Ammonium bicarbonate is a white solid. This coloration is due to the chemical composition of the compound, which includes ammonium ions (NH4+) and bicarbonate ions (HCO3-). The white color is a characteristic of many inorganic compounds that contain these ions, as well as other similar ions. The specific color can vary slightly depending on the purity of the compound and the presence of impurities, but in general, ammonium bicarbonate is consistently white. This information is supported by various chemical databases and literature sources that describe the physical properties of ammonium bicarbonate.