Search found 16 matches

by Laura Picazo 1L
Fri Mar 11, 2016 2:56 pm
Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
Topic: Drawing arrows
Replies: 1
Views: 295

Re: Drawing arrows

Half arrows are used when one electron is moving from the source to the end. The arrow indicates electron flow, so you would draw the arrow starting from the electron rich source to the electron deficient end. Therefore, the arrow indicates where the electrons are going.
by Laura Picazo 1L
Sun Mar 06, 2016 7:53 pm
Forum: *Alkanes
Topic: Atomic number and organic molecule
Replies: 2
Views: 339

Re: Atomic number and organic molecule

The use of atomic numbers is to determine the priority of the groups bonded to sp2 carbons which would then indicate if the molecule is trans (E) or cis (Z).
by Laura Picazo 1L
Sat Feb 27, 2016 4:23 pm
Forum: *Alkanes
Topic: Numbering
Replies: 1
Views: 226

Re: Numbering

That is correct. You want to use the lowest number possible, and not necessarily the sum. Sometimes, the nonexistent "sum rule" does work out, like in the case you have described.
by Laura Picazo 1L
Fri Feb 19, 2016 11:51 am
Forum: General Science Questions
Topic: sig figs if problem uses ln
Replies: 2
Views: 987

Re: sig figs if problem uses ln

The natural log of a number should have the same number of decimal places as there are sig figs in the original number.
by Laura Picazo 1L
Sat Feb 13, 2016 7:25 pm
Forum: General Rate Laws
Topic: Catalyst versus Reaction Intermediate
Replies: 1
Views: 348

Re: Catalyst versus Reaction Intermediate

I don't think it is correct to say that a catalyst is the opposite of a reaction intermediate. A catalyst is a substance that increases the rate of reaction by lowering the activation energy. It is not a part of the reaction, meaning it is neither a product or reactant. Therefore, a catalyst is not ...
by Laura Picazo 1L
Sat Feb 06, 2016 2:09 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Notation of cell diagrams
Replies: 1
Views: 316

Re: Notation of cell diagrams

You use a vertical line to separate the electrode from the aqueous or gas species, and you use a comma to list the species of the same phase.
by Laura Picazo 1L
Fri Jan 29, 2016 6:33 pm
Forum: Calculating Work of Expansion
Topic: Types of Systems
Replies: 3
Views: 672

Re: Types of Systems

During the process of reversible expansion, the pressure from both sides of the system, external and internal, are equal. However, an irreversible expansion demonstrates a difference in external and internal pressures.
by Laura Picazo 1L
Fri Jan 22, 2016 5:22 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: liquid and gas phases coexisting?
Replies: 2
Views: 370

Re: liquid and gas phases coexisting?

Liquid and gas coexist within a range of temperatures during phase transition, meaning that both liquid and gas are present until it reaches a certain temperature.
by Laura Picazo 1L
Sat Jan 16, 2016 2:09 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: q=Csp(delta T)
Replies: 1
Views: 818

Re: q=Csp(delta T)

You use q=cΔT when you calculate the heat energy lost or gained using a calorimeter. The c in this equation is the heat capacity of the calorimeter. You use q=mcΔT to calculate the heat energy lost or gained in open air. The c in this equation is the specific heat of the substance you are heating. I...
by Laura Picazo 1L
Fri Jan 08, 2016 4:57 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: How do you know if something is in its standard state?
Replies: 2
Views: 6096

Re: How do you know if something is in its standard state?

A standard state of a substance is its phase at 1 atm and 25°C. Most reactions are given in their standard state. Regarding elements, liquid is the standard state for mercury and bromine, gas is the standard state for noble gases, halogen, flourine, chlorine, hydrogen, oxygen, and nitrogen, and all ...
by Laura Picazo 1L
Wed Nov 25, 2015 2:30 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: MO Theory Video
Replies: 2
Views: 464

MO Theory Video

We have prepared a review of the molecular orbital theory, including a diagram, bond order, diamagnetism or paramagnetism, and LUMO and HOMO.
by Laura Picazo 1L
Sun Nov 08, 2015 8:08 pm
Forum: Lewis Structures
Topic: Unpaired Electrons
Replies: 1
Views: 377

Unpaired Electrons

Why does the unpaired electron in the lewis structure of NO2 go to N and not O?
by Laura Picazo 1L
Fri Oct 30, 2015 9:44 am
Forum: Hybridization
Topic: Hybridization
Replies: 2
Views: 503

Re: Hybridization

Sigma bonds are formed from end to end overlap, while pi bonds are formed from side to side overlap of p orbitals.
by Laura Picazo 1L
Fri Oct 30, 2015 9:24 am
Forum: Lewis Structures
Topic: exceptions to octets
Replies: 2
Views: 451

Re: exceptions to octets

Another one to remember is chlorine. It can hold more than 8 valence electrons.
by Laura Picazo 1L
Fri Oct 23, 2015 10:14 am
Forum: Hybridization
Topic: Energy Levels and Orbitals
Replies: 2
Views: 439

Re: Energy Levels and Orbitals

Different energy levels represent the distance of electrons from the nucleus. Larger numbers of the energy level mean that it is further away from the nucleus. Orbitals, however, are the space within the energy levels where the electrons are located. The orbitals come in different shapes (s, p, d, f)
by Laura Picazo 1L
Sun Oct 04, 2015 10:28 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: How to approach this problem?
Replies: 1
Views: 468

Re: How to approach this problem?

This problem is asking you to find the sulfide of M. M is an unknown metal so you have to start by finding out what that is. You can do so by subtracting the mass of the oxygen and hydrogen from the molar mass. 74.10 g/mol - (2 x 15.999 + 2 x 1.008) = 40.086 The closest element with that mass is cal...

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