Qualification > Sciences
ALL CIE CHEMISTRY DOUBTS HERE !!
Arthur Bon Zavi:
--- Quote from: raamishstudent on April 19, 2012, 07:25:28 am ---http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Chemistry%20(9701)/9701_s10_qp_11.pdf
qs 8,17,16,24,38,31
--- End quote ---
[8] Strontium (atomic weight - 88)
ONE mole of group 2 element needs ONE mole of chlorine molecule to completely react.
Number of moles of group 2 element (in this case, Strontium)= (2.92)/(88) = 0.033
Number of moles of chlorine = (5.287 - 2.920)/(35.5 X 2) = 0.033
[16] Silicon, Phosphorus, Sulfur
Regarding ionization energy, Phosphorus is an exception as it disturbs the increasing trend towards the right of the periodic table. It satisfies the other condition of lowest melting point.
[17] Second ionization energy
Ionization energy decreases as we go down the group 2 elements as removing outer electron becomes easier because reactivity increases as we descend down the periodic table for group 2.
[24] Propan-2-ol
NaBH4 reduces propanone.
REMEMBER THIS : Secondary alcohol on oxidation gives a ketone, so in return while on reduction, ketone gives a secondary alcohol.
[31] 1 and 2
1 is diamond and 2 is graphite. These show giant molecular structure while 3 forms ionic lattice.
[38] 2 and 3
Numbering of a hydrocarbon chain starts from only one side and cannot start from both sides simultaneously. This is obeyed by 2 and 3.
raamishstudent:
thanks a billion. Can ppl please answer 6,8,22,29,28,32,34,35 of the same ppr
PPr: http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Chemistry%20(9701)/9701_s10_qp_11.pdf
Ms:http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Chemistry%20(9701)/9701_s10_ms_11.pdf
LekhB:
Explain why the carbon chlorine bond photodissociates and the carbon fluorine bond does not?
Physics09:
Exam in three days! Urgent help please!
http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Chemistry%20(9701)/9701_w07_qp_1.pdf
Q: 30 and 21
http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Chemistry%20(9701)/9701_s08_qp_1.pdf
Q:23 and 27
http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Chemistry%20(9701)/9701_w08_qp_1.pdf
Q: 28
Deadly_king:
--- Quote from: LekhB on May 04, 2012, 06:12:11 am ---Explain why the carbon chlorine bond photodissociates and the carbon fluorine bond does not?
--- End quote ---
Carbon-fluorine bond is an extremely strong bond that requires very high amount of energy in order to dissociate ;)
http://en.wikipedia.org/wiki/Carbon%E2%80%93fluorine_bond
Carbon-chlorine bond however is comparatively weaker and thus easy to dissociate ;)
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