510. Ammonium Chromate(VI)

Nomenclature

CAS number: 7788-98-9
Chromic acid (H2CrO4) ammonium salt (1:2); neutral ammonium chromate; diammonium chromate.
CrH8N2O4; mol wt 152.07.
Cr 34.19%, H 5.30%, N 18.42%, O 42.08%.
(NH4)2CrO4.

Description and references

Prepn: Gmelins, Chromium (8th ed.) 52, part B, pp 707-712 (1962).

Properties

Yellow acicular crystals; loses some NH3 in air; decomposes at 185°. d 1.8. Soly in water: 19.78% (0°); 41.20% (75°). Sparingly sol in liquid ammonia, acetone. Slightly sol in methanol. Practically insol in ethanol. The aq soln is alkaline. Keep well closed.

Use

Sensitizing gelatin in photography, in textile printing pastes, in fixing chromate dyes on wool, and as a reagent in analytical chemistry.