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Chem doubts

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MaNi_DaDuDe:

--- Quote from: \m/ |\|!d \m/ on March 25, 2010, 06:47:37 am ---Oh & Thanks Mani :D

--- End quote ---

You're welcome.

Well deserved. ;D

Phosu:
1) jun 09 pp1 q40

2) a 2g sample of hydrogen at temperature T and volume V exerts a presssure P. Deuterium 1H2, is an isotope of hydrogen. which of the following would also exert a pressure P at the same temperature T?
a) 2g of deuterium of volume V
b) 4g of deuterium of volume V/2
c) a mixture of 1g of hydrogen and 2g of deuterium of total volume V
d) a mixture of 2g of hydrogen and 1g of deuterium of total volume 2V

3) Which property applies to halogens as group VII is descended?
a)Hydrogen-halogen bond energy decreases
b) intermolecular forces between the elements decrease
c) ions become less strongly reducing
d) thermal stability of the hydrides increases.

vanibharutham:
Im doing Edexcel Chem
so i cant help with question 2,

but question 3, the answer is A

a) H-F has the strongest bond enthalpy while H-I has the lowest bond enthalpy because F is more electronegative and it is hard to break the bond
b) Intermolecular forces increase down the group because the size of the atom increases so more chance of an instantaneous dipole-induced dipole because there are more electrons
c) OILRIG - oxidation is loss of electron, reduction is gain.... but here we are considering Reducing Power, or how easily they are oxidised....as mentioned earlier.... Flourine is the most electronegative...so it is most difficult to remove electrons from it... so ions become more strongly reducing.
d) Same explanation as bond enthalpy...

sweetie:
Q9 nd 25 of da first 2 papers ( specimen 01)

Q21 and 26 of  next 2 sheets ( may 01)

thats all !!!
plz reply ASAP ;)

nid404:
9) Cl2(g)----> Cl(g) + Cl(g)
atomisation energy...+244kj/mol
Cl(g)--->2Cl- -364 kj/mol

I think the answer should be A

25) A,B and D are incorrect... cuz it's possible to have a gas of this composition, it may be immiscible in water and it can have a mass less than 32...consider HCHO...mass 30
So, C

21)stoichio...
unsaturates...alkenes have formula Cn H2n in this hydrocarbon, there r 10 less hydrogen atoms...5 H2
so 4.1g~0.01 moles of the hydrocarbon will react with 0.05 moles of H2
0.05 moles of H2= 0.05 X2 grams=0.1g
no option?  :-\
C is 0.12g and it will react completely with squalene...so C i guess

26) B it's a tertiary alcohol...won't undergo oxidation

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