Search found 25 matches
- Tue Mar 14, 2017 11:41 am
- Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
- Topic: Where to split molecule [ENDORSED]
- Replies: 3
- Views: 867
Re: Where to split molecule [ENDORSED]
A double bond does not always have the qualifications needed to identify it as cis or trans. There must be a difference in the substituents in order for the classification. For example, in the left image, since both of the substituents with the higher atomic number are on the same side of the double...
- Tue Mar 14, 2017 9:26 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2760021
Re: Post All Chemistry Jokes Here
Chemistry Joke :)
- Tue Mar 14, 2017 9:21 am
- Forum: *Cyclopropanes and Cyclobutanes
- Topic: Conformations [ENDORSED]
- Replies: 4
- Views: 1934
Re: Conformations [ENDORSED]
We need to understand which conformation represents which cycloalkane. For example, for cyclopropane, there is only one conformation being cyclopropane where all C's are on the same plane. For cyclobutane, the most stable conformation is the butterfly. For cyclopentane, the most stable conformation ...
- Tue Mar 07, 2017 10:01 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2760021
Re: Post All Chemistry Jokes Here
Chemistry Joke:)
- Tue Mar 07, 2017 9:29 am
- Forum: *Cycloalkanes
- Topic: Determining the Dominance between a Cycloalkane and a Long Carbon Chain
- Replies: 3
- Views: 839
Re: Determining the Dominance between a Cycloalkane and a Long Carbon Chain
The name for the first line structure you posted would be 1-cyclohexyl-11-methylundecane. This is because there are 11 carbons on the main chain of carbons, meaning the prefix is undec- and then -ane because there are only single carbon-carbon bonds. Then to name the substituents, you first look at ...
- Tue Mar 07, 2017 9:08 am
- Forum: *Alkanes
- Topic: Transition states
- Replies: 3
- Views: 683
Re: Transition states
In the electrophilic addition reaction there are two transition states since there are two steps. Each step correlates with a differing transition state. In the first transition state, the double bond breaks between two carbons, and the electrophile (ex.H-Br) attaches through a tentative bond with t...
- Sun Mar 05, 2017 3:32 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2760021
Re: Post All Chemistry Jokes Here
Chemistry Joke :)
- Sun Mar 05, 2017 3:24 pm
- Forum: *Electrophilic Addition
- Topic: Electrophile Addition vs. SN2 Reaction
- Replies: 2
- Views: 2146
Re: Electrophile Addition vs. SN2 Reaction
Another main difference between electrophilic addition and the bimolecular nucleophilic substitution reaction is that they have two steps and one step, respectively. The electrophilic addition reaction has two steps meaning two transition states, while the bimolecular nucleophilic substitution react...
- Sun Mar 05, 2017 3:13 pm
- Forum: *Electrophilic Addition
- Topic: nucleophile and electrophile reactions
- Replies: 6
- Views: 3165
Re: nucleophile and electrophile reactions
When drawing organic reactions, it is pertinent to use curved arrows in order to represent the electron movement from an e- rich region to a deficient region. In other words, the arrow represents the movement of electrons from a nucleophile to an electrophile. The nucleophile of a reaction is usuall...
- Sun Feb 26, 2017 2:02 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2760021
Re: Post All Chemistry Jokes Here
Chemistry Joke :)
- Sun Feb 26, 2017 1:57 pm
- Forum: *Electrophiles
- Topic: General Question about Nucleophiles vs. Electrophiles
- Replies: 2
- Views: 1567
Re: General Question about Nucleophiles vs. Electrophiles
In order to differentiate if a neutral molecule is a nucleophile or electrophile we must pay attention to the central atom. If the central atom has a electronegativity of delta negative, this means it is electron rich and a nucleophile, and it has free electrons or a pi bond that could be broken to ...
- Sun Feb 26, 2017 1:47 pm
- Forum: *Electrophiles
- Topic: Electrophile/Nucleophile
- Replies: 3
- Views: 1154
Re: Electrophile/Nucleophile
From my understanding, when identifying an atom as a nucleophile, an atom that donates an electron pair to a electrophile due to free electrons or a pi bond, we must pay attention to the electronegativity, therefore we can distinguish the delta negative atom from the delta positive atom. As mentione...
- Sun Feb 19, 2017 6:14 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2760021
- Sun Feb 19, 2017 3:59 pm
- Forum: Zero Order Reactions
- Topic: Homework Question
- Replies: 4
- Views: 960
Re: Homework Question
Hi! For this question, I'm confused as to why we don't square H 2 when it asks for the reaction rate with doubling the concentration of H 2 . Doesn't the equation for the rate law involve k[H 2 ] a , in which a= the coefficient, which would be 2 since we doubled it? Or am I mixing up concepts? Than...
- Sun Feb 19, 2017 3:49 pm
- Forum: Zero Order Reactions
- Topic: Know Which Order It Is [ENDORSED]
- Replies: 2
- Views: 722
Re: Know Which Order It Is [ENDORSED]
As well as this, another thing to consider is the overall order of the reaction. Depending on the amount of reactants, aA+bB=cC+dD, you must find the order of each reactant, then add the sum of the orders to get the OVERALL order. For example, let's say rate law =k[A]^2 * [B]^2, then the overall ord...
- Sun Feb 12, 2017 2:19 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2760021
- Sun Feb 12, 2017 2:07 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: E and E°, G and G°
- Replies: 3
- Views: 1981
Re: E and E°, G and G°
E Cell and E Cell°are different in that E Cell°is the standard cell potential, while E Cell merely represents the cell potential. The Standard Cell Potential is measured when all species taking part are in their standard states. You use the standard cell potentials given for half equations to figure...
- Sun Feb 12, 2017 1:43 pm
- Forum: Balancing Redox Reactions
- Topic: Creating Cell Diagrams
- Replies: 2
- Views: 708
Re: Creating Cell Diagrams
From my understanding, when writing a cell diagram, you leave out all moles and just focus on the molecules given. For example, if you find the final reaction to be 2Ni(OH)^3(s)+Cd(s)-->Cd(OH)^2(s)+2Ni(OH)^2(s) then the cell diagram is Cd(s),Cd(OH)^2(s)|KOH(aq)||Ni(OH)^3(s),Ni(OH)^2(s), Ni(s) All mo...
- Sun Feb 05, 2017 2:46 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2760021
- Sun Feb 05, 2017 2:39 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Irreversible vs reversible pathway
- Replies: 2
- Views: 764
Re: Irreversible vs reversible pathway
If we know that all real processes are irreversible, then how do we know when to use w = -nRT ln V1/V2 instead of w = -P∆V and vice versa? For calculating entropy, do we never use w = -P∆V because it has to be a reversible expansion and isothermal? The equations given will usually specify whether t...
- Sun Feb 05, 2017 2:31 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Trouton's rule
- Replies: 4
- Views: 1308
Re: Trouton's rule
Even though we aren't required to know this, does anyone understand the concept? Can someone please explain it? Thank you.
- Tue Jan 31, 2017 9:20 am
- Forum: Phase Changes & Related Calculations
- Topic: Phase Change Formula
- Replies: 2
- Views: 951
Re: Phase Change Formula
An adiabatic system means that all heat within the system remains, so there is no transfer from the adiabatic system to it's surroundings. Concerning the melting of ice, you must use the H(fusion) (kj/mol) and multiply that by moles. If given grams, you divide by the molar mass of water. This way al...
- Sun Jan 29, 2017 6:33 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Q 8.53
- Replies: 1
- Views: 529
Re: Q 8.53
In the equation, it asks you to calculate the internal energy for the reaction of one mole . Therefore, when you are given 1.40 grams of carbon monoxide, you must convert the grams to moles. Then from here, you take the total heat in kj, and divide by moles. Therefore you're final answer is in kj/mo...
- Sun Jan 22, 2017 3:05 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Can some explain reversible and irreversible processes? [ENDORSED]
- Replies: 2
- Views: 718
Re: Can some explain reversible and irreversible processes? [ENDORSED]
An irreversible process takes less work than a isothermal, reversible process. For an irreversible process, when you graph pressure against volume, you find that the pressure is constant, and the volume fluctuates. This would make a straight line horizontally, resulting in a square-shaped curve, and...
- Tue Jan 10, 2017 9:04 am
- Forum: Phase Changes & Related Calculations
- Topic: Burns Worse from Steam Than Water Example
- Replies: 2
- Views: 824
Re: Burns Worse from Steam Than Water Example
It is important to understand this conceptually. In the example, it is asking you to compare a steam burn to a water burn. When we look at the water burn, if the water is 100 degrees and it reaches 30 degrees, then the amount of heat being released is about 5 kJ, and this is significantly less becau...