Search found 15 matches

by rivera_1J
Sat Mar 12, 2016 8:53 pm
Forum: Phase Changes & Related Calculations
Topic: Final Exam 2015 #1B
Replies: 2
Views: 333

Re: Final Exam 2015 #1B

Professor Lavelle said that was a typo its actually suppose to be 13400J
by rivera_1J
Wed Mar 09, 2016 6:19 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Winter 2011 Final Question
Replies: 2
Views: 442

Re: Winter 2011 Final Question

To calculate residual entropy you use the formula where W is the number of states a molecule can be in and still have the same amount of energy.
by rivera_1J
Mon Mar 07, 2016 5:06 pm
Forum: *Haloalkanes
Topic: Priority in Numbering
Replies: 3
Views: 905

Re: Priority in Numbering

An example of functional groups having priority over halogens is in the course reader page 104
ClCH2CH2CH(OH)CH3 here the alcohol functional group gets numbered as 2 and the chlorine is 4 because functional groups get priority in numbering over substituents and double/triple bonds
example in course reader
by rivera_1J
Wed Mar 02, 2016 12:09 am
Forum: *Alkenes
Topic: # of double bonds in naming
Replies: 2
Views: 388

Re: # of double bonds in naming

From what I've seen from Lavelle's problems it would be better to put the greek prefix instead of a number. Im not sure if its necessarily more proper but it is less confusing because it could also be seen that you are writing the placement of the double bond ex: 1,3-butadiene could also be written ...
by rivera_1J
Mon Feb 29, 2016 10:32 pm
Forum: *Alkynes
Topic: Alkynes for quiz 3?
Replies: 3
Views: 1034

Re: Alkynes for quiz 3?

No we don't have to know functional groups for this quiz
by rivera_1J
Sun Feb 28, 2016 6:07 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 3 Functional Groups
Replies: 1
Views: 334

Re: Quiz 3 Functional Groups

The quiz covers material up to page 99 of the course reader, so no functional groups will not in this quiz
by rivera_1J
Fri Feb 26, 2016 2:03 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Determining shape of molecule
Replies: 1
Views: 332

Re: Determining shape of molecule

Dr Lavelle answered this question before. The molecule is tetrahedral because it is counting through electronic geometry. Electronic geometry counts for all regions of electron density which include lone pairs. Answer: It has a tetrahedral geometry if you count the lone pairs in the geometry, this i...
by rivera_1J
Thu Feb 18, 2016 11:25 pm
Forum: First Order Reactions
Topic: Time units
Replies: 1
Views: 350

Re: Time units

They can be in any unit of time. In the textbook some problems had half lives in minutes and some in seconds, and in one problem in the workbook the half-life was in years
by rivera_1J
Tue Feb 09, 2016 1:51 am
Forum: Calculating Work of Expansion
Topic: Midterm 2012 Q5, Change in Volume
Replies: 3
Views: 484

Re: Midterm 2012 Q5, Change in Volume

The internal energy in step 2 is equal to -50J because it is returning back to its original internal energy. For step 1, we figured out the internal energy had increased by 50J, therefore in order for it to go back to its original internal energy deltaU must decrease by 50J which is why delta u=-50J
by rivera_1J
Tue Feb 02, 2016 2:47 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: equation for irreversible change in temperature
Replies: 1
Views: 330

equation for irreversible change in temperature

So I know you can use the equation delta s= nRln(v2/v1) for both a reversible and an irreversible change in volume my question is can you use the equation delta s= Cln(T2/T1) for both a reversible and and irreversible change in temperature or just reversible, and why?
by rivera_1J
Mon Feb 01, 2016 2:34 am
Forum: Calculating Work of Expansion
Topic: Adiabatic Systems
Replies: 2
Views: 504

Re: Adiabatic Systems

An adiabatic process is one where there is no heat flowing in or out of a system, but temperature can still change. The first law of thermodynamics tells us in order for energy to be conserved, the change of internal energy of a system is dependent on heat and work (delta U=q+w). However since q=0 t...
by rivera_1J
Sun Jan 31, 2016 9:53 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Which has more entropy?
Replies: 4
Views: 2352

Re: Which has more entropy?

yes more complex molecules have higher entropy because they have more bonds, which means they have more possible ways of rotating. Because they can rearrange themselves in various positions they can take up more space.
by rivera_1J
Tue Jan 26, 2016 4:56 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Elements in their most stable form
Replies: 2
Views: 6866

Elements in their most stable form

When calculating the enthalpy of a reaction using standard enthalpy of formation, should we assume an element is in their most stable form, or what should we do if the element that is given is not in their most stable form? How do you convert it into its most stable form?
by rivera_1J
Mon Jan 18, 2016 6:42 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Quiz 1 Chapters
Replies: 3
Views: 632

Re: Quiz 1 Chapters

Quiz one will be covering chapters 8 and 9 thermodynamics and thermochemistry, and I believe we have to know up to Friday of this week
by rivera_1J
Tue Jan 12, 2016 10:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Fifth edition textbook problems
Replies: 1
Views: 1465

Re: Fifth edition textbook problems

Yes the fifth edition textbook chapters are behind by one, so chapter 8 in the sixth edition is chapter 7 in the fifth edition. As for the homework problems, they are almost always the same but sometimes the numbers are different and also the fifth edition doesn't have applied exercises like the six...

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