Search found 36 matches

by DavidEcheverri3J
Fri Nov 30, 2018 1:09 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: hydrogen atom in acid
Replies: 2
Views: 136

Re: hydrogen atom in acid

They loose H atoms more easily so that they can bind to other reactants when in a solution.
by DavidEcheverri3J
Fri Nov 30, 2018 1:05 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: strong acids
Replies: 4
Views: 282

Re: strong acids

How do weak acids react in an aqueous solution?
by DavidEcheverri3J
Fri Nov 30, 2018 12:59 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: H+ Acidic and OH- Basic
Replies: 4
Views: 135

Re: H+ Acidic and OH- Basic

I believe that the idea of acids/bases is somewhat related to polar/nonpolar. Its just ideas and studies that have been conducted in order to better understand bow certain molecules interact in aqueous solutions. This will also help in labs!

Ah-hah!
by DavidEcheverri3J
Sun Nov 25, 2018 4:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 3
Replies: 38
Views: 432

Re: Test 3

Will we also need to know the degrees of the shapes?
by DavidEcheverri3J
Sun Nov 25, 2018 4:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shapes Not covered in Lecture
Replies: 10
Views: 74

Re: Shapes Not covered in Lecture

can someone explain NO2 to me? I can think of multiple VSEPR shapes
by DavidEcheverri3J
Sun Nov 25, 2018 4:57 pm
Forum: Hybridization
Topic: Hybridization
Replies: 5
Views: 35

Re: Hybridization

How many levels of hybridization will we need to know? sp3d2? more?
by DavidEcheverri3J
Fri Nov 16, 2018 1:11 pm
Forum: Lewis Structures
Topic: Maximum amount of bonds
Replies: 5
Views: 53

Re: Maximum amount of bonds

Is it possible for an element in the 3s have more than an octet? this being sodium and magnesium. I am asking due to the fact that they do not have a 3d shell.
by DavidEcheverri3J
Fri Nov 16, 2018 1:10 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Shortcut
Replies: 4
Views: 69

Re: Shortcut

for S/2, instead of counting how many electrons each bond has and dividing by two, you can just count how many lines (bonds) there are and not divide by anything. Just a quick tip to make your life easier. Ah-hah!
by DavidEcheverri3J
Fri Nov 16, 2018 1:08 pm
Forum: Student Social/Study Group
Topic: Chemistry News
Replies: 30
Views: 14294

Re: Chemistry News

The kilogram is being redefined! https://youtu.be/c_e1wITe_ig
by DavidEcheverri3J
Fri Nov 16, 2018 1:07 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg and Wavelength
Replies: 11
Views: 138

Re: Heisenberg and Wavelength

Hey guys, new interesting fact... the kilogram is being redefined! https://youtu.be/c_e1wITe_ig
by DavidEcheverri3J
Fri Nov 09, 2018 1:08 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 13
Views: 92

Re: Bond Angles

What is the lowest degree that bonds can have in between each other? I know that electron repulsion leads to the largest possible degree of separation, but what could the lowest degree be?
by DavidEcheverri3J
Fri Nov 09, 2018 1:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Trigonal Planar
Replies: 8
Views: 42

Re: Trigonal Planar

Does the Trigonal Planar structure means all the atoms are in the same plane? I'm kinda confused because Professor Lavelle added a 3-D structure of BF3. What is its actual structure? 2-D or 3-D? All molecules are 3D. He mentions lewis structure as 2D so that we get the idea on how to draw lewis str...
by DavidEcheverri3J
Fri Nov 09, 2018 1:04 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Trigonal Planar
Replies: 8
Views: 42

Re: Trigonal Planar

What is the meaning of the solid line or the dotted line on Lewis Structures that are 3D?
by DavidEcheverri3J
Sun Nov 04, 2018 4:37 pm
Forum: Limiting Reactant Calculations
Topic: Midterm Review Q2
Replies: 7
Views: 553

Re: Midterm Review Q2

So to solve this problem you first have to write out the equation given in the problem then balance it, getting 4NH3+5O2=>4NO+6H2O. Then you take the grams of NH3 and O2 given and find the moles, multiply it by the mole ratio in the equation to get mols NO, then convert to grams. You find that O2 y...
by DavidEcheverri3J
Sun Nov 04, 2018 4:24 pm
Forum: Limiting Reactant Calculations
Topic: Midterm Review Q2
Replies: 7
Views: 553

Re: Midterm Review Q2

So to solve this problem you first have to write out the equation given in the problem then balance it, getting 4NH3+5O2=>4NO+6H2O. Then you take the grams of NH3 and O2 given and find the moles, multiply it by the mole ratio in the equation to get mols NO, then convert to grams. You find that O2 y...
by DavidEcheverri3J
Sun Nov 04, 2018 1:11 pm
Forum: Administrative Questions and Class Announcements
Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
Replies: 121
Views: 4198

Re: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]

For #6, how are you supposed to convert the molar mass of GarBreadium to kg in order to use the de broglie equation? First you must find the weight of a single atom of GarBreadium -> (3.257g/1mol) x (1mol/6.02x20^23atoms) = 5.24x10^-24 g/atoms. Then you multiply by 1000 (1000g in 1 kg). Lastly you ...
by DavidEcheverri3J
Sat Nov 03, 2018 3:27 pm
Forum: Administrative Questions and Class Announcements
Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
Replies: 121
Views: 4198

Re: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]

can anyone please help me with number 2? I got to dividing the molar mass of 667 by 30.024 and got 22? but i think its wrong because its such a large number. Thus my molecular formula so far is C22H44O22 ?? pls help Same... :( Actually, I just solved it. ill walk you through it: first you want ti d...
by DavidEcheverri3J
Sat Nov 03, 2018 3:19 pm
Forum: Administrative Questions and Class Announcements
Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
Replies: 121
Views: 4198

Re: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]

Karla_Ocampo 4E wrote:can anyone please help me with number 2? I got to dividing the molar mass of 667 by 30.024 and got 22? but i think its wrong because its such a large number. Thus my molecular formula so far is C22H44O22 ?? pls help

Same... :(
by DavidEcheverri3J
Wed Oct 24, 2018 8:18 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Uncertainty in speed
Replies: 4
Views: 1241

Re: Uncertainty in speed

Why is it asking for speed? What does speed have to do with uncertainty of position?
by DavidEcheverri3J
Tue Oct 23, 2018 6:04 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Problem 2.47
Replies: 3
Views: 336

Re: Problem 2.47

Be sure that when removing electrons, the electrons from the ns state are removed first before removing those from the (n-1)d state. (e.g. 4s state electrons before 3d electrons) what this means is, for example in B, 3d^5 comes before 4s^2 when written out, so since 4s^2 is in front that is the orb...
by DavidEcheverri3J
Tue Oct 23, 2018 12:34 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Exercise 2.29
Replies: 9
Views: 579

Re: Exercise 2.29

I will cover this in class in detail. This question is about 20 pages ahead of what we have covered. I am confused with this question which asks "How many electrons can have the the following quantum numbers in an atom, a) n=2, l-1 b)n=4, l=2, m1=-2 c) n=2 d) n=3, l=2, m1=+1 ?" and with 2...
by DavidEcheverri3J
Fri Oct 19, 2018 12:17 pm
Forum: Properties of Electrons
Topic: Speed of an Electron (hw 1.43)
Replies: 5
Views: 1607

Re: Speed of an Electron (hw 1.43)

you could draw a square with the perimeter of the square representing the shell or orbit of an atom and putting an electron there, which would symbolize a potential place where the electron can be.
by DavidEcheverri3J
Fri Oct 19, 2018 12:14 pm
Forum: Properties of Light
Topic: Friday 10/5 Lecture
Replies: 7
Views: 55

Re: Friday 10/5 Lecture

Also, when measuring a photon's energy, you are dealing with nu (Hz)
by DavidEcheverri3J
Fri Oct 19, 2018 12:00 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Clarification on Heisenberg Equation
Replies: 2
Views: 36

Re: Clarification on Heisenberg Equation

I believe that what they are referring to is the fact that electrons move at the speed of light, which is why we use C (3 x 10^8 m.s^-1) in many formulas. So while we can calculate momentum, the electron has already moved a huge distance in barely any time.
by DavidEcheverri3J
Tue Oct 16, 2018 5:07 pm
Forum: Properties of Light
Topic: Photons of light
Replies: 4
Views: 3932

Re: Photons of light

I get how you got E from the wavelength, but why do you need to divide 64 by the answer? (I also understand where the 64 came from) Is it to get the photons isolated from the J??
by DavidEcheverri3J
Tue Oct 16, 2018 4:19 pm
Forum: DeBroglie Equation
Topic: H.W. Problem 1.55
Replies: 3
Views: 484

Re: H.W. Problem 1.55

Why do we have to multiply 3600 by 100. I get that 100 cm is a meter, but wouldn't we then divide 3600 to get 3.6 meters?
by DavidEcheverri3J
Fri Oct 12, 2018 12:19 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical & Molecular Formulas
Replies: 11
Views: 326

Re: Empirical & Molecular Formulas

Jasmine Chow 1F wrote:Can the empirical and molecular formula be the same?

They can be the same as long as the molar mass of the molecule is equal to the molar mass that would be given by the empirical.
by DavidEcheverri3J
Fri Oct 12, 2018 12:17 pm
Forum: Photoelectric Effect
Topic: Variable for frequency
Replies: 6
Views: 35

Re: Variable for frequency

I guess you could replace nu (the greek letter that stands for frequency and looks like a V) with Hz so that it could be easier to differentiate in your own work, but I would make sure to be careful because the question will most likely give you the frequency with a V instead of Hertz.
by DavidEcheverri3J
Fri Oct 12, 2018 12:14 pm
Forum: DeBroglie Equation
Topic: Angstrom?
Replies: 8
Views: 109

Re: Angstrom?

It's important to remember that angstrom is only a measure of distance (meters), so be careful not to call 1 x 10^-10 an angstrom, because it could be 1 x 10^-10 liters or moles or anything, and angstrom wouldn't fit in anything other than meters.
by DavidEcheverri3J
Mon Oct 08, 2018 2:04 pm
Forum: Empirical & Molecular Formulas
Topic: L35
Replies: 3
Views: 915

Re: L35

First, you must convert the 2.50 t of NaBr to grams using the conversion factor 1.0 x 10^6 grams = 1 ton. Then you find the molar mass of NaBr (102.89g) and divide the grams of NaBr by NaBr's molar mass. Next, find the mole ratio between Fe and NaBr which is 3 mol Fe: 8 mol NaBr (don't forget to ma...
by DavidEcheverri3J
Thu Oct 04, 2018 1:15 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity and Dilution
Replies: 8
Views: 1435

Re: Molarity and Dilution

So the 75 mL of the original solution is not required to solve the final molarity?
by DavidEcheverri3J
Wed Oct 03, 2018 6:36 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactant Question
Replies: 7
Views: 629

Re: Limiting Reactant Question

Do you have to find moles before finding limiting reactant?
by DavidEcheverri3J
Tue Oct 02, 2018 11:20 am
Forum: Balancing Chemical Reactions
Topic: Calculating Net Moles
Replies: 3
Views: 658

Re: Calculating Net Moles

I wanted to follow up on this question; I too am hung up on one of the pre/post-assessment questions. It does not seem to be explained in the video module. Here is the question: 8. During a summer camping weekend 4 moles of butane (C4H10) gas were used for cooking. Chose the right balanced equation...
by DavidEcheverri3J
Tue Oct 02, 2018 11:05 am
Forum: Balancing Chemical Reactions
Topic: Net Number of Moles
Replies: 3
Views: 52

Net Number of Moles

What's the best way to find the net number of moles produced in a chemical reaction?
Ex. 4 moles of butane (C4H10) gas were combusted. Find the net number of moles of gas produced.
Ex. was taken from pre-module.
by DavidEcheverri3J
Mon Oct 01, 2018 10:27 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 6992
Views: 771145

Re: Post All Chemistry Jokes Here

Kevin Nguyen 4G wrote:Did you know that you can cool yourself to -273.15˚C and still be 0k?

That joke made ABSOLUTE ZERO sense.
by DavidEcheverri3J
Mon Oct 01, 2018 1:16 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 6992
Views: 771145

Re: Post All Chemistry Jokes Here

Explaining how one side of an equation must equal the other.

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