Replies: 2
Views: 93

Re: Internal Energy State Function

Yes it is a state function because it does not matter the path that it takes to get to the final condition. Also remember delta S and delta H and delta G are state functions as well
by Nicole Jacobs 1C
Mon Feb 12, 2018 10:25 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Monatomic and Diatomic
Replies: 1
Views: 74

Re: Monatomic and Diatomic

Our TA told us that we would be given a diatomic or monatomic obvious molecule, or if it is not obvious, it will be given explicitly in the question
by Nicole Jacobs 1C
Mon Feb 12, 2018 10:24 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Midterm w18 -Last subject?
Replies: 2
Views: 105

Re: Midterm w18 -Last subject?

i think we mostly need to know just how K (and Q) relate to Gibbs free energy for the part of chapter 11 that we will be tested on
by Nicole Jacobs 1C
Wed Feb 07, 2018 4:30 pm
Forum: Balancing Redox Reactions
Topic: Test 2 [ENDORSED]
Replies: 1
Views: 59

Test 2 [ENDORSED]

Will the material covered on Test 2 be up until the 14th or the 16th of February?
by Nicole Jacobs 1C
Tue Feb 06, 2018 11:32 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: W
Replies: 3
Views: 107

Re: W

it also helps to redraw the molecule as many times as you can by rearranging the element placements, almost like you would with a resonance structure, to show how many different states the molecule can have.
by Nicole Jacobs 1C
Tue Feb 06, 2018 11:30 pm
Forum: Van't Hoff Equation
Topic: homework question 11.89
Replies: 1
Views: 165

homework question 11.89

How did they get the equation in 89 and how did they get the partial pressures out of 100? Im confused reading the solution manual for this problem.
by Nicole Jacobs 1C
Tue Feb 06, 2018 11:25 pm
Forum: Phase Changes & Related Calculations
Topic: Environmental impact?
Replies: 6
Views: 377

Environmental impact?

On Outline 1 on Lavelle's website, it states this as the last learning goal bullet: "Understand the environmental impact of burning fossil fuels, and the use of alternative
fuels". Will we have to know this even though Lavelle did not cover this in lecture?
by Nicole Jacobs 1C
Wed Jan 31, 2018 3:42 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: State functions [ENDORSED]
Replies: 7
Views: 170

State functions [ENDORSED]

Are the only state functions we've learned so far deltaH, detltaG, and deltaU? But the w and q are not state functions?
by Nicole Jacobs 1C
Wed Jan 31, 2018 3:39 pm
Forum: Administrative Questions and Class Announcements
Topic: Chem Community Posts
Replies: 5
Views: 296

Re: Chem Community Posts

My TA told us it is due 11:59 in Sundays
by Nicole Jacobs 1C
Wed Jan 31, 2018 3:33 pm
Forum: Phase Changes & Related Calculations
Topic: Example in Lecture
Replies: 4
Views: 159

Re: Example in Lecture

If i understand correctly I think it is because when deltaG is 0, that is the system's boiling point, and when deltaG is negative, the reaction is favorable. So bromine would vaporize, or become a gas from a liquid, at any point equal to or above 333K because this is when Br2 has its boiling point
by Nicole Jacobs 1C
Wed Jan 24, 2018 12:25 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Heat vs. Temp
Replies: 9
Views: 189

Re: Heat vs. Temp

you can also see this with the heating curves. for example, when ice is melted into liquid water, there is a plateau where there is heat being added but the temperature remains constant. this means molecules are transferring energy faster, but there is not a significant increase in the how fast the ...
by Nicole Jacobs 1C
Wed Jan 24, 2018 12:17 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Released
Replies: 3
Views: 99

Re: Heat Released

i believe you would say the amount you found in positive, followed by the word released. for example, -55 kJ could be answered as 55 kJ released. hope that helps!
by Nicole Jacobs 1C
Wed Jan 24, 2018 12:14 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 4
Views: 119

Re: Bond Enthalpies

also, make sure to multiply the bonds by the number of moles for each reactant and each product!
by Nicole Jacobs 1C
Wed Jan 17, 2018 10:01 am
Forum: Phase Changes & Related Calculations
Topic: Formula Sheet? [ENDORSED]
Replies: 3
Views: 145

Formula Sheet? [ENDORSED]

Will we have a formula sheet for this quiz? And will it be the same one as 14A or will it be different?
by Nicole Jacobs 1C
Tue Jan 16, 2018 8:34 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: What does R stand for?
Replies: 13
Views: 573

Re: What does R stand for?

R should also be given on the formula and constant sheet Lavelle gives us for the test
by Nicole Jacobs 1C
Tue Jan 16, 2018 8:32 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Calorimetry
Replies: 2
Views: 136

Re: Calorimetry

our TA also said if the c of the calorimeter is given in the problem you need to add it to q of Cu. Thus, the equation could be q of H2O = q of Cu + q of calorimeter
by Nicole Jacobs 1C
Tue Jan 16, 2018 8:31 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Work function
Replies: 4
Views: 125

Re: Work function

i also think w is negative when the reaction is expansive and the delta V is positive, and 0 when the reaction takes place in a vacuum with free expansion.
by Nicole Jacobs 1C
Thu Jan 11, 2018 8:20 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Chapter 8
Replies: 6
Views: 179

Chapter 8

where do the homework problems start since we are starting halfway through the chapter? Also what section in the book are we starting from within chapter 8?
by Nicole Jacobs 1C
Thu Jan 11, 2018 8:16 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 6
Views: 207

Re: Bond Enthalpies

And vice versa, if you were to add bonds, the reaction would be exothermic because energy is released when bonds are formed. Thus it would be negative if you were talking about the opposite.
by Nicole Jacobs 1C
Thu Jan 11, 2018 8:12 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: standard enthalpiy of formation
Replies: 2
Views: 73

standard enthalpiy of formation

What is the difference between standard enthalpies of formations of solutions and standard enthalpies of formations of gases?
by Nicole Jacobs 1C
Mon Dec 04, 2017 12:47 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Changing K but not changing K? [ENDORSED]
Replies: 1
Views: 94

Changing K but not changing K? [ENDORSED]

I understand that only temperature changes K and that adding more reactants or more products does not change the K, but how come when you do the reverse reaction (1/k) the K value changes?
by Nicole Jacobs 1C
Mon Dec 04, 2017 12:44 pm
Forum: Identifying Acidic & Basic Salts
Topic: strong acid/base?
Replies: 3
Views: 216

strong acid/base?

How can you tell it is a strong acid or strong base just by looking at the molecular formula?
by Nicole Jacobs 1C
Tue Nov 28, 2017 5:15 pm
Forum: Sigma & Pi Bonds
Topic: When do Sigma and Pi bonds occur?
Replies: 4
Views: 234

Re: When do Sigma and Pi bonds occur?

when you have a single bond, it is a sigma bond. A double bond consists of a sigma and pi bond, one for each bond line. A triple bond consists of a sigma and 2 pi bonds, one for each bond line as well.
by Nicole Jacobs 1C
Tue Nov 28, 2017 5:13 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination compounds and complexes
Replies: 2
Views: 118

Re: Coordination compounds and complexes

Also, the coordination sphere is referring to a central (metal) atom and its array of molecules or anions (ligands) around it. The coordination sphere consists of anything within the [ ] of the compound name.
by Nicole Jacobs 1C
Mon Nov 20, 2017 1:50 pm
Forum: Ideal Gases
Topic: 11.3 [ENDORSED]
Replies: 2
Views: 160

Re: 11.3 [ENDORSED]

In lecture, Lavelle said that we should give the K constant based on what is given to us, so if pressures are given, use Kp and if concentrations are given, use Kc.
by Nicole Jacobs 1C
Mon Nov 20, 2017 1:43 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homework Section [ENDORSED]
Replies: 2
Views: 149

Homework Section [ENDORSED]

What range of the homework problems on the syllabus should we do to only practice the 11.1 -11.8 material that will be on the next exam?
by Nicole Jacobs 1C
Sat Nov 18, 2017 11:26 am
Forum: Naming
Topic: Naming Ligands
Replies: 1
Views: 121

Naming Ligands

Do we need to know all the common ligands listed in figure 17.4 for the next exam? Or just the ones discussed in lecture and the ones in our homework?
by Nicole Jacobs 1C
Fri Nov 17, 2017 3:42 pm
Forum: Administrative Questions and Class Announcements
Topic: Class Before Thanksgiving [ENDORSED]
Replies: 2
Views: 198

Class Before Thanksgiving [ENDORSED]

Hi, what sections in the book will the lecture on Wednesday 11/22 cover? I would like to review it on my own since my flight home is that Tuesday before.
by Nicole Jacobs 1C
Wed Nov 15, 2017 5:40 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Understanding sigma and pi bonds?
Replies: 8
Views: 290

Re: Understanding sigma and pi bonds?

another thing to add is that sigma bonds can rotate and pi bonds cannot rotate. if pi bonds rotate, then they will break, causing a chemical reaction
by Nicole Jacobs 1C
Wed Nov 15, 2017 5:38 pm
Forum: Hybridization
Topic: Polar/nonpolar [ENDORSED]
Replies: 14
Views: 1177

Re: Polar/nonpolar [ENDORSED]

can you always use the trick that Lavelle was saying where if water would want to bond on different locations of the molecule, then the molecule is polar for every compound?
by Nicole Jacobs 1C
Wed Nov 08, 2017 9:18 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodes on the Midterm?
Replies: 4
Views: 256

Re: Nodes on the Midterm?

Hi, my TA told our discussion that we only need to know that S does not have any nodes but P does have a node, which is an area of zero electron density. He said that is all we need to know for this class.
by Nicole Jacobs 1C
Wed Nov 08, 2017 9:17 pm
Forum: Lewis Structures
Topic: Polyatomic Ions
Replies: 1
Views: 108

Re: Polyatomic Ions

Hi, my TA told me that we will be given the polyatomic ion's molecular formula if we need to use them on the test!
by Nicole Jacobs 1C
Tue Oct 31, 2017 11:42 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Review [ENDORSED]
Replies: 4
Views: 311

Re: Midterm Review [ENDORSED]

For the midterm, will we be expected to write the compounds/ions given the written name or will the molecular formula of compounds/ions be given to us? (I mean like will we be given just sulfate ion, or will be told that a sulfite ion is SO3^2-?)
by Nicole Jacobs 1C
Mon Oct 30, 2017 1:04 pm
Forum: Lewis Structures
Topic: Homework Question 2.37B [ENDORSED]
Replies: 2
Views: 111

Re: Homework Question 2.37B [ENDORSED]

I think the shielding refers to the reduced affect of the nuclear charge, meaning when there are electrons in an inner shell, the outer shell electrons experience less than actual nuclear charge because electron repulsions work against the pull of the nucleus
by Nicole Jacobs 1C
Mon Oct 30, 2017 1:01 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Review [ENDORSED]
Replies: 4
Views: 311

Midterm Review [ENDORSED]

Is there a website or place where I can look at previous midterm problems to prepare for our midterm next Thursday?
by Nicole Jacobs 1C
Mon Oct 23, 2017 11:08 pm
Forum: Trends in The Periodic Table
Topic: Trends of ionic radius
Replies: 4
Views: 224

Re: Trends of ionic radius

Electrons make the atom bigger because they increase the number of shells the atom has. So losing electrons (becoming cation) would mean you are reducing the number of energy levels and therefore decreasing the size of the atom. Vice versa, since an anion is gaining electrons, it has more shells tha...
by Nicole Jacobs 1C
Mon Oct 23, 2017 11:03 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 3
Replies: 2
Views: 182

Re: Test 3

It says on his website that the test will only cover to the end of chapter 1 and the entire chapter 2
by Nicole Jacobs 1C
Wed Oct 18, 2017 5:07 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Precision and constants [ENDORSED]
Replies: 2
Views: 191

Re: Precision and constants [ENDORSED]

My TA told our discussion to use the exact number of sig figs given to you on Lavelle's formula sheet when solving problems with constant. He told our class not to round them, but rounding will not make a huge difference in your answer if you do every thing else correctly.
by Nicole Jacobs 1C
Wed Oct 18, 2017 5:03 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: E-p distribution
Replies: 2
Views: 131

Re: E-p distribution

I think he meant electron density distribution but I'm not 100% sure
by Nicole Jacobs 1C
Wed Oct 11, 2017 5:45 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Wavelengths of Electromagnetic Radiation
Replies: 4
Views: 207

Re: Wavelengths of Electromagnetic Radiation

Haha it autocorrected mnemonic to pneumonic my bad
by Nicole Jacobs 1C
Wed Oct 11, 2017 5:44 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Wavelengths of Electromagnetic Radiation
Replies: 4
Views: 207

Re: Wavelengths of Electromagnetic Radiation

You can remember it by the pneumonic:
Raul's Mother is Visiting Uncle Xavier's Garden
Radio, Microwave, Infared, Visible, UV, X-ray, Gamma Ray
This follows the electromagnetic spectrum in order from decreasing wavelength (and increasing frequency).
by Nicole Jacobs 1C
Wed Oct 11, 2017 5:39 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Energy Level Series
Replies: 2
Views: 132

Re: Energy Level Series

The energy levels are discrete amounts of energy that the electron jumps to when it gets excited from that specific amount of energy. When the electron moves to a higher energy state, it becomes unstable, and emits the energy it just received to return back down to its stable ground state. The Balme...
by Nicole Jacobs 1C
Wed Oct 04, 2017 11:02 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Amount of a stubstance
Replies: 2
Views: 155

Re: Amount of a stubstance

When a problem is asking for X amount of an element, and that element seems to often occur in a pair (e.g O vs O^2), if the problem doesn't specify, do you solve for the amount as the single element or in a pair? Or does it not matter? Hi, I think for these types of problems, if it is a common diat...
by Nicole Jacobs 1C
Wed Oct 04, 2017 10:53 pm
Forum: SI Units, Unit Conversions
Topic: Sig Figs
Replies: 12
Views: 571

Re: Sig Figs

I get confused with sig figs when there are zeros. For example, if the number is 0.020, is there 2 or 3 sig figs? This example would only have 2 sig figs because only the trailing zeros are significant if they are after a decimal point. Any leading zeros before a non-zero number is not significant,...

Go to advanced search