User:Thanatad/sandbox

Dicarbonate
Names
	IUPAC name Carboxylato carbonate
	Other names Pyrocarbonate
Identifiers
CAS Number	214335-04-3 ;
3D model (JSmol)	Interactive image;
MeSH	pyrocarbonate
PubChem CID	15238643;
CompTox Dashboard (EPA)	DTXSID30570367;
	InChI InChI=1S/C2H2O5/c3-1(4)7-2(5)6/h(H,3,4)(H,5,6)/p-2 Key: ZFTFAPZRGNKQPU-UHFFFAOYSA-L;
	SMILES C(=O)([O-])OC(=O)[O-];
Properties
Chemical formula	C2O5-2 (Basic formula)
Molar mass	104.02 g/mol
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Bismuth subnitrate monohydrate
Names
	IUPAC name oxobismuthanyl nitrate;hydrate
Identifiers
CAS Number	13595-83-0 ;
3D model (JSmol)	Interactive image;
PubChem CID	129842132;
	InChI InChI=1S/Bi.NO3.H2O.O/c;2-1(3)4;;/h;;1H2;/q+1;-1;; Key: HFJNHTDBULDRRH-UHFFFAOYSA-N;
	SMILES [N+](=O)([O-])O[Bi]=O.O;
Properties
Chemical formula	BiH2NO5 (Basic formula)
Molar mass	305 g/mol
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Thanatad/sandbox
Names
	IUPAC name pentabismuth;oxygen(2-);nonahydroxide;tetranitrate
Identifiers
CAS Number	1304-85-4 ;
3D model (JSmol)	Interactive image;
DrugBank	DB13209 ;
MeSH	bismuth+subnitrate
PubChem CID	73415757;
UNII	H19J064BA5;
	InChI InChI=1S/5Bi.4NO3.9H2O.O/c;;;;;42-1(3)4;;;;;;;;;;/h;;;;;;;;;91H2;/q5+3;4-1;;;;;;;;;;-2/p-9 Key: QGWDKKHSDXWPET-UHFFFAOYSA-E;
	SMILES [N+](=O)([O-])[O-].[N+](=O)([O-])[O-].[N+](=O)([O-])[O-].[N+](=O)([O-])[O-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[O-2].[Bi+3].[Bi+3].[Bi+3].[Bi+3].[Bi+3];
Properties
Chemical formula	Bi5H9N4O22 (Basic formula)
Molar mass	1461.99 g/mol
Density	1.79 g/mL (H2O)
Melting point	Decomposes at 260
Boiling point	Decomposes at 260
Solubility in water	Insoluble
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Composition

Dragendroff's reagent is a solution of potassium bismuth iodide prepared from basic bismuth nitrate (Bi(NO₃)₃), tartaric acid, and potassium iodide (KI).

Preparation

Dragendorff's reagent is prepared by mixing a concentrated solution of potassium iodide with a solution of bismuth subnitrate in a diluted acid (acetic acid or tartaric acid, hydrochloric acid or sulfuric acid also rarely being used) as a low pH is mandatory for this reagent.

The formation is as follows: The black precipitate of bismuth iodide is formed from the reaction of bismuth ion and potassium iodide.

Bi³⁺
+ 3 KI → BiI
₃ + 3 K⁺

Then, the reaction between bismuth ion and excess potassium iodide will produce a soluble complex of potassium tetraiodobismuthate which has an orange color.

Bi³⁺
+ KI → K(BiI₄)

Reaction

Most of the alkaloids have a tertiary amine group, so the explanation for color reaction could be the following:

R₃N + HX → [R₃NH]⁺ + X

(X = anions of acid)

Then the insoluble complex salt is formed from the reaction between ammonium salt and potassium tetraiodobismuthate.

[R₃NH]⁺X⁻ + K[BiI₄] → [R₃NH]⁺[BiI₄]⁻ + KX

This ion pair has different colors: yellow, orange, red, and brown, which depend on the nature of alkaloids.