At room temperature, citric acid is white crystalline powder, odorless and extremely sour [2], its density is 1.542g/cm3, its melting point is 153-159℃, and water and carbon dioxide are differentiated and launched above a hundred seventy five℃. citric acid is without problems soluble in water and ethanol, its solubility is 59% at 20℃, and the ph of its 2% aqueous solution is 2.1. the crystal form of citric acid is exclusive due to distinctive crystallization conditions. it's miles barely weathered in dry air and hygroscopic in humid air. when heated, citric acid may be differentiated into diverse merchandise, that could react with acid, alkali, glycerin, and so on.