PS8.1.3/PS8.1.5 Review

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that in a chemical reaction, the total mass of the reactants equals the total mass of the products; mass is neither created nor destroyed.

Front

In the reaction 2H₂ + O₂ → 2H₂O, how many hydrogen atoms are present on both sides of the equation?

Back

There are 4 hydrogen atoms present on both sides of the equation.

Front

What does a coefficient in front of a molecule indicate in a chemical equation?

Back

A coefficient indicates how many molecules of that substance are present in the reaction.

Front

In the chemical formula H₂O, what does the subscript '2' indicate?

Back

The subscript '2' indicates that there are 2 hydrogen atoms in one molecule of water.

Front

How do you calculate the mass of reactants in a chemical reaction?

Back

To calculate the mass of reactants, you add the masses of all reactants together; this total must equal the mass of the products.

Front

What is a chemical equation?

Back

A chemical equation is a symbolic representation of a chemical reaction, showing the reactants and products along with their quantities.

Front

What is the difference between a reactant and a product?

Back

Reactants are substances that undergo a chemical change, while products are the substances formed as a result of that change.

Front

What is a subscript in a chemical formula?

Back

A subscript indicates the number of atoms of the element in a molecule; for example, in H₂O, the '2' indicates 2 hydrogen atoms.

Front

What is the purpose of balancing a chemical equation?

Back

Balancing a chemical equation ensures that the number of atoms for each element is the same on both sides, adhering to the law of conservation of mass.

Front

What is the significance of the arrow in a chemical equation?

Back

The arrow in a chemical equation indicates the direction of the reaction, showing the conversion of reactants to products.