CHEMISTRY COMMUNITY

Tiffanny_Carranza_2D

can someone clarify this question? I am not sure what it is asking
maybe i just don't know how to start it.

Without using a calculator, estimate what amount of Br 2 (in
moles) can be obtained from 0.30 mol ClO 2 in the reaction
6 ClO2(g) 1 2 BrF3(l) S 6 ClO2F(s) 1 Br2(l).

Tiffanny_Carranza_2D

for sapling question 14

we get that the pka is 8.49

and the ph is 6.10

how are we supposed to know whether it is charged, neutral or unknown?

thankyou

Tiffanny_Carranza_2D

I am having trouble classify acids and bases
for example sapling problem #7

Classify these salts as acidic, basic, or neutral

K2SO3, NH4Br, Na2S, KCl,LiBr

Tiffanny_Carranza_2D

Hello, what equation do we use to find OH-?

for example in
Determine the [OH−] , pH, and pOH of a solution with a [H+] of 7.9×10−7 M at 25 °C.
thank you.

Tiffanny_Carranza_2D

what is the hybridization of N in NH3?

I didn't understand How professor got SP3 can someone clarify the steps? thank you

Tiffanny_Carranza_2D

How do I find a conjugate base and acid of a formula for example HSO4-

please help, thank you.

Tiffanny_Carranza_2D

Could someone elaborate more on Kyle's process of easily identifying the amphoteric substance out of a list of substances that you are given? I still do not quite understand. Are there any patterns we should look out for? I read that you could figure it out by seeing which compound has hydrogen the...

Tiffanny_Carranza_2D

hello how does one decide whether a formula is a strong acid, weak acid, strong base, or weak base? for example how would i figure out what Ba(OH)2 is? thank you Strong Acid: Big size | Longer Bond Length | Weaker Bonds | Easily donates Proton -> Stronger Acid orrrrr if Resonance to stabilize acid ...

Tiffanny_Carranza_2D

hello how does one decide whether a formula is a strong acid, weak acid, strong base, or weak base?
for example how would i figure out what Ba(OH)2 is?

thank you

Tiffanny_Carranza_2D

How are the NH3 ligands neutral ?

Tiffanny_Carranza_2D

If you draw the molecule en, you will notice that the two nitrogens on either side of the molecule each have a lone pair, and there are spacers in between the nitrogens, indicating that two bonds can be formed between this ligand and the metal atom. Therefore, en is bidentate, and it has a coordina...

Tiffanny_Carranza_2D

is the coordination number for (en) 2?

if it is do you guys know why it isn't 1?

Tiffanny_Carranza_2D

hello, how does one find a coordination number?

Tiffanny_Carranza_2D

hello I cannot figure out the oxidation number of this compound, i thought it was -6 or -8 because cl has 6 and then there is a 2- but both of those arr incorrect.

[PtCl6]2−

Tiffanny_Carranza_2D

I am having trouble knowing how to name compounds so far I got this:

[Co(NH3)4Cl2]Cl
tetra ammine chloro colbat (II) chloride

im not sure what is wrong about that

Tiffanny_Carranza_2D

Ralph Zhang 2L wrote:There should be no resonance structures, the last one you are missing is the carbons forming a triangle shape with their bonds.

hi when do we know not to include a resonance structure? or should we just assume that for all questions?

thank you so much for your response btw

Tiffanny_Carranza_2D

i keep getting question 17 wrong on sapling it say to draw 3 structures of c3h4 I am not sure what I am doing wrong because I got one structure with two double bonds and 2 Hydrogens on ea. end the other two are the same but flipped with one triple bond 1 hydrogen on one end and 3 hydrogens on the ot...

Tiffanny_Carranza_2D

hello, I wanted to know how did you do sapling hw question 17

I am not sure how to recognize angle size yet, how did you guys figure it out or how did you get yourself to remember?

thank you

Tiffanny_Carranza_2D

magalysantos_1F wrote:I think what it's really asking is the smallest bond angle possible, and because this is a linear shape, it would be 180 degrees. These measurements were talked about in the lectures, so you don't have to necessarily do any calculations :)

thank you!

Tiffanny_Carranza_2D

Question three is telling me to to say which what the smallest angle would be
X-Y-X ( Y has 2 lone pairs on top and one lone pair on the bottom?

How does one determine the angle?
thank you.

Tiffanny_Carranza_2D

in today's lecture I did not understand why parts of C2H4 had SP2 and others had SP3, I thought that they were all supposed to be SP2.

Tiffanny_Carranza_2D

how do you determine the amount of regions of electron density?

thank you

Tiffanny_Carranza_2D

hello

on problem 2B9

the lewis structures are different for example b) k3P

is drawn out [k]+[k]+[k]+ [p]-3 ( p has 6 electron pairs)

why arent the answers shown with bonds, the atoms are separate like that but in question 2B11 the answers are given with bonds?

thank you.

Tiffanny_Carranza_2D

hello,
i am a little confused about problem 2 A 5 in the textbook hw

for a) Cu+ I got [Ar] 3d8 4s2

but I know the answer is [Ar] 3d10

i would like an explanation as to why 4s2 was dropped, if 4s is supposed to fill up first?

Tiffanny_Carranza_2D

the answer key says that the answer is p3-,s2-, cl-

but the order i got was cl-,s2-, p3- because the question asked to put them in order of increasing radius, is the book mistaken or is my order wrong?

thank you

Tiffanny_Carranza_2D

for n=4 l=2 ml= -2 you get 4D the D orbital would mean that ml= -2,-1,0,+1,+2 since there is (x,y,z) and ml=-2 then we would be within the first aspect of the D orbital, x. what would be an example of being in the second aspect of the D orbital y? and then would the number of orbitals be 2? thank you.

Tiffanny_Carranza_2D

are we supposed to know how to calculate bond length?

if so what equation or how do we do that?
thank you

Tiffanny_Carranza_2D

Ashley Kim 3I wrote:Are you referring to electronegativity trends in general? Because if so, the electronegativity trend happens to be that across a period is more electronegative, and up a group is more electronegative.

yes thank you!

Tiffanny_Carranza_2D

hello

how do you check on a periodic table the length of the bond length?

thank you

Tiffanny_Carranza_2D

hi I am having trouble starting problem 9 on sapling

Which of the Lewis structures of the perchlorate ion are most plausible based on formal charge?

im not sure what its asking

thank you

Tiffanny_Carranza_2D

can anyone explain how do you know when a species is an acid or a base?

thank you

Tiffanny_Carranza_2D

how does one know which atom is the most electronegative?

Tiffanny_Carranza_2D

hello, i am currently doing a problem for CO3^2-

so far I got
.. ..
: O -----C------O:
.. || ..
O
..
I am not sure where to put the formal charge. I got -2.

Tiffanny_Carranza_2D

how do we know when something is delta + or -

at the end of lecture today, professor did H-o-H and he said O was delta -

how did he know?

thank you

Tiffanny_Carranza_2D

Na+(g) + Cl- (g) --> NaCl(s)
energy released = 787 kJmol-1

how is the energy released found?

Tiffanny_Carranza_2D

The negative or positive sign outside the brackets represents the charge of the molecule. For example, if you are drawing the lewis structure of NO3-, you would put a - outside the bracket. If you are drawing SO42-, you would put 2- outside of the brackets. Hope this helps! thank you for your help....

Tiffanny_Carranza_2D

Hi, so to assign formal charges for each atom in a molecule you, would use the formula: Formal Charge = Valence electrons - (shared electrons/2 + lone pairs). For instance, in NH4, each hydrogen has 1 valence electron, 2 shared electrons between it and nitrogen, and no lone pairs. You would plug th...

Tiffanny_Carranza_2D

something I was confused about in lecture was when professor put a negative sign outside of the brackets of a lewis structure

[Leis Structure]-

how do we know when to put a negative or a +?

thank you.

Tiffanny_Carranza_2D

The water pulls apart Na and Cl which breaks the ionic bond

Tiffanny_Carranza_2D

hello, I am a little confused on how to assign "formal charges", for example in the sapling Hw problem #2 for NH4+

thank you

Tiffanny_Carranza_2D

today in lecture, professor this math :
O

O S O

O

SO4^2-

S=6e-

4x6e-= 24e-
2e-
----------
32 e-

I want to know where he got 6e- from and how did 32e- result from all of that?

thank you.

Tiffanny_Carranza_2D

hello I am having a lot of trouble with this problem for the energy of an electron. I did: Ke=1/2(m)(v^2) for m i put in the mass of an electron: 9.109x10^-31 I got v from: v= (3.0x10^8 m/s)/(2.1x10^-6 m)= 1.42x10^14s Ke= 1/2(9.109x10^-31 kg )((1.42x10^14 s) ^2) the answer I got was Ke= 9.18x10^-3....

Tiffanny_Carranza_2D

hello I am having a lot of trouble with this problem for the energy of an electron. I did: Ke=1/2(m)(v^2) for m i put in the mass of an electron: 9.109x10^-31 I got v from: v= (3.0x10^8 m/s)/(2.1x10^-6 m)= 1.42x10^14s Ke= 1/2(9.109x10^-31 kg )((1.42x10^14 s) ^2) the answer I got was Ke= 9.18x10^-3. ...

Tiffanny_Carranza_2D

I believe that the first and second waves in the right column would work! Basically, if you repeated this same wave segment where the previous wave segment ended, it should create a continuous wave. Because the first and the second waves create a pattern in which the last iteration of the wave coul...

Tiffanny_Carranza_2D

in this question they want us to find Δx and they give us two numbers " what is the uncertainty in the position of an electron moving at 8x10^6 m/s with an uncertainty of Δv= 0.01x10^6m/s?" how do I know which number to use? I used the second one but I would like to know why they gave us 8...

Tiffanny_Carranza_2D

hi, I didn't understand why professor would put different elements when talking about a certain one, for example:

Cr:[Ar] 3d^5,4s

please help, thank you.

Tiffanny_Carranza_2D

can anyone explain how professor got C: 1s^2, 2s^2, 2Px,2py

I didn't really understand this part of lecture.

thank you!

Tiffanny_Carranza_2D

For this problem I watched a video that told me to plug in the work function for e in λ= hc/e. But I am not sure why it is okay to plug in the workfunction for e. thank you.

Tiffanny_Carranza_2D

I am unsure what to do when n=6 for example. in sapling question 13 how do you know how to solve for the electrons. i thought you couldn't have a number over 3. thank you

Tiffanny_Carranza_2D

thank you!

Tiffanny_Carranza_2D

Professor's email said to turn of randomization on Sapling, does anyone know how to do that I can't figure it out. thank you !

Tiffanny_Carranza_2D

I am confused on this problem, I keep getting it wrong: i multiplied the 445g of ice by the enthalpy of fusion which was 333.6j/g and I got 1.48x10^5j then I used E=hc/wavelength, THE WAVELENGTH FOR ME WAS 843nm so i converted to meters and got 8.43x10^-16 E= ((6.626x10^-34j.s)(3.0x10^8m.s))/(8.43x1...

Tiffanny_Carranza_2D

when converting a unit fir example 5.11x10^-4CM to meters do we just mulitply by 10^-2? i got the correct answer doing this but I would just like some reasurance that it is the right way to do it?

Tiffanny_Carranza_2D

will we be required to know how to use the rydberg equation? or is it okay to do the problem the way that professor did it today in class?

Tiffanny_Carranza_2D

Does anyone know where professor got -1/16 and -1/4 when doing the first worked example? he did -1/16HR-(-1/4HR)

Tiffanny_Carranza_2D

for work function problems how do we do the math? do we just use a calculator for problems like this? (6.626x10^-34)(3x10^8)/3.61x10^-19

Tiffanny_Carranza_2D

if increasing the wave amplitude of light didn't eject electrons, then what does? why did they switch from one light to the UV light? was the UV light an increase in the amplitude of light or what caused the metal to release electrons if it wasn't because of the wave amplitude?

Tiffanny_Carranza_2D

hi, can anyone please explain atomic spectra from today's lecture? I didn't understand thank you.

Tiffanny_Carranza_2D

Tiffanny_Carranza_2D

Does anyone know if this applies for the textbook homework as well? I'm not sure if we are supposed to turn it in somewhere.

Tiffanny_Carranza_2D

Tiffanny_Carranza_2D

thank you so much for this! I will definitely try to participate in this. It is very important to stay connected especially with a challenging subject like 14A.

Tiffanny_Carranza_2D

Tiffanny_Carranza_2D

Does anyone know where to find a physical copy of the textbook? I bought the e-book but I would really like a physical copy.
thank you (:

Tiffanny_Carranza_2D

Tiffanny_carranza_2D

I just want to say thank you to all of you under this post, it has been very helpful in completing the homework

Tiffanny_Carranza_2D

Tiffanny_Carranza_2D In todays lecture professor was going over the problem " what is the limiting reactant when 100g, H20, reacts with 100g CaC2?" After calculating the reactant moles and got CaC2= 1.56mol and H20=5.55mol, he said that CaC2 was the limiting reactant because it wasn't at a...

Tiffanny_Carranza_2D

HI, Does anyone where to access the textbook homework? I haven't received my textbook from the uclastore yet.

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