Nessler's Reagent

Synonym(s):Potassium tetraiodomercurate – Potassium hydroxide solution

CAS NO.：7783-33-7
Empirical Formula: HgI4K2
Molecular Weight: 786.4
MDL number: MFCD00049656
EINECS: 231-990-4
SAFETY DATA SHEET (SDS)
Update Date: 2024-12-18 14:08:52

What is Nessler's Reagent?

Chemical properties

light yellow liquid

The Uses of Nessler's Reagent

Detecting the presence of ammonia, particularly in very small amounts.

The Uses of Nessler's Reagent

Mercury(II) potassium iodide is used as a pharmaceutical intermediate. It is also used as reagents, chemical research and organic intermediates.

Definition

Nessler's Reagent is a periodometallate salt that is solution of mercuric iodide in potassium iodide. It contains a tetraiodomercurate(2-).

Preparation

It is prepared by mixing 2g potassium iodide in 5ml water. To this solution, 3g of mercury (II) iodide is added, and the resulting solution is made to 20ml. Finally, 40g potassium hydroxide (30 %) is added to provide the alkaline base.

General Description

Mercuric potassium iodide, [solid] appears as odorless yellow crystals. Crystallizes with either one, two or three molecules of water. Soluble in water and denser than water. Commercially available in the anhydrous form. Highly toxic by ingestion, inhalation, and skin absorption.

Air & Water Reactions

Deliquescent. Very water soluble.

Reactivity Profile

MERCURIC POTASSIUM IODIDE is incompatible with acetylene, ammonia, chlorine dioxide, azides, calcium (amalgam formation), sodium carbide, lithium, rubidium, copper . NESSLER'S REAGENT behave in aqueous solution as a weak acid.

Hazard

Highly toxic by ingestion, inhalation, and skin absorption.

Health Hazard

Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

Fire Hazard

Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Containers may explode when heated. Runoff may pollute waterways.

Safety Profile

A poison. Moderately toxic by skin contact and intraperitoneal routes. When heated to decomposition it emits very toxic fumes of Hg, K2O, and I-. See also MERCURY.

Properties of Nessler's Reagent

Melting point:	120-127 °C(lit.)
Boiling point:	105°C
Density	1.16 g/mL at 20 °C
Flash point:	>230 °F
solubility	very soluble in H2O; soluble in ethanol,ethyl ether, acetone
form	Liquid
color	Yellow to orange
Specific Gravity	1.097
Odor	Odorless
Water Solubility	Soluble in water.
Sensitive	Hygroscopic
Merck	13,7773
Exposure limits	ACGIH: TWA 0.025 mg/m3 (Skin) NIOSH: IDLH 10 mg/m3; TWA 0.05 mg/m3; Ceiling 0.1 mg/m3
Stability:	Stable, but light sensitive. Incompatible with strong oxidizing agents.
EPA Substance Registry System	Potassium mercuric iodide (7783-33-7)

Safety information for Nessler's Reagent

Signal word	Danger
Pictogram(s)	Corrosion Corrosives GHS05 Skull and Crossbones Acute Toxicity GHS06 Health Hazard GHS08 Environment GHS09
GHS Hazard Statements	H290:Corrosive to Metals H310:Acute toxicity,dermal H314:Skin corrosion/irritation H373:Specific target organ toxicity, repeated exposure H410:Hazardous to the aquatic environment, long-term hazard
Precautionary Statement Codes	P273:Avoid release to the environment. P280:Wear protective gloves/protective clothing/eye protection/face protection. P314:Get medical advice/attention if you feel unwell. P303+P361+P353:IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower. P305+P351+P338:IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.