Search found 34 matches

by Michelle Yu 1L
Sun Mar 13, 2016 11:48 am
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Winter 2014 final question 7 part F newman projections
Replies: 3
Views: 609

Re: Winter 2014 final question 7 part F newman projections

Rachel Colbath 2G wrote:How would we know that the chlorine is bigger than the methyl group when arranging the second most stable conformation?


Chlorine has an atomic mass of 35.45 while methyl (CH3) is about 15 (add up the all the atomic mass. C=12 H=1). Therefore Chlorine is bigger.
by Michelle Yu 1L
Sun Mar 13, 2016 8:24 am
Forum: Phase Changes & Related Calculations
Topic: Winter 2012 Final Question 1B
Replies: 1
Views: 292

Winter 2012 Final Question 1B

How do you know it is 4 mol x 2 mol?
by Michelle Yu 1L
Sun Mar 13, 2016 7:36 am
Forum: Phase Changes & Related Calculations
Topic: Winter 2011 Final question 1A
Replies: 3
Views: 528

Winter 2011 Final question 1A

How is mass=50.0g when it is given 50.0 ml of water?
by Michelle Yu 1L
Sun Mar 13, 2016 7:31 am
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Stable conformation for 1-chloro-3methylcyclohexane
Replies: 1
Views: 379

Stable conformation for 1-chloro-3methylcyclohexane

For 8C, Isn't the geometric isomer suppose to be trans and not cis since both substituents are equatorial position.
by Michelle Yu 1L
Sun Mar 13, 2016 6:19 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Which requires more heat
Replies: 1
Views: 483

Which requires more heat

which requires more heat: breaking one mole of carbon-carbon single bonds or melting one mole ice.

Why does breaking one mole of carbon-carbon single bonds require more heat?
Does breaking bonds require more heat in general compared to other things?
by Michelle Yu 1L
Sun Mar 13, 2016 12:56 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Winter 2013 Final Question 3A
Replies: 3
Views: 433

Re: Winter 2013 Final Question 3A

It's a minus because it's the oxidation version of the reaction (noticed that they flipped it so that the electrons are on the right side of the equation) When they did the math, they subtracted the reduction potential. That's why they substracted a positive number. I am still confused. When I was ...
by Michelle Yu 1L
Sat Mar 12, 2016 11:14 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Winter 2013 Q2A
Replies: 3
Views: 419

Re: Winter 2013 Q2A

I don't get why you multiply the 3 to the 2nd redox reaction (O2 +2H+ + 2e- = H2O)
by Michelle Yu 1L
Sat Mar 12, 2016 11:04 pm
Forum: *Cycloalkanes
Topic: Winter Final 2012 Question 6B
Replies: 3
Views: 638

Re: Winter Final 2012 Question 6B

There was a similar problem where it was drawn like the this neopentyl but instead of neo it was named tert in final 2012 the first one of 6D. so I am confused between the two.
by Michelle Yu 1L
Sat Mar 12, 2016 9:14 pm
Forum: *Cycloalkanes
Topic: Winter Final 2012 Question 6B
Replies: 3
Views: 638

Winter Final 2012 Question 6B

for the 1-isopropyl -3- neopentylcyclohexane, how do you know it is neopentyl?
by Michelle Yu 1L
Sat Mar 12, 2016 9:02 pm
Forum: *Cycloalkenes
Topic: Winter 2012 Final Exam Q5
Replies: 3
Views: 566

Re: Winter 2012 Final Exam Q5

whenever theres a double bond, you look to see if its a cis or trans
as you can see on the structure which is a cyclooctene, it is a cis because the CH2 are on the same side or whenever it looks like half a hexane.
by Michelle Yu 1L
Sat Mar 12, 2016 4:21 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacity
Replies: 2
Views: 373

Heat Capacity

Between ethane and ethene, ethane has a higher heat capacity. Why?
by Michelle Yu 1L
Tue Mar 08, 2016 10:12 pm
Forum: *Free Energy of Activation vs Activation Energy
Topic: Free energy/ Ea graph, forward or reverse reaction favored?
Replies: 1
Views: 485

Free energy/ Ea graph, forward or reverse reaction favored?

By looking at an free energy of activation vs activation energy graph, how can you tell if the forward reaction is favored or the reverse when you have a higher TS1 than TS2 and vise versa?
by Michelle Yu 1L
Fri Mar 04, 2016 10:22 am
Forum: Administrative Questions and Class Announcements
Topic: Quiz 3 Winter 2016
Replies: 48
Views: 19102

Re: Quiz 3 Winter 2016

functional group is not on the quiz
by Michelle Yu 1L
Sun Feb 28, 2016 11:40 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Rate-Determining Step
Replies: 2
Views: 415

Rate-Determining Step

Why is the rate determining step important?
by Michelle Yu 1L
Fri Feb 19, 2016 11:27 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Quiz Preparation
Replies: 2
Views: 473

Re: Quiz Preparation

By look at k units, i believe it is second order reaction. So i used the second order equation, however, i don't have the time to figure out the concentration. Is there any way i can get the time or is there another equation to solve this.
by Michelle Yu 1L
Thu Feb 18, 2016 2:30 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: units of k
Replies: 2
Views: 338

Re: units of k

how did you arrive to
ml^1/2*g^-1/2*s^-1
by Michelle Yu 1L
Tue Feb 16, 2016 4:39 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: units of k
Replies: 2
Views: 338

units of k

What would be the units of k for an overall order of 3/2 if the concentrations were expressed in grams per milliliter?
(Questions is in chemistry textbook pg 620)
by Michelle Yu 1L
Wed Feb 10, 2016 7:56 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Entropy concepts
Replies: 3
Views: 538

Re: Entropy concepts

The more mass the more disorder. the molecules are able to switch to many different states. i believe.
by Michelle Yu 1L
Wed Feb 10, 2016 1:06 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: cell potential
Replies: 1
Views: 273

cell potential

When it ask for cell potential, is it E or E^o?
by Michelle Yu 1L
Thu Jan 28, 2016 3:39 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 4
Views: 1043

Re: Bond Enthalpies

so the reactants always break bonds and products form bonds?
by Michelle Yu 1L
Thu Jan 28, 2016 2:44 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 4
Views: 1043

Bond Enthalpies

I am still very confused on how do you know what bonds are being broken to what bonds are being formed.
by Michelle Yu 1L
Sun Jan 24, 2016 10:56 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Entropy
Replies: 1
Views: 314

Entropy

What does it mean when entropy is a state function?
by Michelle Yu 1L
Mon Dec 07, 2015 7:56 am
Forum: Lewis Acids & Bases
Topic: strong or weak acid
Replies: 6
Views: 843

Re: strong or weak acid

You can tell if an acid is strong if it has a lot of oxygen or high oxidation number, or weak bond strength between the two molecules. When you have a lot of oxygen, you can withdraw more electrons. An example of strong bond strength is HF. F is so electronegative that when it bonds with a proton, i...
by Michelle Yu 1L
Sat Dec 05, 2015 12:28 pm
Forum: *Biological Importance of Buffer Solutions
Topic: Mixed Solutions.
Replies: 2
Views: 1188

Mixed Solutions.

I'm confused of why when you add solid sodium acetate to an acetic acid solution, the concentration of H3O+ decreases and why when HCl is added to a benzoic acid solution, the percentage of benzoic acid that is deprotonanted decreases and why when solid NH4Cl is added to an ammonia solution, the con...
by Michelle Yu 1L
Sat Dec 05, 2015 11:32 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Chapter 12 Question 69b
Replies: 2
Views: 442

Chapter 12 Question 69b

The question tells us to find the pH with given 0.055 M AlCl3(aq).

In the solution book, the chemical equation is
Al(H2O)6 3+ (aq) + H2O = H3O+(aq) + Al(H2O)5 OH2+

why did Cl get replaced with H2O?
by Michelle Yu 1L
Mon Nov 30, 2015 12:05 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Video Quiz #3 Question #4
Replies: 1
Views: 349

Video Quiz #3 Question #4

This is from Quiz #3. Question #4.
I showed how to find the total pressure using PV=nRT
And then I showed how to find the equilibrium constant by find the partial pressure using mole fractions.
by Michelle Yu 1L
Thu Nov 19, 2015 11:12 pm
Forum: Ideal Gases
Topic: Finding the equilibrium expression K help
Replies: 4
Views: 620

Re: Finding the equilibrium expression K help

If the chemical equation has (aq), you would convert everything to M.
If the chemical equation has liquid or solid, then it equals to 1.
by Michelle Yu 1L
Tue Nov 03, 2015 6:46 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Order
Replies: 5
Views: 1748

Re: Bond Order

I'm not sure if it has resonance or not, but i know that the bigger the bond order, the more stable the molecule because there are more bonding than aniti bonding i think.
by Michelle Yu 1L
Tue Nov 03, 2015 5:42 pm
Forum: Lewis Structures
Topic: Lewis Structure of NO3-
Replies: 2
Views: 503

Lewis Structure of NO3-

Why can't NO3- have 2 double bonds of oxygen?
by Michelle Yu 1L
Tue Nov 03, 2015 5:36 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Order
Replies: 5
Views: 1748

Bond Order

I know that when BO=3, it means a triple bond.
However if I get BO=1.5, what kind of bond is that?
by Michelle Yu 1L
Mon Nov 02, 2015 5:11 pm
Forum: Limiting Reactant Calculations
Topic: Fall 2010 Midterm Question 1B
Replies: 3
Views: 435

Fall 2010 Midterm Question 1B

2A + 1B --> 3C

If one mole of A is mixed with one mole of B which is the limiting reactant?

I'm confused on how the limiting reactant is A. How will you approach this problem? Do i do molar ratio, if so how?
by Michelle Yu 1L
Fri Oct 30, 2015 5:29 am
Forum: Lewis Structures
Topic: Lewis Sturcture of (CH3)2Be
Replies: 1
Views: 888

Lewis Sturcture of (CH3)2Be

Im confused on how to draw the lewis structure since Be is a metal. I know that a Be attaches to CH3 but how do you draw it?

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