Search found 37 matches

by ALegala_3I
Wed Nov 13, 2019 11:39 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: intermolecular forces
Replies: 8
Views: 21

Re: intermolecular forces

Dipoles occur when there is an unequal sharing of electrons. Each atom in a molecule has a partial charge which is either negative or positive. When one charge is significantly larger than another, or the electronegativity difference is great, a dipole is produced. Lone pairs on the central atom als...
by ALegala_3I
Wed Nov 13, 2019 9:08 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: London Forces and Dipole-Dipole
Replies: 5
Views: 19

Re: London Forces and Dipole-Dipole

London Dispersion forces act on all molecules and atoms. This includes nonpolar molecules, monoatomic gases, and in molecules that also exhibit dipole-dipole interactions.
by ALegala_3I
Tue Nov 12, 2019 9:01 am
Forum: Dipole Moments
Topic: 3f.15
Replies: 3
Views: 24

Re: 3f.15

According to the problem, the boiling point of AsF3 is 68C and AsF5 is -53. You can first approach this problem by drawing the Lewis structures for both molecules to find out the intermolecular forces that each molecule has. AsF3 has a lewis structure in which a lone pair on the Arsenic atom. This m...
by ALegala_3I
Tue Nov 12, 2019 8:51 am
Forum: Dipole Moments
Topic: 3F.11
Replies: 3
Views: 16

Re: 3F.11

Hydrogen bonds form when hydrogen interacts with nitrogen, oxygen, or fluorine. In this problem, only d can create hydrogen bonds because it has nitrogen and oxygen.
by ALegala_3I
Mon Nov 11, 2019 11:31 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Induced Dipole/ Induced Dipole
Replies: 4
Views: 13

Re: Induced Dipole/ Induced Dipole

London Dispersion forces are known as induced-dipole–induced-dipole interaction. Interactions that are proportional to 1/r6 are commonly regarded as van der Waals interactions. So London Dispersion forces are a type of van der Waals interaction.
by ALegala_3I
Wed Nov 06, 2019 8:15 am
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 2
Views: 26

Re: Formal Charge

Electronegativity is the electron pulling power of an atom. The atoms that are more electronegative will want the electron more in real life. The negative formal charge indicates an excess of an electron. Since more electronegative atoms will have a greater power to pull this electron, they will gen...
by ALegala_3I
Tue Nov 05, 2019 9:12 am
Forum: Lewis Structures
Topic: 2C.9
Replies: 1
Views: 6

Re: 2C.9

Sulfur is one of the exceptions that Dr. Lavelle mentioned in terms of being able to have an expanded octet. It can bond to 6 atoms and have an expanded octet with 12 electrons.
by ALegala_3I
Tue Nov 05, 2019 9:08 am
Forum: Bond Lengths & Energies
Topic: 2D.9
Replies: 1
Views: 13

Re: 2D.9

The Question for 2.D.9: Arrange the cations Rb+1, Be+2, and Sr+2 in order of increasing polarizing power. Explain your reasoning. The cations with the smallest radius and largest charge have the greatest polarizing power. Of the three, beryllium has the smallest radius, so it would have the greatest...
by ALegala_3I
Mon Nov 04, 2019 9:04 am
Forum: Electronegativity
Topic: Trend of Electronegativity
Replies: 22
Views: 72

Re: Trend of Electronegativity

Electronegativity is the electron pulling power of an atom. As you move to the right of the periodic table, the electronegativity increases because atoms get closer and closer to having a full octet. As you move up the periodic table, electronegativity also increases because there is less shielding ...
by ALegala_3I
Mon Nov 04, 2019 9:00 am
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Trends
Replies: 3
Views: 30

Re: Trends

Cations with a smaller radius and a more positive charge have greater polarizing power. For example, K+ > K in polarizing power. Anions with a larger radius and a more negative charge have greater polarizability because they have more electrons. So I->Br-, in polarizability.
by ALegala_3I
Wed Oct 30, 2019 7:39 pm
Forum: Resonance Structures
Topic: Determining the Pairing for Lewis Structures
Replies: 2
Views: 15

Determining the Pairing for Lewis Structures

How do we know when the hydrogen will be attached to the central atom vs other atoms? Like in the case of HClO2, why is the hydrogen attached to the oxygen and not the chlorine? https://img1.daumcdn.net/thumb/R720x0.q80/?scode=mtistory2&fname=http%3A%2F%2Fcfile7.uf.tistory.com%2Fimage%2F999FF54C...
by ALegala_3I
Wed Oct 30, 2019 7:34 pm
Forum: Lewis Structures
Topic: Radicals
Replies: 2
Views: 17

Re: Radicals

Radicals are fairly uncommon because they are highly unstable and reactive. They will generally only stay in that form for a short period of time before interacting with other molecules to get a pair.
by ALegala_3I
Tue Oct 29, 2019 2:03 pm
Forum: Ionic & Covalent Bonds
Topic: Octet Rule
Replies: 8
Views: 40

Re: Octet Rule

Professor Lavelle said that phosphorus, sulfur, and chlorine can have expanded octets. This is due to the fact that they have empty p orbitals which can accommodate additional electrons.
by ALegala_3I
Tue Oct 29, 2019 2:00 pm
Forum: Ionic & Covalent Bonds
Topic: Homework 2A.21
Replies: 1
Views: 16

Re: Homework 2A.21

Ag is one of the exceptions to the build up principle. It would normally have a configuration of [Kr]4d10 5s1 because the atom would be most stable when the d shell is completely full rather than the s shell. When you remove an electron from Ag, it will be removed from the outermost shell which is 5...
by ALegala_3I
Mon Oct 28, 2019 7:32 pm
Forum: Lewis Structures
Topic: Homework problem 2C.3
Replies: 5
Views: 37

Re: Homework problem 2C.3

As of right now, I believe that we do not need to memorize the molecular formula for these molecules since we did not cover it in class. On a test, I think it would be given to us and we would just have to draw the lewis structure.
by ALegala_3I
Mon Oct 28, 2019 7:29 pm
Forum: Ionic & Covalent Bonds
Topic: ionic bonding 2A.13
Replies: 1
Views: 19

Re: ionic bonding 2A.13

Chlorine has the ground state electron configuration of [Ne]3s1 3p5. An electron is always removed from the outermost subshell present. In this case, the outermost subshell is 3p.
by ALegala_3I
Wed Oct 23, 2019 9:02 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 1D.23
Replies: 2
Views: 28

Re: 1D.23

For b and d, you would go off of the ml number. In a 4p atom in which l=1, there are 3 possibly orbitals orientations as stated above. This means that an electron in the 4p orbital could have the following configurations: n=4, l=1, ml = 1; n=4, l=1, ml = 0, and n=4, l=1, ml = -1. When you are given ...
by ALegala_3I
Tue Oct 22, 2019 8:23 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Aufbau principle
Replies: 2
Views: 14

Re: Aufbau principle

Aufbau principle is just rules for how electrons fill atomic orbitals. It states that electrons will always fill the lowest energy state first. For example, an electron will be in the 1s orbital before the 2s orbital. It also states that electrons will be added to different orbitals with parallel sp...
by ALegala_3I
Tue Oct 22, 2019 8:47 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configurations for electrons in the D subshell
Replies: 5
Views: 33

Re: Electron Configurations for electrons in the D subshell

This filling of the d orbital over the s orbital will also occur for elements such as chromium. Instead of being [Ar]3d44s2, the electron configuration will be [Ar]3d54s1.
by ALegala_3I
Mon Oct 21, 2019 8:53 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Exceptions in Electron Configurations
Replies: 5
Views: 32

Re: Exceptions in Electron Configurations

Do all the elements in group 6 and 11 have electron configurations similar to copper and chromium?
by ALegala_3I
Mon Oct 21, 2019 8:48 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: terminology - "orbitals", "shells", "subshells"
Replies: 2
Views: 20

Re: terminology - "orbitals", "shells", "subshells"

The principal quantum number (n) specifies the shell of the electrons in an atom. For example, 4p corresponds to 4 shells of electrons in the atom. The angular momentum number (l) signifies the sub-shells. The magnetic quantum number describes the amount of orbitals in a sub shell. There are 3 orbit...
by ALegala_3I
Wed Oct 16, 2019 7:50 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Which equation to use for determining uncertainty?
Replies: 4
Views: 17

Which equation to use for determining uncertainty?

Hi, In the textbook, a modified equation for the uncertainty principle is used with the variable h bar (see below). What does this variable signify? Which equation should we use: the one from the textbook or the one that is taught in class? https://scitechdaily.com/images/heisenberg-uncertainty-prin...
by ALegala_3I
Tue Oct 15, 2019 7:58 am
Forum: DeBroglie Equation
Topic: de Broglie vs Heisenberg
Replies: 2
Views: 19

Re: de Broglie vs Heisenberg

To add on, the Heisenberg equation is specifically used in regards to uncertainty. The questions will usually ask you what the uncertainty in the velocity is or it will give you a range of values for velocity. This is your main indicator to use the Heisenberg equation over the deBroglie equation.
by ALegala_3I
Mon Oct 14, 2019 8:19 pm
Forum: DeBroglie Equation
Topic: DeBroglie
Replies: 3
Views: 18

Re: DeBroglie

DeBroglie's proposed that all particles should be considered to have wave like properties. So he devised the equation: wavelength(lambda) = Planck's constant(h)/ momentum(p). In this equation, we are treating light like a wave and finding the wavelength based on the mass and velocity of the particle.
by ALegala_3I
Mon Oct 14, 2019 8:16 am
Forum: Einstein Equation
Topic: Einstein Equation
Replies: 4
Views: 31

Re: Einstein Equation

You use the equation E=hv when you are trying to find out the energy of a photon of light. If you know the frequency of this photon, then you can multiply it by Planck's constant to find the total energy of the photon.
by ALegala_3I
Mon Oct 14, 2019 8:13 am
Forum: Properties of Light
Topic: Memorizing Values for Tests
Replies: 3
Views: 9

Re: Memorizing Values for Tests

The values of c (speed), Planck's constant, and Rydberg's constant are on the formula sheet, which will be given to you for every exam.
by ALegala_3I
Wed Oct 09, 2019 2:13 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Light energy
Replies: 3
Views: 34

Re: Light energy

I think it will be helpful to know which types of light have the largest wavelengths and the shortest. For example, radio waves have the greatest wavelength while gamma rays of the shortest. It will essentially be beneficial to know the order. https://www.radio2space.com/wp-content/uploads/2013/07/c...
by ALegala_3I
Wed Oct 09, 2019 9:22 am
Forum: Empirical & Molecular Formulas
Topic: Molecular formula
Replies: 6
Views: 79

Re: Molecular formula

To clarify, when you divide by the least number of moles. The answer you are getting is a molar ratio of atoms in the molecule. This is relative to the other atoms in the molecule. We want this ratio to be a whole number because we can only have a whole number of atoms. To find the molecular formula...
by ALegala_3I
Tue Oct 08, 2019 11:11 am
Forum: Properties of Light
Topic: Light intensity
Replies: 6
Views: 40

Re: Light intensity

In terms of wave properties, higher intensity means a greater wave amplitude and therefore a greater amount of energy. In the photoelectric experiment, it was found that increasing the intensity of light did not increase the energy of light. So this experiment supported the idea that light did not h...
by ALegala_3I
Mon Oct 07, 2019 11:08 am
Forum: SI Units, Unit Conversions
Topic: Angstrom(Å)
Replies: 4
Views: 25

Re: Angstrom(Å)

An angstrom is not a SI unit. It is used and recognized by many scientists but it is not part of the International System. An angstrom represents 10^-10m. This can be converted to other SI units like nanometers or picometers.
by ALegala_3I
Mon Oct 07, 2019 11:05 am
Forum: SI Units, Unit Conversions
Topic: Molar Ratio
Replies: 4
Views: 33

Re: Molar Ratio

To clarify the statement above, a molar ratio refers to BOTH the stoichemetric coefficients in a chemical equation and the moles of atoms in a molecule. For example, the chemical equation C2H4 + 3O2 → 2CO2 + 2H2O. There is a molar ratio of 2 water molecules to 2 carbon dioxide molecules. Within the ...
by ALegala_3I
Wed Oct 02, 2019 9:28 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Tips on how to write a formula out from the name
Replies: 9
Views: 106

Re: Tips on how to write a formula out from the name

There are several polyatomic ions which are good to memorize. There is a list of nomenclature in the beginning of the book which can be useful for future problems.
by ALegala_3I
Tue Oct 01, 2019 11:49 am
Forum: Balancing Chemical Reactions
Topic: Tips for Balancing Chemical Equations [ENDORSED]
Replies: 14
Views: 126

Re: Tips for Balancing Chemical Reactions [ENDORSED]

I would first write down the number of atoms of each element that is present for the reactant side and the product side. I would then begin to balance my equation and typically leave hydrogen and oxygen for the end. As I balance, I would readjust the initial numbers that were written at the beginnin...
by ALegala_3I
Mon Sep 30, 2019 7:53 pm
Forum: Significant Figures
Topic: How to Write Out Final Answers
Replies: 5
Views: 42

Re: How to Write Out Final Answers

Both 9.87 mL and 9.87 x 10^-3 L have the same value. Regardless of how it is written, the amount that would be measured for the actual experiment would be the same. If the question asks you for the volume in a specific measurement then you would have to choose one or the other.
by ALegala_3I
Sun Sep 29, 2019 2:33 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical Formula
Replies: 6
Views: 48

Re: Empirical Formula

While the empirical and molecular formulas can be different, there are situations in which the two formulas are the same. This can be determined by dividing the molar mass of the molecular formula by the molar mass of the empirical formula. If the ratio is 1, the empirical and molecular formulas for...
by ALegala_3I
Sun Sep 29, 2019 8:42 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: MOLARITY
Replies: 17
Views: 626

Re: MOLARITY

Does anyone know the difference between molarity and molality? Molarity is moles of solute per liter of solution(mol/L). Molality is the moles of solute per kilogram of solvent (mol/kg). While both have the same values in the numerator, they differ in the denominator. For the denominator of molarit...
by ALegala_3I
Sat Sep 28, 2019 12:31 pm
Forum: SI Units, Unit Conversions
Topic: Formula units vs molecules vs atoms? [ENDORSED]
Replies: 7
Views: 110

Re: Formula units vs molecules vs atoms? [ENDORSED]

I am still confused on the concept of formula units. How many formula units would be in 46g of NaCl?

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