Search found 30 matches

by AshleyLamba1H
Sun Jun 10, 2018 12:21 am
Forum: Lewis Structures
Topic: Drawing Lewis Structures on the Final Exam
Replies: 5
Views: 238

Re: Drawing Lewis Structures on the Final Exam

I'm pretty sure that when you state the bond angles for structures that have lone pairs (which decrease bond angle size), you can just say that the bond angles are "less than [blank] degrees." For example, for the molecule SnCl2, the VSEPR structure is AX2E, and the bond angle is <120 degr...
by AshleyLamba1H
Sun Jun 10, 2018 12:09 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Drawing Tetrahedral Structures
Replies: 4
Views: 135

Re: Drawing Tetrahedral Structures

Drawing black triangles and dashed triangles is helpful to fully grasp the shape of the structure. I don't believe we have to draw VSEPR models though. ^
by AshleyLamba1H
Sun Jun 10, 2018 12:06 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Shape of AX5E
Replies: 5
Views: 306

Re: Shape of AX5E

I believe it is still a square pyramidal, however the bond angles would be slightly less than 90 degrees.
by AshleyLamba1H
Sun Jun 03, 2018 7:24 pm
Forum: Hybridization
Topic: Amplitude and Hybridization
Replies: 2
Views: 99

Re: Amplitude and Hybridization

You might find this video about hybridization helpful! https://www.khanacademy.org/science/org ... elocalized
by AshleyLamba1H
Sun Jun 03, 2018 6:54 pm
Forum: Hybridization
Topic: strength of sigma and pi bonds
Replies: 10
Views: 392

Re: strength of sigma and pi bonds

Pi bonds have a sideways overlap while sigma bonds have an axial overlap. Axial overlaps have a higher amount of overlapping than sideways overlaps do.
by AshleyLamba1H
Sun Jun 03, 2018 6:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: "-dral" Vs "-dron"
Replies: 2
Views: 89

Re: "-dral" Vs "-dron"

There is no difference between the two, you can use them interchangeably.
by AshleyLamba1H
Sun May 27, 2018 10:59 pm
Forum: Dipole Moments
Topic: Non-polar and dipoles
Replies: 3
Views: 141

Re: Non-polar and dipoles

Non polar molecules can have dipoles if they are symmetrical. For example, CO2 has a linear shape. The dipoles on each end of the molecule point towards the center atom (C), thus canceling each other out and making the molecule non polar. You can refer to pages 117-119 in the textbook for assistance.
by AshleyLamba1H
Sun May 27, 2018 10:55 pm
Forum: Dipole Moments
Topic: dipole moments and polarization
Replies: 3
Views: 113

Re: dipole moments and polarization

Water has the VSEPR type AX4, which is tetrahedral. However, two of these ends are lone pairs, which leaves the two hydrogens connected to oxygen in a bent shape. This is why water is a polar molecule. CH4 on the other hand is non polar; although its shape is also tetrahedral, the central atom has n...
by AshleyLamba1H
Sun May 27, 2018 10:34 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Any Other Shapes?
Replies: 7
Views: 336

Re: Any Other Shapes?

I am fairly certain that we covered every shape listed in the textbook. You can refer to Figure 4.7 on page 118 in the textbook for a table of all the shapes.
by AshleyLamba1H
Sat May 19, 2018 11:51 pm
Forum: Dipole Moments
Topic: Positive and Negative Dipole [ENDORSED]
Replies: 2
Views: 116

Re: Positive and Negative Dipole [ENDORSED]

If you need additional assistance with positive and negative dipoles, I found this video helpful: https://www.khanacademy.org/science/che ... ole-moment
by AshleyLamba1H
Sat May 19, 2018 11:45 pm
Forum: Lewis Structures
Topic: HW 3.39
Replies: 3
Views: 152

Re: HW 3.39

To answer your first question, the chem mods have said on other posts that you do not need to know how to find the molecular formula when given the name of a molecule. On exams, the molecular formula will be given.
by AshleyLamba1H
Sat May 19, 2018 11:28 pm
Forum: Bond Lengths & Energies
Topic: calculating bond length
Replies: 3
Views: 147

Re: calculating bond length

I don't believe we need to know how to calculate bond length, I think the important thing to remember is that single bonds are the longest and weakest, while triple bonds are the shortest and strongest.
by AshleyLamba1H
Sun May 13, 2018 10:01 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Calculating formal charges
Replies: 5
Views: 196

Re: Calculating formal charges

I found this video about formal charges on Khan Academy very helpful: https://www.khanacademy.org/science/che ... structures
by AshleyLamba1H
Sun May 13, 2018 9:53 pm
Forum: Lewis Structures
Topic: Benzine
Replies: 3
Views: 130

Re: Benzine

I was wondering the same thing. If we have to draw the full ring structure, do we need to write down every resonance structure as well?
by AshleyLamba1H
Sun May 13, 2018 9:51 pm
Forum: Sigma & Pi Bonds
Topic: Sigma Bonds
Replies: 5
Views: 236

Re: Sigma Bonds

An orbital can be thought of as a cloud of space that holds up to two electrons. A covalent bond results from the overlap between these orbitals.
by AshleyLamba1H
Sun May 06, 2018 5:26 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: What Exactly IS an Orbital?
Replies: 2
Views: 115

Re: What Exactly IS an Orbital?

Here is a Khan Academy video about orbitals that I found helpful: https://www.khanacademy.org/science/che ... v/orbitals
by AshleyLamba1H
Sun May 06, 2018 5:22 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: half full?
Replies: 5
Views: 150

Re: half full?

An atom is half full when one electron is in each orbital. An atom is completely full when there are two electrons in each orbital. Remember that electrons fill all the empty orbitals first before pairing with electrons in them.
by AshleyLamba1H
Sun May 06, 2018 5:10 pm
Forum: Trends in The Periodic Table
Topic: 2.67 part C (electron affinity)
Replies: 3
Views: 93

Re: 2.67 part C (electron affinity)

I am confused about this too, does anyone know which page in the textbook electron affinity is addressed? I can't seem to find it
by AshleyLamba1H
Sun Apr 29, 2018 12:56 am
Forum: Einstein Equation
Topic: Difference Between Equations
Replies: 4
Views: 210

Re: Difference Between Equations

The v in E = hv is frequency (of photons), while the v in E = (1/2)mv^2 is velocity (of electrons or other objects).
by AshleyLamba1H
Sun Apr 29, 2018 12:49 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Example 1.7a in the Textbook [ENDORSED]
Replies: 4
Views: 177

Re: Example 1.7a in the Textbook [ENDORSED]

The equation to find momentum is p = mv (momentum = mass * velocity). To find the change in momentum, you would put a delta in front of every variable except mass, because in the case of the marble, its mass is not changing.
by AshleyLamba1H
Sun Apr 29, 2018 12:37 am
Forum: Photoelectric Effect
Topic: Test 2 #7 [ENDORSED]
Replies: 3
Views: 174

Re: Test 2 #7 [ENDORSED]

Could you post a photo of the question please? That would be helpful for people to answer your question.
by AshleyLamba1H
Sun Apr 22, 2018 1:35 am
Forum: Photoelectric Effect
Topic: Threshold Energy [ENDORSED]
Replies: 4
Views: 138

Re: Threshold Energy [ENDORSED]

Threshold energy is the energy/work required to eject an electron. I believe that work function and threshold energy are the same thing.
by AshleyLamba1H
Sun Apr 22, 2018 1:18 am
Forum: Properties of Light
Topic: Homework 1.15
Replies: 3
Views: 172

Re: Homework 1.15

You can find this equation on page 7 of the chemistry textbook. There is also a very helpful example using this equation on the same page. That example helped me better understand how to use this equation and what it means.
by AshleyLamba1H
Sun Apr 22, 2018 1:03 am
Forum: Significant Figures
Topic: Sig Fig Accuracy [ENDORSED]
Replies: 6
Views: 357

Re: Sig Fig Accuracy [ENDORSED]

I'm pretty sure that rounding significant figures should not be applied to each step, because that will decrease the accuracy of your final answer. In between each step, you should be sure to keep more significant figures than there are supposed to be to retain accuracy.
by AshleyLamba1H
Sat Apr 14, 2018 11:34 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Definition of moles [ENDORSED]
Replies: 5
Views: 234

Re: Definition of moles [ENDORSED]

You are correct that moles are 6.022 x 10^23 amount of "things". However, I think you are getting confused over the meaning of a "mol of [element]". A mol of carbon and a mol of oxygen are different because we are comparing their masses. In this case, a mol of oxygen (16.00 g) ha...
by AshleyLamba1H
Sat Apr 14, 2018 11:23 am
Forum: SI Units, Unit Conversions
Topic: Volume V Density [ENDORSED]
Replies: 5
Views: 272

Re: Volume V Density [ENDORSED]

You need to know the volume of an object to calculate its density. For example, let's say there are two balls with equal mass. However, their volumes differ: one ball has a radius of 5 cm and the other has a radius of 1 cm. Following the density equation (D = m/V), we know that the larger ball is le...
by AshleyLamba1H
Sat Apr 14, 2018 11:14 am
Forum: Significant Figures
Topic: Significant figures
Replies: 4
Views: 262

Re: Significant figures

If you go to the class website there is a page with more information called "Everything you want to know about significant figures," under the Math Assistance tab. You might find that helpful.
by AshleyLamba1H
Sun Apr 08, 2018 6:23 pm
Forum: Balancing Chemical Reactions
Topic: H. 21
Replies: 4
Views: 244

Re: H. 21

You should set the problem up so you are solving for a system of equations:
C: 10a+ 0b = 1c + 0d + 1e
H: 15h + 0b = 0c + 2d + 4e
N: 1a + 0b = 0c + 0d + 2e
O: 0a + 2b = 2c + 1d + 1e

Solve for each variable.
by AshleyLamba1H
Sun Apr 08, 2018 6:14 pm
Forum: Molarity, Solutions, Dilutions
Topic: G.23 from HW [ENDORSED]
Replies: 4
Views: 251

Re: G.23 from HW [ENDORSED]

The units for molar concentration is mol/L. Therefore, you must first convert the amount of grams of Cl- to moles, and then divide that by .100 L (100 mL).
by AshleyLamba1H
Sun Apr 08, 2018 5:53 pm
Forum: SI Units, Unit Conversions
Topic: Problem E.9 in textbook
Replies: 3
Views: 179

Re: Problem E.9 in textbook

Firstly, you must find the formula for magnesium sulfate heptahydrate. The formula is MgSO4 · 7 H2O. To find the mass of this molecule, you must add up the molar masses of the individual atoms in the molecule, which gets you 246.48 g/mol. Knowing this will help you find the number of atoms that are ...

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