Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: UG on 08/02/2009 01:34:55

Title: What is Benedicts solution?
Post by: UG on 08/02/2009 01:34:55

[?][?] Can u tell me what it is?

Title: What is Benedicts solution?
Post by: Chemistry4me on 08/02/2009 01:40:47

Benedict's solution contains aqueous copper (II) ions Cu²⁺ (which gives the reagent a blue colour) in alkaline conditions. To prevent the Cu²⁺ from precipitating out as Cu(OH)2, the Cu²⁺ is complexed with citrate ions.

When Benedicts solution is added to an aldehyde and warmed, a reddish brown ppt of copper(I) oxide Cu₂O forms:

For example:

CH₃CHO + 4OH^- + 2Cu²⁺ > CH₃COOH + Cu₂O + 2H₂O

Title: What is Benedicts solution?
Post by: UG on 08/02/2009 01:46:55

When Benedict's solution oxidizes ethanal to ethanoic acid, an ion is the oxidant.
a) What is its name and formula
b) what is the color change
c)Whats the reduction half-equation

Can sombody tell me  [?]

Title: What is Benedicts solution?
Post by: Chemistry4me on 08/02/2009 01:48:07

This sounds exactly the same as the example I gave! [:D]

Title: What is Benedicts solution?
Post by: Chemistry4me on 08/02/2009 01:53:11

The ion is copper (II) ion Cu²⁺
The blue solution turns to a reddish-orange precipitate (Cu₂O)
The reduction half-equation is:

Cu²⁺ + H₂O + e^- > Cu₂O + 2H⁺
 

Title: What is Benedicts solution?
Post by: UG on 08/02/2009 03:09:21

Thank you [;D]