A beaker is filled one-third full of sugar. A layer of highly concentrated sulfuric acid is poured on the top. Over a period of seconds, you notice a substantial change in the look of the sugar. It becomes darkened and begins to bubble up and form a stiff black material which vents a strong vapor. Upon the completion of the reaction, you take a knife to the substance and notice it crumbles like a fine powder. How do you explain what happens? Be sure to use the terms physical properties, chemical properties, reactivity, reactants, evidence of reaction, evolving of a gas, color change, density, texture, and chemical change.