Answer:
B. A chemical change occurred which caused the liquid's physical properties to change.
Explanation:
The reduction of the temperature of the system meant that the reaction absorbed heat energy from it. This shows that a chemical reaction was in progress. New products were formed, and this is proved by the change in the color to blue.
Use higher concentration of acid to produce 2 moles of hydrogen to form water
The emperical formula for benzene (C6H6) is “CH”.
