Evidence of Chemical Reactions (TCI Lesson 12)

Front

What is a chemical reaction?

Back

A process where substances (reactants) transform into new substances (products) with different properties.

Front

What are some signs that a chemical reaction has occurred?

Back

Signs include color change, temperature change, gas production (bubbles), formation of a precipitate, and odor change.

Front

What is density and why is it important in identifying chemical reactions?

Back

Density is the mass per unit volume of a substance. It is important because significant changes in density can indicate a chemical reaction.

Front

What happens when two clear colorless solutions react?

Back

They may produce a new substance, which can be observed as a color change, temperature change, or formation of a precipitate.

Front

What is a precipitate?

Back

A solid that forms and settles out of a liquid mixture during a chemical reaction.

Front

What does it mean if bubbles form during a reaction?

Back

Bubbles indicate that a gas is being produced, which is a sign of a chemical reaction.

Front

What is the chemical formula for glucose?

Back

C6H12O6.

Front

What is the chemical formula for ethanol?

Back

C2H6O.

Front

How do the chemical formulas for glucose and ethanol differ?

Back

They differ in the ratio of elements; glucose has more carbon and hydrogen atoms compared to ethanol.

Front

What is rust and how does it form?

Back

Rust is iron oxide formed when iron reacts with oxygen and moisture in the environment.