Question

Which of the following is a reliable way to observe that a chemical change has occurred when two substances come in contact with one anotherO monitor for the release of a gasO observe a color changeO test for the release of heatconduct a test to determine the chemical makeup of the molecules

Answer 1

conduct a test to determine the chemical makeup of the molecules

Step-by-step explanation

A change in which one or more new substances are formed is called a chemical change. A chemical change is also called a chemical reaction.

There are five signs of a chemical change namely:

i. Color Change.

ii. Production of an odor.

iii. Change of Temperature.

iv. Evolution of a gas (formation of bubbles)

v. Precipitate (formation of a solid).

Therefore, a reliable way to observe that a chemical change has occurred when two substances come in contact with one another is to conduct a test to determine the chemical makeup of the molecules.