Law of Conservation of Mass

Front

What is the Law of Conservation of Mass?

Back

Mass is never created or destroyed in a chemical reaction.

Front

In the reaction AB -> A + B, if AB has 12g and B has 5g, how many grams should product A have?

Back

7g

Front

In a reaction A + B -> C, if A has 5g and C has 9g, how many grams does reactant B have?

Back

4g

Front

In the equation @@2H_2 + O_2 ightarrow 2H_2O@@, how does the Law of Conservation of Mass apply?

Back

The total mass of reactants equals the total mass of products.

Front

How many atoms of Carbon are on the reactant side in the equation 2Fe_2O_3 + 3C -> 4Fe + 3 CO_2?

Back

3

Front

What happens to the mass of reactants during a chemical reaction?

Back

The mass remains constant; it is conserved.

Front

If 10g of reactants produce 10g of products, what does this demonstrate?

Back

It demonstrates the Law of Conservation of Mass.

Front

What is an example of a physical change where mass is conserved?

Back

Melting ice; the mass of ice before melting equals the mass of water after melting.

Front

In a balanced chemical equation, what must be true about the number of atoms of each element?

Back

The number of atoms of each element must be the same on both sides of the equation.

Front

What is the significance of balancing chemical equations?

Back

It ensures that the Law of Conservation of Mass is upheld.