A colorless crystalline solid that is extremely poisonous (0.one g would be a lethal dose). Analysis of the solid and vapor states implies a dimerized composition of As4O6. While in the processing of As2O3 the oxide is Usually minimized withcarbon: 2As2O3+3C?→As4+3CO2 The reaction is endothermic and is also performed at http://https//chemscenter.com