In a classroom demonstration, a teacher pours sulfuric acid on some granulated sugar in a beaker. The sugar turns yellow and then black. Smoke rises and a strong smell is released. This demonstration is an example of what kind of change?

The questions have been asked in several important state and regional science exams in the United States. For example: TAKS-Texas Assessment of Knowledge and Skills, New York State Educational Department Regents exams, California Standards Test, etc.