Zinc carbonate

Zinc carbonate is the inorganic compound with the formula ZnCO₃. It is a white solid that is insoluble in water. It exists in nature as the mineral smithsonite. It is prepared by treating cold solutions of zinc sulfate with potassium bicarbonate. Upon warming, it converts to basic zinc carbonate (Zn₅(CO₃)₂(OH)₆).^[6]

Zinc carbonate

Zn2+ [CO32−]
Identifiers
CAS Number	3486-35-9 basic: 5263-02-5
3D model (JSmol)	Interactive image
ChemSpider	17943 monohydrate: 11570234 basic: 10129674
ECHA InfoCard	100.020.435
EC Number	222-477-6 basic: 226-076-7
PubChem CID	19005 basic: 11955398
UNII	K8290PTQ4F
UN number	9157
CompTox Dashboard (EPA)	DTXSID5049817
InChI InChI=1S/CH2O3.Zn/c2-1(3)4;/h(H2,2,3,4);/q;+2/p-2 Key: FMRLDPWIRHBCCC-UHFFFAOYSA-L
SMILES C(=O)([O-])[O-].[Zn+2]
Properties
Chemical formula	ZnCO3
Molar mass	125.4
Appearance	white solid
Density	4.434 g/cm3[1]
Melting point	140 °C (284 °F; 413 K)[1] (decomposes)
Solubility in water	0.91 mg/L[1]
Solubility product (Ksp)	1.46×10−10[2]
Magnetic susceptibility (χ)	−34×10−6 cm3/mol[3]
Refractive index (nD)	n1=1.621, n2=1.848[4]
Structure[5]
Crystal structure	Calcite, hR30, No. 167
Space group	R3c
Lattice constant	a = 4.6528 Å, c = 15.025 Å
Formula units (Z)	6
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H319, H410, H411
Precautionary statements	P264, P273, P280, P302+P352, P305+P351+P338, P321, P332+P313, P337+P313, P362, P391, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Structure

Zinc carbonate crystallizes in the same dense motif as calcium carbonate. Color code: red = O, green = Zn.

Zinc carbonate adopts the same structure as calcite (calcium carbonate).^[7] Zinc is octahedral and each carbonate is bonded to six Zn centers such that oxygen atoms are three-coordinate.