Zinc phosphate

• Trizinc bis (orthophosphate )
• Trizinkdiphosphat
• Zinc orthophosphate

• 7779-90-0
• 14485-28-0 (dihydrate )
• 7543-51-3 (tetrahydrate )
• 13847-22-8 ( mixture of zinc phosphates )

White odorless solid

Fixed

3.75 g · cm -3

> 900 ° C

Practically insoluble in water

Attention

> 5000 mg · kg -1 ( LD50, rat, oral)

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Zinc phosphate is a chemical compound selected from the group of phosphates and zinc compounds.

Occurrence

Of course, as a tetrahydrate of zinc phosphate is present as the mineral in the form of orthorhombic hopeite and triclinic Parahopeit than hydroxide as the mineral Tarbuttit and in conjunction with iron and manganese as phosphophyllite.

Production and representation

Zinc phosphate (as tetrahydrate) can be obtained by reaction of zinc oxide with phosphoric acid.

The extraction by the reaction of zinc sulfate with disodium hydrogen phosphate is possible.

Properties

Zinc phosphate is a white, odorless solid that is insoluble in water but soluble in dilute mineral acids. It comes in addition to the anhydrous ago as mono-, di-and tetrahydrate. Zinc phosphate monohydrate, Zn 3 (PO 4) 2 · H2O is located in the centric space group P 21 / c ( C52h ) with four formula units per unit cell and the lattice constants a = 8.696 (6 ), b = 4.891 (2) and c = 16.695 (9 ) Å and β = 94.94 ( 3) ° before. Zinc phosphate dihydrate crystallizes in the centric space group P 2 / c ( C52h ) and eight formula units with lattice constants a = 10.451 (7), b = 5.036 (3) and c = 31.437 (15 ) Å, and β = 92.46 °. Zinc phosphate tetrahydrate is a dimorphic the orthophosphate acts as orthorhombic hopeite or triclinic Parahopeit, wherein three of the former again modifications are known, but which differ only in the arrangement of the hydrogen atoms. Parahopeit crystallizes in the centric space group pi1 ( C1i ) with one formula unit per unit cell and the lattice constants a = 5.768 (5 ), b = 7.550 ( 5), c = 5.276 (5 ) Å, α = 93.4 °, β = 91, 2 °, and γ = 91.4 °. Hopeit crystallizes in the centric space group Pnma ( D162h ) with four formula units per unit cell and the lattice constants a = 10.597 ( 3), b = 18.318 (8) and c = 5.031 (1) Å. α - Hopeite converts at temperatures > 105 ° C, β - Hopeite from > 140 ° C and p- Hopeite from> 163 ° C in other forms in order. From 250 ° C to obtain the anhydrous variant.

Use

Zinc phosphate is used as the anticorrosive pigment and the manufacture of dental cements.

Related compounds

• Pyrophosphate Zn2P2O7
• Dizinkcyclotetraphosphat Zn2P4O12
• Zinc hydrogen phosphate ZnHPO4
• Zinkhydroxidphosphat Zn2 ( OH) PO4