## Search found 44 matches

Mon Feb 11, 2019 2:42 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Using R
Replies: 10
Views: 358

### Re: Using R

So we know which form of R to use based off of the formula sheet provided to us? Can someone clairfy the possible unit values (atm or joules or Torr) per form of R?
Mon Feb 11, 2019 2:38 pm
Forum: Environment, Fossil Fuels, Alternative Fuels
Topic: midterm
Replies: 3
Views: 497

### Re: midterm

Just to clarify/confirm - environment, fossil fuels, and alternative fuels will not be on the midterm exam? If they will be, what topics are they associated with...thermodynamics?
Mon Feb 11, 2019 2:36 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Statistical vs Residual Entropy
Replies: 4
Views: 205

### Re: Statistical vs Residual Entropy

Will we need to be able to identify the difference between statistical vs residual entropy on the midterm?
Mon Feb 11, 2019 2:35 pm
Forum: Ideal Gases
Topic: The Difference between Q and Kc [ENDORSED]
Replies: 18
Views: 1818

### Re: The Difference between Q and Kc[ENDORSED]

Both Q and K are calculated using the same equations - Q can calculate a particular point of the reaction / K calculates the reaction at equilibrium!
Mon Feb 11, 2019 2:32 pm
Forum: Ideal Gases
Replies: 147
Views: 104704

Reading the textbook and working through the practice problems provided in each section - in addition to the homework problems per week - really helped better my understanding behind the details of the ideal gases and thermodynamics!!
Mon Feb 11, 2019 2:31 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond enthalpies
Replies: 10
Views: 341

### Re: Bond enthalpies

Will the bond dissociation energies definitely be given?
Mon Feb 11, 2019 2:30 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Explaining Hess's Law with enthalpy = a state function?
Replies: 3
Views: 161

### Re: Explaining Hess's Law with enthalpy = a state function?

Are the basic units for enthalpy always kJ?
Tue Jan 15, 2019 6:43 pm
Forum: Equilibrium Constants & Calculating Concentrations
Replies: 3
Views: 146

Multiplying the equilibrium constants of the two equations gives you the final outcome of the reaction
Tue Jan 15, 2019 6:41 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE table
Replies: 4
Views: 189

### Re: ICE table

Is the ICE table used purely to find missing concentrations?
Tue Jan 15, 2019 6:39 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: If you calcuate Kp and Kc for the same reaction, will they be the same?
Replies: 2
Views: 124

### Re: If you calcuate Kp and Kc for the same reaction, will they be the same?

It varies based on reaction. You know whether Kp and Kc are the same based on your calculations!
Tue Jan 08, 2019 6:15 pm
Forum: Ideal Gases
Topic: Pressure units
Replies: 4
Views: 230

### Re: Pressure units

I think we are fine labeling the units for Kp as either bars or atmosphere. Whereas, Kc is identified in molar/moles.
Tue Jan 08, 2019 6:13 pm
Forum: Ideal Gases
Topic: Q and K [ENDORSED]
Replies: 35
Views: 1684

### Re: Q and K[ENDORSED]

K is found using concentrations at equilibrium, BUT to calculate Q do we just use the initial concentrations or concentrations at any given time?
Tue Jan 08, 2019 6:11 pm
Forum: Ideal Gases
Topic: Equilibrium Constants
Replies: 4
Views: 198

### Re: Equilibrium Constants

By doubling the the number of moles of a specific molecule, do the coefficients and exponents work proportional to one another in order to maintain the equilibrium of K?
Fri Dec 07, 2018 3:12 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Ranking strong acids and bases
Replies: 4
Views: 259

### Re: Ranking strong acids and bases

Can someone further explain how to rank strong acids versus bases?
Fri Nov 16, 2018 2:05 pm
Forum: Ionic & Covalent Bonds
Topic: Hydrogen Bond
Replies: 7
Views: 445

### Re: Hydrogen Bond

Intramolecular forces are the forces that hold atoms together within a molecule. Intermolecular forces are forces that exist between molecules.
Fri Nov 16, 2018 2:03 pm
Forum: Dipole Moments
Topic: Test
Replies: 15
Views: 484

### Re: Test

The next test, following the midterm, is week 9 - after Thanksgiving. Can anyone provide a list of the remaining topics (dipole moments, sigma/pi bonds, and electronegativity) that will be covered on the week 9 test?
Fri Nov 16, 2018 1:59 pm
Forum: Dipole Moments
Topic: Dipole Moments
Replies: 6
Views: 208

### Re: Dipole Moments

Do dipole moments always rely on whether a molecule is polar or nonpolar?
Thu Nov 15, 2018 8:28 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Why is H3O+ bond angle 109.5?
Replies: 2
Views: 8734

### Re: Why is H3O+ bond angle 109.5?

Why is it a tetrahedral and not a trigonal planar? Are there other examples of this other than with H3O+?
Thu Nov 08, 2018 8:06 pm
Forum: Hybridization
Topic: How to figure out hybridization
Replies: 5
Views: 815

### Re: How to figure out hybridization

When you say regions of electron density, are you referring to using the periodic table? Could you explain how to look for this please?
Thu Nov 08, 2018 8:04 pm
Forum: Hybridization
Topic: Pi bonds in triple bond
Replies: 17
Views: 807

### Re: Pi bonds in triple bond

^What are the exceptions for the octet rule in triple bonds?
Thu Nov 08, 2018 8:03 pm
Forum: Hybridization
Topic: 4.41
Replies: 4
Views: 751

### Re: 4.41

Does anyone have a good way to remember the degrees per shape?
Wed Nov 07, 2018 5:35 pm
Forum: Bond Lengths & Energies
Topic: Calculating Bond Lengths
Replies: 4
Views: 197

### Re: Calculating Bond Lengths

Weak (longer) bonds are easily broken and more likely involved in reaction.
Strong (shorter) bonds are harder to break and less reactive.
Wed Nov 07, 2018 5:31 pm
Forum: Bond Lengths & Energies
Topic: bond lengths and strengths
Replies: 9
Views: 342

### Re: bond lengths and strengths

Strength of a bond is measured by its' dissociation energy (the energy required to break a bond)
Wed Nov 07, 2018 5:28 pm
Forum: Ionic & Covalent Bonds
Topic: ionic bonds and covalent character [ENDORSED]
Replies: 2
Views: 109

### Re: ionic bonds and covalent character[ENDORSED]

What is covalent bond dissociation? Could someone please simplify the process... thank you!!
Wed Nov 07, 2018 5:26 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Dispersion/ Induced dipole-Induced dipole
Replies: 2
Views: 113

### Re: Dispersion/ Induced dipole-Induced dipole

Can someone please explain whether dipole moments are always polar or not? Thanks!!
Mon Oct 29, 2018 1:22 pm
Forum: Ideal Gases
Replies: 147
Views: 104704

I find it helpful to read the textbook, but I also get confused a lot after! I then will watch Crash Course on Youtube for whatever concept it is that I am confused by. They often work through examples and explain the topic step by step. I think it really helps for clarity and betters my understandi...
Mon Oct 29, 2018 1:20 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Paramagnetism
Replies: 3
Views: 434

### Re: Paramagnetism

How can we apply paramagnetism in chemistry 14A? Can someone possible provide an example? I would appreciate it!!
Mon Oct 29, 2018 1:15 pm
Forum: Trends in The Periodic Table
Replies: 6
Views: 337

Elements increase in atomic size down the periodic table, as they gain shells, and decrease across the periodic table (from left to right)!
Mon Oct 29, 2018 1:14 pm
Forum: Trends in The Periodic Table
Topic: Ionization energies
Replies: 9
Views: 899

### Re: Ionization energies

Atomic radius... - increases in atomic size down the periodic table, as shells increase - decreases across the periodic table from left to right Ionization energy (the energy needed to add to remove an electron)... - decreases down the periodic table - increases across the period table from left to ...
Mon Oct 29, 2018 1:11 pm
Forum: Photoelectric Effect
Topic: Work Function
Replies: 14
Views: 959

### Re: Work Function

Mon Oct 29, 2018 1:10 pm
Forum: Einstein Equation
Topic: E=hv
Replies: 43
Views: 4519

### Re: E=hv

I understand that... The E in E = hv represents the energy of a photon. The E in Ek = 1/2(mv^2) represents the excess energy after an electron is removed from a metal. ...but, can someone please clarify what the specific values are that we need to assign as hv and 1/2(mv^2)? Sorry if this was alread...
Mon Oct 29, 2018 1:07 pm
Forum: *Shrodinger Equation
Topic: Help on how to find l, ml, and ms
Replies: 6
Views: 10444

### Re: Help on how to find l, ml, and ms

SHELL --> n = 1,...,infinity
SUBSHELL --> l = {0,...,n-1}
ORIENTATION OF ORBITAL SPIN --> ml = {-l,...+l}
SPIN --> ms = {-1/2, +1/2}

These are the fundamental rules needed to determine sub-shell notation, electron configuration, valence electrons, unpaired electrons, etc.!
Mon Oct 29, 2018 1:04 pm
Forum: *Shrodinger Equation
Topic: Schrodinger's Equation
Replies: 6
Views: 734

### Re: Schrodinger's Equation

I know we have not needed to yet, but will we need to be able to apply Schrodinger's Equation on the midterm exam?
Mon Oct 29, 2018 1:01 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8047
Views: 1413048

### Re: Post All Chemistry Jokes Here

Old chemists never die, they just stop reacting.
Mon Oct 29, 2018 1:00 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8047
Views: 1413048

### Re: Post All Chemistry Jokes Here

Why do chemists like nitrates so much?
They're cheaper than day rates.
Mon Oct 29, 2018 12:59 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8047
Views: 1413048

### Re: Post All Chemistry Jokes Here

He just couldn't put it down.
Mon Oct 29, 2018 12:57 pm
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 198
Views: 140491

### Re: Rusty on High School Chem[ENDORSED]

I have been reviewing each concept after lecture by watching the Crash Course videos on YouTube. They have been helpful in clarifying and breaking down what is being taught in class. I definitely recommend watching a few. Hope it helps!
Mon Oct 29, 2018 12:53 pm
Forum: Administrative Questions and Class Announcements
Topic: Exam
Replies: 7
Views: 462

### Re: Exam

Does anyone know roughly how long the midterm exam will be?
Mon Oct 29, 2018 12:52 pm
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student [ENDORSED]
Replies: 217
Views: 115293

### Re: Advice from a Medical Student[ENDORSED]

I am a pre-med, first year student who needed this advice, especially regarding the chemistry series. Thanks so much!!
Mon Oct 29, 2018 12:49 pm
Forum: Hybridization
Topic: Electron Configuration - Orbital Diagrams
Replies: 1
Views: 197

### Electron Configuration - Orbital Diagrams

In drawing out an orbital diagram for an element, can someone explain the easiest steps to take? I know you have to take the electron configuration and work from there, but how can you be sure that your orbital diagram correctly translates from the electron configuration?
Wed Oct 03, 2018 5:58 pm
Forum: Limiting Reactant Calculations
Topic: M.11
Replies: 8
Views: 900

### Re: M.11

Is O2 or P4 the limiting reactant for part a? Can someone please explain which and why. Thanks so much!
Wed Oct 03, 2018 5:51 pm
Forum: Balancing Chemical Reactions
Topic: Balancing equations (Problem H21 6th edition)
Replies: 3
Views: 139

### Re: Balancing equations (Problem H21 6th edition)

Going off of what the initial post asked, does anyone know a more simple, yet speedier way to balance even the more general equations? Any faster method than just moving through the equation, element by element?
Wed Oct 03, 2018 5:49 pm
Forum: Empirical & Molecular Formulas
Topic: Resources given on tests [ENDORSED]
Replies: 3
Views: 240

### Re: Resources given on tests[ENDORSED]

Are we definitely provided a periodic table for the test? We are also permitted to use calculators during the test, correct?
Wed Oct 03, 2018 5:43 pm
Forum: Empirical & Molecular Formulas
Topic: Problem F5 (7th Edition)
Replies: 3
Views: 636

### Problem F5 (7th Edition)

Problem F5 asks for the mass percentage composition of L-carnitine, C7H15NO3, a compound taken as a dietary supplement to reduce muscle fatigue. My first step was to take each element and multiple its' coefficient by its' molar mass: 7C --> 7(12.01) = 84.07 15H --> 15(1.01) = 15.15 1N --> 1(14.007) ...