CHEMISTRY COMMUNITY

DavidEcheverri3J

They loose H atoms more easily so that they can bind to other reactants when in a solution.

DavidEcheverri3J

How do weak acids react in an aqueous solution?

DavidEcheverri3J

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!

DavidEcheverri3J

Will we also need to know the degrees of the shapes?

DavidEcheverri3J

can someone explain NO2 to me? I can think of multiple VSEPR shapes

DavidEcheverri3J

How many levels of hybridization will we need to know? sp3d2? more?

DavidEcheverri3J

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.

DavidEcheverri3J

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!

DavidEcheverri3J

The kilogram is being redefined! https://youtu.be/c_e1wITe_ig

DavidEcheverri3J

Hey guys, new interesting fact... the kilogram is being redefined! https://youtu.be/c_e1wITe_ig

DavidEcheverri3J

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?

DavidEcheverri3J

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...

DavidEcheverri3J

What is the meaning of the solid line or the dotted line on Lewis Structures that are 3D?

DavidEcheverri3J

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...

DavidEcheverri3J

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...

DavidEcheverri3J

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 ...

DavidEcheverri3J

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...

DavidEcheverri3J

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... :(

DavidEcheverri3J

Why is it asking for speed? What does speed have to do with uncertainty of position?

DavidEcheverri3J

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...

DavidEcheverri3J

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...

DavidEcheverri3J

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.

DavidEcheverri3J

Also, when measuring a photon's energy, you are dealing with nu (Hz)

DavidEcheverri3J

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.

DavidEcheverri3J

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??

DavidEcheverri3J

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?

DavidEcheverri3J

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.

DavidEcheverri3J

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.

DavidEcheverri3J

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.

DavidEcheverri3J

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...

DavidEcheverri3J

So the 75 mL of the original solution is not required to solve the final molarity?

DavidEcheverri3J

Do you have to find moles before finding limiting reactant?

DavidEcheverri3J

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...

DavidEcheverri3J

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.

DavidEcheverri3J

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.

DavidEcheverri3J

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

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