Lead(II) iodate
Lead(II) iodate is an inorganic compound with the molecular formula Pb(IO3)2. It is naturally found as heavy white powder.
Names | |
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IUPAC name
diiodyloxylead | |
Other names
Lead(II) iodate | |
Identifiers | |
3D model (JSmol) |
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108301 (G) | |
ChemSpider | |
ECHA InfoCard | 100.042.866 |
EC Number |
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PubChem CID |
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Properties | |
Pb(IO3)2 | |
Molar mass | 557.01 g/mol |
Appearance | white crystal powder |
Density | 6.5 g/cm3 |
Melting point | 300 °C (572 °F; 573 K) |
3.61·10−5 M[1] | |
Solubility product (Ksp) |
3.69·10−13 [2] |
−131·10−6 cm3/mol [2] | |
Structure | |
orthorhombic[2] | |
Thermochemistry | |
Std molar entropy (S⦵298) |
312.9632 J/(mol·K) |
Std enthalpy of formation (ΔfH⦵298) |
−495.3856 kJ/mol |
Pharmacology | |
Pharmacokinetics: | |
Ingestion limit: 50 μg/m3 | |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards |
oxidizer |
GHS labelling:[3] | |
Danger | |
H272, H302, H332, H360, H373, H410 | |
P203, P210, P220, P260, P261, P264, P270, P271, P273, P280, P301+P317, P304+P340, P317, P318, P319, P330, P370+P378, P391, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references |
Production
One way to produce lead(II) iodate involves the reaction of lead nitrate with double moles of potassium iodate. Lead iodate can be precipitated precisely by simultaneous dropwise addition of equivalent solutions of lead nitrate and potassium iodate with water as a solvent at around 60 °C.[1]
Pb(NO3)2(aq) + KIO3(aq) → KNO3(aq) + Pb(IO3)2(s)
Industrial mass production methods use a less precise method due to higher quantities of reactants. Many other group 1 elements can be used in place of potassium to add iodate to the reaction due to solubility of group 1 element iodates.
Uses
One use for the compound lead(II) iodate is the volumetric determination of lead content in ore. The determination of lead content in a sample of ore begins with the precipitation and separation of lead as a sulfate. The solution of this lead sulfate product is then slightly acidified and the lead is precipitated out as lead(II) iodate out by adding potassium iodate. Lead(II) iodate can then be titrated in the presence of hydrochloric acid and chloroform to indicate the exact amount of lead that was dissolved from the original ore sample. In this chemical process lead(II) iodate is used to isolate the lead found in a sample of ore from other chemicals present so that it can be studied and quantitated effectively.[4]
- PbSO4(aq) + KIO3(aq) → K2SO4(aq) + Pb(IO3)2(s)
References
- Mer, Victor K. La; Goldman, Frederick H. (1930-07-01). "The Solubility of Lead Iodate in Water and in 0.1 N Salt Solutions". Journal of the American Chemical Society. 52 (7): 2791–2793. doi:10.1021/ja01370a032. ISSN 0002-7863.
- CRC handbook of chemistry and physics : a ready-reference book of chemical and physical data. William M. Haynes, David R. Lide, Thomas J. Bruno (2016-2017, 97th ed.). Boca Raton, Florida. 2016. ISBN 978-1-4987-5428-6. OCLC 930681942.
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: CS1 maint: location missing publisher (link) CS1 maint: others (link) - "Lead iodate". pubchem.ncbi.nlm.nih.gov.
- The Journal of Industrial and Engineering Chemistry. American Chemical Society. 1914. p. 399.
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