Qualification > Sciences
ALL CIE CHEMISTRY DOUBTS HERE !!
samriddh:
--- Quote from: Twinkle Charms on September 18, 2010, 01:29:30 pm ---hello all =]
just been two days i started chem A level (both AS & A2) and any doubts i find ill be postin here...
so my first doubt,
can someone please clearly explain me what orbitals are ???
accordin to the definition, it says tht they are space around the nucleus where there is max. probablity of findin the electron within its orbit.
for example when n=3; l=0,1,2
so by 0,1,2 does it mean 0 from the nucleus (like coverin all the orbits in between as well> n=1 and n=2) ???
--- End quote ---
well orbitals are simply spaces where electrons most likely travel to while moving around the nucleus...and the number like u said n=1,2,3 etc are generally shells numbers which contain several orbitals...
it's like shells( like K,L,M,N...etc) contain subshells(1s, 2s etc where 1s means s subshell form shell no. one) now s-subshell contains 2 orbitals....
well it's my first post in this site so i dont know if u will find this much helpful but nonetheless i thought you could use some help so i posted..:)
Romeesa-Chan:
--- Quote from: EMO123 on June 16, 2011, 03:42:14 pm ---May/June 2007
Paper 04
Q-2 c)
Q-3 b)
Q-4
more doubts coming from me soon
--- End quote ---
Ans 2.c- part i:
Gas A:
16 = O
17 = OH
18 = H2O
Therefore, it'll be H2O
Gas B:
14 = N
16 = O
28 = N2 (14+14)
30 = NO (14+16)
44 = N2O (14+14+16)
Therefore, it'll be N2O
part ii: NH4NO3 ? N2O + 2H2
Ans3.b- Not so sure.
(i) Pb is in two oxidation states: +2 and +4
The ratio will be 1:2
(ii) Pb3O4 ? 3PbO + ½O2
(iii) Pb3O4 + 4HNO3 ? 2Pb(NO3)2 + PbO2 + 2H2O
(iv) Pb2+ more basic than Pb4+
Ans4- The d-orbital will be split in two ways: along the axis and in between the axes.
(ii) Ligands have lone pair of electrons which is how they form a covalent bond with the transition metal ion. The electrons in the orbitals pointing towards the ligands have higher energy.
c(i)- Accoring to graph and data given:
C= red and D=blue
c(ii)- More energy less wavelength. Therefore, at C.
Hope that's cleared. :D
EMO123:
--- Quote from: Romeesa Chan on June 23, 2011, 07:23:53 pm ---Ans 2.c- part i:
Gas A:
16 = O
17 = OH
18 = H2O
Therefore, it'll be H2O
Gas B:
14 = N
16 = O
28 = N2 (14+14)
30 = NO (14+16)
44 = N2O (14+14+16)
Therefore, it'll be N2O
part ii: NH4NO3 ? N2O + 2H2
Ans3.b- Not so sure.
(i) Pb is in two oxidation states: +2 and +4
The ratio will be 1:2
(ii) Pb3O4 ? 3PbO + ½O2
(iii) Pb3O4 + 4HNO3 ? 2Pb(NO3)2 + PbO2 + 2H2O
(iv) Pb2+ more basic than Pb4+
Ans4- The d-orbital will be split in two ways: along the axis and in between the axes.
(ii) Ligands have lone pair of electrons which is how they form a covalent bond with the transition metal ion. The electrons in the orbitals pointing towards the ligands have higher energy.
c(i)- Accoring to graph and data given:
C= red and D=blue
c(ii)- More energy less wavelength. Therefore, at C.
Hope that's cleared. :D
--- End quote ---
thanx dear it really helped i can +rep after about 1 hour so i will do it in the morning now i have gtg
Romeesa-Chan:
--- Quote from: EMO123 on June 23, 2011, 07:40:28 pm ---thanx dear it really helped i can +rep after about 1 hour so i will do it in the morning now i have gtg
--- End quote ---
Welcome. :D Glad to help! :D
Pray for my exam! (:
EMO123:
--- Quote from: Romeesa Chan on June 23, 2011, 07:41:21 pm ---Welcome. :D Glad to help! :D
Pray for my exam! (:
--- End quote ---
best of lucksssssssss
do your level best
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