## Search found 33 matches

Fri Mar 17, 2017 9:47 am
Replies: 2
Views: 806

Since this is not part of 14B syllabus, I doubt it would make a difference which Carbon you attach the Halide to. The question usually specifies the product formed, so just follow that. This is how it works --> ASYMMETRIC ACROSS DOUBLE BOND - both carbons have different number of hydrogens attached ...
Wed Mar 15, 2017 11:35 pm
Forum: *Cycloalkanes
Topic: Numbering counterclockwise or clockwise
Replies: 4
Views: 3743

### Re: Numbering counterclockwise or clockwise

The priority goes --

Functional Groups > Bonds (triple>double) > substituents.

So you would choose a numbering such that the functional group gets the lowest value.
Wed Mar 15, 2017 9:03 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Flipping an Ecell equation
Replies: 1
Views: 468

### Re: Flipping an Ecell equation

E 0 cell = E 0 cathode - E 0 anode For a Spontaneous (favorable) cell E 0 cell is positive. So if both reduction reactions are given, try plugging the values into the equation above to see which combination gives you a positive value. The combination giving the positive value will tell you which rea...
Wed Mar 15, 2017 8:56 pm
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: How to determine higher stability
Replies: 2
Views: 440

### Re: How to determine higher stability

Chloro and Bromo groups are large in size. Hence if they are placed close to each other, they will experience very high repulsion (ie the structure is unstable). They also experience repulsion from the hydrogen groups. To minimize the repulsion, thereby making the structure stable, these two groups ...
Tue Mar 14, 2017 11:07 pm
Forum: *Cycloalkanes
Topic: Numbering counterclockwise or clockwise
Replies: 4
Views: 3743

### Re: Numbering counterclockwise or clockwise

The first priority of numbering is given to the alkene group, that is the double bond. While numbering the carbons, we always go along the double bond. So in this case, we choose the lowest number for the carbon with the double bond, with the Cl group attached to it. This makes our double bond and o...
Tue Mar 14, 2017 10:56 pm
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Angle of 60/180 or 0 and 120
Replies: 3
Views: 585

### Re: Angle of 60/180 or 0 and 120

I drew them out below.
The dihedral angle is between the Chloro and the Bromo groups.

Hope this helps.
Tue Mar 14, 2017 12:09 pm
Forum: *Cycloalkanes
Topic: Benzene [ENDORSED]
Replies: 3
Views: 1090

### Re: Benzene[ENDORSED]

Oh... I'm so sorry.

Yes.
Amines too.
Tue Mar 14, 2017 11:56 am
Forum: *Haloalkanes
Topic: Practice Problem Sets [ENDORSED]
Replies: 1
Views: 728

### Re: Practice Problem Sets[ENDORSED]

Naming structures with multiple double bonds follows the same principle as all other compounds. There is however, one small difference -- You retain the 'a' after the prefix (indicating the number of carbons) and put di, tri .... to indicate how many double bonds there are. For Example - CH 2 =CH-CH...
Tue Mar 14, 2017 11:49 am
Forum: *Cycloalkanes
Topic: Benzene [ENDORSED]
Replies: 3
Views: 1090

### Re: Benzene[ENDORSED]

Dr. Lavelle hasn't covered benzene as a substituent in class. So, the questions assigned for homework also neglect the larger benzene problems. When benzene is the main ring, then you just write benzene For example - Chloro Benzene 1,2 Dichloro Benzene (orthodichlorobenzene) etc.. It is written as a...
Tue Mar 14, 2017 11:40 am
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Angle of 60/180 or 0 and 120
Replies: 3
Views: 585

### Re: Angle of 60/180 or 0 and 120

You could draw the same structure if all the atoms bound to both the carbons are the same. For example - Ethane Or even if all were the same except one. For example - Bromo- ehtane However, when there are different groups around the carbons, say a Bromine (bromo), on one of the carbons, and Chlorine...
Fri Mar 10, 2017 9:30 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8199
Views: 1430067

### Re: Post All Chemistry Jokes Here

1st Chemist: "What's new?"
2nd Chemist: c over lambda.
Fri Mar 10, 2017 9:18 am
Forum: *Amines
Topic: Numbering of carbons in amines
Replies: 1
Views: 660

### Numbering of carbons in amines

In amine compounds with multiple hydrocarbon substituents (2 or 3), if one of them has a substituent, which direction do we start naming it in. Should the Carbon attached to the Nitrogen get the lowest number (1) or should we try to make the substituent get the lowest number?
Fri Mar 03, 2017 11:15 pm
Forum: Administrative Questions and Class Announcements
Topic: Extra Review Session Winter 2017
Replies: 7
Views: 1706

### Re: Extra Review Session Winter 2017

Please find attached the recording of winter 2017 post midterm review
Fri Mar 03, 2017 9:30 am
Forum: *Alkanes
Topic: Naming Organic Compounds (substituents)
Replies: 1
Views: 386

### Naming Organic Compounds (substituents)

How to name an organic compound that has a hydrocarbon chain with substituents as a substituent. eg - CH3-CH-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3 | H-C-H H-C-H H-C-H H-C-Br H-C-H H For some reason, this post shows the substituent attached to the 1st carbon. It is attached to the second Carbon.
Sat Feb 25, 2017 11:38 am
Forum: *Enzyme Kinetics
Topic: Catalyst [ENDORSED]
Replies: 2
Views: 374

### Catalyst[ENDORSED]

Are catalysts included in the overall rate law of a reaction?
Fri Feb 17, 2017 9:19 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8199
Views: 1430067

### Re: Post All Chemistry Jokes Here

Chemistry Lab.
Fri Feb 17, 2017 9:11 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8199
Views: 1430067

### Re: Post All Chemistry Jokes Here

I have many chemistry jokes.
....
I'm just afraid they won't get a good Reaction.
Thu Feb 09, 2017 12:38 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Delta G vs Delta G0
Replies: 5
Views: 4453

### Delta G vs Delta G0

When asked for delta G, being given Delta H0 and Delta S0, should we just plug in the given temperature (Delta G0 = DeltaH0 - T DeltaS0) or
calculate Delta G using -

Delta G = DeltaG0 + RT ln(Q) <Where DeltaG0 = DeltaH0 - (298)DeltaS0>

????
Mon Feb 06, 2017 7:18 pm
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: Half reactions for electrolysis [ENDORSED]
Replies: 1
Views: 369

### Half reactions for electrolysis[ENDORSED]

How is writing half reactions for electrolysis different from electrolytic cells?
We only have one solution, so how do we go abut doing that?
Wed Feb 01, 2017 10:58 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge?
Replies: 3
Views: 363

### Re: Salt Bridge?

The salt bridge completes the circuit hence allowing current to pass through the system. The wires allow movement of electrons. The salt bridge allows movement of counter ions from one side to the other.
Tue Jan 24, 2017 1:32 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Energy of a Gas?
Replies: 2
Views: 415

### Energy of a Gas?

Do we have to prove or remember the proofs for
Energies of ideal gases - (mono atomic - 3/2 nRT and diatomic - 5/2 nRT)?

When do we use these in thermodynamics?
Fri Jan 20, 2017 11:34 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Work on or by the system? [ENDORSED]
Replies: 1
Views: 333

### Work on or by the system?[ENDORSED]

If the sign of Delta H is negative, is the work being done on the system or by the system/
Fri Jan 13, 2017 7:24 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Units of Reaction Enthalpies
Replies: 11
Views: 1578

### Re: Units of Reaction Enthalpies

But what if the product generated is not one mole in quantity?
Or if there are multiple products? (so multiple moles of each)
Thu Jan 12, 2017 6:08 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Units of Reaction Enthalpies
Replies: 11
Views: 1578

### Units of Reaction Enthalpies

When we calculate reaction enthalpies for reaction that have more than one product or the balanced reaction has multiple moles of a product; what unit should we use?
Should we write kJ/mol or just kJ (since there are multiple moles)?
Fri Dec 02, 2016 2:09 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8199
Views: 1430067

### Re: Post All Chemistry Jokes Here

What do you call a fish made of two sodium atoms?

2Na
Fri Dec 02, 2016 1:54 pm
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: Making a buffer through titration [ENDORSED]
Replies: 1
Views: 365

### Making a buffer through titration[ENDORSED]

During titration, how do we calculate the amount of base or acid required to make a buffer of a desired pH?
Tue Nov 22, 2016 4:26 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Percentage dissociation
Replies: 1
Views: 318

### Percentage dissociation

What happens if percentage of dissociation is greater than 5%? Does it make all our calculations and approximation of (m-x=m) wrong?
Can we not use this if t is greater than 5%?
Tue Nov 22, 2016 4:20 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8199
Views: 1430067

### Re: Post All Chemistry Jokes Here

A neutron walks into a bar and asks how much for a drink. The bartender replies "For you, No Charge."
Thu Nov 17, 2016 4:53 pm
Forum: Amphoteric Compounds
Topic: With respect to other compounds....
Replies: 1
Views: 492

### With respect to other compounds....

Amphoteric substances behave as either acids or bases in different situations. So I assume that their nature depends on the other compounds they interact with.
What happens when we study these compounds individually? Are they acidic or basic, or neither?
Sat Nov 12, 2016 10:55 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Aqueous Ions
Replies: 1
Views: 314

### Aqueous Ions

While calculating K, why do we consider only gases?
We don't consider liquid and solids, but why do we consider aqueous ions?
Wed Nov 02, 2016 11:09 am
Forum: Dipole Moments
Topic: Net Dipole Moment
Replies: 1
Views: 776

### Net Dipole Moment

How to determine if a compound has a net dipole moment or not? What factors is the net dipole moment based on?
Sat Oct 22, 2016 2:30 pm
Forum: Electronegativity
Topic: Electronegativity vs Electron Affinity
Replies: 4
Views: 1198

### Electronegativity vs Electron Affinity

How is Electronegativity different from electron affinity?
Why does Electron affinity have a unit?
Why doesn't Electronegativity have a unit?
Thu Oct 13, 2016 12:11 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: s and d orbitals
Replies: 3
Views: 556

### s and d orbitals

While writing the electronic configurations, we fill up orbitals from lowest to highest energy. For K and Ca we write the [Ar]4s (4s1 and 4s2). However, the next element, Sc , we write 3d before 4s. Is this the standard convention or does the energy of the 4s orbital increase due to the presence of ...