Trimanganese tetraoxide Property

Melting point:

1705°C

Density 

4.8 g/mL at 25 °C(lit.)

vapor pressure 

0Pa at 25℃

solubility 

insoluble in H2O; soluble in HCl

form 

Powder

color 

brown

Specific Gravity

4.856

Water Solubility 

insoluble H2O [KIR81]; soluble HCl, releasing Cl2 [MER06]

Merck 

13,5759

Stability:

Stable.

CAS DataBase Reference

1317-35-7(CAS DataBase Reference)

EPA Substance Registry System

Manganese tetraoxide (1317-35-7)

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-36

WGK Germany 

2

RTECS 

OP0895000

Toxicity

mouse,LC,inhalation,> 3608ug/m3/2H (3.608mg/m3),American Industrial Hygiene Association Journal. Vol. 41, Pg. 494, 1980.

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H226Flammable liquid and vapour

H315Causes skin irritation

H319Causes serious eye irritation

Precautionary statements

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

P233Keep container tightly closed.

P240Ground/bond container and receiving equipment.

P241Use explosion-proof electrical/ventilating/lighting/…/equipment.

P242Use only non-sparking tools.

P243Take precautionary measures against static discharge.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P303+P361+P353IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P332+P313IF SKIN irritation occurs: Get medical advice/attention.

P337+P313IF eye irritation persists: Get medical advice/attention.

P370+P378In case of fire: Use … for extinction.

P403+P235Store in a well-ventilated place. Keep cool.

Trimanganese tetraoxide Chemical Properties,Usage,Production

Physical Properties

Black tetragonal crystal; exhibits two allotropic modifications—a stable alpha phase, occurring in tetragonal crystalline form (as hausmannite) and an unstable beta modification; Moh’s hardness 5.5; insoluble in water; soluble in hydrochloric acid.

Occurrence and Use

Manganese(II,III) oxide occurs in nature as the mineral hausmannite [1309-55-3]. It is used to make ferrites and thermistors. The oxide also is used in the thermite process for producing manganese.

Preparation

Manganese(II,III) oxide is made by heating manganese(IV) oxide, MnO2, or manganese(III) oxide, Mn2O3, above 950°C. When Mn2O3 is heated in air, the temperature should be above 940°C, but if heated in oxygen, the temperature should be above 1,090°C. Also, heating manganese(III) oxide at 230°C in hydrogen yields Mn3O4. However, further heating above 300°C converts Mn3O4 formed to green manganese(II) oxide, MnO.
Manganese(II,III) oxide also is obtained by heating the dioxide, MnO2, with carbon at 600 to 700°C.

Reactions

Manganese(II,III) oxide reacts with dilute acids forming the corresponding manganous salt and manganese(IV) oxide, MnO2:
Mn3O4 + 2H2SO4 → 2MnSO4 + MnO2 + 2H2O
The oxide, however, dissolves slowly in cold sulfuric acid forming a red solution that also contains manganic sulfate, Mn2(SO4)3:
Mn3O4 + 4H2SO4 → MnSO4 + Mn2(SO4)3 + 4H2O
Reaction with acetic acid yields manganese(II) acetate and manganese(III) oxide:
Mn3O4 + 2CH3COOH → Mn(CH3COO)2 + Mn2O3 + H2O
Manganese(II,III) oxide is reduced to manganese metal when heated with powdered aluminum (the Thermite process). The reaction is vigorous and exothermic:
3Mn3O4 + 8Al → 4Al2O3 + 9Mn

Chemical Properties

Grass-green powder. but converted to Mn 3O4 if heated in air. Soluble in acids; insoluble in water. Noncombustible.

Uses

Textile printing, analytical chemistry, catalyst in manufacture of allyl alcohol, ceramics, paints, colored glass, bleaching tallow, animal feeds, fertilizers, food additive and dietary supplement.

General Description

Manganese(II,III) oxide is a transition metal oxide that is formed by annealing manganese oxide in the air above 1000°C. It can be used for a variety of applications such as catalysis, electrochromic devices, and other energy storage applications.

Reactivity Profile

Trimanganese tetraoxide is non-combustible but decomposes, generating toxic fumes when strongly heated strongly in the air. A good oxidizing agent. Reacts with hydrochloric acid to form gaseous chlorine and soluble manganese salts.

Hazard

Chronic manganese poisoning and pulmonary effects.

Health Hazard

Manganese tetroxide affects the central nervous system, and toxicity occurs mostly in chronic form (manganism).

Flammability and Explosibility

Non flammable

Safety Profile

Experimental reproductive effects. Reacts violently @ <l00℃. See also MANGANESE COMPOUNDS.