Mercurous oxide，black

Chemical Properties

Black powder.Soluble in acids; insoluble in water.

General Description

Black or brownish-black powder. Not a true compound but rather an intimate mixture of metallic mercury and mercuric oxide. Insoluble in water and denser than water (density 9.8 g / cm3). Hence sinks in water.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

Mixtures of "Mercurous oxide，black" with barium oxide react vigorously with hydrogen sulfide in air. Explosions may result [Mellor 10:140. 1946-47]. Dissolves in nitric acid. Reacts with hydrochloric acid to give insoluble mercurous chloride (calomel). Contact of the metal oxide caused the explosive decomposition of hydrogen peroxide [Bretherick 5th ed., 1995]. Mixtures with phosphorus or sulfur explode by impact and friction respectively, [Mellor, 1940, Vol. 4, 77].

Hazard

Highly toxic.

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. Flammable by chemical reaction; an oxiduer. Explosive reaction with hydrogen peroxide, chlorine + ethylene. Reacts violently with molten potassium, molten sodmm, S, (HzS + BaO + air). Forms explosive mixtures with nonmetals [e.g., phosphorus (impactsensitive), sulfur (friction-sensitive)]. Incompatible with alkali metals, reducing materials. Dangerous; when heated to decomposition it emits highly toxic fumes of Hg. See also MERCURY COMPOUNDS, INORGANIC.