Search found 72 matches

by Sarah_Kang_2K
Mon Mar 11, 2019 10:48 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: increasing pressure, what happens to concentration?
Replies: 10
Views: 181

Re: increasing pressure, what happens to concentration?

When pressure increases, the gaseous molecules on both sides of the reaction increasingly collide with each other. In order to alleviate/compensate for these increased collisions, the reaction favors the side with the less number of moles of gaseous molecules.
by Sarah_Kang_2K
Mon Mar 11, 2019 10:45 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ignoring x
Replies: 16
Views: 358

Re: ignoring x

You can ignore x when approximating (when K<10^-3), but make sure to check your work after to make sure x is indeed less than or equal to 5% deprotonation!
by Sarah_Kang_2K
Mon Mar 11, 2019 10:44 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatelier's Principle
Replies: 3
Views: 66

Re: Le Chatelier's Principle

Le Chatelier's principle predicts how the equilibrium will shift in response to changes in volume, temperature, pressure, the addition or removal of gaseous molecules, etc.
by Sarah_Kang_2K
Fri Mar 08, 2019 10:12 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: E˚ vs E
Replies: 13
Views: 197

Re: E˚ vs E

E˚is under standard conditions (pressure=1 bar, concentration= 1 mol/L, etc.)
by Sarah_Kang_2K
Fri Mar 08, 2019 10:11 am
Forum: Second Order Reactions
Topic: Final
Replies: 30
Views: 422

Re: Final

The final will cover all of the material we've learned this quarter.
by Sarah_Kang_2K
Fri Mar 08, 2019 10:10 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Lecture Notes Week 9 Wednesday (3/6)
Replies: 3
Views: 70

Re: Lecture Notes Week 9 Wednesday (3/6)

This is really helpful, thank you!
by Sarah_Kang_2K
Fri Mar 01, 2019 4:18 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Finding n for the equation ΔG⁰=-nFE⁰
Replies: 8
Views: 107

Re: Finding n for the equation ΔG⁰=-nFE⁰

When it says "write the balanced half reactions", does this mean balance O's and H's, as well as electrons?
Or is it just like Cu2+(aq)--> Cu(s)
by Sarah_Kang_2K
Wed Feb 27, 2019 4:37 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Thermodynamic Stability
Replies: 2
Views: 72

Re: Thermodynamic Stability

According to the textbook, the terms "stable" and "unstable" refer to the thermodynamic tendency of a substance to decompose into its elements. Furthermore, a thermodynamically stable compound just means a compound that has a negative standard Gibbs free energy of formation. So i...
by Sarah_Kang_2K
Wed Feb 27, 2019 4:35 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Why does reaction free energy depend on pressure and the equal constant?
Replies: 3
Views: 68

Why does reaction free energy depend on pressure and the equal constant?

On Outline 4, one of the bullet points listed says: "Understand why reaction free energy depends on pressure and the equilibrium constant". If someone could please clarify what this means, or direct me to the relevant section in the textbook (6th ed.) that talks about this, that would be m...
by Sarah_Kang_2K
Wed Feb 20, 2019 1:39 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Spontaneous vs Not Spontaneous
Replies: 7
Views: 100

Re: Spontaneous vs Not Spontaneous

Delta G must be negative in order for a reaction to be spontaneous.
by Sarah_Kang_2K
Wed Feb 20, 2019 1:39 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Units of Gibbs Free Energy
Replies: 5
Views: 83

Re: Units of Gibbs Free Energy

Gibbs free energy is an extensive property.
by Sarah_Kang_2K
Wed Feb 20, 2019 1:36 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Reverse Reaction
Replies: 8
Views: 122

Re: Reverse Reaction

Calculating K for reverse reactions involves taking the inverse of K for the forward reaction (1/K)
by Sarah_Kang_2K
Wed Feb 13, 2019 10:26 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Delta U equal to zero
Replies: 2
Views: 55

Re: Delta U equal to zero

Delta U = 0 for any isothermal expansion of an ideal gas, it doesn't have to be reversible.
by Sarah_Kang_2K
Wed Feb 13, 2019 10:25 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: How to calculate change in entropy due to change in temperature
Replies: 1
Views: 45

How to calculate change in entropy due to change in temperature

I believe this has been posted on the forum already, but I can't seem to find the thread, but for the change in entropy formula due to changes in temperature, do we use: delta S = nCln(T2/T1) or do we use delta S = Cln(T2/T1) I'm confused as to how we include the number of moles (n) into the formula.
by Sarah_Kang_2K
Tue Feb 12, 2019 9:59 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: entropy change
Replies: 2
Views: 46

Re: entropy change

Temperature is negatively proportional to entropy change. Thus, higher temperatures result in smaller values of the change in entropy.
by Sarah_Kang_2K
Tue Feb 12, 2019 9:57 am
Forum: Calculating Work of Expansion
Topic: 0 work vs no work
Replies: 4
Views: 89

Re: 0 work vs no work

They mean the same thing: essentially that no work is done by the system.
by Sarah_Kang_2K
Sun Feb 03, 2019 5:42 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: MIDTERM MATERIAL QUESTION
Replies: 2
Views: 67

MIDTERM MATERIAL QUESTION

Professor Lavelle mentioned the midterm would cover up to the end of entropy.
For the 6th edition textbook, what chapter/section does this correlate to? Are we responsible for Chapter 9 up to 9.10 (Overall Change in Entropy)?
by Sarah_Kang_2K
Wed Jan 30, 2019 11:51 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Homework
Replies: 9
Views: 127

Re: Homework

I jumped around too, but found the textbook chapters to be helpful in gaining a conceptual understanding before trying to solve the problems.
by Sarah_Kang_2K
Wed Jan 30, 2019 11:50 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Homework #3
Replies: 2
Views: 39

Re: Homework #3

Yes we should complete the problems from the thermochemistry material.
by Sarah_Kang_2K
Fri Jan 25, 2019 1:50 pm
Forum: Phase Changes & Related Calculations
Topic: Lecture 1/23
Replies: 3
Views: 81

Lecture 1/23

Can anyone please fill me in on what Dr. Lavelle went over in class this past Wednesday? I wasn't able to make it due to traffic. Thank you in advance!
by Sarah_Kang_2K
Thu Jan 24, 2019 9:44 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Test 1
Replies: 1
Views: 38

Re: Test 1

I assume so, since we've done practice problems on it.

Follow up question: Does anyone know if we'll be tested on solutions of salts of polyprotic acids?
by Sarah_Kang_2K
Thu Jan 24, 2019 4:45 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Test 1
Replies: 8
Views: 159

Re: Test 1

For Test 1, what do we need to know about pH of weak acid/base and its salt? Should we just know how to solve it, or do we need a deeper conceptual knowledge of it? I'm a little confused because we didn't go over this in discussion last week. If someone could clarify, that'd be great!
by Sarah_Kang_2K
Thu Jan 24, 2019 4:44 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Tricks for identifying Strong/Weak Acids & Bases
Replies: 5
Views: 102

Re: Tricks for identifying Strong/Weak Acids & Bases

For Test 1, what should we know about the pH of weak acids and weak bases and its salt? We didn't go over this in discussion. Do we just need to know how to calculate it?
by Sarah_Kang_2K
Thu Jan 24, 2019 3:12 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: using Ka and Kb to predict strengths of acids and bases
Replies: 3
Views: 146

using Ka and Kb to predict strengths of acids and bases

I'm a bit confused on how we use Ka and Kb to predict the strengths of acids and bases. Particularly, how we use Kb In lecture, we learned that if Ka > 10^3, this indicates a strong acid and if Ka < 10^-3, this indicates a weak acid. Does this logic apply to bases too? So if Kb>10^3, does this indic...
by Sarah_Kang_2K
Wed Jan 23, 2019 2:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: How to know when to use partial pressure or molar concentrations?
Replies: 4
Views: 85

How to know when to use partial pressure or molar concentrations?

If the problem doesn't specify whether to use partial pressure or molar concentrations, how do we know which to use? For example, if a problem gives us the initial molar concentrations of the gaseous reactants, but doesn't specify whether to use partial pressures or concentrations, do we automatical...
by Sarah_Kang_2K
Wed Jan 23, 2019 2:55 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K vs Kc
Replies: 3
Views: 72

Re: K vs Kc

In Example 11.7 (Calculating the equilibrium composition by approximation) of the 6th edition textbook, the problem tells us to solve for partial pressures. I tried using both partial pressures and molar concentrations to solve this problem, but when I used the concentration, it gave me a different ...
by Sarah_Kang_2K
Thu Jan 17, 2019 8:00 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Weak and Strong Acids and Bases [ENDORSED]
Replies: 2
Views: 66

Re: Weak and Strong Acids and Bases [ENDORSED]

Questions will give us the pH or some other measures that will allow us to calculate the pH or pOH of the substance.
by Sarah_Kang_2K
Tue Jan 15, 2019 5:31 pm
Forum: General Science Questions
Topic: Lecture Powerpoints
Replies: 9
Views: 253

Re: Lecture Powerpoints

Thank you!!! Much appreciated.
by Sarah_Kang_2K
Mon Jan 14, 2019 3:33 pm
Forum: General Science Questions
Topic: Lecture Powerpoints
Replies: 9
Views: 253

Re: Lecture Powerpoints

Would anyone be able to inform me of what we covered in lecture today 11/14?
I wasn't able to make it. Thanks in advance!
by Sarah_Kang_2K
Wed Jan 09, 2019 9:55 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Discussion Points
Replies: 3
Views: 46

Re: Discussion Points

The TA's go through the discussion forum at the end of the quarter, and as long as you post at least 3 times a week, you will get the full 30 points for the chemistry community discussion forum!
by Sarah_Kang_2K
Tue Jan 08, 2019 6:56 pm
Forum: Ideal Gases
Topic: Solid/Liquid in Reactions
Replies: 4
Views: 62

Re: Solid/Liquid in Reactions

Solids aren't included in the equilibrium constant because there is no such thing as "concentration of a solid".
For liquids, liquids act as a solvent, and the change in concentration of a solvent is insignificant. Thus, we don't include pure liquids in the equilibrium constant.
by Sarah_Kang_2K
Tue Jan 08, 2019 6:53 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: hw questions - points
Replies: 9
Views: 147

Re: hw questions - points

Homework questions are a separate category. We get 7 points a week for homework and 3 points a week for chemistry community posts, given that you do all of them.
by Sarah_Kang_2K
Tue Jan 08, 2019 11:21 am
Forum: Student Social/Study Group
Topic: lecture notes first day of class
Replies: 2
Views: 90

Re: lecture notes first day of class

Professor Lavelle usually doesn't post the lecture slides, but if you look at the audio-visual topics, you should be able to find a video that covers what we went over in class yesterday.
by Sarah_Kang_2K
Fri Dec 07, 2018 3:50 pm
Forum: Lewis Acids & Bases
Topic: How to tell if an ion is acidic or basic?
Replies: 2
Views: 51

Re: How to tell if an ion is acidic or basic?

Will we need to know how to do this for the final?
by Sarah_Kang_2K
Fri Dec 07, 2018 3:48 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Ranking strong acids and bases
Replies: 4
Views: 84

Re: Ranking strong acids and bases

For binary acids, the more polar the H-A bond/the greater the electronegativity of A, the stronger the acid H-A the weaker the H-A bond, the stronger the acid For oxoacids, the greater the electronegativity of the central atom, the stronger the oxoacid the greater the # of oxygen atoms attached to t...
by Sarah_Kang_2K
Fri Dec 07, 2018 3:46 pm
Forum: Calculating the pH of Salt Solutions
Topic: pH on final
Replies: 5
Views: 469

Re: pH on final

Do we need to know how to calculate the pH of salt solutions with an acidic cation or a basic anion? (this is from 12.13 in the 6th edition)
by Sarah_Kang_2K
Fri Dec 07, 2018 3:45 pm
Forum: Conjugate Acids & Bases
Topic: Cojugate Acids and Bases
Replies: 5
Views: 182

Re: Cojugate Acids and Bases

You add an H+ ion to a base to make a conjugate acid, and remove an H+ ion from an acid to make a conjugate base.
by Sarah_Kang_2K
Tue Nov 27, 2018 3:08 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 3
Replies: 38
Views: 640

Re: Test 3

Hi guys.
What do we need to know about Acids and Bases for Test 3?
by Sarah_Kang_2K
Mon Nov 26, 2018 11:23 am
Forum: Student Social/Study Group
Topic: Test 3
Replies: 6
Views: 306

Re: Test 3

Yes, Test 3 will pick up where the Midterm left off.
by Sarah_Kang_2K
Mon Nov 26, 2018 11:22 am
Forum: Dipole Moments
Topic: Polarizability vs Polarizing power
Replies: 8
Views: 138

Re: Polarizability vs Polarizing power

You should refer to page 79 of the textbook for a summary of the 2 concepts!
by Sarah_Kang_2K
Mon Nov 26, 2018 11:20 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Water as a solvent
Replies: 2
Views: 70

Re: Water as a solvent

Water is considered the universal solvent because: Water molecules carry partial charges (the hydrogen side of the water molecule carries a slight positive electric charge, while the oxygen side carries a slight negative electric charge). This structure allows water molecules to dissociate ionic com...
by Sarah_Kang_2K
Tue Nov 20, 2018 11:40 pm
Forum: Hybridization
Topic: Unhybridized orbitals
Replies: 10
Views: 201

Re: Unhybridized orbitals

Unhybridized orbitals refer to your standard s, p, d, f orbitals. Hybridized orbitals pertain to electrons that can exist between these orbitals. Someone correct me if I'm wrong?
by Sarah_Kang_2K
Tue Nov 20, 2018 11:39 pm
Forum: Lewis Structures
Topic: Midterm question
Replies: 8
Views: 128

Re: Midterm question

They passed the midterms back after lecture last Wednesday.
by Sarah_Kang_2K
Tue Nov 20, 2018 11:38 pm
Forum: Administrative Questions and Class Announcements
Topic: Thanksgiving Wednesday Class
Replies: 19
Views: 398

Re: Thanksgiving Wednesday Class

There is no lecture tomorrow.
by Sarah_Kang_2K
Wed Nov 14, 2018 5:22 pm
Forum: Administrative Questions and Class Announcements
Topic: Grades
Replies: 5
Views: 161

Re: Grades

The syllabus says the class isn't curved, but I believe Dr. Lavelle may use a slight curve once all the scores are in.
by Sarah_Kang_2K
Wed Nov 14, 2018 5:21 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Q4B
Replies: 4
Views: 155

Re: Midterm Q4B

Electron diffraction supports the idea of light having wave-like properties, in addition to particle-like properties. Thus, De Broglie's Hypothesis is best supported by this.
by Sarah_Kang_2K
Wed Nov 14, 2018 11:47 am
Forum: Student Social/Study Group
Topic: Test 3
Replies: 6
Views: 306

Re: Test 3

Does anyone know if we get our midterms back after lecture today?
by Sarah_Kang_2K
Thu Nov 08, 2018 3:48 pm
Forum: Administrative Questions and Class Announcements
Topic: Which chapters can we do for homework?
Replies: 3
Views: 145

Which chapters can we do for homework?

Can we do problems from Outline 3 for this week's hw?
by Sarah_Kang_2K
Mon Nov 05, 2018 1:43 pm
Forum: Ionic & Covalent Bonds
Topic: Midterm Material
Replies: 3
Views: 111

Re: Midterm Material

Also, what should we know about Lewis acids and bases?
by Sarah_Kang_2K
Mon Nov 05, 2018 1:04 pm
Forum: Ionic & Covalent Bonds
Topic: Midterm Material
Replies: 3
Views: 111

Midterm Material

Dr. Lavelle mentioned that we are only responsible for Bonding up to 3.11. However Outline includes concepts about electronegativity and ionic and covalent bond length. Does this mean that electronegativity, strengths of ionic and covalent bonds, bond lengths, covalent bond dissociation energy, etc....
by Sarah_Kang_2K
Mon Nov 05, 2018 10:43 am
Forum: Ionic & Covalent Bonds
Topic: Coloumb potential energy on the midterm?? [ENDORSED]
Replies: 1
Views: 95

Coloumb potential energy on the midterm?? [ENDORSED]

Will we need to know how to use the formula for coloumb potential energy of interactions for the midterm today??
It's the formula that's in Chapter 3.4 of the 6th edition.
It isn't stated on the outline, but just wanted to make sure.
by Sarah_Kang_2K
Mon Nov 05, 2018 7:57 am
Forum: Sigma & Pi Bonds
Topic: Midterm1
Replies: 10
Views: 285

Re: Midterm1

Where is our midterm held today???
by Sarah_Kang_2K
Thu Nov 01, 2018 9:08 am
Forum: General Science Questions
Topic: Calculator for midterm
Replies: 4
Views: 162

Re: Calculator for midterm

You can also post on the Free and For sale page on Facebook and see if anyone is renting or selling theirs!
by Sarah_Kang_2K
Thu Nov 01, 2018 9:06 am
Forum: *Shrodinger Equation
Topic: Schrodinger's Equation
Replies: 6
Views: 373

Re: Schrodinger's Equation

You should also know the relationship between wave function and probability density (wavefunction^2).
by Sarah_Kang_2K
Tue Oct 30, 2018 3:24 pm
Forum: Student Social/Study Group
Topic: Midterm- what do we need to know about atomic orbitals
Replies: 2
Views: 132

Midterm- what do we need to know about atomic orbitals

For our upcoming midterm, what should we know about atomic orbitals? In Outline 2, it says to be able to describe the interpretation of atomic orbitals in terms of probability. Does this mean we should know the formulas for spherical polar coordinates, radical wave function, angular wave function, e...
by Sarah_Kang_2K
Thu Oct 25, 2018 8:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2 Material?
Replies: 2
Views: 141

Test 2 Material?

Will we be tested on Shrodinger's equation for Test 2?
by Sarah_Kang_2K
Thu Oct 25, 2018 9:06 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra Module #37
Replies: 2
Views: 124

Re: Atomic Spectra Module #37

Is this from Outline 2 or 3?
by Sarah_Kang_2K
Thu Oct 25, 2018 9:04 am
Forum: Administrative Questions and Class Announcements
Topic: HW for this week [ENDORSED]
Replies: 4
Views: 174

Re: HW for this week [ENDORSED]

I am wondering this too.
by Sarah_Kang_2K
Wed Oct 24, 2018 11:08 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: How do I identify excited state through the electronic configuration
Replies: 5
Views: 157

Re: How do I identify excited state through the electronic configuration

Would anyone be able to share their notes from monday lecture with me? I wasn't able to make it. If so, if you could email me at sarah27kang@gmail.com, it'd be greatly appreciated!
by Sarah_Kang_2K
Tue Oct 23, 2018 9:01 am
Forum: Administrative Questions and Class Announcements
Topic: TEST 3 during Thanksgiving week?
Replies: 5
Views: 220

TEST 3 during Thanksgiving week?

For Test 3 that starts in discussion section November 20th, does anyone know when the Thursday/Friday sections will take the test, since it's Thanksgiving break starting Thursday?
Thanks!
by Sarah_Kang_2K
Thu Oct 18, 2018 12:16 am
Forum: Photoelectric Effect
Topic: Test #2
Replies: 9
Views: 226

Re: Test #2

Yes, Teest #2 covers topics on Outline #2.
by Sarah_Kang_2K
Tue Oct 16, 2018 9:12 am
Forum: *Particle in a Box
Topic: Hw assignment?
Replies: 7
Views: 331

Re: Hw assignment?

Yes, we are still in the Quantum section! He mentioned in lecture not to do questions from the Fundamentals section, for the Week 3 homework.
by Sarah_Kang_2K
Tue Oct 16, 2018 9:11 am
Forum: Student Social/Study Group
Topic: Note Taking
Replies: 32
Views: 1502

Re: Note Taking

I think it's best to take notes by hand, and then after lecture that night, re-read your notes and highlight important topics as well as read confusing topics in the textbook.
by Sarah_Kang_2K
Tue Oct 16, 2018 9:09 am
Forum: Administrative Questions and Class Announcements
Topic: Writing in Pen
Replies: 13
Views: 294

Re: Writing in Pen

They sell erasable pens on Amazon. I'd also recommend bringing white-out just in case you need to correct something!
by Sarah_Kang_2K
Mon Oct 08, 2018 5:50 pm
Forum: Properties of Light
Topic: Difference between "intensity of light" and "frequency of light"
Replies: 3
Views: 103

Difference between "intensity of light" and "frequency of light"

In the equation, E=hv where v = frequency, what is the difference between intensity and frequency of light? In lecture, Professor Lavelle mentioned increasing the intensity of the light does not increase the energy of the individual photon. So, frequency and intensity can't refer to the same thing, ...
by Sarah_Kang_2K
Mon Oct 08, 2018 2:07 pm
Forum: Student Social/Study Group
Topic: Missed today's lecture (10/8) could anyone share their notes?
Replies: 3
Views: 96

Missed today's lecture (10/8) could anyone share their notes?

Hi all,
I was unable to attend lecture today due to a family event back home. Would anyone be willing to share a picture of their notes with me so that I can catch up on what I missed?

If so, could you please text me at 805-708-6286?

Thank you.
by Sarah_Kang_2K
Sun Oct 07, 2018 12:00 pm
Forum: Administrative Questions and Class Announcements
Topic: WHAT TYPE OF CALCULATOR IS ALLOWED ON EXAMS??
Replies: 5
Views: 164

Re: WHAT TYPE OF CALCULATOR IS ALLOWED ON EXAMS??

Hi Christine,
Okay thanks so would the TI-30 calculators be allowed? Scientific calculators are ones that still allow us to calculate 6.022X10^23 and exponents, right?
by Sarah_Kang_2K
Sun Oct 07, 2018 11:02 am
Forum: Administrative Questions and Class Announcements
Topic: WHAT TYPE OF CALCULATOR IS ALLOWED ON EXAMS??
Replies: 5
Views: 164

WHAT TYPE OF CALCULATOR IS ALLOWED ON EXAMS??

Hi. For Chem 14A, are we allowed to use TI-84 calculators on the exams?
If not, could somebody please tell me which calculators are allowed? TI 30 calculators perhaps?

Thank you!
by Sarah_Kang_2K
Thu Oct 04, 2018 4:24 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Conversion of grams to moles
Replies: 4
Views: 88

Re: Conversion of grams to moles

Yes, you need to take into account subscripts when finding the molar mass of a compound. For example, in order to find the molar mass of CO2, you would add the molar mass of carbon plus twice the molar mass of oxygen. This gives you the molar mass of CO2. You can then use the molar mass of CO2 and t...
by Sarah_Kang_2K
Thu Oct 04, 2018 4:17 pm
Forum: Empirical & Molecular Formulas
Topic: chemical formulas
Replies: 4
Views: 116

Re: chemical formulas

Cl on its own would refer to the ion form (Cl-). Cl2, along with N2, H2, and O2 are all gaseous forms of the elements.
by Sarah_Kang_2K
Thu Oct 04, 2018 12:32 pm
Forum: Significant Figures
Topic: Sig Fig's in Problem E.21.d
Replies: 3
Views: 85

Sig Fig's in Problem E.21.d

On Question E.21.d of the 6th edition textbook, the first step is to calculate the molar mass of glucose (C6H12O6). I am confused as to why the final molar mass contains 5 sig fig's and not 4. Here is my work: 6(12.011) + 12(1.008) + 6(15.999) = 180.2 g/mol The textbook solutions states that the ans...

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