## Search found 18 matches

Mon Mar 13, 2017 8:39 pm
Forum: *Cycloalkenes
Topic: Homework question #21 a
Replies: 1
Views: 758

### Re: Homework question #21 a

Double bonds get priority over substituents in having the lowest number.
Sun Mar 12, 2017 10:01 pm
Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
Topic: Course reader page 103- cis
Replies: 2
Views: 350

### Re: Course reader page 103- cis

It actually doesn't need to be the same group on both sides, you're just looking at which group has the highest priority on each side. Both CH3 and CH2CH3 have a higher priority than H because C has a higher atomic number than H, so those are the groups you use to determine if it's cis or trans.
Sun Mar 12, 2017 9:42 pm
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Delta G (knot)=-RTlnKeq on Page 108 in CR [ENDORSED]
Replies: 1
Views: 359

### Re: Delta G (knot)=-RTlnKeq on Page 108 in CR[ENDORSED]

It's actually ΔG° = -2.3030RTlogKeq (note: log instead of ln). 2.3030 is the conversion between log and natural log, i.e. 2.3030log(x) = ln(x).
Sun Mar 12, 2017 9:36 pm
Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
Topic: cis-trans
Replies: 2
Views: 360

### Re: cis-trans

Rachel_Bressler_3I wrote:first compare the molar mass of the carbon molecules parallel to each other. If both of the highest priority are on the same side, it is cis, and if they are on opposite sides are trans.

I think it's the atomic number, not molar mass, of the atoms that are bonded to each carbon, right?
Sun Mar 12, 2017 1:49 pm
Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
Topic: p.15 Organic Textbook geometric isomer
Replies: 3
Views: 460

### Re: p.15 Organic Textbook geometric isomer

I think it's because a geometric isomer has the same connectivity as well as molecular formula. If you look at 2-Methyl-1-propene, the C atom on the right of the double bond does not have an H connected to it like 1-Butene does. I don't know if this is right but I think that makes the hybridization...
Sun Feb 19, 2017 10:26 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8544
Views: 1474273

### Re: Post All Chemistry Jokes Here

Fri Feb 03, 2017 6:16 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Calculating entropy
Replies: 1
Views: 266

### Re: Calculating entropy

I think the two equations you're thinking of are actually ΔS = nCln(T2/T1) and ΔS = nRln(V2/V1). The first equation is used for changes in temperature while the second one is used for changes in volume.
Fri Feb 03, 2017 6:03 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 8.117
Replies: 1
Views: 326

### Re: 8.117

The question is asking for the change in internal energy for the production of 1 mole of H 2 , while the equation involves 3 moles of H 2 . This means that you need to divide the whole reaction by three, giving: (1/3)CH 4 (g) + (1/3)H 2 O(g) --> (1/3)CO 2 (g) + H 2 (g) There are now 2/3 moles of gas...
Fri Feb 03, 2017 5:46 pm
Forum: Balancing Redox Reactions
Topic: Ecell properties
Replies: 2
Views: 1166

### Re: Ecell properties

Extensive properties are those that depend on the amount of substance in a system, such as mass, volume, enthalpy, and entropy. (Enthalpy and entropy being extensive is the reason why you need to multiply by the number of moles of each substance when you calculate ΔH rxn or ΔS rxn .) On the other ha...
Sun Jan 22, 2017 7:39 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Chp. 8 hwk
Replies: 1
Views: 340

### Re: Chp. 8 hwk

The molar kinetic energy of a noble gas is equal to (3/2)RT (there's an explanation for this on pages 277-278 of the textbook), where R = 8.314 J/K/mol and T is the temperature in Kelvin. So for part (a) you would calculate (3/2)(8.314)(55.85+273).
Tue Nov 29, 2016 12:04 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8544
Views: 1474273

### Re: Post All Chemistry Jokes Here

How much do neutrons cost?

Nothing, they're free of charge.
Mon Nov 28, 2016 11:46 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8544
Views: 1474273

### Re: Post All Chemistry Jokes Here

What do you get when 6.02x1023 mosquitoes bite you?

Molearia.
Sun Nov 27, 2016 9:23 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Quiz Workbook P 49 Q9
Replies: 2
Views: 484

### Re: Quiz Workbook P 49 Q9

I think this response from another thread should help. Essentially you're finding what the concentration of BrCl would be if only 8.12% of it remains, then assuming that the concentration of the products increases by the same amount that the concentration of BrCl decreased by.
Sun Nov 27, 2016 8:05 pm
Forum: Lewis Acids & Bases
Topic: HW 12.17
Replies: 4
Views: 689

### Re: HW 12.17

I don't know the precise answer, but on page 469 of the textbook it says that metals form basic oxides, while nonmetals (like sulfur) form acidic oxides.
Tue Nov 15, 2016 7:34 pm
Forum: Naming
Topic: Is (OH)2 aqua? [ENDORSED]
Replies: 1
Views: 291

### Re: Is (OH)2 aqua?[ENDORSED]

That's actually (OH2), not (OH)2. OH2 is another way of writing H2O.
Tue Oct 25, 2016 11:03 pm
Forum: Sigma & Pi Bonds
Topic: Skipping Problems on Quiz 2 Prep?
Replies: 2
Views: 499

### Re: Skipping Problems on Quiz 2 Prep?

I'm pretty sure that you can skip the past quizzes (Fall 2014 and Fall 2015) entirely for the Quiz 2 prep because they seem to cover only chapter 4 material. The actual hand-in quiz that will be scored, along with Quiz 2 itself, only covers topics from chapters 2-3, so don't skip any questions on th...
Tue Oct 25, 2016 10:47 pm
Forum: Hybridization
Topic: Will hybrid orbitals be on the quiz?
Replies: 2
Views: 332

### Re: Will hybrid orbitals be on the quiz?

I don't believe so, as those are chapter 4 topics, while Quiz 2 is only supposed to cover chapters 2 and 3.
Sun Oct 16, 2016 7:19 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8544
Views: 1474273

### Re: Post All Chemistry Jokes Here

What don't you understand about copper? It makes perfect cents.