Zinc Hydroxide - Zn(OH)2

What is Zinc Hydroxide?

Zinc hydroxide is an inorganic chemical compound with formula Zn(OH)2. It occurs naturally in three rare minerals namely wulfingite, ashoverite and sweetite. It is an amphoteric hydroxide. Zinc hydroxide reacts with both bases and acids. It is an insoluble hydroxide which reacts with strong acid and gets dissolved.

Zn(OH)2

Zinc hydroxide

Density

3.05 g/cm³

Molecular Weight/ Molar Mass

99.424 g/mol

Melting Point

125° C (257° F)

Chemical Formula

H2O2Zn

Zinc Hydroxide Structure – Zn(OH)2

Zinc Hydroxide

Physical Properties of Zinc Hydroxide – Zn(OH)2

Odour

Odourless

Appearance

Dull white flocculent precipitate

Valency of Zn

2

pH

8.88

Oxidation state

+2

Solubility

Slightly soluble in water, insoluble in alcohol

Chemical Properties of Zinc Hydroxide – Zn(OH)2

  • Aluminium reacts with zinc hydroxide solution gives a white precipitate which is soluble in excess of the reagent yo form complex Al(OH)4 indicates the presence of aluminium.
  • 2Al3+(aq) + 3Zn(OH)2(aq) → 2Al(OH)3(s) + 3Zn

  • Zinc cations react with hydrogen sulfide in the presence of ammonia and ammonium chloride forms a white precipitate of zinc sulfide which is soluble in acids..
  • Zn2+(aq) + S2- → ZnS(s)

Uses of Zinc Hydroxide – Zn(OH)2

  • Used in medicine as an adsorbing agent.
  • Utilized for careful dressings where it works as a retentive. Huge bandages that are utilized post medical procedure are covered with the zinc compound for engrossing the blood from the injury.
  • Used as an intermediate for commercial production of pesticides and pigments.

Practise This Question

Which of the following is not a characteristic of Planck's quantum theory of radiation?