How do I know if a chemical reaction has occurred?!?

The video tutorial explains chemical reactions, highlighting that they occur when substances change their chemical structure. It distinguishes between physical and chemical changes, using water as an example. The tutorial outlines five indicators of chemical reactions: formation of precipitate, gas, water, color change, and temperature change. Each indicator is explained in detail, emphasizing how they help identify chemical reactions.

What distinguishes a chemical reaction from a physical change?

• A change in temperature

• A change in state of matter

• A change in chemical structure

• A change in color

Which of the following is NOT an indicator of a chemical reaction?

• Formation of water

• Formation of a solid

• Formation of a gas

• Formation of a precipitate

What is a precipitate in the context of a chemical reaction?

• A liquid formed from a gas

• A color change in a solution

• A solid formed in a solution

• A gas formed during a reaction

How can a color change indicate a chemical reaction?

• It shows a change in temperature

• It is due to dilution

• It indicates a new substance has formed

• It results from a change in state

What does a temperature change in a chemical reaction signify?

• The reaction is complete

• A precipitate is formed

• A new gas is formed

• Energy is absorbed or released