Home
Class 12
CHEMISTRY
Explain the following: (i). Copper hyd...

Explain the following:
(i). Copper hydroxide is soluble in ammonium hydroxide but not in sodium hydroxide.
(ii). A dark blue precipitate is formed when sodium hydroxide solution is added to copper sulphate solution. The precipitate darkens on heating.

Text Solution

Verified by Experts

(i). `Cu(OH)_2` dissolves by forming a complex.
`Cu(OH)_2+4NH_4OHto[Cu(NH_3)_4](OH)_2+4H_2O`
`Cu(OH)_2` is insoluble in NaOH as no such complex is formed.
(ii). `NaOH` reacts with `CuSO_4` when dark blue ppt. Of `Cu(OH)_2` is formed. This ppt. On heating forms CuO which is black in colour. Hence the colour darkens on heating.
`CuSO_4+2NaOHtounderset((Blue))(Cu(OH)_2)+Na_2SO_4`
`Cu(OH)_2overset(Delta)tounderset((Black))(CuO)+H_2O`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • D AND F BLOCK ELEMENTS

    CENGAGE CHEMISTRY|Exercise Ex 6.2 Subjective (Compound Of Zn:)|1 Videos

  • D AND F BLOCK ELEMENTS

    CENGAGE CHEMISTRY|Exercise Ex 6.2 Subjective (Compound Of Ag:)|2 Videos

  • D AND F BLOCK ELEMENTS

    CENGAGE CHEMISTRY|Exercise Ex 6.2 Subjective (Compound Of Fe :)|7 Videos

  • COORDINATION COMPOUNDS

    CENGAGE CHEMISTRY|Exercise Archives Subjective|18 Videos

  • ELECTROCHEMISTRY

    CENGAGE CHEMISTRY|Exercise Archieves Subjective|35 Videos

Similar Questions

Explore conceptually related problems

When sodium hydroxide solution is electrolysed :

Explain the following facts: (a). Copper hydroxide is soluble in ammonium hydroxide but not in sodium hydeoxide. (b). Addition of an alkali to cuprous chloride solution gives a yellow precipitate which gradually changes to a red colour.

Knowledge Check

  • When Al is added to sodium hydroxide solution:

    A
    no reaction takes place
    B
    oxygen is evolved
    C
    water is produced
    D
    hydrogen is evolved

  • On adding ammonium chloride to a solution ammonium hydroxide

    A
    Dissociation of `NH_4OH` increases
    B
    Concentration of OH increases
    C
    Concentration of OH decreases
    D
    Concentration of OH remains unchanged

  • A pair of metals which dissolves in sodium hydroxide solution is

    A
    `Cu,K`
    B
    Fe, Mg
    C
    Ag, Cu
    D
    Sn, Zn

    • Similar Questions

    Explore conceptually related problems

    What is observed when sodium chloride is added to a colloidal solution of ferric hydroxide?

    ………….has an oxide which is soluble is sodium hydroxide

    Aluminium hydroxide is soluble in excess of sodium hydroxide forming the ion

    Which of the following metal hydroxides does not dissolve in sodium hydroxide solution?

    Which of the following is soluble in sodium hydroxide

    Home
    Profile