Search found 23 matches

by 904642541
Fri Mar 11, 2016 11:04 pm
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Numbering the carbons
Replies: 2
Views: 534

Re: Numbering the carbons

The carbons can be numbered either way as long as you are consistent in counting clockwise or counterclockwise.
by 904642541
Fri Mar 04, 2016 9:49 am
Forum: *Alkynes
Topic: Alkene, Alkyne
Replies: 1
Views: 809

Re: Alkene, Alkyne

Alkenes and Alkynes are said to have equal priority. That means both "ene" and "yne" will be present in the name. This link can help:
http://www.laney.edu/wp/cheli-fossum/files/2012/01/Naming-Alkenes-and-Alkynes-rules.pdf
by 904642541
Sun Feb 28, 2016 2:57 pm
Forum: *Nucleophiles
Topic: Neutral element
Replies: 1
Views: 504

Re: Neutral element

Electrophiles are elements/compounds that want electrons. Electrophiles are therefore considered lewis acids. They are electron deficient. Nucleophiles are electron rich and are willing to give up electrons. Nucleophiles are usually negatively charged. So it depends on the reaction.
by 904642541
Fri Feb 19, 2016 11:26 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Grading
Replies: 1
Views: 378

Re: Midterm Grading

Yes, you can ask the TA on what was incorrect with the work you have done. You can get a possible regrade.
by 904642541
Fri Feb 12, 2016 8:35 pm
Forum: Second Order Reactions
Topic: Half life equations
Replies: 1
Views: 392

Re: Half life equations

I believe you should be familiar with the meaning of the equation and how it is used, not much on the step-by-step process of derivation (although I think you should go over it briefly).
by 904642541
Fri Feb 05, 2016 8:12 pm
Forum: General Rate Laws
Topic: General Rate Law Orders
Replies: 2
Views: 439

Re: General Rate Law Orders

First order reaction's graph is a negative slope line whereas second order reaction's graph is a positive slope line.
by 904642541
Fri Jan 29, 2016 10:53 pm
Forum: Van't Hoff Equation
Topic: Van't Hoff Equation
Replies: 2
Views: 561

Re: Van't Hoff Equation

The development of this equation is based off of the thermodynamics equation: deltaG=deltaH-TdeltaS and the Gibbs free energy isotherm equation: G=-RTlnK This link is helpful in displaying the relationship: http://www.chem.purdue.edu/gchelp/howtosolveit/Thermodynamics/K_from_DelG.html"onclick="windo...
by 904642541
Sat Jan 23, 2016 10:39 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy graph
Replies: 1
Views: 310

Re: Gibbs Free Energy graph

The horizontal line indicates "when G is a minimum." That means that the system can no longer change, and that the system is at equilibrium and therefore 0.
by 904642541
Fri Jan 15, 2016 9:34 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: kJ vs kJ/mol
Replies: 2
Views: 853

Re: kJ vs kJ/mol

If the question is asking you about the amount of energy you use the units kJ (if asked in kJ).
If question is asking you about the amount of energy per mole of a substance then you use the units kJ/mol.
by 904642541
Fri Jan 08, 2016 10:37 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Specific Heat Capacity-formula
Replies: 2
Views: 1148

Re: Specific Heat Capacity-formula

Molar heat capacity is the heat required to raise the temperature of 1 mole of a substance by 1 C at a constant temperature.
Qp = nCpT
Where,
Qp = heat required
n = number of moles of substance
Cp = molar heat capacity of a gas at constant temperature
T = temperature change
by 904642541
Fri Dec 04, 2015 10:42 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Numbers and Shape
Replies: 3
Views: 1094

Re: Coordination Numbers and Shape

Coordination numbers is the total points of attachment to the central element. Ex: Coordination number 4: tetrahedral (can be) square planar Coordination number 6 : octahedral etc. Helpful website: http://chemwiki.ucdavis.edu/Inorganic_Chemistry/Coordination_Chemistry/Basics_of_Coordination_Chemistr...
by 904642541
Fri Nov 27, 2015 10:33 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Homework Question 12.65
Replies: 1
Views: 418

Re: Homework Question 12.65

A salt consists of a cation and anion. If the cation can form a strong base and the anion can form a strong acid > the salt is neutral. If the cation forms a strong base and the anion a weak acid > it's basic. If the cation forms a weak base and the anion a strong acid > it's acidic. Example: NaCH3C...
by 904642541
Thu Nov 19, 2015 11:11 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Acid or Base in a Reaction
Replies: 1
Views: 343

Re: Acid or Base in a Reaction

Acids are compounds that give off H+. Bases are compounds that accept H+ ions. With that being said, if there is a high concentration of H+ ions that means that you have an acid (more specifically a strong acid). If there is little to no H+ concentration that means you have a base. The pH calculatio...
by 904642541
Thu Nov 19, 2015 10:55 pm
Forum: Naming
Topic: Naming Order
Replies: 2
Views: 419

Re: Naming Order

You place them in alphabetical order. Always name cation before anion.
by 904642541
Thu Nov 19, 2015 10:53 pm
Forum: Naming
Topic: Iron [ENDORSED]
Replies: 6
Views: 983

Re: Iron [ENDORSED]

As a cation it would be iron, as an anion it would be ferrate.
by 904642541
Fri Nov 13, 2015 6:18 pm
Forum: Naming
Topic: Tips for naming compounds
Replies: 1
Views: 399

Re: Tips for naming compounds

1. always name the cation before anion 2. name ligands in alphabetical order then metal atom/ion (metal atoms/ions are written before ligand in chemical formulas) get familiar with common ligands 3. greek prefixes used to designate the number for each type of ligand if ligand already has a greek pre...
by 904642541
Thu Nov 05, 2015 11:11 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: HOMO and LUMO significance
Replies: 1
Views: 802

Re: HOMO and LUMO significance

The HOMO-LUMO energy gap is significant in that it defines the color that the molecule emits/reflects. Moreover, it describes the type of photon that it absorbs in order to make a jump. Small gaps in long conjugated molecules explain why the compounds have a color. These gaps also describe reactivit...
by 904642541
Fri Oct 30, 2015 9:26 am
Forum: Hybridization
Topic: NaCL vs FRCL covalent
Replies: 1
Views: 421

Re: NaCL vs FRCL covalent

Electronegativity between the two atoms should be less than 0.4 to be considered a covalent bond. Fr has a smaller electronegativity compared to Na (the trend: the more electronegative atoms reside on the top right corner: increases from left to right and from down to up). Thus the smaller electrone...
by 904642541
Thu Oct 22, 2015 11:43 pm
Forum: Bond Lengths & Energies
Topic: Bond Order
Replies: 2
Views: 567

Re: Bond Order

Bond order means the number of chemical bonds between a pair of atoms.
by 904642541
Thu Oct 15, 2015 10:32 pm
Forum: Resonance Structures
Topic: What is or isn't a Resonance Structure?
Replies: 2
Views: 581

Re: What is or isn't a Resonance Structure?

They have the same molecular formula and moreover the same number of electrons. However, the connectivity of the molecules is different (the double bond can be switched between the oxygen atoms).
by 904642541
Thu Oct 08, 2015 11:31 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Subshell vs. Orbital
Replies: 1
Views: 607

Re: Subshell vs. Orbital

A shell can be described by using the quantum number "n", thus the same energy. (They have the same "n" value) Ex: n=2 is a shell A sub-shell can be described as having the same "n" and "l" quantum numbers, thus the same energy and shape. Ex: 2s is a sub-shell...
by 904642541
Thu Oct 01, 2015 10:36 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: How to obtain wavelength using the Rydberg formula
Replies: 3
Views: 774

Re: How to obtain wavelength using the Rydberg formula

Hello.
The Rydberg Equation allows you to solve for frequency with the given info, from there you plug in the frequency to the c=(frequency)*(wavelength) equation to solve for wavelength.

Hope this helps.
by 904642541
Thu Oct 01, 2015 10:25 pm
Forum: Balancing Chemical Reactions
Topic: Clarifying the State of the Reactants and Products
Replies: 4
Views: 782

Re: Clarifying the State of the Reactants and Products

Hello. Mentioning the states of matter in a chemical equation is helpful because some molecules such H2O can be presented as a gas (water vapor) rather than a liquid.

One example, the combustion of ethanol:
C2H5OH(l) + O2(g) > CO2(g) + H2O(g)

Hope this helps.

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