Search found 33 matches

by cristinapadilla_1E
Mon Dec 03, 2018 12:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AX3E
Replies: 18
Views: 274

Re: AX3E

In order to really break this down to know that it is trigonal pyramidal, you must understand the notation used in VSEPR Model. A is the central atom X is the number of bonded atoms E is the number of lone pairs One example of a trigonal pyramidal shaped molecule is NH3. N is the central atom, there...
by cristinapadilla_1E
Mon Dec 03, 2018 12:32 pm
Forum: Amphoteric Compounds
Topic: Examples
Replies: 6
Views: 104

Re: Examples

Some amphoteric examples we discussed in lecture are:
BeO, Al2O3, Ga2O3, SnO2, Sb2O5, and PbO2
by cristinapadilla_1E
Mon Dec 03, 2018 12:31 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted Acids/Bases Vs. Arrhenius Acids/Bases
Replies: 1
Views: 37

Bronsted Acids/Bases Vs. Arrhenius Acids/Bases

In the fundamentals J portion of the 7th edition textbook it talks about Arrhenius Acids/Bases. I don't recall learning about those types during lecture. Does anybody know if we need to know this for the final exam and what are some key distinguishers between Arrhenius and Bronsted acids/bases? Than...
by cristinapadilla_1E
Sat Dec 01, 2018 3:26 pm
Forum: Naming
Topic: Naming
Replies: 3
Views: 69

Re: Naming

Memorizing common polyatomic ion formulas as well as their chargers will only benefit you for the exam!
by cristinapadilla_1E
Sat Dec 01, 2018 3:25 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar Molecules
Replies: 12
Views: 170

Re: Polar Molecules

Although looking at a molecule simply to determine whether or not it is polar or nonpolar, it is more accurate to use VESPR theory in order to deduce whether it is or not forsure.
by cristinapadilla_1E
Sat Dec 01, 2018 3:23 pm
Forum: Lewis Acids & Bases
Topic: lewis acid and bases
Replies: 3
Views: 78

Re: lewis acid and bases

The structures does affect whether or not it is an acid or a base. The resonance of a molecule is what affects it due to the ranging kPa value.
by cristinapadilla_1E
Wed Nov 28, 2018 4:45 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Transition Metals and their binding
Replies: 1
Views: 65

Transition Metals and their binding

During the lecture, it was stated how transition metals are often bound to cage-like molecules. Are there any other examples other than the porphyrin ligand one we went over in class? I am having trouble visualizing it.
by cristinapadilla_1E
Tue Nov 27, 2018 2:50 pm
Forum: Hybridization
Topic: s-character
Replies: 6
Views: 384

Re: s-character

To add on to what s-character is and how to determine how much s-character is present, triple bonds have more s-character than single bonds. The more s-character, the shorter and tighter the bond is.
by cristinapadilla_1E
Fri Nov 16, 2018 8:55 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond strength
Replies: 2
Views: 49

Bond strength

What is the reasoning and how can we deduce why bond strength goes in this order:

lone-lone pair > lone-bonding pair > bonding-bonding pair
by cristinapadilla_1E
Fri Nov 16, 2018 8:54 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Sulfite Ion and its Bond Angle
Replies: 3
Views: 49

Sulfite Ion and its Bond Angle

In class we discussed the sulfite ion SO3 2-. I still don’t understand why the bond angle would be 106 rather than 109.5. Can someone explain?
by cristinapadilla_1E
Fri Nov 16, 2018 8:52 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Linear Shape of O2
Replies: 4
Views: 81

Linear Shape of O2

I thought that linear shaped molecules can’t have dipole moments. How is O2 an exception to this?
by cristinapadilla_1E
Fri Nov 09, 2018 12:35 pm
Forum: Dipole Moments
Topic: Bond Lengths
Replies: 3
Views: 82

Re: Bond Lengths

Bond lengths are given and in Angstrom units.
by cristinapadilla_1E
Fri Nov 09, 2018 12:34 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape
Replies: 2
Views: 56

Re: Molecular Shape

We started the molecular shape and structure topic and covered VSESPR models and a few shapes.
by cristinapadilla_1E
Fri Nov 09, 2018 12:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Different Shapes
Replies: 4
Views: 83

Re: Different Shapes

In class we covered three important shapes so far. They are linear (180 degrees w/ 2 bonding pairs), trigonal planar (120 degrees w/ 3 bonding pairs), and tetrahedral (109.5 degrees w/ 4 bonding pairs).
by cristinapadilla_1E
Fri Nov 09, 2018 12:29 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Trigonal Planar
Replies: 8
Views: 112

Re: Trigonal Planar

All molecule structures are 3D!
by cristinapadilla_1E
Thu Nov 01, 2018 2:53 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molar Mass
Replies: 8
Views: 457

Re: Molar Mass

The units for molar mass are grams per mol.
by cristinapadilla_1E
Thu Nov 01, 2018 2:36 pm
Forum: Trends in The Periodic Table
Topic: Trends in first ionization energies
Replies: 3
Views: 69

Trends in first ionization energies

What are the trends in first ionization energies throughout the periodic table?
by cristinapadilla_1E
Thu Nov 01, 2018 2:33 pm
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 14
Views: 301

Re: Drawing Lewis Structures

When drawing Lewis structures, follow this format: 1) Count the number of valence electrons for each atom. 2) Count atom with lowest ionization energy as the central atom (H is never the central atom). 3) Arrange atoms symmetrically around central atom. 4) Calculate the formal charges so that they a...
by cristinapadilla_1E
Fri Oct 26, 2018 11:10 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Isoelectronic Molecules
Replies: 2
Views: 60

Isoelectronic Molecules

I know we went over one example in lecture that displayed isoelectronic molecules. Can someone give another series of examples?
by cristinapadilla_1E
Fri Oct 26, 2018 11:06 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Covalent Radius
Replies: 2
Views: 69

Re: Covalent Radius

Covalent radius is just the radius of two atoms (nonmetals) that are joined by covalent bonds.
by cristinapadilla_1E
Fri Oct 26, 2018 11:02 am
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 8
Views: 132

Re: Electron Affinity

In terms of electron affinity, there are patterns that you must recognize and memorize. As you go across a period, electron affinity increases. As you go down a group, electron affinity decreases.
by cristinapadilla_1E
Wed Oct 17, 2018 12:43 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Atomic Radius
Replies: 3
Views: 40

Re: Atomic Radius

Covalent radius only pertains to atoms present in a covalent bond whereas atomic radius can be of any atom.
by cristinapadilla_1E
Wed Oct 17, 2018 12:35 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Difference in orbitals
Replies: 3
Views: 71

Re: Difference in orbitals

F-orbitals have more complicated shapes, meaning that there are more lobes. Having more lobes means that there is a more complicated shape in regards to displaying itself on a plane.
by cristinapadilla_1E
Wed Oct 17, 2018 12:16 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbital Notations
Replies: 3
Views: 51

Orbital Notations

We brushed upon this in class, but I just want to clarify.. Why are the subscripts in the d-orbitals squared? Is it because there are four lobes? For example One of the orbitals has an electron density distribution located along the x and y axis: d (subscript x^2 -y^2)
by cristinapadilla_1E
Thu Oct 11, 2018 5:58 pm
Forum: Administrative Questions and Class Announcements
Topic: chem test tmrw
Replies: 6
Views: 190

Re: chem test tmrw

There is a page of formulas and a periodic table on the front of the test!
by cristinapadilla_1E
Thu Oct 11, 2018 5:57 pm
Forum: Properties of Light
Topic: Unit conversion in 1B.5
Replies: 1
Views: 26

Re: Unit conversion in 1B.5

Ev (energy volts) =1.6 X 10^-19 J
by cristinapadilla_1E
Thu Oct 11, 2018 5:54 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect
Replies: 3
Views: 56

Re: Photoelectric Effect

They descend one level at a time since each level is discrete and not continuous.
by cristinapadilla_1E
Thu Oct 11, 2018 5:44 pm
Forum: Photoelectric Effect
Topic: Work function
Replies: 7
Views: 136

Re: Work function

Work function, also known threshold energy, is the minimum energy required to release an electron.
by cristinapadilla_1E
Wed Oct 10, 2018 2:28 pm
Forum: Significant Figures
Topic: Calculators
Replies: 16
Views: 491

Re: Calculators

Based off of experience from taking the quiz today, calculators are not provided. They sell cheap ones at the bookstore!
by cristinapadilla_1E
Thu Oct 04, 2018 8:33 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Molecular weight vs molar mass
Replies: 3
Views: 80

Re: Molecular weight vs molar mass

Molecular weight is the gravitational pull whereas mass is the quantity of matter.
by cristinapadilla_1E
Thu Oct 04, 2018 8:28 pm
Forum: Significant Figures
Topic: Limiting Reactants
Replies: 6
Views: 91

Re: Limiting Reactants

Limiting reactant is the reactant with the least amount of mol produced.
by cristinapadilla_1E
Thu Oct 04, 2018 8:26 pm
Forum: Molarity, Solutions, Dilutions
Topic: Finding the Molar Mass of a metal
Replies: 2
Views: 45

Re: Finding the Molar Mass of a metal

Also, to understand why it is calcium sulfide is because the subscript on OH is 2. By noticing the subscript you can deduce that the metal must be from the second group due to its charge.
by cristinapadilla_1E
Wed Oct 03, 2018 2:06 pm
Forum: Balancing Chemical Reactions
Topic: Combustion Reactions.
Replies: 8
Views: 232

Re: Combustion Reactions.

O2 will always be one of the reactants and the products will always be H2O and CO2.

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