Take your best shot at my Destroyer GChem Questions

[NumbaOneStunna]

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[27]: What is the hybridization of AsF4, that is does the left over electron (not lone pair, I'm asking a slightly diff question) on As count as an electron domain?

[50]:What is the solubility of Fe(OH)2 in .025M FeCl2?
I get how to do this problem, but my question is if it read what is the solubility of Z3Y4? What am I solving for the solubility of Z or Y in the solution? Or am I solving for X where X is in the ksp expression (3*X)^3 * (4*X)^4?

[85]: In H20 which is the weakest base?
Why can't it be HClO4 instead of ClO4-? H2ClO4 seems physically possible, and that would be the stronger acid giving the weaker base upon deprotenation. What's wrong with my logic?

[86]: I can balance the equation but I dont know what normality is ( I thought it was the factor used when things dissociate into many atoms) and how it relates to the change in oxidation state. Can someone explain this?

[88]: Can someone explain why delta G is zero during phase changes?


Thanks everyone in advance!

 

[peerless218]

bang!!! Just did.....

haha jk, ya sorry but it's been almost a year and I dont remember any of gen chem stuff. Good luck though!!

 

[NumbaOneStunna]

*Bump* Anyone?

 

[RHONDAROBINSON]

For number 27, the electron domain geometry is tetrahedral(sp3 hybridization) and the molecular geometry is trigonal pyramidal because of the one lone pair that is on the As.
Also, check out Chad's Chemistry reviews at http:www.coursesaver.com/chad/Dat Review.

Rhonda

 

[NumbaOneStunna]

For number 27, the electron domain geometry is tetrahedral(sp3 hybridization) and the molecular geometry is trigonal pyramidal because of the one lone pair that is on the As.
Also, check out Chad's Chemistry reviews at http:www.coursesaver.com/chad/Dat Review.

Rhonda

My question is slightly diff from the books. I'm asking if a single electron (not a lone pair) counts as an electron domain.

 

[Shinpe]

[27]: What is the hybridization of AsF4, that is does the left over electron (not lone pair, I'm asking a slightly diff question) on As count as an electron domain?

I think you should get something in between a tetrahedral and trigonal bipyramidal here. The lone electron has some repulsion but not quite as much as the lone pair. Similar to case of NO2 where you would have less than 120 degrees.

[50]:What is the solubility of Fe(OH)2 in .025M FeCl2?
I get how to do this problem, but my question is if it read what is the solubility of Z3Y4? What am I solving for the solubility of Z or Y in the solution? Or am I solving for X where X is in the ksp expression (3*X)^3 * (4*X)^4?

It is X that you are looking for. That's the initial concentration of Z3Y4 you could use to give you 4X of Y and 3X of Z.

[85]: In H20 which is the weakest base?
Why can't it be HClO4 instead of ClO4-? H2ClO4 seems physically possible, and that would be the stronger acid giving the weaker base upon deprotenation. What's wrong with my logic?

I made a thread about this question a week or two ago, you can search for it by searching for threads I've started, but the final consensus was that HClO4 is not considered a base at all since it would technically never happen that HClO4 would take on an H. Kinda weird for me but some one said some textbooks said that too. Highly doubt sth so tricky would show up on DAT, but then again u never know.

[86]: I can balance the equation but I dont know what normality is ( I thought it was the factor used when things dissociate into many atoms) and how it relates to the change in oxidation state. Can someone explain this?

No clue since don't have book on me

[88]: Can someone explain why delta G is zero during phase changes?

When you're at a phase change, you're at equilibrium, like when you have a mixture of ice and water. At equilibrium, Del.G is zero.

Thanks everyone in advance!

Good luck

 

[whawha]

My question is slightly diff from the books. I'm asking if a single electron (not a lone pair) counts as an electron domain.

Only pairs are counted as an electron domain.

 

[Shinpe]

Only pairs are counted as an electron domain.

I don't think that's entirely true. Nitrogen dioxide (NO2) would be predicted to have a linear molecular conformation that way, but it is actually bent with an angle of 134 (according to wiki and destroyer), so the lone electrons do have an effect, just not as large as lone pairs.

 

[NumbaOneStunna]

Thanks for the help Shinpe.

Also I saw this in an Achiever explanation for Gchem, is this true?

"Without the need to express a full chemical equation, it is obvious that only 0.5 mole of H2SO4 is required to neutralize every mole of NaOH."
I know that H2SO4 has two H+'s to give up but I thought the second one would be very very hard to give up (or does H2SO4 only have 2 readily ionizable H+'s in a neutralization reaction as opposed to just being in water and contributing H+'s?) . Does anyone know the pka for HSO4-?
Man i feel stupid for missing this question =p

**Another Question***
What is the net ionic eqtn for the rxn between FeS and HCl
FeS(s) + 2H+(aq) ---> H2S(g) + Fe2+(aq)

This question involves knowing that FeS is a solid - how are we supposed to know that if the general solubility rules don't apply (grp 1 metal, NH4+, or NO3- = def solub., if not defintely sol. Ag+,Pb2+, and Hg2(2+) are insoluble)?
8H


***I don't get anything about this one, can someone walk me through it?
What percentage of iron is present in the ore, if a 1.120 g sample requires 25.00 ml of 0.050 M KMnO4 to fully oxidize all of the dissolved Fe2+?
8H+ + 5Fe2+ + MnO4- ------> 5Fe3+ + Mn2+ + 4H2O


Thanks.