Which of the following processes is a chemical change?
A) Dry ice sublimes when left on the demo table in lecture.
B) The light on a candle burns until a bell jar is placed over it for a period of time.
C) When a few drops of red food coloring are added to a beaker of hot water, the water immediately turns red.
D) Liquid nitrogen dumped onto the floor vaporizes at room temperature.
E) None of the above processes are chemical changes.

Question

Quizplus · Accepted Answer

The burning of a candle involves chemical reactions, such as combustion, where the wax (typically a hydrocarbon) reacts with oxygen in the air to produce carbon dioxide, water, and heat. This is a chemical change because it results in the formation of new substances.

Which of the Following Processes Is a Chemical Change