Search found 36 matches

by Yang Chen 2E
Sat Mar 17, 2018 8:50 pm
Forum: *Alcohols
Topic: study tips
Replies: 3
Views: 415

Re: study tips

Subscribing to this topic
by Yang Chen 2E
Sat Mar 17, 2018 8:48 pm
Forum: *Cycloalkanes
Topic: Naming Cycloalkanes
Replies: 2
Views: 396

Re: Naming Cycloalkanes

Isn't tert supposed to be "three"? (I'm thinking its like protein structures)
by Yang Chen 2E
Wed Mar 14, 2018 12:10 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.61 and Equation used to solve it
Replies: 3
Views: 131

15.61 and Equation used to solve it

According to a person on Chemistry community, you solve this problem by deriving an equation using the Arrhenius equation and getting rid of A using this method: k/k' = (e^-Ea/RT)/(e^-Ea/RT') k/k' = e^(-Ea/RT + Ea/RT') ln (k/k') = -Ea/RT + Ea/RT' ln (k/k') = (Ea/R)(1/T' - 1/T) Why are we able to com...
by Yang Chen 2E
Sun Mar 11, 2018 10:42 pm
Forum: Administrative Questions and Class Announcements
Topic: Friday 7:30-9:00 Session
Replies: 1
Views: 173

Friday 7:30-9:00 Session

When will the questions for the 7:30-9:00 review session be posted or will they be given during the session?
by Yang Chen 2E
Sun Mar 11, 2018 10:41 pm
Forum: Administrative Questions and Class Announcements
Topic: Organic Chem on Final
Replies: 9
Views: 416

Re: Organic Chem on Final

I am also curious if organic chemistry will be covered as I don't see it in the outline.
by Yang Chen 2E
Sun Feb 25, 2018 11:34 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Midterm Question 7 Sig Figs
Replies: 2
Views: 94

Midterm Question 7 Sig Figs

For question 7, if you were to follow the rule of significant figures for each calculation, the final answer should be -2.4. I got marked off a point since the more exact answer is -2.7. Is there any chance I could restore a point for this?
by Yang Chen 2E
Mon Feb 19, 2018 8:36 pm
Forum: Balancing Redox Reactions
Topic: Anode vs Cathode and their Equations
Replies: 1
Views: 73

Anode vs Cathode and their Equations

Just to be clear, given two half equations, the Cathode consists of the more electronegative atom right? Also, for all of the half equations, are the E(cathode)/E(anode) values flipped if we were to flip the sign of the equation?
by Yang Chen 2E
Mon Feb 19, 2018 8:36 pm
Forum: Balancing Redox Reactions
Topic: Anode vs Cathode and their Equations
Replies: 2
Views: 107

Anode vs Cathode and their Equations

Just to be clear, given two half equations, the Cathode consists of the more electronegative atom right? Also, for all of the half equations, are the E(cathode)/E(anode) values flipped if we were to flip the sign of the equation?
by Yang Chen 2E
Sun Feb 18, 2018 11:18 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Electromotive force and Why is E a Maximum
Replies: 2
Views: 89

Electromotive force and Why is E a Maximum

On the learning objectives for chapter 14, I've noticed this: Know the definition of the electromotive force (emf, ℰ) and why it represents the maximum
potential difference. Can someone please explain this?
by Yang Chen 2E
Sun Feb 18, 2018 9:50 pm
Forum: Balancing Redox Reactions
Topic: HW 14.11 d
Replies: 1
Views: 81

HW 14.11 d

I don't really get what the solution manual is saying in terms of this question. Why is OH- part of the product of the cathode? Is it because the cathode is the side with OH-?
by Yang Chen 2E
Wed Feb 14, 2018 1:37 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Test 1 Question 3b
Replies: 2
Views: 115

Test 1 Question 3b

"A balloon filled with gas is expanded to a larger volume and lower pressure while maintaining the same temperature." Is heat being transferred here? Can someone please explain why the answer is yes?
by Yang Chen 2E
Sun Feb 11, 2018 11:57 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Entropy
Replies: 6
Views: 201

Re: Entropy

Are we supposed to know how many energy states a "unit" of vibrational energy adds on?
by Yang Chen 2E
Sun Feb 11, 2018 11:06 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 9.43 HW
Replies: 3
Views: 209

9.43 HW

Does anyone know what the answer for this question would be in J/degrees C?
by Yang Chen 2E
Sun Feb 11, 2018 9:14 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: H2(g) --> H2(g)
Replies: 2
Views: 121

Re: H2(g) --> H2(g)

I don't think delta G will be zero as you said you are only referring to H2. Delta G can only be applied to processes like phase changes or reactions.
by Yang Chen 2E
Sun Feb 04, 2018 11:15 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 9.13 Equation Confusion
Replies: 3
Views: 109

Re: 9.13 Equation Confusion

Does anyone know what the soluition manual's equation can be applied to or does it not exist in reality?
by Yang Chen 2E
Sun Feb 04, 2018 10:57 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Open, closed, or isolated test 1 question
Replies: 10
Views: 474

Re: Open, closed, or isolated test 1 question

Usually vials are open systems because matter and energy can enter them due to lack of a lid. If there IS a lid however, it would be a closed system (unless that vial was in some sort of light blocking vacuum chamber).
by Yang Chen 2E
Sun Feb 04, 2018 10:55 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Equipartition Theorem
Replies: 3
Views: 122

Re: Equipartition Theorem

What is the equipartition theorem by the way?
by Yang Chen 2E
Sun Jan 28, 2018 11:04 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Exothermic vs Exergonic and Endothermic vs Endergonic
Replies: 3
Views: 766

Exothermic vs Exergonic and Endothermic vs Endergonic

I'm not sure which forum to post this on so I will place this here. I'm a little confused about Exothermic vs Exergonic and Endothermic vs Endergonic. In my LS7A class, one of the questions stated that a reaction in an open system with a positive change in enthalpy is exergonic. I'm not sure as why ...
by Yang Chen 2E
Wed Jan 24, 2018 12:58 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Homework 8.101d [ENDORSED]
Replies: 1
Views: 88

Homework 8.101d [ENDORSED]

When the question asked for work, the answer was given in joules by multiplying the number by some sort of constant but it just asked for how much work takes place. I thought work was just supposed to be -(external pressure)*volume change?
by Yang Chen 2E
Sat Jan 20, 2018 10:40 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: standard enthalpy of formation [ENDORSED]
Replies: 4
Views: 150

Re: standard enthalpy of formation [ENDORSED]

This is what I wrote down: when all reactants and products are in their standard states at 1 ATM of pressure, the reaction enthalpy is called the standard reaction enthalpy (ΔH°) the standard reaction enthalpy for the formation of one molecule of a substance from its elements in their most stable fo...
by Yang Chen 2E
Fri Jan 19, 2018 12:10 pm
Forum: Phase Changes & Related Calculations
Topic: Delta U
Replies: 2
Views: 103

Delta U

Just to clarify, delta U is change in a system's internal energy right? I was looking through my notes and couldn't find a definition for it.
by Yang Chen 2E
Mon Jan 15, 2018 2:16 pm
Forum: Calculating Work of Expansion
Topic: Question 8.11 Reversible v Irreversible actions
Replies: 2
Views: 130

Re: Question 8.11 Reversible v Irreversible actions

Basically a reversible process means that if an infinitely small change happens to a variable, the process can be reversed. Page 265 of the textbook goes into depth about this.
by Yang Chen 2E
Sun Jan 14, 2018 12:10 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Different Molar Heat Capacities For Gases
Replies: 5
Views: 186

Re: Different Molar Heat Capacities For Gases

I'm still confused on the reason why there are two separate molar heat capacities. I know that substances expand when heated which would change the heat capacity assuming we have constant pressure, but what happens if we have a constant volume? How would having a constant volume affect molar heat ca...
by Yang Chen 2E
Sat Jan 13, 2018 10:43 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Not a State Property
Replies: 6
Views: 164

Re: Heat Not a State Property

Heat is dependent on the path that is taken to create it, so it is not a state property.
by Yang Chen 2E
Fri Jan 12, 2018 2:13 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Different Molar Heat Capacities For Gases
Replies: 5
Views: 186

Different Molar Heat Capacities For Gases

I'm still extremely confused on how gases could have multiple molar heat capacities. If you were to change the pressure or volume of a gas, you technically don't have to change the amount of moles of gas within the container right?
by Yang Chen 2E
Thu Dec 07, 2017 5:26 pm
Forum: Lewis Acids & Bases
Topic: Lewis Structure in identifying Acid or Base
Replies: 2
Views: 147

Re: Lewis Structure in identifying Acid or Base

If you're looking at lewis structures, you can tell which one is an acid or base by following the lewis definition of acids/bases. Lewis acids will have electron pairs to donate while lewis bases will have electron pairs they can receive.
by Yang Chen 2E
Thu Dec 07, 2017 5:20 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Hw 12.55
Replies: 2
Views: 114

Re: Hw 12.55

I think it has to do with the first being a weak acid, but the second one still counts as a weak acid. I'm not sure when we can omit or need to retain x.
by Yang Chen 2E
Sat Nov 25, 2017 4:35 pm
Forum: Hybridization
Topic: Question 4.95
Replies: 2
Views: 139

Question 4.95

I'm not sure what the number in from of the hybrid orbitals represent (eg 2sp). Why do lone electron pairs not have this number? Would we have to write these numbers for our tests as well since many of the homework problems don't seem to require it in the answer?
by Yang Chen 2E
Thu Nov 23, 2017 11:08 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Homework 4.41
Replies: 2
Views: 165

Homework 4.41

The question wants us to draw the lewis structure of CH2CHCN, determine the hybridization of the carbon atom orbitals, and determine the bond angles. I'm wondering if the double bond between the first and second carbon would cause the H-C-C bond angle to be more than 120 degrees and the H-C-H bond t...
by Yang Chen 2E
Thu Nov 23, 2017 10:28 pm
Forum: Lewis Structures
Topic: Homework 4.23
Replies: 1
Views: 120

Homework 4.23

Just to be clear, the lewis structure of OSbCl3 contains and expanded octet for Sb right? The answer key labels the Sb with a normal octet.
by Yang Chen 2E
Sun Nov 19, 2017 7:17 pm
Forum: Coordinate Covalent Bonds
Topic: Naming Conventions [ENDORSED]
Replies: 2
Views: 350

Re: Naming Conventions [ENDORSED]

This is what I put down: Naming for coordination compounds involve the greek prefix(number of specific ligand)+ligand name for each ligand in alphabetical order, then transition metal cation name with roman numerals for oxidation state. If there are anions outside of the formula, you add the ion nam...
by Yang Chen 2E
Sun Nov 19, 2017 6:58 pm
Forum: Air Pollution & Acid Rain
Topic: Acid Rain Damage [ENDORSED]
Replies: 5
Views: 548

Re: Acid Rain Damage [ENDORSED]

Acid rain changes soil pH and usually contains higher concentrations of solutes in the rain. Many different plants, especially ones that live in high rainfall areas, can't tolerate the pH change and the solute increase due to the way their roots work. This is because the solutes can build up in the ...
by Yang Chen 2E
Mon Oct 30, 2017 1:05 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Question 2.47d [ENDORSED]
Replies: 2
Views: 186

Re: Question 2.47d [ENDORSED]

Oooooooh wait ok I made a mistake with the electron configuration. Thank you for correcting me.

FYI for anyone who's confused about the gold configuration, one of the 6s electrons jumps to the almost filled 5d orbital creating the 6s1.
by Yang Chen 2E
Mon Oct 30, 2017 12:49 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Question 2.47d [ENDORSED]
Replies: 2
Views: 186

Question 2.47d [ENDORSED]

In this question, they are asking to identify which orbital an electron will be removed from to form a +1 ion. It asked for Au but the answer key says the electron will be taken from the 6s orbital. Isn't gold supposed to have an electron taken from its 6d orbital? Is the answer wrong?
by Yang Chen 2E
Sun Oct 08, 2017 9:56 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Different Series Energy Levels [ENDORSED]
Replies: 1
Views: 112

Different Series Energy Levels [ENDORSED]

Is there a way to determine which spectral series to use for initial/ending energy levels and what are their initial/ending energy levels? Our textbook problems (1.15) require us to determine the series to do the problems and was wondering if there is a condensed version of all of the series we are ...
by Yang Chen 2E
Tue Oct 03, 2017 9:28 am
Forum: SI Units, Unit Conversions
Topic: Formula Units [ENDORSED]
Replies: 9
Views: 479

Re: Formula Units [ENDORSED]

I would have to agree with the second post here. Consider the formula unit like a molecule and use the same method as you would for calculating the number of molecules.

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