CHEM AND BIO HELP AND TIPS HERE

[$H00t!N& $t@r]

vin check ur pm...

[guMnam]

Hey guys can u help me plz

I have two questions here: http://www.freeexampapers.us/IGCSE/Chemistry/CIE/2006%20Nov/0620_w06_qp_1.pdf

Q)27 and 31, plz explain

And 1 question here: http://www.freeexampapers.us/IGCSE/Chemistry/CIE/2007%20Nov/0620_w07_qp_1.pdf

Q) 11

Thanks in advance

ANS FOR 11 IS D CAZ 3*CARBON + 2*OXYGEN + 6* HYDROGEN = 74
for 31 it is 1&3..B and i cant explain it..lol...and for 27 it is B cazof the dif in reactivity

[Baladya]

Q27  easy .. B
Carbon is more reactive than copper therefore it'll displace Cu to from CO2 and is less reactive and will result in no change

Q27 easy .. B
nitrogen oxides .. nitrogen and oxygen are "taken" from the atmosphere rest others are naturally in fuels

No dude, first they say that all are in fuels, and the question says which are PRODUCTS, so in my book all of them are produced when fossil fuels are burnt

[Baladya]

ANS FOR 11 IS D CAZ 3*CARBON + 2*OXYGEN + 6* HYDROGEN = 74

what are u saying?? ur answer doesnt explain why 8 molecules!! Can u plz clear it ?

[The Golden Girl =D]

Hey guys can u help me plz

I have two questions here: http://www.freeexampapers.us/IGCSE/Chemistry/CIE/2006%20Nov/0620_w06_qp_1.pdf

Q)27 and 31, plz explain

And 1 question here: http://www.freeexampapers.us/IGCSE/Chemistry/CIE/2007%20Nov/0620_w07_qp_1.pdf

Q) 11

Thanks in advance

3ashan Q 11 laszim tirsum il compounds , k !


as for question 27 fi nov 06 ......Mg is above carbon fi il reactivity series hence carbon can't displace it , fahamtah?

as for Q 31 .it's C 3ashan , nitrgon oxide is formed when nitrogen reacts with air .....li2ano nitrogen mish maugood fi il fuel .....nitrogen doesn't exist in fuel , right? ..... so that's the reason

[Baladya]

i cant understand ACIDS,BASES AND SALTS chapter and i am really facing difficulties with it!

if anyone have some goood notes...pls let me know!!

I don't have but if u dont understand anything i have time

[soraam]

sulpher and carbon are present in fossil fuel so their oxides have a chance to form

[Baladya]

3ashan Q 11 laszim tirsum il compounds , k !


as for question 27 fi nov 06 ......Mg is above carbon fi il reactivity series hence carbon can't displace it , fahamtah?

as for Q 31 .it's C 3ashan , nitrgon oxide is formed when nitrogen reacts with air .....li2ano nitrogen mish maugood fi il fuel .....nitrogen doesn't exist in fuel , right? ..... so that's the reason

omg i was looking for someone to answer me and then suddenly three people answering xD Thanks i guess i understood bilmasry

[The Golden Girl =D]

omg i was looking for someone to answer me and then suddenly three people answering xD Thanks i guess i understood bilmasry

looooooooooool

[Baladya]

Q27  easy .. B
Carbon is more reactive than copper therefore it'll displace Cu to from CO2 and is less reactive and will result in no change

Q27 easy .. B
nitrogen oxides .. nitrogen and oxygen are "taken" from the atmosphere rest others are naturally in fuels


2007 Nov

Q11 start start balancing 8 oxygen from A .. always complete combustion of hydro-carbon fuel s give CO2 and H2O .. incomplete give CO and H2O

C5H11OH  +  8O2  ---> CO2  + H2O
impossible to balance oxygen!!

C6H9OH  +  8O2 ---> cO2 + H2O
try to balance !!

after balancing ..
C6H9OH  +  8O2 ---> 6CO2 + 5H2O

ans is B

thx for the detailed explaination

[guMnam]

what are u saying?? ur answer doesnt explain why 8 molecules!! Can u plz clear it ?

opas sry i ans q 10..q11..wait

[Vin]

i have another question...p1 chem 2006 m/j  q19

ans is C for sure ..

try to write an equation for each ..
Cu  +  H2SO4  ----> not possible as Cu is less reactive so cannot displace H2 therefore Cu as a  metal is present and no ions

Cu(OH)2  +  H2SO4  ---> CuSO4  +  H2O
this is a neutralisation reaction .. so salt and water are formed .. here Cu+2 are present Cu⁺²SO₄^-2 = CuSO4

CuCO3  +  H2SO4  ---> CuSO4  +  H2O  + CO2
again salt  Cu⁺²SO₄^-2 = CuSO4

so check 2 and 3 so the ans is C

[Vin]

opas sry i ans q 10..q11..wait

already answered no worries !!

[Vin]

O sh*t lol i fail again I think they are talkin about bio
By the way Vin help plsss 

  ?? WTF ??

[Baladya]

Exactly xD

Guys okay all thanks i understand all questions xD