Search found 31 matches

by Alexandra Ortega 4D
Tue Dec 04, 2018 1:52 am
Forum: Lewis Acids & Bases
Topic: Identifying Acids and Bases
Replies: 5
Views: 164

Re: Identifying Acids and Bases

In a chemical equation in which acids and bases are reacting with water, you could identify an acid because their products tend to be either a hydronium ion or proton, while the products of bases are h usually hydroxide ions.
by Alexandra Ortega 4D
Tue Dec 04, 2018 1:36 am
Forum: Naming
Topic: Do we need to know en, edta?
Replies: 2
Views: 81

Re: Do we need to know en, edta?

I believe just knowing that en is bidentate and edta is hexadentate will suffice for the final.
by Alexandra Ortega 4D
Tue Dec 04, 2018 1:28 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Shape of Complex
Replies: 1
Views: 79

Shape of Complex

Complexes with coordination number 4 are either tetrahedral or square planar. How do we determine whether a coordination compound has a tetrahedral or square planar shape?
by Alexandra Ortega 4D
Tue Nov 27, 2018 11:15 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw Shape Bond Angles
Replies: 8
Views: 153

Re: Seesaw Shape Bond Angles

The lone pair pushes down on the other bonds which makes the angles slightly less than 90 and slightly less than 120.
by Alexandra Ortega 4D
Tue Nov 27, 2018 11:10 pm
Forum: Hybridization
Topic: Drawing Hybrid Orbitals
Replies: 3
Views: 109

Re: Drawing Hybrid Orbitals

I don't think we will need to draw hybrid orbitals, but I am not sure. If we do. You would just use the diagram for the valence electrons of the central atom and show that the orbitals can be hybridized, or mixed, with each other to form sp or spd hybrid orbitals.
by Alexandra Ortega 4D
Tue Nov 27, 2018 10:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 6th edition 4.5
Replies: 2
Views: 73

Re: 6th edition 4.5

It is only asking for the shape or molecular geometry, not the arrangement of electrons, so you would only need to say that it is angular or bent.
by Alexandra Ortega 4D
Tue Nov 27, 2018 10:37 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 6th edition 4.7 pt b
Replies: 1
Views: 78

Re: 6th edition 4.7 pt b

There are two OSCl bond angles, but they are both slightly less than 109.5. The question asks how many different bond angles there are, so you would say that angles are identical.
by Alexandra Ortega 4D
Tue Nov 20, 2018 8:15 pm
Forum: Hybridization
Topic: Test 3
Replies: 8
Views: 180

Re: Test 3

Test 3 will cover the end of bonding (3.12 (6 Ed.) and 2D (7 Ed.)) and will cover all of molecular shape and structure.
by Alexandra Ortega 4D
Tue Nov 20, 2018 8:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR
Replies: 5
Views: 139

Re: VSEPR

Yes,lone pairs affect the shape and name because they push down on the rest of the bonds. So, a molecule becomes bent when there are lone pairs on the central atom. However, if there were no lone pairs on the central atom, then the molecule would actually be linear.
by Alexandra Ortega 4D
Tue Nov 20, 2018 7:53 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR
Replies: 2
Views: 85

Re: VSEPR

I believe we will need to know the molecular shape for molecules with more than one central atom. We will probably have to know how to find the molecular shape of simple organic molecules, such as C2H4.
by Alexandra Ortega 4D
Sun Nov 18, 2018 9:03 pm
Forum: Hybridization
Topic: Hybridization
Replies: 2
Views: 66

Re: Hybridization

To add on, hybridization is when two atomic orbitals fuse to form newly hybridized orbitals, which influence molecular geometry and bonding properties. The concept suggest that s and p orbitals will be hybridized to match the bond angles of the attached groups. The number of hybrid orbitals must be ...
by Alexandra Ortega 4D
Sun Nov 18, 2018 8:55 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sigma/Pi bonds
Replies: 7
Views: 135

Re: Sigma/Pi bonds

Sigma bonds usually interact end to end and allow rotation of bonded atoms, while pi bonds overlap side by side and do not allow rotation of bound atoms. Single bonds consist of only one sigma bonds and double bonds consist of one sigma and one pi bond. So, the first bond between to atoms must be a ...
by Alexandra Ortega 4D
Sun Nov 18, 2018 8:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Angles Less Than a Certain Value
Replies: 4
Views: 104

Re: Angles Less Than a Certain Value

For molecules with bond angles less than 109.5, such as sulfite, we say that the lone pair exerts a stronger force on the other bonding angles and it pushes them down. For molecules with bond angles less than 109.5 that have bonds with different elements, such as CH3Cl, we say that since the bonds a...
by Alexandra Ortega 4D
Sun Nov 11, 2018 10:58 pm
Forum: Dipole Moments
Topic: How do you draw dipole moments
Replies: 6
Views: 125

Re: How do you draw dipole moments

We draw dipole moments by using an arrow pointing towards the most electronegative atom that has a line running through it on the other end.
by Alexandra Ortega 4D
Sun Nov 11, 2018 10:34 pm
Forum: Octet Exceptions
Topic: octet exceptions
Replies: 4
Views: 125

Re: octet exceptions

Elements in the 13th column do not form octets because they are simply more stable with less than 8 valence electrons, such as boron which only forms 3 bonds. Boron only has 3 valence electrons to begin with, so it does not have enough electrons to form more than 3 covalent bonds.
by Alexandra Ortega 4D
Sun Nov 11, 2018 10:19 pm
Forum: Resonance Structures
Topic: Drawing resonance
Replies: 17
Views: 619

Re: Drawing resonance

I believe we should draw all resonance structures for molecules to show our understanding that lewis structures can have multiple bonds on different equivalent locations and that the actual molecule is a blend or average of all resonance structures.
by Alexandra Ortega 4D
Sat Nov 03, 2018 2:18 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Ground state
Replies: 2
Views: 53

Re: Ground state

If the question is already giving you the ions, I believe you just need to put the electron configuration for them rather than the neutral atom.
by Alexandra Ortega 4D
Sat Nov 03, 2018 1:56 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Test #2 Question #2
Replies: 3
Views: 338

Re: Test #2 Question #2

To add on, you would need to multiply the given mass value of .160kg with your velocity once you have converted it into m/s. By multiplying them together, you will get your value for momentum, which you must multiply by 2x10^-6 to find the uncertainty in momentum. Once you have found this value, you...
by Alexandra Ortega 4D
Sat Nov 03, 2018 1:35 pm
Forum: *Particle in a Box
Topic: Midterm
Replies: 17
Views: 1133

Re: Midterm

I remember Lavelle mentioning that the midterm will have 8 questions, one of which will be a problem from homework. I am pretty sure that it will be free response. I was wondering how to find the midterm from last year on CCLE.
by Alexandra Ortega 4D
Sun Oct 28, 2018 7:12 pm
Forum: Ionic & Covalent Bonds
Topic: Exceptions
Replies: 4
Views: 138

Re: Exceptions

H, He, Li, and Be are exceptions to the octet rule because they only have electrons in the s orbital so the maximum amount of electrons they can have in their outer shell is 2. Therefore, they will never be able to have 8 valence electrons.
by Alexandra Ortega 4D
Sun Oct 28, 2018 7:03 pm
Forum: Ionic & Covalent Bonds
Topic: ionic vs. covalent bonds
Replies: 3
Views: 87

Re: ionic vs. covalent bonds

In chemistry, ionic bonds are considered to be stronger because of their coulombic attractions between ions. They involve the transfer of electrons, unlike covalent bonds which involve the sharing of electrons. However, as mentioned, in aqueous environments, ionic compounds dissociate into their res...
by Alexandra Ortega 4D
Tue Oct 23, 2018 11:55 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Chem Homework 1.45 Question Mistake?
Replies: 3
Views: 162

Re: Chem Homework 1.45 Question Mistake?

I believe the answer to the question may be a mistake, since the only way to get the answer from the solution manual is by using 5 instead of 10. Just keep in mind that you are supposed to double the +/- value when solving problems dealing with Heisenberg's Uncertainty Principle.
by Alexandra Ortega 4D
Sun Oct 21, 2018 7:09 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: What is a nodal plane?
Replies: 5
Views: 247

Re: What is a nodal plane?

A nodal plane is a plane where there is no probability of finding an electron. There is no electron density distribution in a nodal plane.
by Alexandra Ortega 4D
Sun Oct 21, 2018 6:49 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Labeling Electron Orbitals
Replies: 5
Views: 155

Re: Labeling Electron Orbitals

You can tell what shell an electron is in by the quantum numbers. So, remember n determines the shell or size, l determines the orbital(s, p, d, or f), ml determines orbitals of subshell or plane (x,y,z), and ms determines spin. The shells are given by the quantum numbers and I think we just have to...
by Alexandra Ortega 4D
Sun Oct 21, 2018 6:33 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Shape of Orbitals
Replies: 3
Views: 78

Re: Shape of Orbitals

The different shapes of orbitals are s(spherical shape with no nodal planes), p(2 lobes on either side of nucleus with a nodal plane at the nucleus), d(3 have lobes located on XY-YZ-ZX planes, 1 has lobes located on x & y planes, 1 has lobes located along z-axis & donut in XY plane), and f(w...
by Alexandra Ortega 4D
Sun Oct 14, 2018 7:27 pm
Forum: Properties of Electrons
Topic: Wave Length Calculations
Replies: 5
Views: 102

Re: Wave Length Calculations

Values smaller then 10^-18 are considered immeasurable because they would be too small to be detected by the technology we have nowadays. That is considered the defining line in our terms. However, that does not mean that wavelengths smaller than that do not exist. We just do not detect them. Only p...
by Alexandra Ortega 4D
Sun Oct 14, 2018 7:10 pm
Forum: Properties of Electrons
Topic: Energy Q
Replies: 4
Views: 77

Re: Energy Q

Energy is quantized because there are restrictions in the values that can be used to measure it.
For example, the energy levels of electrons are quantized so values for n can only be whole numbers, such as 1, 2, 3 etc.
by Alexandra Ortega 4D
Sun Oct 14, 2018 6:27 pm
Forum: Photoelectric Effect
Topic: Photoelectric effect
Replies: 5
Views: 122

Re: Photoelectric effect

Typically, ultraviolet radiation is used to perform the photoelectric experiments. UV light has shorter wavelengths than other electromagnetic radiation, like visible light, which is why it is used. The electromagnetic radiation being used in these experiments must have enough energy for one photon ...
by Alexandra Ortega 4D
Sun Oct 07, 2018 5:53 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molar Mass
Replies: 8
Views: 553

Re: Molar Mass

The mass of an atom is usually listed under their chemical symbol in their specific box on the periodic table. The value is usually given to two decimal places. If you need the molar mass of an entire compound, you will need to calculate it using the molar masses of each individual atom and finding ...
by Alexandra Ortega 4D
Sun Oct 07, 2018 5:48 pm
Forum: Significant Figures
Topic: knowing how many sig figs to use
Replies: 17
Views: 696

Re: knowing how many sig figs to use

The number of sig figs that you should have in your answer is usually the number of sig figs given in the numerical values in the problem you are solving, unless it otherwise specified. If you are given 140. kg then your final answer should also have 3 sig figs. In addition, you should not round to ...
by Alexandra Ortega 4D
Sun Oct 07, 2018 5:42 pm
Forum: Significant Figures
Topic: Decimal point
Replies: 14
Views: 282

Re: Decimal point

The reason 120 has 2 significant figures while 120. has 3 is that the decimal tells you that any zeros before and after it are considered significant. So, 120 has 2 sig figs, while 120. has 3 sig figs and 120.0 has 4 sig figs. The zeros after nonzero numbers are only significant if there is a decima...

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