Search found 28 matches
- Wed Mar 09, 2016 4:41 pm
- Forum: *Electrophiles
- Topic: Electrophilic Characteristics of CO2 and CH3Cl
- Replies: 1
- Views: 2525
Re: Electrophilic Characteristics of CO2 and CH3Cl
CO2 is an electrophile because of the lone pairs on each Oxygen. Yes, there are double bonds, but I think the lone pairs on the oxygens will have priority in reactions. Also, the electronegativity of the oxygens pulls on the electrons making the carbon a partially positive charge making it electroph...
- Wed Mar 09, 2016 4:32 pm
- Forum: *ChemDraw
- Topic: Newman Projections
- Replies: 2
- Views: 808
Re: Newman Projections
Yes we will. If you do the practice finals, there are questions regarding drawing Newman projections.
- Sat Mar 05, 2016 11:59 pm
- Forum: *Alkenes
- Topic: (E)-3-Phenylprop-2-enal Pg. 60 Org Chem Text
- Replies: 1
- Views: 457
(E)-3-Phenylprop-2-enal Pg. 60 Org Chem Text
Why is the parent chain the propene instead of the benzene ring?
- Sat Mar 05, 2016 10:41 pm
- Forum: *Alkanes
- Topic: Functional groups we have to know
- Replies: 4
- Views: 624
Re: Functional groups we have to know
I think you should know the functional groups presented in Chapter 2 Section 1,2,4,5,6, and 10 as those are the sections assigned in the syllabus. They can all be fair game.
- Sun Feb 28, 2016 12:03 am
- Forum: *Alkanes
- Topic: Quiz 3 Prep Question #4
- Replies: 1
- Views: 358
Re: Quiz 3 Prep Question #4
Hi, the picture shows where you should start counting the carbons for the main parent chain.
- Sun Feb 21, 2016 8:53 pm
- Forum: *Organic Reaction Mechanisms in General
- Topic: Example of a single sided arrow
- Replies: 1
- Views: 377
Re: Example of a single sided arrow
An example of when a single sided arrow would be used would be for radical type of reactions. Let's say element X has 7 valence electrons. If it transfers 1 of its electrons to another radical or molecule, we would use the single sided arrow because it is only transferring 1 of its electrons to bind...
- Sat Feb 13, 2016 10:16 pm
- Forum: First Order Reactions
- Topic: HW question 15.37
- Replies: 1
- Views: 419
Re: HW question 15.37
Since the vessel is sealed, the volume will stay the same. We do not need the concentrations and just need masses of SO2Cl2, which can be substituted into the equation in replace of the concentrations since it is proportional. You can do it either way and still end up with the same answer.
- Sun Feb 07, 2016 12:05 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 14.15 c)
- Replies: 2
- Views: 363
Re: 14.15 c)
There is solid cadmium and nickel that can conduct electricity, which is why we do not need to use platinum. However, I am not sure why we need KOH in the cell diagram myself.
- Sun Jan 31, 2016 3:22 pm
- Forum: Balancing Redox Reactions
- Topic: How do you know the Oxidation number??
- Replies: 1
- Views: 4807
Re: How do you know the Oxidation number??
We know the oxidation of Mn in MnO4- because we know the oxidation number of oxygen. In group 17, the oxidation number of the halogens is -1. In group 16, the oxidation number of these elements is -2. Since there are 4 oxygen atoms in one MnO4- compound, the total charge of the 4 oxygen atoms is 4 x...
- Sun Jan 24, 2016 2:19 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: HW 9.65 Stability
- Replies: 2
- Views: 1614
Re: HW 9.65 Stability
If a compound becomes less stable, that means that the deltaG becomes less negative. This means that it becomes less spontaneous. The question asks us to find which compounds become less stable as temperature increases. So we should find the compounds whose deltaG becomes less negative when temperat...
- Mon Jan 18, 2016 2:30 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: q
- Replies: 1
- Views: 376
Re: q
On page 278-279 of the textbook, it explains how delta H = q. At constant pressure: deltaH = deltaU + PdeltaV. Since delta U is equal to q+w, we substitute q+w into the delta H equation. deltaH = q + w + PdeltaV. If we assume that a system can do no other work besides expansion work, w = -PdeltaV. T...
- Mon Jan 11, 2016 2:04 pm
- Forum: Phase Changes & Related Calculations
- Topic: Final Temperature After Adding Ice Cube to Hot Water
- Replies: 1
- Views: 687
Final Temperature After Adding Ice Cube to Hot Water
In homework question 8.41, a 50.0 g ice cube at 0.0 degrees Celsius is added to 400.0g of water at 45 degrees Celsius. We are asked to find the final temperature of the system? What equation am I supposed to use to find the heat absorbed by the ice cube and the heat released by the water. How do I s...
- Fri Jan 08, 2016 4:42 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Work/Internal Energy
- Replies: 1
- Views: 355
Re: Work/Internal Energy
Internal energy is the total store of energy in a system or substance. This includes the atoms, electrons, nuclei, etc. Work is the transfer of energy. So when you do work on a system, you increase its internal energy which allows it to do more work on its own. But when the system starts to do work ...
- Fri Jan 08, 2016 4:33 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy
- Replies: 1
- Views: 342
Re: Enthalpy
Enthalpy is the total heat content of a substance. We refer usually to the change in enthalpy (deltaH) because we cannot directly measure the total enthalpy of a system. We have to refer to the change in enthalpy which measures the amount of heat absorbed or released. Enthalpy is equal to the intern...
- Mon Nov 30, 2015 10:17 am
- Forum: Amphoteric Compounds
- Topic: How am i able to tell if something is amphiprotic ?
- Replies: 2
- Views: 28726
Re: How am i able to tell if something is amphiprotic ?
An amphiprotic substance can accept or donate at least one proton, usually H+. So in order for a substance to be amphiprotic, it must be able to accept an H+ ion or give away an H+ ion. An example would be (HCO3)^-. It can accept a proton to become (H2CO3), or it can donate away its proton to become...
- Mon Nov 16, 2015 3:33 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ICE Chart Original Value Change
- Replies: 3
- Views: 682
ICE Chart Original Value Change
In HW problem number 11.67, we are given the original partial pressures of each molecule. When making the ICE chart, it says that it is easier to push the reaction as far to the left as possible then start from new initial conditions. What are other situations in which we must change the initial val...
- Sat Nov 14, 2015 1:33 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Adding Reactant Effect on K
- Replies: 1
- Views: 568
Re: Adding Reactant Effect on K
Yes Q would change. Instead of Q=K, it is now Q<K. HCl is in the reactants, so adding more reactant would make the denominator in the equation Q=(Products)/(Reactants) bigger, decreasing the Q value. The reaction will start to make more products until equilibrium is reached again.
- Sat Nov 07, 2015 4:26 pm
- Forum: Naming
- Topic: Formula for tetraamminediaquacobalt(III) bromide?
- Replies: 1
- Views: 829
Re: Formula for tetraamminediaquacobalt(III) bromide?
Br (Bromine) is the anion in this compound. We see that cobalt has a charge of +3. The four ammines and the 2 aquas are neutral. In order to create a neutral overall compound, we need to have an anion with a total charge of 3-. Bromide is a halogen and has an oxidation state of -1. Three bromide ion...
- Mon Nov 02, 2015 9:49 am
- Forum: Properties of Light
- Topic: Electromagnetic Specturm
- Replies: 1
- Views: 387
Re: Electromagnetic Specturm
I think you should have a general understanding of each light's location on the electromagnetic spectrum. We probably do not need to know exact values -- only the position on the spectrum.
- Sun Nov 01, 2015 2:07 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Bond Orders with decimals
- Replies: 3
- Views: 1827
Re: Bond Orders with decimals
Bond order most of the time is equal to the number of bonds there are between two atoms. So, a bond order of 1.5 can be considered something less than a double bond, but more than a single bond.
- Tue Oct 27, 2015 8:23 pm
- Forum: Hybridization
- Topic: Hybridization with d-orbitals
- Replies: 2
- Views: 517
Re: Hybridization with d-orbitals
Both are acceptable.
- Sat Oct 24, 2015 3:56 pm
- Forum: Hybridization
- Topic: HW 4.43
- Replies: 1
- Views: 300
HW 4.43
Why exactly does the bond angle of a hybrid orbital increase if the s-character of a hybrid orbital is increased?
- Fri Oct 23, 2015 11:18 pm
- Forum: Lewis Structures
- Topic: Lewis Structure of IO3-
- Replies: 1
- Views: 1453
Lewis Structure of IO3-
On homework problem 4.13c, we are asked to draw the lewis structure of IO3-. In the solutions manual, it says that there are multiple resonance forms of this structure. Is it possible for one resonance structure to have the central Iodine atom be double bonded to each of the three Oxygen atoms while...
- Thu Oct 22, 2015 4:51 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configurations for 3.9
- Replies: 3
- Views: 597
Re: Electron Configurations for 3.9
I believe a 4s state is lower in energy than a 3d orbital until the 4s orbital is fully occupied.
- Thu Oct 22, 2015 4:48 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Maximum oxidation number
- Replies: 2
- Views: 523
Re: Maximum oxidation number
You can find the maximum oxidation number of an element by first identifying how many valence electrons there are for that element. There was one homework problem in the book (3.23) asking for the maximum positive and maximum negative oxidation numbers for chlorine. Chlorine has 7 valence electrons ...
- Sun Oct 18, 2015 3:02 pm
- Forum: Bond Lengths & Energies
- Topic: 3.87 Homework Problem
- Replies: 3
- Views: 945
Re: 3.87 Homework Problem
CF4 should have the strongest C--X bond since F has the shortest atomic radius. Cl and Br have larger atomic radii than F meaning that their valence electrons are farther away from the nucleus. Cl has valence electrons in the 3P subshells, while Br has valence electrons in the 4P subshells. Since th...
- Wed Oct 07, 2015 4:24 pm
- Forum: *Shrodinger Equation
- Topic: Quantum numbers
- Replies: 1
- Views: 383
Re: Quantum numbers
The positive and negative spin of an electron just symbolizes the different spins of each electron in a specific orbital. For an electron with +1/2 spin, an up arrow is used in the electron configuration diagram which tells us that the electron is spinning in a counterclockwise direction. For an ele...
- Thu Oct 01, 2015 4:31 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric effect
- Replies: 1
- Views: 424
Re: Photoelectric effect
The photoelectric effect tells us that light acts as a particle for this experiment. In order for an electron to be removed from a metal surface, the energy of a photon must match the energy required to eject (work function). For waves, if we want more energy, increasing intensity increases the ampl...