The allotropy of carbon used in the decolourization of sugar is
Answer Details
The allotropy of carbon that is used in the decolourization of sugar is activated charcoal, which is also known as activated carbon. Activated charcoal is a highly porous form of carbon that has a large surface area available for adsorption. When sugar solution is passed through activated charcoal, impurities, such as colorants and other organic compounds, are adsorbed onto the surface of the activated charcoal, leaving behind a decolorized solution. Therefore, the answer to the question is charcoal.