A reaction occurs between two liquids. Before the reaction, liquid A is clear and colorless. Liquid B clear and light blue in color. When the two liquids are combined in a closed system, a cloudy, pale green solution is formed. Which or the following describes what has occurred?

A. A chemical reaction where mass was conserved
B. A physical reaction where mass was conserved
C. A chemical reaction where mass was not conserved
D. A physical reaction reaction where mass was not conserved

C. A chemical reaction where mass was not conserved

In a chemical reaction, new substances are formed with different properties than the original substances. This often involves a change in mass as atoms are rearranged to form the new compounds. Since the colors and clarity of the original liquids changed in this reaction, it is likely a chemical reaction where mass was not conserved.