Physics, Chemistry and Biology: Post your doubts here!

Phoenix Blood

Phoenix Blood

Messages
5,753
Reaction score
26,985
Points
698
My Name said:
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Chemistry
(0620)/0620_w07_qp_1.pdf
question
11 HUH? dont get the question
18 why not A
21 dont get wat exactly theyu are asking
29 ALL ALLOYS CONDUCT ELECTRICITY NEVR NEW -_________-


Phoenix Blood thnx :p
Click to expand...
11) B
In combustion, each hydrogen atom requires only a quarter of an oxygen molecule. In B, the
6 carbons require 6 molecules of oxygen: the 10 hydrogens require 10/4 molecules less the half molecule
already present. Thus the answer is (6 + 10/4 – 1/2) = 8.

18) Copper does not react with dilute sulphuric acid, hence won't form copper(II)sulphate.

21) C
A solution contains both copper(II) sulphate and sodium chloride. When some of the solution is put into aqueous barium chloride, a
blue precipitate is observed. When some of the solution is put into aqueous silver nitrate , a white precipitate is observed. Does this hold true for each case?
So, the copper(II) sulphate and sodium chloride show no change in aqueous barium chloride, no no blue ppt. will be observed.
However, in aqueous silver nitrate, the chloride ions from sodium chloride will show a white ppt..

29) An alloy is a mixture or solid solution composed of a metal and another element. Because all metals conduct electricity, the property goes for all alloys as well.
 
M

My Name

Messages
4,988
Reaction score
23,955
Points
523
Phoenix Blood said:
11) B
In combustion, each hydrogen atom requires only a quarter of an oxygen molecule. In B, the
6 carbons require 6 molecules of oxygen: the 10 hydrogens require 10/4 molecules less the half molecule
already present. Thus the answer is (6 + 10/4 – 1/2) = 8.

18) Copper does not react with dilute sulphuric acid, hence won't form copper(II)sulphate....oops i forgot

21) C
A solution contains both copper(II) sulphate and sodium chloride. When some of the solution is put into aqueous barium chloride, a
blue precipitate is observed. When some of the solution is put into aqueous silver nitrate , a white precipitate is observed. Does this hold true for each case?
So, the copper(II) sulphate and sodium chloride show no change in aqueous barium chloride, no no blue ppt. will be observed.
However, in aqueous silver nitrate, the chloride ions from sodium chloride will show a white ppt..

29) An alloy is a mixture or solid solution composed of a metal and another element. Because all metals conduct electricity, the property goes for all alloys as well.okie i just wasnot sure
Click to expand...
 
Phoenix Blood

Phoenix Blood

Messages
5,753
Reaction score
26,985
Points
698
Phoenix Blood

Phoenix Blood

Messages
5,753
Reaction score
26,985
Points
698
My Name said:
a few silly n short doubts Phoenix Blood
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_w03_ms_1 2 3 5 6.pdf

question 3 part a

is it necessary to fill the lines

question 11 I think part c is actually the answer of part b i

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_w04_ms_3.pdf

question 1 part why 2 mark
Click to expand...
3,a, One mark will be for the position. Not necessary to fill the lines, but for the other mark, talk a little about the position or how you came to it.

There isn't any question c in the paper. http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_w03_qp_3.pdf
The answer for b,i and b,ii match
 
You must log in or register to reply here.
Top