Ammonium dichromate products

A. Tanuary 17, 1986 explosion at a Diamond Shamrock Chemical plant near Ashtabula, Ohio, killed two employees, critically injured another, and caused lesser injuries to at least a dozen other workers. The blast involved 2,000 lb of ammonium dichromate in the unit for its production at the plant,... 

Sulfoalkylated naphthol compounds are effective as dispersants in aqueous cement slurries. The compounds can also be applied in an admixture with water-soluble inorganic compounds of chromium to provide additives of increased overall effectiveness. Particularly suitable are sodium chromate or ammonium dichromate. a-Naphthol is reacted in an alkaline aqueous medium with formaldehyde to create condensation products. The aldehyde can be reacted with bisulfite to produce sulfoalkylated products [1404,1410]. 

In a Downstream Decomposing facility not the subject of this example, intentional chemistry is performed as ammonium dichromate is heated to decomposition to make chromium dioxide, which is used in the production of magnetic tape products. In the Upstream Feeds facility under study, physical processing is performed as ammonium dichromate is fed through a screw conveyor. The Preliminary Screening Method is to be used as a first-cut determination whether chemical reactivity hazards will need to be managed in the physical processing facility. 

Reduction of Ammonium Dichromate. Chromium(III) oxide can be obtained by thermal decomposition of ammonium dichromate. Above ca. 200 °C, a highly voluminous product is formed with elimination of nitrogen [3.48]. The pigment is obtained after addition of alkali salts (e.g., sodium sulfate) and subsequent calcination [3.49]. 

Chromium compounds exhibit a variety of bright colors. When solid ammonium dichromate, (NH4)2Cr207, a vivid orange compound, is ignited, a spectacular reaction occurs, as shown in the two photographs on the next page. Although the reaction is somewhat more complex, let s assume here that the products... 

From the description given, the reactant is solid ammonium dichromate, (NH4)2Cr207(s), and the products are nitrogen gas, N2(g), water vapor, H20(g), and solid chromium(III) oxide, Cr203(s). The formula for chromium(III) oxide can be determined by recognizing that the Roman numeral III means that Cr3+ ions are present. For a neutral compound the formula must then be Cr203, since each oxide ion is O2-. 

Chromium(III) oxide, CrgOg, is a product of the oxidation of the metal and of the thermal decomposition of ammonium dichromate ... 

MiniLab 2 When a pile of orange ammonium dichromate is ignited, it decomposes in an exothermic reaction in which the green product and flames shoot upward like an erupting volcano. (CAUTION Do NOT perform this reaction.)... 

Nitrogen can be obtained by (a) passing ammonia over red-hot copper(II) oxide and (b) heating ammonium dichromate [one of the products is Cr(III) oxide]. Write a balanced equation for each preparation. 

Write the mole ratios for this reaction that relate ammonium dichromate to the products. 

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