Physics, Chemistry and Biology: Post your doubts here!

[orange1234]

can someone help me https://www.xtremepapers.com/community/forums/cambridge-igcse.11/

 

[fatimanasir]

chem p1 & p6, german and math p2

ahh good luck

 

[ZaqZainab]

where did you find that pink solid will be formed at bottom (i know that.. but i am interested if you have more sources for studying for ATP...) i mainly studied from table that i sent you

send me te table plz

 

[ZaqZainab]

The equation is correct, observations would be 1) pink solid formed at the bottom. 2) solution turns colorless from blue. 3) maybe rise in temp or smell.... check from ms and pls tell me the 3rd observation or post the link....

there is no ms for this paper so i checked out the examiners report which said Three different observations were required for the reaction between zinc and aqueous copper(II)
sulphate. Possible answers included: zinc dissolves, reacts; a red or copper deposit; solution
warms up, bubbles, effervesces or a gas is evolved.

 

[MMK95]

send me te table plz

http://chemistryforsg-olevel.blogspot.com/2012/01/qualitative-analysis-testing-for_02.html

 

[TheManiac]

there is no ms for this paper so i checked out the examiners report which said Three different observations were required for the reaction between zinc and aqueous copper(II)
sulphate. Possible answers included: zinc dissolves, reacts; a red or copper deposit; solution
warms up, bubbles, effervesces or a gas is evolved.

observations are also colors and ppt formed, all physical properties so MMK95 answered correct to you

 

[ZaqZainab]

observations are also colors and ppt formed, all physical properties so MMK95 answered correct to you

What is the pink solid should it not be black because of copper left over

 

[TheManiac]

What is the pink solid should it not be black because of copper left over

no it is not black it is pink.. and it goes on surface.

 

[TheManiac]

but substance is blue

 

[semsemhosam]

What is the pink solid should it not be black because of copper left over

copper oxide is black but copper is pink-brown

 

[TheManiac]

copper oxide is black but copper is pink-brown

bro we are talking about Zn+CuSO4->Cu+ZnSO4
Cu goes on top of blue substance and it is pink

 

[semsemhosam]

bro we are talking about Zn+CuSO4->Cu+ZnSO4
Cu goes on top of blue substance and it is pink

yes that's what i said .. you said copper should be black and i replied that it should be pink .. and i am a girl btw

 

[semsemhosam]

mayb i misunderstood ..

 

[TheManiac]

mayb i misunderstood ..

i never said that it should be black
P.S.
sorry i didnt saw your gender

 

[semsemhosam]

i never said that it should be black

yea .. i actually wanted to reply to the other person not u .. srry 'bout that

 

[TheManiac]

yea .. i actually wanted to reply to the other person not u .. srry 'bout that

np

 

[MMK95]

bro we are talking about Zn+CuSO4->Cu+ZnSO4
Cu goes on top of blue substance and it is pink

Cu cant be on the top, and after the reaction the solution would be colorless. ( copper sulfate is blue and zinc sulfate is colorless)

 

[TheManiac]

Cu cant be on the top, and after the reaction the solution would be colorless. ( copper sulfate is blue and zinc sulfate is colorless)

yes i know it will turn to colorless (it will be clear) but i think that Cu will go on surface of substance

 

[MMK95]

yes i know it will turn to colorless (it will be clear) but i think that Cu will go on surface of substance

Density of copper is 8.9gm/cm^3 while density of aqueous zinc sulfate in 3.9gm/cm^3, so Cu would be at the bottom.........

 

[TheManiac]

Density of copper is 8.9gm/cm^3 while density of aqueous zinc sulfate in 3.9gm/cm^3, so Cu would be at the bottom.........

my mistake