Chem `

Question

Use equations to explain the observation
1.when a few drops of copper(II) sulphate solution are added to the reagent in bottles dliute sodium hydroxide solution or duilte sulphuric acid, a pale blue precipitate forms.

2. When carbon dioxide is pass through the reagent in dilute sulphuric acid, a white precipitate forms.

THX~

Answer 1

1. When copper(II) sulphate solution is added to sodium hydroxide solution, a blue precipitate is formed.
Cu^2+(aq) + 2OH^-(aq) → Cu(OH)2(s)

When copper(II) sulphate solution is added to dilute sulphuric acid, there is NO REACTION.

******

2. When carbon dioxide is passed through dilute sulphuric acid, ther is NO REACTION.

2007-03-19 01:38:02 補充：
產生藍色沉澱的 full equation :CuSO4(aq) 2NaOH(aq) → Cu(OH)2(s) Na2SO4(aq)

2007-03-19 01:40:07 補充：
唔好人地話有反應，你就作條 equation。HCO3 根本就冇呢樣野，SO3 遇水有劇烈反應，亂作 equation。

Answer 2

1.
CuSO4+ 2NaOH ---> Cu(OH)2(s)+ Na2SO4

2.
2CO2+ 2H2SO4(aq.) ---> 2HCO3 + 2SO3