Balancing Chemical Equations/Conservation of Mass

Front

What is a chemical change?

Back

A chemical change always involves the formation of a new substance.

Front

What does the law of conservation of mass state?

Back

In a closed system, the mass of the reactants must equal the mass of the products.

Front

If the mass of reactants is 25g, what must the mass of products be in a closed system?

Back

25g, to follow the law of conservation of mass.

Front

What is a sign that a chemical reaction has occurred?

Back

Formation of a gas.

Front

What can be concluded if the mass of a dissolved salt before dissolving is greater than after mixing?

Back

Some water evaporated from the container.

Front

How many elements are in the compound C6H12O6?

Back

3 elements: Carbon (C), Hydrogen (H), and Oxygen (O).

Front

What is the definition of a reactant?

Back

A reactant is a substance that undergoes a chemical change in a reaction.

Front

What is the definition of a product?

Back

A product is a substance that is formed as a result of a chemical reaction.

Front

What is an example of a physical change?

Back

Dissolving salt in water is a physical change, as no new substance is formed.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change does not alter the chemical composition of a substance, while a chemical change does.