Chemistry: Post your doubts here!

[princess Anu]

but there was one MCQ related to this in my test

 

[Camille96]

Hi, anyone can give me some electrophoresis-based questions that cambridge normally give? It's rare these questions and i doubt we might get one this time. June 14 p41 had one.

 

[abdul moeed rana]

this is in syllabus, and it's not difficult 120 and 90 is the answer

please give me the bond angles n their that r in the syllabus.
all of the please!

 

[huh]

this is in syllabus, and it's not difficult 120 and 90 is the answer

I can't believe I was so stupid. I completely forgot about the Curriculum Content. Thank you so much.

 

[Maqb0ol]

please give me the bond angles n their that r in the syllabus.
all of the please!

Here u go bro "
BF3 (trigonal), CO2 (linear),
CH4 (tetrahedral), NH3 (pyramidal), H2O (non-linear), SF6 (octahedral),
PF5 (trigonal bipyramid) "

 

[Maqb0ol]

My pleas

I can't believe I was so stupid. I completely forgot about the Curriculum Content. Thank you so much.

My pleasure

 

[vitakix]

somebody please explain how is the shape of I3^- linear?
doesn't it have 2 bonding and 3 lone?

because they have three lone pairs they're gonna be placed on each side of the structure which ends up in a linear structure/180 degrees

 

[Charlotte20102013]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w09_qp_21.pdf
Q 5 (d) (i) What is the compound formed? How do I determine this? When sulfuric acid is added to alcohol, shouldn't alkene be formed? Or is it ester? (since there is also carb acid functional group in the alcohol so carbacid+alcohol+sulfuric acid=ester?? Does this count?)
Mark scheme: http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w09_ms_21.pdf
Another question
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s13_qp_22.pdf
Q 5 (d) (i&ii) Can someone explain this to me? How to obtain answer for (i)? Why can't the answer for (ii) be W or Z?
Mark scheme: http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s13_ms_22.pdf
Thanks in advance!

 

[Bilal Khan]

http://hschemsolutions.com/files/Download/4.7 VSEPR II(SLN).pdf

To all those having doubts with determining shapes of molecules

♣♠ Magnanimous ♣♠

Its just that i forget the bond angles .

 

[RoOkaYya G]

Its just that i forget the bond angles .

jst learn it with help of hybridisation itll be easy

 

[Bilal Khan]

Here u go bro "
BF3 (trigonal), CO2 (linear),
CH4 (tetrahedral), NH3 (pyramidal), H2O (non-linear), SF6 (octahedral),
PF5 (trigonal bipyramid) "

BeCl2 ( linear ) , PCl3 ( trigonal pramidal )

 

[Bilal Khan]

jst learn it with help of hybridisation itll be easy

BTW , most of these are not in syllabus . dont need to learn .

 

[RoOkaYya G]

BTW , most of these are not in syllabus . dont need to learn .

hmm
but u need to knw the mechanism of it. so tht when it ask u abt any molecule...u can derive it

 

[Bilal Khan]

hmm
but u need to knw the mechanism of it. so tht when it ask u abt any molecule...u can derive it

I never understood the mechanism , its all cramming .

 

[RoOkaYya G]

I never understood the mechanism , its all cramming .

yeah it is

 

[Maqb0ol]

BeCl2 ( linear ) , PCl3 ( trigonal pramidal )

Bro the last two you qouted aren't in the syllabus, i think we don't need to learn it

 

[Natitah18]

What do you guys predict for tomorrow's paper? I'm guessing there will be questions on Equilibria like Le Chatelier's and so on. Share your predictions

 

[Charchit]

What do you guys predict for tomorrow's paper? I'm guessing there will be questions on Equilibria like Le Chatelier's and so on. Share your predictions

I think they'll ask from polymers and electrolysis

 

[Natitah18]

I think they'll ask from polymers and electrolysis

Yeah, maybe on extraction of Aluminium? Cause like the diaphgram cell for brine has came out quite a number of times already

 

[princess Anu]

how do we know they are going to arrange themselves 180 degree apart?