Ascorbic acid is a naturally occurring organic compound with antioxidant properties. It is a white solid, but impure samples can appear yellowish. It dissolves well in water to give mildly acidic solutions. Ascorbic acid is one form ("vitamer") of vitamin C
A 2655 (OTTO) L-Ascorbic acid, extra pure, 99% Cas 50-81-7 - used as a reductant in photographic developer solutions (among others) and as a preservative.