i want to ask Cu and CuO when add con.H2SO4時係米會both都會出SO2

Question

i want to ask Cu and CuO when add con.H2SO4時係米會both都會出SO2
ans in eng plz thx
Also if add con.HCL係米可以分辨到Cu and CuO?

其實個問題係咁ga
which of the following substances can be used to separate copper from a mixture of copper and copper oxide?
A.conHCL
B.conH2SO4
C.Dilute sodium hydroxide solution
D.water

我想知點解b唔得
唔該曬~eng {plx

Answer 1

Neither of them will produce SO2
Cu is not able to react with H2SO4
CuO + H2SO4 = CuSO4 (blue)+ H2O

Answer 2

i want to ask Cu and CuO when add con.H2SO4時係米會both都會出SO2

When Cu is added to concentrated H2SO4 at room temperature, no reaction occurs. When heated, Cu would react with concentrated H2SO4 to give SO2 gas.
Cu + 2H2SO4 → CuSO4­ + 2H2O + SO2

CuO does not react with 98% H2SO4, because the amount of H+(aq) in the 98% H2SO4 is too small. However, CuO would react with (dissolves in ) a concentrated solution of H2SO4 to give a blue solution of CuSO4, but without giving SO2.
CuO(s) + 2H+(aq) → Cu2+(aq) + H2O(l)
or : CuO(s) + H2SO4(aq) → CuSO4(aq) + H2O(l)

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Also if add con.HCL係米可以分辨到Cu and CuO?

Concentrated HCl can be used to distinguish between Cu and CuO.

Cu does not reacts with concentrated HCl.

CuO reacts with (dissolves in) concentrated HCl solution to give a blue solution of CuCl2.
CuO(s) + 2H+(aq) → Cu2+(aq) + H2O(l)
or : CuO(s) + 2HCl(aq) → CuCl2(aq) + H2O(l)

Answer 3

I think only copper will have reaction with concentrated sulphuric acid
since conc.sulphuric acid is a oxidizing agent
Copper will oxidize to copper(II) iron
conc.sulphuric acid will reduce to sulphate ion and sulphur dioxide
the the half equation represent the two reactant
Cu(s)--------->Cu 2+(aq) ＋ 2e-
2H2SO4(l)＋2e- ---------------------->SO4 2-(aq) ＋ SO2(g)＋２H2O(l)
at the same time
copper(II) ion in copper(ii) oxidize cannot give out 2electrons to start the reaction
so that only copper can react with conc.H2SO4 and give SO2

Yes,because the concentration of HCl will not affect the way of reaction of copper and
copper(II) oxide.
It will not have any reaction with copper
but reaction with copper(II) oxide to give water and copper(II) chloride CuCl

2007-02-15 22:56:47 補充：
something i need to addbecause of the concentrationH2SO4 ACT AS A OXIDIZING AGENT RATHER THAN A TYPICAL ACID

Answer 4

CuO + conc. H2SO4 --> CuSO4 + H2O a typical neutralization no SO2 is evolved.
Cu + conc. 2H2SO4 (最好+ heating) --> CuSO4 + SO2 + 2H2O redox reaction SO2 is evolved (唔加熱個反應唔明顯)

2HCl + CuO --> CuCl2 + H2O a green/blue solution is formed
However, there is no reaction between Cu and HCl

Answer 5

both of them will release SO2
because conc. H2SO4 has oxidizing power.

you can refer to CE Chemistry book